Seminars 2018

Title:Protein Engineering applied to the creation of optogenetic tools for visualization of dynamic biological activities
Speaker:Professor Robert E. CAMPBELL
Date:21st December 2018
Time:10.30am to 12.30pm 
Venue:Executive Classroom 1 (Level 3), MAS Atrium
Host:Associate Professor Xing Bengang
Abstract

Light-based technologies are revolutionizing our understanding of the brain at the most fundamental level and steadily guiding researchers towards new diagnostic and therapeutic approaches. As a form of energy, light is a powerful and attractive tool for biological research. When properly harnessed, light can enable us to non-invasively visualize and control biology as it happens in neurons both in vitro and in vivo. Over the past two decades, researchers have been inventing an increasing number of ways to harness optical methods to probe cells and tissues in model organisms. A major breakthrough in this direction was the discovery, cloning, and expression of the jellyfish green fluorescent protein (FP). Another major breakthrough came a decade later, when researchers discovered that the light-gated cation channel, channelrhodopsin, could be functionally expressed in neurons. These two technologies are the prototypical examples of optogenetic tools, proteins that interact with light and enable researchers to either visualize (i.e., an indicator) or manipulate (i.e., an actuator) cells. The Campbell research group is focused on adding new capabilities to the toolbox of optogenetic tools using the technique of protein engineering (as was recognized with the 2018 Nobel Prize in Chemistry to Prof. Frances Arnold). The most impactful class of FP-based indicators are the Ca2+ indicators that change their fluorescence intensity or color in response to a change in Ca2+ concentration. These indicators are ideally used in combination with optogenetic actuators to enable simultaneous control and visualization of cellular signalling with precise spatial and temporal resolution, particularly in the area of neuroscience. However, a major challenge to the simultaneous use of multiple optogenetic tools is overlap of their spectral profiles. An effective approach to overcoming this challenge is to engineer a broader range of colours of optogenetic tools. In this seminar I will describe our most recent efforts to use protein engineering to make a new generation of genetically encoded Ca2+ indicators with improved properties and an expanded range of colours and potential applications. Specifically, I will present our efforts to engineer red and near-infrared Ca2+ indicators that are suitable for use in combination with blue-light activatable optogenetic actuators. I will also discuss efforts to develop indicators for a broader range of analytes, including physiologically relevant ions and metabolites. We expect that these new tools will represent a step forward for the field of optogenetics and lay the foundation for future breakthroughs in our understanding of cell biology, in both healthy and disease states.

Title:Chiral phosphate in Rh+ - and Ir+ -asymmetric catalysis
Speaker:Professor Marion BARBAZANGES
Date:20th December 2018
Time:3.00pm to 4.30pm   
Venue:SPMS Lecture Theatre 5
Host:Associate Professor Hélène Bertrand / Associate Prof Leong Weng Kee
Abstract

Chirality control is a major challenge for synthetic chemists, especially given the importance of optically active drugs. Several methods exist to control the enantioselectivity, such as chirality transfer from a nonracemic substrate, asymmetric organocatalysis or organometallic catalysis. This latter approach is traditionally allowed by the introduction of a chiral ligand on the metal M. In the "chiral counterion strategy", the information is carried by the counterion of the cationic metal species.1 In most cases, it is a sterically hindered phosphate derived from BINOL, (S)-TRIP , that is used as the vector of the chiral information. In the context of cycloisomerization reactions as well as [2+2+2]-cycloadditions, we will discuss our results on carbon-carbon bond formation using the chiral counterion strategy. Particular attention will be paid to the nature of the catalytic species involved. In those cases, is the phosphate (S)-TRIP a real counter-ion, or an X-type ligand?2

References 1. Selected reviews: a) J. Lacour, D. Moraleda, Chem. Commun. 2009, 7073; b) C. Zhong, X. Shi, Eur. J. Org. Chem. 2010, 2999; c) R. J. Phipps, G. L. Hamilton, F. D. Toste, Nat. Chem. 2012, 4, 603; d) M. Mahlau, B. List, Isr. J. Chem. 2012, 52, 630; e) M. Mahlau, B. List, Angew. Chem. Int. Ed. 2013, 52, 518; e) E. P. Ávila, G. W. Amarante, ChemCatChem 2012, 4, 1713; f) A. Parra, S. Reboredo, A. M. Martín Castro, J. Alemán, Org. Biomol. Chem. 2012, 10, 5001; g) K. Brak, E. N. Jacobsen, Angew. Chem. Int. Ed. 2013, 52, 534; h) D. Parmar, E. Sugiono, S. Raja, M. Rueping, Chem. Rev. 2014, 114, 9047. 2. (a) M. Barbazanges, M. Augé, J. Moussa, H. Amouri, C. Aubert, C. Desmarets, L. Fensterbank, V. Gandon, M. Malacria, C. Ollivier, Chem. Eur. J. 2011, 17, 13789-13794; (b) M. Augé, M. Barbazanges, A. T. Tran, A. Simonneau, P. Elley, H. Amouri, C. Aubert, L. Fensterbank, V. Gandon, M. Malacria, J. Moussa, C. Ollivier, Chem. Commun. 2013, 49, 7833-7835; (c) C. Aubert, M. Barbazanges, A. Jutand, S. H. Kyne, C. Ollivier, L. Fensterbank, Pure Appl. Chem. 2014, 86, 273. (d) M. Augé, A. Feraldi-Xypolia, M. Barbazanges, C. Aubert, L. Fensterbank, V. Gandon, E. Kolodziej, C. Ollivier, Org. Lett., 2015, 17, 3754; (e) M. Barbazanges, E. Caytan, D. Lesage, C. Aubert, L. Fensterbank, V. Gandon, C. Ollivier, Chem. Eur. J. 2016, 22, 8553-8558;

Title:Artificial Photosynthesis for Solar Energy Conversion 
Speaker:Professor Li-Zhu Wu
Date:20th December 2018
Time:1.00pm to 3.00pm   
Venue:SPMS Lecture Theatre 5
Host:Professor Shunsuke Chiba
Abstract

With the increasing concern over the global energy crisis and the greenhouse effect caused by carbon dioxide emission, the development of carbon-neutral and renewable-energy solutions has attracted considerable interest in both the scientific and industrial communities. Inspired by the ability of natural photosynthesis to convert solar energy into chemical energy, the scientific community long ago recognized the potential of light-driven reactions (photochemistry) as a powerful approach to chemical synthesis. From the high energy intermediate generated by photoinduced excitation of organic molecules, unique reaction manifolds can be accesses that are generally unavailable to conventional thermal pathways. Our group has long engaged in the photochemistry research related to 1) Artificial photosynthesis for solar energy conversion; 2) Visible light catalysis for efficient organic transformation; 3) Photoinduced electron transfer, energy transfer and chemical reactions in supramolecular systems. In this presentation, we will compile several stories to illustrate photochemical approaches that may be useful in the design of artificial photosynthetic systems for effective chemical transformation.

Acknowledgements Financial supports from the Ministry of Science and Technology of China, the National Natural Science Foundation of China and the Chinese Academy of Sciences are highly acknowledged.

Title:Potential Applications of Crown Ether-based Recognitions
Speaker:Associate Professor Ken Cham-Fai Leung
Date:20th December 2018
Time:11.00am to 12.30pm 
Venue:SPMS Lecture Theatre 5
Host:Assistant Professor Soo Han Sen
Abstract: 

It is well-known that crown ethers can be bound with ammonium ions. This type of molecular recognition has generated many complex interlocking structures. In particular, crown ether-ammonium rotaxane, which is responsive to different pH values, can exhibit a controlled molecular motion within its molecular components. Rotaxane-based organocatalysis presents a new direction toward controlled one-pot catalytic reactions. By combining molecular switches and catalysts, fluorescence and pH-responsive switching along with the exclusive selectivity of dual catalytic reactions are demonstrated. A newly designed [2]rotaxane catalyst containing an anthracene group was used to visualize the catalytic reaction process upon switching the macrocycle.1 On the other area in controlled drug delivery, type III-B rotaxane dendrimers are hyperbranched macromolecules with mechanical bonds on every branching unit. By utilizing multiple molecular shuttling of the mechanical bonds within the sphere-like macromolecule, a collective three-dimensional contract-extend molecular motion was demonstrated by diffusion ordered spectroscopy (DOSY). The binding of an anti-cancer drug chlorambucil and pH-triggered switching of the dendrimers were also characterized by 1H NMR spectroscopy.2 Recently, we have demonstrated enantio-differentiation based on chiral crown ethers immobilized on chiral nanoparticles.3 New dynamic crown ether-based rotaxanes were also synthesized and characterized by X-ray crystal analysis.

Reference 1. Kwan, C.-S.; Chan, A. S. C.; Leung, K. C.-F. Org. Lett. 2016, 18, 976-979. 2. Kwan, C.-S.; Zhao, R.; Van Hove, M. A.; Cai, Z.; Leung, K. C.-F. Nat. Commun. 2018, 9, 497. 3. Yang, L.; Kwan, C.-S.; Zhang, L.; Li, X.; Han, Y.; Leung, K. C.-F.; Yang, Y.; Huang, Z. Adv. Funct. Mater., in press

Title:Utilizing the power of light and light-sensitive molecules to visualize and treat cancer
Speaker:Professor Samuel Achilefu
Date:20th December 2018
Time:10.00am to 11.00am   
Venue:Executive Classroom 1 (Level 3), MAS Atrium
Host:Associate Professor Xing Bengang
Abstract

 

Advances in cancer biology and instrumentation have allowed the development of novel strategies to improve cancer management. Central to these efforts is the discovery of highly cancer-selective molecular probes and light-sensitive drugs to improve the accuracy of cancer diagnosis, selectively destroy cancerous tissue, and minimize off-target toxicities. This presentation will highlight how we have coupled the pathophysiology of cancer to design small molecules that can identify cancer cells and tumor microenvironment. The second part of this talk will focus on our efforts to utilize small molecules and nanoparticles to induce cancer cell death via photodynamic therapy (PDT). New strategies to overcome the tissue depth limitation of PDT will be discussed. Through these integrated efforts, we hope to improve the treatment outcome of cancer and spur the development of novel molecules that will enable the early detection and eradication of cancer.

Title:Coordination Chemistry of 1st-row Transition Metal Pincer Complexes
Speaker:Associate Professor Yunho Lee
Date:17th December 2018
Time:11.00am to 12.30pm  
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Soo Han Sen
Abstract

Transition metal adduct formations with small molecules such as N2, H2, CO and CO2 are drawing much attention due to their importance in developing synthetic catalysts for various industrial processes. The chemistry is based on pincer complexes with attention to the uniqueness of the coordination geometry (square-planar or pseudotetrahedral), which is crucial in allowing for particular reactivity toward small molecules. In our laboratory, a series of pincer complexes with low-valent 1st row transition metals are currently under investigation. Synthesis and characterization of four coordinate (PEP)M-L complexes (E = N or P and M = Co, Ni) will be described, where the L site is occupied by various ligands such as NHR2, N2, COx and COOR. Regarding the geometry and reactivity relationship, a (PPP)M scaffold reveals the interconversion between square planar and tetrahedral geometry, in which reversible alkoxy group transfer occurs between a phosphide moiety of a PPP ligand and a nickel ion via unanticipated metal-ligand cooperation. This unusual group transfer reaction is tightly coupled with metal’s local geometry and its 0/II redox couple. In fact, a central phosphide moiety of a PPP ligand acts as a single electron donor to form a P radical revealing the metal-ligand cooperativity involving a single electron exchange between Ni and P. By employing such cooperativity, nitrene group transfer was successfully accomplished to generate a dimeric nickel(0)-CO species along with mesitylamine and mesityl isocyanate. In contrast, a (PNP)M scaffold presents unusual reactivity occurring at the structurally rigidified nickel center. Unique open-shell reactivity of a T-shaped nickel(I) metalloradical supported by a rigidified acridanebased pincer ligand will be discussed. Having a sterically exposed half-filled dx2-y2 orbital, this three-coordinate NiI species reveals unique open-shell reactivity including the homolytic cleavage of various σ-bonds, such as H-H, N-N, and C-C.

References:  “A P-P Bond as a Redox Reservoir and an Active Reaction Site” Angew. Chem., Int. Ed. 2018, 57, 14159-14163. • “Selective Transformation of CO2 to CO at a Single Nickel Center” Acc. Chem. Res., 2018, 51, 1144-1152. • “Direct CO2 addition to a Ni(0)-CO species allowing the selective generation of a nickel(II) carboxylate with expulsion of CO” J. Am. Chem. Soc., 2018, 140, 2179-2185. • “A T-Shaped Ni(I) Metalloradical Species” Angew. Chem., Int. Ed. 2017, 56, 9502. • “Phosphinite-Ni0 Mediated Formation of a Phosphide-NiII-OCOOMe Species via Uncommon Metal-Ligand Cooperation.” J. Am. Chem. Soc. 2015, 137, 4280.

Title:Gold Catalysis: Fun with Functionalized Carbenes
Speaker:Professor Dr A. Stephen K. Hashmi
Date:14th December 2018
Time:11.00am to 12.30pm  
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Bates, Roderick W.
Abstract

Triggered by new reactivity patterns discovered in 2000,[1] gold catalysis has become a very successful sector of catalysis research.[2] After methodology development and mechanistic studies in the last years applications in total synthesis became a hot topic in gold catalysis. Typical intermediates would be vinylgold/arylgold species or gold carbene species, recently also gold vinylidene intermediates,[3] in the last two years even photoredox catalysis with gold complexes evolved, including catalytic cycles involving gold(I) and gold(III). Gold-catalyzed reactions involving functionalized gold carbene intermediates represent another new and significant variation of the reactivity patterns of gold catalysis. New reactivity patterns will be discussed in detail with a number of new reactions, the presentation will combine both experimental and computational results. Examples will involve the use of anthranils, 1,2,4-oxadiazoles and 1,3,5-triazinanes. Furthermore, oxygen transfer to the functionalized carbene centers and insertions into alkyl-C,H bonds will be addressed in detail.

References [1] a) A. S. K. Hashmi, L. Schwarz, J.-H. Choi, T. M. Frost, Angew. Chem. Int. Ed. 2000, 39, 2285-2288; b) A. S. K. Hashmi, T. M. Frost, J. W. Bats, J. Am. Chem. Soc. 2000, 122, 11553-11554. [2] A. S. K. Hashmi, Chem. Rev. 2007, 107, 3180-3211. [3] I. Braun, A. M. Asiri, A. S. K. Hashmi, ACS Catal. 2013, 3, 1902-1907.

Title:Detection and Generation of Hydrogen Peroxide by Functional Model Complexes
Speaker:Professor Yutaka Hitomi
Date:14th December 2018
Time:10.00am to 11.00pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Xing Bengang
Abstract

Hydrogen peroxide (H2O2 ) has been known to be a harmful metabolic product, and a component of the immune response to microbial invasion; however, to date, it is also acknowledged as a messenger molecule related to cell proliferation, migration, and differentiation. The location and timing of H2O2 generation are of particular importance for understanding its intracellular functions. H2O2 can be visualized using fluorescent probes, which have unique H2O2 -responsive components. Some of these H2O2 -specific probes have been successfully applied to intracellular H2O2 imaging. Recently, we introduced metal complexes as H2O2-responsive components to develop fluorescent H2O2 probes [1,2]. These metal-complex-based H2O2 fluorescent probes are characterized by rapid responses to H2O2 , when compared with other probes having organic molecules-based responsive components. The first generation of metal-based H2O2 fluorescent probe, named MBFh1, comprises a nonheme iron complex and a nonfluorescent 3,7- dihydroxyphenoxazine derivative. Upon addition of H2O2 , the iron complex reacts with H2O2 to form an oxidized product, resorufin, via the intramolecular oxidation reaction similar to the oxidation of AmplexRed by H2O2 -activated horseradish peroxidase. However, MBFh1 decomposed under cell culture conditions, probably through hydrolysis of the amide moiety, hampering its application to fluorescence imaging of intracellular H2O2 . To sufficiently improve the stability of the metal complex-based H2O2 probe to visualize intracellular H2O2 , we developed the second generation of metalbased H2O2 fluorescent probe, named MBFh2, which comprises a stable O-alkyl resorufin derivative as a profluorophore and a nonheme iron-based peroxidase mimetic [3]. MBFh2 was successfully applied to the fluorescence imaging of intracellular H2O2 .

References [1] Y. Hitomi, T. Takeyasu, T. Funabiki and M. Kodera, Anal. Chem., 2011, 83, 9213-9216. [2] Y. Hitomi, T. Takeyasu, and M. Kodera, Chem. Commun., DOI: 10.1039/C3CC44471F. [3] Y. Hitomi, K. Hiramatsu, K. Arakawa, T. Takeyasu, M. Hata and M. Kodera, Dalton Trans. 2013, 42 (36), 12878-12882.

Title:Functional Metallomics: From Biological Evaluation of Metal Complexes to Their Characterization in Cells
Speaker:Professor Clotilde POLICAR
Date:7th December 2018
Time:10.00am to 11.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Hélène Bertrand / Associate Professor Leong Weng Kee
Abstract

In this talk, the design of small manganese complexes showing a superoxide dismutase like activity will be introduced. Cellular models can be used to evaluate their anti-oxidant activity directly in a biological context where they can be characterized, including quantification and imaging. 1,2 A second part will be focused on the development of M(CO) as probes for multimodal imaging, including orginal modalities such as IR-imaging and micro-X-fluorescence. 3-5,6 ,7 ,8

References (1) Bernard, A.-S.; Giroud, C.; Ching, H. Y. V.; Meunier, A.; Ambike, V.; Amatore, C.; Guille Collignon, M.; Lemaître, F.; Policar, C. Dalton Trans. 2012, 41, 6399. (2) Mathieu, E.; Bernard, A.-S.; Delsuc, N.; Quevrain, E.; Gazzah, G.; Lai, B.; Chain, F.; Langella, P.; Bachelet, M.; Masliah, J.; Seksik, P.; Policar, C. Inorg. Chem. 2017, 56, 2545−2555. (3) Policar, C.; Waern, J. B.; Plamont, M. A.; Clède, S.; Mayet, C.; Prazeres, R.; Ortega, J.-M.; Vessières, A.; Dazzi, A. Angew. Chem. Int. Ed. 2011, 50, 860. (4) Clède, S.; Lambert, F.; Sandt, C.; Gueroui, Z.; Plamont, M.-A.; Dumas, P.; Vessières, A.; Policar, C. Chem. Commun. 2012, 48, 7729. (5) Clède, S.; Delsuc, N.; Laugel, C.; Lambert, F.; Sandt, C.; Baillet-Guffroy, A.; Policar, C. Chem. Commun. 2015, 51, 2687. (6) Hostachy, S.; Policar, C.; Delsuc, N. Coord. Chem. Rev. 2017, 351, 172. (7) Henry, L.; Delsuc, N.; Laugel, C.; Lambert, F.; Sandt, C.; Hostachy, S.; Bernard, A.-S.; Bertrand, H. C.; Grimaud, L.; Baillet-Guffroy, A.; Policar, C. Bioconj. Chem. 2018. (8) Hostachy, S.; Masuda, M.; Miki, T.; Hamachi, I.; Sagan, S.; Lequin, O.; Medjoubi, K.; Somogyi, A.; Delsuc, N.; Policar, C. Chem. Sci. 2018, 9, 4483.

Title:Transition-Metal-Catalyzed Decarboxylative Coupling Reactions
Speaker:Professor Sunwoo Lee
Date:5th December 2018
Time:11.00am to 12.30pm 
Venue:Hilbert Space Conference Room
Host:Associate Professor Naohiko Yoshikai
Abstract

Transition-metal-catalyzed decarboxylative coupling of alkynoic acids have been studied by our lab for a decade. Since our first report that palladium-catalyzed reactions of aryl halides and propiolic acids afforded the symmetrical and unsymmetrical diaryl alkynes in good yields, a variety of related methodology have been reported by many research groups including us. The development of simple and convenient method for the preparation of aryl alkynoic acids made it easy accessible tool for the introduction of alkynyl group in organic synthesis. Although the decarboxylative coupling of alkynoic acids and Sonogahsira type coupling of terminal alkyne showed similar reactivity in most cases, the unique reactivity of alkynoic acid has been found. It is noteworthy that arylpropiolic acids readily prepared from the coupling reaction of aryl halides and propiolic acid without column chromatography procedure. In this presentation, we would like to discuss some of our recent research progress towards the decarboxylative coupling reactions of alkynoic acids. The synthesis of alkynyl ketone, propargyl amine, allyl nitrile and multihalogenated compounds will be presented.

Title:Embracing Safer Environment – Holistic Approach to Analyte Selectivity and Detection
Speaker:Mr Klaus Buckendahl
Date:30th November 2018
Time:09.30am to 11.00am 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Atsushi Goto
Abstract

With rapid economic development in recent years, the world is facing several climatic changes due to the increased discharge of pollutants into the environment. With more activists trying to curb these rising concerns for the Earth, monitoring regime should be established and put in place in as a useful tool to supplement efforts by the environmentalists. This presentation will give an overview of the different technologies in areas of environmental monitoring, as well as case studies to illustrate industrial practices in accordance to international standards or regulations

 

Title:Versatile Metallic Nanodendritesfor SERS/Electrochemical Analysis and Peptide-Incorporated SERS Schemes for Bio-analyte Detection
Speaker:Professor Hoeil Chung
Date:29th November 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Ling Xing Yi
Abstract

PA three dimensional (3D) gold (Au) nanodendrite network porous structure constructed by a simple electrochemical synthetic method, and its utility for sensitive electrochemical measurement will be presented. The 3D nanodendrite network porous structure was constructed on a platinum surface through electrodeposition of Au under the presence of hydrogen bubbles generated from the same surface. With the use of 3D nanodendrite network porous structure, a much more sensitive detection of As(III) was possible due to its large surface area. Also, a toehold-mediated DNA displacement-based SERS sensor for detecting point mutations in the BIGH3 gene associated with the most common corneal dystrophies (CDs) will be discussed. SERS-efficient Ag@Au bimetallic nanodendrite was employed to ensure sensitivity. Based on tests that used clinical homozygous and heterozygous CD samples, a single-base mismatched DNA sequence was identifiable within 30 minutes with a limit of detection of 400 fM. In addition, a strategy to improve the sensitivity for detecting a protein biomarker through signal multiplication by manipulating multiple peptide-based SERS probes to bind the biomarker (Protective antigen (PA)) was studied. Each probe was added sequentially and an optimal probe-addition sequence was determined to provide maximal sensitivity. The limit of detection was 0.1 aM. Finally, asymmetrical flow field-flow fractionation (AF4) has been evaluated for detection of PA. Further, an analytical scheme, incorporating field-flow fractionation (FFF)-based separation of target-specific polystyrene particle probes of different sizes and amplified SERS tagging, was demonstrated for detection of multiple microRNAs.

References 1 Hoeil Chung et al, Anal. Chem., 2016, 88, 11288-11292. 2. Hoeil Chung et al, Anal. Chem., 2016, 88, 3465−3470. 3. Hoeil Chung et al, Journal of Chromatography A, 2015, 1422, 239–246. 4. Hoeil Chung et al, Analytica Chimica Acta, 2015, 885, 132–139. 5. Hoeil Chung et al, Journal of Chromatography A, 2018, 1556, 97–102. 6. Hoeil Chung et al, Biosensors and Bioelectronics, 2011, 27(1), 183-186.

 

Title:Silicon-Containing Linkers for MOF Construction
Speaker:Professor Paul Lickiss
Date:21st November 2018
Time:10.30am to 12.00pm 
Venue:Hilbert Space Conference Room 
Host:Associate Professor Roderick W Bates
Abstract

Porous materials containing silicon, often in siloxane (Si-O-Si) linkages are well known and include zeolites, organosilicas, and POSS hybrids. However, MOFs incorporating Si are relatively uncommon, especially those containing Si-O bonds. This is despite the fact that organosilicon linkers may offer advantages, such as ease of synthesis for complicated polyfunctional linkers, low toxicity, low chemical reactivity and thermal stability. We have prepared a variety of organosilicon linkers and applied them in the construction of coordination polymers and MOFs. Simple disiloxanes, Si-centred tetrazolate linkers, and Si-centred polycarboxylic acids have all given interesting materials on reaction with metal salts. For example, the highly-connected organosilicon polycarboxylic acids (below) have been prepared and applied in the construction of MOFs. L1-H6 itself crystallizes as an unusual interpenetrated 3D hydrogen-bonded framework. Reaction of L1-H6 with Zn(II) gave a MOF with fsy topology, the first reported1 example of a 3D-connected MOF incorporating Si-O-Si functionality. Cleavage of L1-H6 gives a silanol-based triacid L2-H3 which is shown to give a coordination polymer with Zn(II), consisting of 2D layers which assemble by hydrogen-bonding to afford a 3D supramolecular structure with flu topology. The tetracarboxylic acid L3-H4 crystallizes through hydrogenbonding to give a quadruply interpentrated structure comprising 4 identical mog nets. Reaction of L3-H4 with Zr(IV) afforded, a 3D MOF built from 8-connected Zr-based nodes cross-linked by L3 to afford a porous MOF with the rarely encountered scu-derived tty topology.

[1] L. C. Delmas, P. N. Horton, A. J. P. White, S. J. Coles, P. D. Lickiss and R. P. Davies, Chem. Commun., 2017, 53, 12524.

 

Title:Functionalisation of Graphite and 2D Materials: Applications in Electrocatalysis and Separation
Speaker:Professor Robert A. W. Dryfe
Date:13th November 2018
Time:10.30am to 12.00pm 
Venue:Hilbert Space Conference Room 
Host:Associate Professor Richard D Webster
Abstract

There is much current interest in the applications of 2D materials in the context of energy storage. Another topical area is the transport of liquids and gases within the “nano-capillaries” that can be created with such materials, with particular interest in filtration and other separation-based applications. In this talk, we will discuss our recent work on the wetting of graphitic surfaces: it is clear that near “frictionless” interactions occur at the graphite-water interface [1]. We also describe methods to functionalise graphite surfaces, with covalent organic bonds and with metals/metal oxides, during the electrochemical exfoliation of graphite to graphene [2-4]. Applications of these materials in energy conversion/storage will be discussed. Finally, we will discuss the functionalisation of few-layer MoS2 materials, and the use of such membranes for de-salination of water [5].

References: D.J Lomax et al, “Ultra-low voltage electrowetting using graphite surfaces”, Soft Matter, 12,(2016) 8798–8804 A. Ejigu et al, “Single Stage Simultaneous Electrochemical Exfoliation and Functionalization of Graphene”, ACS Appl. Mater. Int., 9, (2017), 710–721 A. Ejigu et al, “Optimisation of electrolytic solvents for simultaneous electrochemical exfoliation and functionalisation of graphene with metal nanostructures”, Carbon, 128, (2018), 257–266 A. Ejigu et al, “On the Role of Transition Metal Salts during Electrochemical Exfoliation of Graphite: Antioxidants or Metal Oxide Decorators for Energy Storage Applications”, Adv. Func. Mater, in press. W. Hirunpinyopas et al, “Desalination and Nanofiltration through Functionalized Laminar MoS2 Membranes”, ACS Nano, 11, (2017), 11082–11090.

 

Title:New Strategies for Carbon Dioxide Incorporation through C–C Bond Forming Process
Speaker:Professor Tsuyoshi Mita
Date:5th November 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract

Since carbon dioxide (CO2 ) is an abundant, inexpensive, nontoxic, and renewable C1 source, many efforts have been made for the development of catalytic/noncatalytic CO2 incorporation reactions over the past decade. For the purpose of preparing value-added chemicals from CO2 , we have made considerable efforts toward the synthesis of useful carboxylic acids (e.g. α-amino acids, γ-butyrolactones, aliphatic acids) with new synthetic protocols involving C–C bond forming reactions.

 

Title:Challenge: Mimicking transition metals using Si
Speaker:Professor Tsuyoshi Kato
Date:26th October 2018 
Time:10.30am to 12.00pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor So Cheuk Wai 

 

Title:Total Synthesis of Biologically Important Natural Products Enabled by Development of Novel Synthetic Methods and Strategies
Speaker:Professor Frank Grossman
Date:2nd October 2018
Time:2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Tan Howe Siang 
Abstract

 

The concept of pump-probe spectroscopy is exemplified with the photoelectron spectroscopy of the sodium dimer. Theoretical concepts and approximations are discussed, including some detailed "hands-on" calculations. The interpretation of the outcome in terms of the dynamical reflection principle will conclude the presentation.

 

Title:Total Synthesis of Biologically Important Natural Products Enabled by Development of Novel Synthetic Methods and Strategies
Speaker:Professor Zhen Yang
Date:2nd October 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Naohiko Yoshikai 
Abstract

The total synthesis of complex natural products provides a unique opportunity to conduct fundamental research in chemistry and biology. Our group is pursuing total synthesis of naturally occurring structurally complex molecules, and some of them are listed in the following table. The densely-packed arrays of stereogenic centers that constitute these polycyclic targets challenge the limits of current technology and inspire the development of new synthetic methods and strategies. This seminar will describe the methods and strategies we have developed to synthesize biologically important natural products

Reference: 1. Han, Y.-X.; Jiang, Y.-L.; Li, Y.; Yu, H.-X.; Tong, B.-Q.; Niu, Z.; Zhou, S.-J.; Liu, S.; Lan, Y.; Chen, J.-H.; Yang, Z. Nature Commun. 2017, 8, 14233.。 2. Li, F.-Z.; Tu, Q.; Chen, S.; Zhu, L.; Lan, Y.; Gong, J.-X.; Yang, Z. Angew. Chem. Int. Ed. 2017, 56, 5844-5848 3. Liu, D.-D.; Sun, T.-W.; Wang, K.-Y.; Lu, Y.; Zhang, S.-L.; Li, Y.-H.; Jiang, Y.-L.; Chen, J.-H.; Yang, Z. J. Am. Chem. Soc. 2017, 139, 5732−5735. 4. Huang, J.; Gu, Y.; Guo, K.; Zhu, L.; Lan, Y.; Gong, J.; Yang, Z. Angew. Chem. Int. Ed. 2017, 56, 7890-7893. 5. Zhang, P.-P.; Yan, Z-M.; Li, Y.-H.; Gong, G.-X.; Yang, Z. “Enantioselective Total Synthesis of (−)-Pavidolide B”, J. Am. Chem. Soc. 2017, 139, 13989−13992. 6. Huang, Z.-H.; Huang, J.; Qu, Y.-Z.; Zhang, W.-B.; Gong, J.-X.; Yang, Z. Angew. Chem. Int. Ed. 2018, 57, 8744 –8748.

 

Title:Overcoming Steric Hindrance and Molecular Strain by Rhodium-Catalyzed Cycloaddition
Speaker:Professor Ken Tanaka
Date:14th September 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba 
Abstract

Overcoming steric hindrance is crucial for the synthesis of sterically demanding aromatic compounds, such as biaryls and helicenes. For the synthesis of biaryls, the transition-metal-catalyzed cross-coupling reactions have been employed, however, this approach suffers from low efficiency due to the difficulty of the sterically demanding aryl-aryl bond formation. On the other hand, the [2+2+2] cycloaddition of three acetylenes to form benzene is highly exothermic and irreversible process, although high temperature or a catalyst is required because of entropic and kinetic considerations. In 2003, our research group reported that a cationic rhodium(I)/biaryl bisphosphine complex shows exceptionally high catalytic activity and selectivity toward the [2+2+2] cycloaddition. This catalyst was successfully applied to the conceptually new biaryl synthesis by the double [2+2+2] cycloaddition, in which the sterically demanding aryl-aryl bond formation is replaced to the sterically less demanding alkyne-alkyne bond formation followed by the highly exothermic and irreversible benzene ring construction. In this talk, I will disclose the application of this rhodium catalyst to the synthesis of various biaryls and helicenes. Overcoming molecular strain for the synthesis of highly strained cyclic -conjugated compounds will also be disclosed.

References 1. For reviews, see: a) K. Tanaka, Chem. Asian J. 2009, 4, 508. b) Y. Shibata, K. Tanaka, Synthesis 2012, 44, 323. c) Transition-Metal-Mediated Aromatic Ring Construction, ed. by K. Tanaka, Wiley, Hoboken, 2013, part 1. 2. For our accounts, see: a) K. Tanaka, Synlett 2007, 1977. b) K. Tanaka, Y. Kimura, K. Murayama, Bull. Chem. Soc. Jpn. 2015, 88, 3375. c) K. Tanaka, Bull. Chem. Soc. Jpn. 2018, 91, 187.

 

Title:Catalyzing and Controlling Chemical Reactions with Electric Fields
Speaker:Professor Michelle Coote
Date:13th September 2018
Time:10.30am to 11.30am 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Ling Xing Yi
Abstract

Chemists appreciate that the rate of redox reactions can be manipulated by means of an electrical potential gradient. However, it was only in 2016 that it was shown that an external electric field can also be used to catalyze non-redox reactions, thereby opening up a new dimension to chemical catalysis [1] . So-called electrostatic catalysis arises because most chemical species have some degree of polarity and so can be stabilized by an appropriately aligned electric field; when this occurs to a greater extent in transition states compared with reactants, reactions are catalyzed [2] . However, by their nature such effects are highly directional and so implementing them in practical chemical systems is problematic. We have been using a combination of theory and experiment to explore various solutions to this problem. The first is using surface chemistry techniques, in conjunction with the break-junction technique in scanning tunnelling microscopy [1] . This allows us to detect chemical reaction events at the single molecule level, whilst delivering an oriented electrical field-stimulus across the approaching reactants. The second is making use of the electric fields within the double layers of electrochemical cells to manipulate both redox and non-redox unimolecular reactions. Here we find that molecules actually self-align and interact with electrolyte ions to facilitate catalysis [3] . Finally, in an approach that is truly scalable, we have instead addressed problem of orientation of the electric field by making use of appropriately placed charged functional groups to provide the electrostatic stabilization for solution-phase reactions [4] . In this way, the direction of the local field experienced by the reaction centre is fixed, and by associating the stabilization or destabilization with the protonation state of an acid or base group, it has the advantage of providing a convenient pH switch. In this talk our experimental and theoretical results will be presented and the prospects for electrostatic catalysis discussed.

[1] Aragones, Haworth, Darwish, Ciampi, Bloomfield, Wallace, Diez-Perez, Coote, Nature, 2016, 531; Ciampi Darwish, Aitken, Diez-Perez, Coote, Chem. Soc. Rev., 2018, 47, 5146 [2] Shaik, Mandal, Ramanan, Nat. Chem. 2016, 8, 1091-1098 & Chem. Soc. Rev., 2018,47, 5125-5145 [3] Zhang, Laborda, Darwish, Noble, Tyrell, Pluczyk, Le Brun, Wallace, Gonzalez, Coote, Ciampi, J. Am. Chem. Soc., 2018, 140, 766. [4] Gryn’ova, Marshall, Blanksby, Coote, Nat. Chem., 2013, 5, 474; Gryn’ova, Coote, J. Am. Chem. Soc, 2013, 135, 15392; Klinska, Smith, Gryn’ova, Banwell, Coote, Chem. Sci., 2015, 6, 5623; Gryn'ova, Smith, Coote, Phys. Chem. Chem. Phys., 2017, 19, 22678; Aitken, Coote, Phys. Chem. Chem. Phys., 2018, 20, 10671.

 

Title:Small r Big D
Speaker:Dr Ken Lee
Date:5th September 2018
Time:11.00am to 12.00pm
Venue:SPMS MAS Executive Classroom 2 
Host:Professor Tan Choon Hong 
Abstract

 

Ken is currently a Senior Research Scientist from Centre for Biomedical and Life Sciences, and concurrently, a Senior Manager from Food Innovation and Resource Centre, Department for Technology, Innovation and Enterprise, Singapore Polytechnic. He will briefly share some of his current and completed r&D work in the areas of Pharmaceutical, Environment and Food. He will also present, in detail, one of his completed projects on the development of a rapid on-site water pathogens detection kit.

 

 

Title:Natural Product on Demand: A Bioinspired Approach
Speaker:Professor Ran Hong
Date:29th August 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Naohiko Yoshikai
Abstract

Nature product is known as an endless resource for organic synthesis as well as drug discovery [1] . Despite numerous synthetic efforts devoted to this field, practical synthesis toward promising drug leads remains a formidable challenge. Efficient strategies in combination of novel synthetic methods are still highly desirable. In this presentation, we will discuss our recent progress towards the efficient synthesis of selected polyketides, which show intriguing chemical structure and biological activities. Novel chemical transformations have been developed to address challenging problems being encountered during the synthesis event [2,3] . This presentation will cover enzymatic catalysis, synthetic method development as well as devising efficient strategy (a bioinspired approach in particular) to complete the total synthesis of complex polyketides.

References: [1] (a) Macrolide Antibiotics: Chemistry, Biology, and Practice, 2nd Ed.; S. Ōmura. Academic Press, 2002. (b) Polyketides: Biosynthesis, Biological Activity, and Genetic Engineering (Eds.: S. R. Baerson, A. M. Rimando), American Chemical Society, Washington, DC, 2007. (c) C. Hertweck, Angew. Chem. Int. Ed. 2009, 48, 4688. [2] (a) L. Yang, G. He, R. Yin, L. Zhu, X. Wang, R. Hong, Angew. Chem., Int. Ed. 2014, 53, 11600. (b) Yang, Z. Lin, S.-H. Huang, R. Hong, Angew. Chem. Int. Ed. 2016, 55, 6280. [3] (a) K. Zheng, D. Shen, R. Hong, J. Am. Chem. Soc. 2017, 139, 12939. (b) L. Yang, Z. Lin, S. Shao, R. Hong, 2018,submitted for preparation.

 

Title:Ab initio modeling of complex chemical phenomena in aqueous solution
Speaker:Dr Mirza Galib
Date:23rd August 2018
Time:10.00am to 11.00am 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Edwin Yeow 
Abstract

Water plays a vital role in many physical and chemical processes. However, its structure and dynamics at a molecular level yet not fully understood. Computer simulations at the atomic scale play an important role in understanding the microscopic structure of water. However, the quality of the simulated results significantly depends on the accuracy of the interaction potential used in the simulation. The difficulty in producing a correct description of the interaction potential for water lies in the delicate balance between covalent bonds, hydrogen bonds and the weak van der Waals interactions. Unfortunately, the widely used classical point charge model fails to produce that balance in specific cases, especially when bulk water symmetry is broken. A solution to this problem is to use a fully ab initio model that can describe these balances of strong and weak forces more perfectly. In this talk, I will present an ab initio model of water using a revised version of the PBE DFT functional along with dispersion correction that can produce a near quantitative agreement for the structure of bulk ambient water.1 Interestingly, this successful modeling of water allows us to use simulation in conjunction with experiment to study more complex chemical phenomenon in water. As an example, I will show how DFT MD along with simulated XANES spectra provide unprecedented information of solvation structure around ions2 and elucidate the CaCO3 nucleation mechanisms in water3. 1. Galib, Mirza, et al. "Mass density fluctuations in quantum and classical descriptions of liquid water." The Journal of chemical physics, 146.24 (2017) 2. Galib, Mirza, et al. "Unraveling the Spectral Signatures of Solvent Ordering in K-edge XANES of Aqueous Na+" The Journal of chemical physics, Accepted 2018.

 

Title:New Trifluoromethylation Reactions with Fluoroform-Derived CuCF3 and Domino Synthesis of Trifluoromethylated Heterocycles
Speaker:Professor Gavin Chit Tsui
Date:14th August 2018
Time:11.00am to 12.30pm   
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Ling Xing Yi
Abstract


Fluorinated molecules continue to be of major interest for the applications in pharmaceuticals, agrochemicals and functional materials. The constant search for more efficient, selective and convenient trifluoromethylation methods is an important yet challenging priority. We herein present the recent development of novel trifluoromethylation methods using the fluoroform(CF3H)-derived CuCF3 . By employing common feedstocks such as terminal alkynes and simple alkenes, a variety of valuable CF3 -containing building blocks including the trifluoromethylated alkynes,1 alkenes2 and β-trifluoromethyl alcohols3 can be synthesized in one step. These processes, namely trifluoromethylation, hydrotrifluoromethylation and hydroxytrifluoromethylation, allow the distinctive construction of C(sp)-CF3 , C(sp2 )-CF3 and C(sp3 )-CF3 bonds, respectively. Furthermore, we have developed an unprecedented three-component vicinal trifluoromethylation-allylation of arynes where two carbon-carbon bonds (C-CF3 and C-allyl) are formed in one pot to provide the trifluoromethylated allylarenes. 4 Overall, the ultimate CF3 source in these versatile fluorinated molecules is the inexpensive industrial by-product fluoroform from Teflon manufacturing.

We have also investigated the synthesis of diverse trifluoromethylated heterocycles via domino strategies with copper. An interrupted click reaction, using CuI/phen as the catalyst and (trifluoromethyl)trimethylsilane (TMSCF3 ) as the nucleophilic CF3 source, has been developed to synthesize 5-trifluoromethyl 1,2,3-triazoles in one step from readily available terminal alkynes and azides. 5 The reaction shows complete regioselectivity, broad substrate scope and good functional group tolerability. Moreover, domino 5-endo-dig cyclization/trifluoromethylation of α,β-alkynic tosylhydrazones and propargylic N-hydroxylamines allows convenient access to 4-(trifluoromethyl)pyrazoles6 and 4-trifluoromethyl4-isoxazolines,7 respectively. These reactions are facilitated by the Cu(OTf)2 /TMSCF3 /KF combination. By employing easily accessible 2- alkynylanilines and the low-cost fluoroform-derived CuCF3 reagent, both 2- and 3-(trifluoromethyl)indoles can be prepared in good yields with no ambiguity of the CF3 position. 8-9 Applications of the above methods in the expedient synthesis of CF3 -containing drug analogues such as rufinamide, celecoxib, bazedoxifene and melatonin have also been successfully demonstrated.

References: (1) He, L.; Tsui, G. C. Org. Lett. 2016, 18, 2800-2803. (2) He, L.; Yang, X.; Tsui, G. C. J. Org. Chem. 2017, 82, 6192-6201. (3) Yang, X.; He, L.; Tsui, G. C. Org. Lett. 2017, 19, 2446-2449. (4) Yang, X.; Tsui, G. C. Org. Lett. 2018, 20, 1179-1182. (5) Cheung, K. P. S.; Tsui, G. C. Org. Lett. 2017, 19, 2881- 2884. (6) Wang, Q.; He, L.; Li, K. K.; Tsui, G. C. Org. Lett. 2017, 19, 658-661. (7) Wang, Q.; Tsui, G. C. J. Org. Chem. 2018, 83, 2971-2979. (8) Ye, Y.; Cheung, K. P. S.; He, L.; Tsui, G. C. Org. Lett. 2018, 20, 1676-1679. (9) Ye, Y.; Cheung, K. P. S.; He, L.; Tsui, G. C. Org. Chem. Front. 2018, accepted.

 

Title:Microfluidic Devices as Miniaturized Analytical Platforms
Speaker:Professor Lourdes Basabe-Desmont
Date:8th August 2018
Time:10.00am to 11.00am
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Ling Xing Yi
Abstract

 

Microfluidics systems are needed interfaces in order to bring nanotechnologies with analytical applications to the end users. The lab-on-a-chip research field involves the development of integrated microfluidic systems and it requires multidisciplinar imput from applied chemistry, physisc and biology. The Microfluidics Cluster UPV/EHU was established in June 2015 by Lourdes Basabe and Fernando Benito, it is a strategic alliance between two research teams working on Micro- and Nanotechnologies for Lab-on-a-Chip applications at the University of the Basque Country. We focus on applied and translational research. Through the combination of microfluidics, sensors and actuators, we develop integrated microsystems, with applications in biomedical diagnostics, environmental analysis, chemistry, sport science, biology and medicine. We are a multidisciplinary team comprised by chemists, biologists and engineers, in close collaboration with sport and environmental scientists, medical doctors, and industry. In this talk, I will describe the general research activities of the BIOMICS-microfluidics Research Group on surface engineering for cell culture and monitoring, and on self-powered microfluidic systems for blood analysis.

REFERENCES 1. Hierarchical Self-Assembly of Gold Nanoparticles into Patterned Plasmonic Nanostructures. Hamon, Cyrille; Novikov, Sergey; Scarabelli, Leonardo; Basabe-Desmonts, Lourdes; Liz-Marzan, Luis M, ACS NANO, 2014, 8, 10, 10694-10703 2. Tunable Nanoparticle and Cell Assembly Using Combined Self-Powered Microfluidics and Microcontact Printing. Hamon, C.; HenriksenLacey, M.; La Porta, A.; Rosique, M.; Langer,

 

Title:Materials by Design: Why Do We Care? How Do We Make It Happen?
Speaker:Dr. Thao T. Tran
Date:7th August 2018
Time:3.00pm to 4.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Loh Zhi Heng 
Abstract

In this talk, I will present an update on the current status of our ability to design and discover a few different classes of materials and discuss their relevance to transforming our society. Specific examples will be chosen from our work including: (i) a design principle of how to break inversion symmetry for the discovery of new nonlinear optical materials; (ii) a new rubidium aluminum borate material exhibiting large nonlinear optical responses and potential for solid-state lasers applications; (iii) a rational design strategy for the tuning of direct and indirect band gaps in semiconductors with the potential for impact on energy technology; and (iv) a realization of S = 1/2 spin chain, a prototype of spin liquid, in a vacancy-ordered mixed-metal copper material. Particular focus will be placed on the current abilities for and limitations on selectively breaking and forming chemical bonds in solid state.

1. Tran, T.T., He, J., Rondinelli, M. J., Halasyamani, P.S., J. Am. Chem. Soc., 137, 10504-10507, 2015. 2. Tran, T.T., Rondinelli, M. J., Halasyamani, P.S., J. Am. Chem. Soc., 139, 1285-1295, 2017. 3. Tran, T.T., Rondinelli, M. J., Halasyamani, P.S., Angew. Chem. Int. Ed., 56, 1-6, 2017. 4. Tran, T.T., Panella, J. R., Chamorro, J. R., Morey, J. R., McQueen, T.M., Mater. Horiz., 4, 688-693, 2017. 5. Tran, T. T., McQueen, T. M., Submitted 2018.

 

Title:Chemical Reactivity: From Computational Understanding to New Design
Speaker:Dr. Bhaskar Monda
Date:6th August 2018
Time:2.00pm to 3.00pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract

Understanding chemical reactivity is central to chemistry research and the development of novel chemical systems. The continued development of powerful computational methods has advanced the chemical reactivity understanding at the electronic level. By connecting reaction energetics, molecular orbital interactions, and spectroscopy together, computational chemistry can provide invaluable insights into the chemical reactivity. As such, a synergy between computation and experiment has tremendous potential for enabling new developments, which the current chemistry research has witnessed over the recent years. This talk will encompass the use of computational methods for a wide range of catalytic reactions to showcase different aspects of chemical reactivity. In particular, examples from organic electron donor promoted organocatalysis, non-noble metal based CO2 hydrogenation, and oxo-iron mediated C–H and C=C oxidation reactions will be discussed. The elegant correlation between governing reaction steps, electronic structure, and reactivity will be highlighted. The case of oxoiron complexes will demonstrate how spectroscopic results from magnetic circular dichroism (MCD), electron paramagnetic resonance (EPR), and Mössbauer spectroscopy correlate with the electronic structure and thereby help to decipher the complex structure-activity relations. Overall, this talk will exhibit high-end applications of advanced computational techniques, mainly based on correlated ab initio methods, to decipher the correlation between electronic structure, reactivity, and spectroscopic properties in chemical systems, which in turn trigger in silico design.

References 1. Doni, E.; Mondal, B.; O’Sullivan, S.; Tuttle, T.; Murphy, J. A. J. Am. Chem. Soc. 2013, 135, 10934. 2. Mondal, B.; Song, J.; Neese, F.; Ye, S. Curr. Op. Chem. Biol. 2015, 25, 103. 3. Mondal, B.; Neese, F.; Ye, S. Inorg. Chem. 2016, 55, 5438. 4. Ye, S.; Kupper, C.; Meyer, S.; Andris, E.; Navrátil, R.; Krahe, O.; Mondal, B.; Atanasov, M.; Bill, E.; Roithová, J.; Meyer, F.; Neese, F. J. Am. Chem. Soc. 2016, 138, 14312. 5. Kupper, C.; Mondal, B.; Serrano-Plana, J.; Klawitter, I.; Neese, F.; Costas, M.; Ye, S.; Meyer, F. J. Am. Chem. Soc. 2017, 139, 8939. 6. Mondal, B.; Neese, F.; Bill, E.; Ye, S. J. Am. Chem. Soc. 2018, DOI:10.1021/jacs.8b04275.

 

Title:New Insights into an Old Target: Study of bacterial peptidoglycan biosynthesis and beyond
Speaker:Dr Qiao Yuan
Date:31st July 2018
Time:10.30am to 11.30am
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract

Bacterial peptidoglycan (PG), an exoskeleton structure that protects the cell from lysis, is essential in bacteria but absent in mammalian cells. Therefore, the peptidoglycan biosynthetic pathway is targeted of many classes of antibiotics, including the beta-lactams family. Beta-lactams inhibit the transpeptidase domain of penicillin-binding proteins (PBPs), the enzymes responsible for the final step of bacterial peptidoglycan biosynthesis. Mutations of transpeptidases in Staphylococcus aureus (S. aureus) have been implicated in resistance in the clinic (commonly known as MRSA infections). Despite the fact that PBPs are important antibiotic targets, there have been no direct assays to monitor their enzyamtic activities, primarily due to inaccessibily to the appropriate Lipid II substrates, which are complex molecules that exist at low abundance in nature. In this talk, I will present a series of recent findings that has led us to the substrates as well as new insights into PBPs activities in MRSA. Our work has not only established new tools for studies of bacterial peptidoglycan biosynthesis, but also sheds important implications on potential treatment for MRSA infections.

 

Title:A Quantum Chemical Journey in Understanding Carbon-Carbon Bond Catalysis
Speaker:Dr Richmond Lee
Date:30th July 2018
Time:10.00am to 11.00am
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract

Chemical transformation of the carbon-carbon bond is an important process to access a myriad of important molecules. It takes a broad and united effort from experiment and theory in order to establish a more coherent chemical picture of reactivity and stability during bond formation or breakage guided by catalysts. The goal of theoretical studies with quantum chemistry is to generate a better understanding of the chemical systems in focus and allow predictions to be made in order to improve the catalyst and/or desired chemical processes. Therefore in a bid to probe reaction mechanisms of interest, i.e. C-C bond forming processes, quantum chemistry was employed to investigate the origin of stereo-selective or chemo-divergent formation of C-C bonds under various catalytic systems. My work on thiourea-based catalysis and the more recent ion-pair catalysis will be discussed.

 

Title:Smarter Microfluidics with Smart Materials
Speaker:Professor Fernando Benito-Lopez
Date:25th July 2018
Time:11.00am to 12.00pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Ling Xing Yi
Abstract

The Microfluidics Cluster UPV/EHU was established in June 2015 by Lourdes Basabe and Fernando Benito as a strategic alliance between two research teams working on Micro- and Nanotechnologies for Lab-on-a-Chip applications at the University of the Basque Country. Through the combination of microfluidics, sensors and actuators, we develop integrated microsystems, with applications in biomedical diagnostics, environmental analysis, chemistry, sport science, biology and medicine. We are a multidisciplinary team comprised by chemists, biologists and engineers, in close collaboration with sport and environmental scientists, medical doctors, and industry. In this seminar, I will describe the general research activities of the AMMa-LOAC Group on the integration of smart materials in microfluidic devices, in order to provide new functionalities to Lab-on-a-Chip platforms. The integration of chemo/biosensors and actuators based on smart materials, in the microchannels of a microfluidic device, is enabling new ways of fluidic control, manipulation and sensing that is overpassing existing technology, with applications in environmental and sport sciences, among others.

References 1- Driving Flows in Microfluidic Paper-Based Analytical Devices with a Cholinium Based Poly Ionic Liquid Hydrogel, T. Akyazi, A. Tudor, D. Diamond, L. Basabe-Desmonts, L. Florea, F. Benito-Lopez,* Sens. Actuators B, 2018, 261, 372-378. 2- Light-responsive Materials for Microfluidic Applications, J. ter Schiphorst, J. Saez, D. Diamond, F. Benito Lopez,*A. Schenning,* Lab Chip, 2018, 18, 699-709. 3- Reusable Ionogel-based Photo-actuators in a Lab-on-a-disc, J. Saez, T. Glennon, M. Czugala, A. Tudor, J. Ducreé, D. Diamond, L. Florea, F. Benito-Lopez,* Sens. Actuators B, 2018, 257, 963-970.

 

Title:Metallic Nanoparticles: Strategies for on-surface synthesis, 3D patterning and studying plasmon-induced chemistry at the nanoscale
Speaker:Professor Safi Jradi
Date:19th July 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Ling Xing Yi
Abstract

In this talk, I will first present some strategies for the fabrication and assembly of plasmonic nanostructures. I will particularly show a simple and versatile approach based on polymer self-assembly for on-surface synthesis and assembly of gold and silver nanoparticules (NPs) with different shapes including nanorings, nanocubes, and nanohexagones. Next, I will show some photoinduced synthesis and assembly methods of NPs in a spatially controlled manner using femtosecond laser. More particularly, I will present a recently developed strategy for the directed assembly of NPs within complex 1D and 3D microstructures made by 2-photon polymerization of a home-mode functionalized photopolymer. I will give some examples of sensing applications in SERS. In the second part of my presentation, I will introduce some approaches for studying plasmon-induced chemistry at the nanoscale. I will particularly show how near-field polymerization can be used to map the electromagnetic and thermal field at the surface of photoexcited plasmonic NPs. Finally, I will show some examples of fabrication of hybrid plasmonic nanosources with tunable emission color and active SNOM nanoprobes using photopolymers containing Quantum Dots.

 

Title:Data-driven drug discovery and repositioning by machine learning
Speaker:Professor Yoshihiro Yamanishi
Date:16th July 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba 
Abstract

Drug repositioning, or the identification of new indications of drugs (i.e., new applicable diseases), is an efficient strategy for drug development, and it has received remarkable attention in pharmaceutical science. The drug repositioning approach can increase the success rate of drug development and to reduce the cost in terms of time, risk, and expenditure. In this study, we developed novel machine learning methods for automatic drug repositioning in order to predict unknown indications of known drugs or drug candidate compounds. The prediction is performed based on the analysis of various large-scale omics data of drugs, compounds, genes, proteins, and diseases in a framework of supervised network inference. Our results show that the proposed method outperforms previous methods in terms of accuracy and applicability. We performed a comprehensive prediction of new indications of all approved drugs and bioactive compounds for a wide range of diseases defined in the International Classification of Diseases. We show several biologically meaningful examples of newly predicted drug indications for cancers and neurodegenerative diseases. The proposed methods are expected to be useful for various pharmaceutical applications in drug discovery.

 

Title:Organic Chemistry Inspired by the Organometallic Chemistry of Gold
Speaker:Professor F. Dean Toste
Date:29th June 2018
Time:2.00pm to 3.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba 

 

Title:The versatility of xanthates for macromolecular engineering
Speaker:Professor Mathias Destarac
Date:29th June 2018
Time:10.30am to 12.00pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Atsushi Goto
Abstract:

Over the last twenty years, xanthates of general structure R-S(C=S)-OR’ have been largely studied as chain transfer agents for reversible addition-fragmentation chain transfer (RAFT) polymerization. In particular, O-ethyl xanthates (R’=Et) are well-suited to control the polymerization of monomers of disparate reactivities, typically from acrylates or acrylamides1,2 to vinyl monomers.3,4 This allowed the synthesis of many original block copolymers which will be exemplified, with a special focus given on aqueous RAFT polymerization. In another context, we recently applied our knowledge of the free-radical chemistry of xanthates to the synthesis of -thiolactones.5 Their application for polymer “click” end-functionalization and reversible-deactivation radical polymerization will be presented.

1. E. Read, A. Guinaudeau, D.J. Wilson, A. Cadix, F. Violleau, M. Destarac. Polym. Chem. 2014, 5, 2202-2207. 2. L. Despax, J. Fitremann, M. Destarac, S. Harrisson. Polym. Chem., 2016, 7, 3375-3377. 3. A. Guinaudeau, O. Coutelier, A. Sandeau, S. Mazières, H-D. Nguyen Thi, V. Le Drogo, D. J. Wilson, M. Destarac. Macromolecules 2014, 47, 41-50. 4. L. Seiler, J. Loiseau, F. Leising, P. Boustingorry, S. Harrisson, M. Destarac. Polym. Chem. 2017, 8, 3825-3832. 5. M. Langlais, I. Kulai, O. Coutelier, M. Destarac. Macromolecules 2017, 50, 3524-3531.

 

Title:Protein Chemistry and Functional Proteomics: Photocaging, Crosslinking and Capture Unknown Enzyme Substrates
Speaker:Professor Zhaohui Sunny Zhou
Date:23rd May 2018
Time:2.30pm to 4.00pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Li Tianhu
Abstract:

 

In the first part of my talk, I will describe new site-specific methods to install novel switches that can be removed reversibly. One example is by light and native form can be restored – a process often referred to as photocaging. Unique to light, both temporal and spatial control can be achieved. An additional advantage is that the payload, if any, can be released simultaneously. Our method and newly developed switches have broad applications such as biological probes (e.g., neurotransmission), fusion protein, antibody drug conjugates (ADCs) and controlled drug release.

Next, scientific research, to a significant degree, is about discovering the unknowns. However, without a priori knowledge of the chemical nature and sites of protein modifications or enzyme substrates, it is extremely challenging to deploy proper separation methods and search algorithms. To this end, my laboratory (a.k.a. SunnyLand) has devised chemo-enzymatic approaches that compliment instrumental methods to identify enzyme substrates and new crosslinking chemistry.

First, identification of an enzyme’s substrates is the first step toward understanding its function yet remains a major challenge. A fundamental impediment is the transient nature of interactions between an enzyme and its substrates or products. Based on the venerable concept of multisubstrate-adduct inhibitors, we have devise functional probes for enzyme-catalyzed in situ formation of substrate adduct. The resulting bisubstrate-adduct tightly binds to the corresponding enzyme, facilitating its subsequent analysis (JACS, 2016, 138, 2877). Furthermore, these complexes between the enzyme and its substrates in cellular milieu were directly observed by native mass spectrometry, providing a facile method for large scale proteomic analysis (ChemBiochem, 2017, 18, 613).

Second, we have devised a probe (brominated coumarin azide) to detect azides, and examined various workflows and their scopes and limitations. This study can be useful for both bioconjugation and activity-based profiling. See Bioconjugate Chemistry, 2017, 28, 2302-9. doi: 10.1021/acs.bioconjchem.7b00354

Lastly, we have devised the XChem-Finder workflow to identify and elucidate protein cross-linking without pre-defined chemistry, including a novel photo-oxidative histidine-histidine crosslink in an antibody (Anal Chem 2014, 86,86, 4940 and Anal Chem 2013, 85, 5900). The workflow can also be useful for study protein-protein interaction by crosslinking.

 

Title:Designed DNA Nano-Switches as Sensitive Electrochemical Biosensors
Speaker:Professor Hogan Yu
Date:22nd May 2018
Time:2.30pm to 4.00pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Assistant Professor Shao Fangwei
Abstract:

 

Functional nucleic acid receptors (aptamers) have emerged as effective and robust recognition elements for use in electrochemical biosensors[1] . Analytical readouts from aptamer-based biosensors (whether optical, electrochemical, or otherwise) derive primarily from global-scale conformational changes induced in the aptamer domain by analyte binding. For certain classes of biosensors that offer electrochemical readout, analyte-induced conformational change in an electrode-bound aptamer alters the distance between the electrode surface and a redox label appended to the aptamer; as a result, the rate of electron transfer between the electrode and redox label is responsive to analyte binding. Herein, we describe a unique biosensor design principle that represents a distinct alternative to this paradigm[2] . We demonstrate the ready applicability of this design principle in the de novo creation of electrochemical sensors for a clinical analyte of current interest. The function of the class of biosensors we describe, termed “DNA nano-switches”, is designed to depend on the integrity of duplex DNA-mediated charge transfer between an electrode and a redox label.

[1] Tang, Y.; Ge, B.; Sen, D.; Yu, H.-Z. Chem. Soc. Rev. 2014, 43, 518–529 [2] Thomas, J. M.; Chakraborty, B.; Sen, D.; Yu, H.-Z. J. Am. Chem. Soc. 2012, 134, 13823–13833.

 

 

 

Title:The chemical bond overlap polarizability and covalency. Concepts and applications: from diatomic molecules to solids
Speaker:Professor Oscar L. Malta
Date:4th May 2018
Time:2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Xing Bengang 
Abstract:

The concepts of chemical bond overlap polarizability (OP) and ionic specific valence (ISV) have been introduced, about a decade ago (2002), in the context of the ligand field theory applied to lanthanide compounds. 1 These concepts led to relevant conclusions on the interpretation of the non-spherical ligand field interaction in terms of covalency. 1 They have also been explored in a more general context outside the scope of ligand field theory. 2,3 Thus, they have proven to be useful in the case of diatomic molecules, allowing to establish a new covalency scale in excellent agreement with Pauling’s scale2 and analytically quantifiable in terms of the OP. An analysis on this subject in 2005, in which the overlap region is regarded as a localized plasmon-like mode of oscillation (chemical bond overlap plasmon - CBOP), characterized by the OP, has raised the possibility of absorption and inelastic scattering of radiation, specifically by the overlap region, in an oscillation mode distinguishable from the collective plasmon of the system. Predicted oscillator strengths and scattering cross sections for diatomic molecules are considerably high and can be measured in the UV up to the near soft-X-rays spectral regions2 . The possibility of detecting the CBOP in diatomic molecules by electron energy-loss measurements has also been analyzed. 4,5 Different treatments by using the Valence Bond Theory and a Localized Molecular Orbital approach have been evoked to describe de OP concept and the CBOP proposal, in polyatomic molecules and hydrogen bonding. The CBOP has been shown as a promising tool for quantifying covalency also in solid-state materials, opening a way to classifying materials in terms of average covalent fractions. Interesting questions could be raised on possible relationships between macroscopic properties of materials and the OP concept. For instance, a good correlation has been found between the non-linear index of refraction (n2 ) and the OP, though the comparison has been made between the precursor diatomic molecule and the solid-state material. Some unassigned bands in the electron energy-loss and absorption spectra of crystalline alkaline-earth chalcogenides and some alkali and alkali-earth metals in solid-state systems have been discussed in terms of the CBOP, raising the possibility of new assignments alternative to exciton or band-to-band transitions. 5

Refs (origin of the subject) 1 O. L. Malta, H. J. Batista, L. D. Carlos, Chem. Phys. 282, 21 (2002). 2 O. L. Malta, Chem. Phys. Lett. 406, 192 (2005). 3 L. D. Carlos, O. L. Malta, R. Q. Albuquerque, Chem. Phys. Lett. 415, 238 (2005). 4 Oscar L. Malta, R. T. Moura Jr., R. L. Longo, J. Braz. Chem. Soc., 21, 476 (2010). 5 R. T. Moura Jr., Oscar L. Malta, R. L. Longo, Int. J. Quant. Chem. 111, 1626 (2011).

 

Title:New methodologies for the synthesis of biologically active natural products
Speaker:Professor Martin Banwell
Date:30th April 2018 
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Roderick Bates
Abstract:

A variety of methodologies and/or combinations of methodologies have been developed in our labs for the synthesis of a diverse range of biologically active natural products. These methodologies include but not confined to biotransformations, photoisomerisations, two-metal cross-couplings, oxidative and reductive cyclizations as well as redox neutral ones. Recent applications of such processes to various target compounds, especially alkaloids, will be described. 1

References 1. For representative examples of some of such processes see (a) Nugent, J.; Matoušová, E.; Banwell, M. G. Eur. J. Org. Chem. 2015, 3771-3778; (b) Lan, P.; Banwell, M. G.; Willis, A. C. Org. Lett. 2015, 17, 166–169; (c) Tang, F.; Banwell, M. G.; Willis, A. C. J. Org. Chem. 2016, 81, 2950-2957; (d) Tang, F.; Banwell, M. G.; Willis, A. C. J. Org. Chem. 2016, 81, 10551-10557; (e) Zhang, Y.; Banwell, M. G.; Carr, P. D.; Willis, A. C. Org. Lett. 2016, 18, 704-707; Nugent, J.; Matoušová, E.; Banwell, M. G., Willis, A. C. J. Org. Chem. 2017, 82, 12569-12589; Ma, X.; Yan, Q.; Banwell, M. G.; Ward, J. S. Org. Lett., 2018, 20, 142-145.

 

Title:Coordination Chemistry of Gold(I) Metalloligands with Thiol-containing Amino Acids
Speaker:Professor Takumi Konno
Date:27th April 2018
Time:2.30pm to 4.00pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Leong Weng Kee
Abstract:

Design and creation of heterometallic polynuclear and supramolecular architectures, in which discrete molecules are aggregated via noncovalent interactions, have attracted much attention in recent years because of their intriguing structures and chemical properties. To synthesize this class of coordination compounds, we are interested in the use of pre-designed metalloligands having simple aliphatic thiols, such as 2-aminoethanethiol, L-cysteine, and D-penicillamine (D-H2pen), instead of organic and inorganic ligands. In this presentation, we will present the rational construction of a variety of chiral coordination compounds based on a two-coordinated gold(I) metalloligand with D-pen, which possesses non-coordinating amine and carboxylate groups as potential coordination sites, besides thiolato donor groups. A digold(I) metalloligand system containing both D-pen and diphosphine ligands will also be presented.

 

Title:Recent Progress in NiH-Catalyzed Remote Functionalization
Speaker:Professor Zhu Shaolin
Date:26th April 2018
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Naohiko Yoshikai
Abstract:

A major area of research focus in the Zhu lab is NiH-catalyzed remote functionalization chemistry. By synergistic combination of NiH chemistry and cross-coupling, we have developed remote C(sp3)–H arylation, alkylation, amination with divergent site-selectivity.

 

Title:Upconversion Super Dots for Super-Resolution Imaging and Single Molecule Tracking
Speaker:Professor Jin Dayong
Date:25th April 2018
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Zhao Yanli
Abstract:

Advances in super-resolution fluorescence imaging have enabled revolutionary new insight in the spatial and temporal behaviour of the cell. These developments have resulted in a need for the development of robust probes to facilitate long-term tracking of single molecules and realtime super-resolution imaging of sub-cellular structures. In my lecture, I will first showcase several new nanotechnology approaches to super-resolution imaging by leveraging optical-switching properties of new classes of luminescent nanoparticles, unlocking new modes of super-resolution microscopy with much higher photon yields than are currently available. I will then summarize our recent achievements by engineering time-resolved photonics devices and reagents to find cells earlier, quicker and with better resolution. These include the discovery of the Super Dots for single molecule detection and point-of-care diagnostics (Nature Nanotechnology 2013), demonstration of a time-domain multiplexing technology for high throughput biotechnology discoveries (Nature Photonics; Nature Communication 2014), creation of the large library of contrast agents for multi-functional bio-imaging and nanomedicine (Nature Communications 2016), invention of a low-power high contrast super resolution microscopy by achieving the highest optical resolution of 1/36 of the excitation wavelength (Nature 2017), the new discovery of thermal phonon enhanced upconversion Thermal Dots (Nature Photonics 2018), and our new development of a microscopy technique, aimed at improving the resolution and sensitivity of nanoscale imaging, leading to direct tracking of a single molecule inside a living cell by eye (Light: Science & Applications 2018).

Our Key Papers [1] Zhao J, et al, Nature Nanotechnology, 8, 729-734 (2013), [2] Lu Y, et al, Nature Communications, 5, 3741 (2014), [3] Lu Y, et al, Nature Photonics, 8, 32-36 (2014), [4] Zhou B, et al, Nature Nanotechnology, 10 (11), 924-936 (2015) [4] Liu D, et al, Nature Communications, doi:10.1038/ncomms10254 (2016), [5] Liu Y, et al, Nature, 543 (7644), 229 (2017) [6] Wang F, et al, Light: Science & Applications, doi: 10.1038/lsa.2018.7 (2018) [7] Zhou J, et al, Nature Photonics, 12 (3), 154 (2018) [8] Jin D, et al, Nature Methods, in press (2018) [9] Wen S, et al, Nature Communications, in press (2018) [10] Lin G, et al, Chem, DOI: https://doi.org/10.1016/j.chempr.2018.01.009 (2018)

 

Title:Synthesis of diverse heterocyclic scaffolds by functionalization and cyclization
Speaker:Professor Nopporn Thasana
Date:24th April 2018
Time:2.00pm to 3.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Roderick Bates
Abstract:

Oxazolone is a useful intermediate in synthetic organic chemistry. It can prepare a variety of useful substances, natural products, biologically active compounds, and pharmaceutics. We have focused on the application of the oxazolone to develop such a methodology of cyclization and exploit it for the synthesis of a variety of heterocycles. This lecture will describe the synthesis of various heterocyclic scaffolds including imidazoloisoquinoline, benzoquinolizine, benzazocinone, and benzylindenamide. The biological activity studied and application to synthesize natural product, such as Clausena alkaloid will be also presented. Moreover the synthesis of lactone and lactam molecules using Cu(I)-mediated/MW-assisted C-O and C-N bond formation to synthesize bioactive benzopyranone (urolithins A-C), novobiocin, and indolo-2-carboxamide analogs will be presented. The annulation between coumarin derivatives and isoquinolines using base-mediated cascade cyclisation, the C-C, C-O and C-N bond formations, to construct a complex framework oxazocinoisoquinoline will be also mentioned.

 

Title:Electron-Catalyzed Cross-Coupling Reactions
Speaker:Professor Eiji Shirakawa
Date:29th March 2018
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Tamio Hayashi 
Abstract:

We have developed a transition metal-free version of the cross-coupling reaction of organometallic compounds with aryl and alkenyl halides, where an electron derived from the organometallic reagents act as a catalyst instead of a transition metal. The electron-catalyzed crosscoupling reaction is applicable to diverse organometals such as arylmagnesium, arylzinc, alkylzinc, alkynylzinc and arylboron reagents as well as magnesium diarylamides.

References [1] Aryl Grignard reagents: Shirakawa, E.; Hayashi, Y.; Itoh, K.; Watabe, R.; Uchiyama, N.; Konagaya, W.; Masui, S.; Hayashi, T. Angew. Chem., Int. Ed. 2012, 51, 218; Uchiyama, N.; Shirakawa, E.; Hayashi, T. Chem. Commun. 2012, 49, 364. [2] Arylzinc reagents: Shirakawa, E.; Tamakuni, F.; Kusano, E.; Uchiyama, N.; Konagaya, W.; Watabe, R.; Hayashi, T. Angew. Chem., Int. Ed. 2014, 53, 521–525. [3] Alkylzinc reagents: Okura, K.; Shirakawa, E. Eur. J. Org. Chem. 2016, 3043. [4] Alkynylzinc reagents: Okura, K.; Kawashima, H.; Tamakuni, F.; Nishida, N.; Shirakawa, E. Chem. Commun. 2016, 52, 14019.

 

Title:Four-dimensional Imaging in Chemistry and Materials Science
Speaker:Dr Omar F. Mohammed
Date:27th March 2018
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Xing Bengang 
Abstract:

Understanding light-triggered charge carrier dynamics on photovoltaic-material surfaces and at interfaces has been a key element and one of the major challenges for the development of real-world energy devices. For this reason, studying charge carrier dynamics at photoactive material surfaces and interfaces have been among the most active areas of research in the last decade [1-4]. However, the ability to access carrier dynamics selectively on material surfaces with high spatial and temporal control in a photo-induced reaction is a particularly challenging task that can only be achieved by applying four-dimensional (4D) ultrafast electron microscopy (4D UEM) along with time-resolved laser spectroscopy. For this purpose, we established and developed the second generation 4D S-UEM and demonstrate the ability to take timeresolved secondary electrons images (snapshots) of material surfaces with 650 fs and 4 nm temporal and spatial resolutions, respectively. In this method, the surface of the photoactive materials is excited by a clocking optical pulse and the photo-induced changes will be imaged using a pulsed primary electron beam as a probe pulse, generating secondary electrons, which are emitted from the top surface of the material in a manner that is extremely sensitive to the localization of the electron and hole on the surface and at the donor-acceptor interfaces. This method provides direct and controllable ultrafast dynamical information in many photoactive materials commonly used in solar cells and photocatalysis. For instance, we have clearly demonstrated in space and time how the surface morphology, surface passivation, thickness of the absorber layer, grains, surface defects and nanostructured features can significantly impact the overall dynamical processes on the surface of absorber layers including nanomaterials and single crystals [5-8]. Finally, charge carrier dynamics in semiconductor quantum dots and perovskite single crystal using femtosecond laser spectroscopy will be also presented and discussed.

References 1- O. M. Bakr, O. F. Mohammed., Science 355, 1260 (2017). 2- A. O. El-Ballouli, E. Alarousu, M. Bernardi, S. M. Aly, A. P. Lagrow, O. M. Bakr, O. F. Mohammed., J. Am. Chem. Soc. 136, 6952 (2014). 3- R. Begum, M. R. Parida, A. L. Abdelhady, B. Murali, N. Alyami, G. H. Ahmed, M. N. Hedhili, O. M. Bakr, and O. F. Mohammed., J. Am. Chem. Soc. 139, 731 (2017). 4- O. F. Mohammed, D.-S. Yang, S. Pal, A. H. Zewail, J. Am. Chem. Soc. 133, 7708 (2011). 5- J. Sun, V. A. Melnikov, J. I. Khan, O. F. Mohammed, J. Phys. Chem. Lett. 6, 3884 (2015). 6- R. Bose, J. Sun, J. I. Khan, B. S. Shaheen, A. Adhikari, T. K. Ng, V. M. Burlakov, M. P. Parida, D. Priante, A. Goriely, B. S. Ooi, O. M. Bakr, O. F. Mohammed, Adv. Mater. 28, 5106 (2016). 7- B. S. Shaheen, J. Sun, D-S Yang, and O. F. Mohammed, J. Phys. Chem. Lett. 8, 2455 (2017). 8- R. Bose, A. Bera, M. R. Parida, A. Adhikari, B. S. Shaheen, E. Alarousu, J. Sun, T. Wu, O. M. Bakr, O. F. Mohammed, Nano Lett. 16, 4417 (2016).

 

Title:Asymmetric C-H activation: Towards unprecedented ligands and biologically active molecules
Speaker:Professor Françoise Colober
Date:20th March 2018
Time:2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba 
Abstract:

Over the decades, non-activated C-H bonds have been considered as dormant functionalities, hardly exploitable in the context of multistep synthesis of complex scaffolds. However, since few years, the C-H activation of arenes, and more recently alkanes, expanded tremendously. Nevertheless general strategies giving access to a large panel of stereogenic molecules are still missing. Following this objective we have recently developed an asymmetric C-H activation pathway to build up very efficiently an unlimited panel of atropisomerically pure biaryls. This concept involves direct, Pd-catalyzed functionalization of the biaryl precursors bearing a sulfoxide moiety. The stereogenic sulfoxide plays a role of both, directing group and chiral auxiliary, hence allowing the atroposelective C-H activation and subsequent functionalization with an array of coupling partners (C-C, C-O, C-X bond formation). 1 Recently we have also discovered that sulfoxide may be efficiently applied in the context of unprecedented atroposelective C-N couplings. 2 Furthermore, traceless character of the sulfoxide moiety permits various postmodifications of the newly generated axially chiral compounds. Then we targeted new strategies for the stereoselective C(sp3 )-H functionalization employing a chiral bidentate directing group bearing an enantiopure sulfoxide. These original methods use an easily removable and recoverable directing group, (S)-2-(p-tolylsulfinyl)aniline (accessible in one step with 80% yield and full enantiomeric purity), allowing various stereoselective transformations, such as arylation, acetoxylation or challenging olefination, in good to excellent yields.

1 a) Q. Dherbassy, G. Schwertz, M. Chessé, C. K. Hazra, J. Wencel-Delord, F. Colobert, Chem. Eur. J. 2016, 22, 1735 ; b) C. K. Hazra, Q. Dherbassy, J. Wencel-Delord, F. Colobert, Angew. Chem. Int. Ed. 2014, 53, 13871. c) Q. Dherbassy, J. Wencel-Delord, F. Colobert, Tetrahedron 2016, 72, 5238–5245. (d) Dherbassy, Q. ; Djukic, J-P.; Wencel-Delord, J. ; Colobert, F. Angew. Chem. Int. Ed. 2018, doi.org/10.1002/anie.201801130. 2 Rae, J.; Frey, J.; Choppin, S.; Wencel-Delord, J. ; Colobert, F. ACS Cat. 2018, doi.org/ 10.1021/acscatal.7b04343. 3 a) S. Jerhaoui, F. Chahdoura, C. Rose, J-P. Djukic, J. Wencel-Delord, F. Colobert, F. Chem. Eur. J. 2016, 22, 17397. b) S. Jerhaoui, J-P. Djukic, J. Wencel-Delord, F. Colobert, F. Chem. Eur. J. 2017, 23, 15594. c) S. Jerhaoui, P. Poutrel, J-P. Djukic, J. Wencel-Delord, F. Colobert, F. Org. Chem. Front., 2018, 5, 409.

 

Title:Triptycene-Derived Macrocyclic Hosts for Controllable Molecular Recognition and Self-Assembly
Speaker:Professor Chen Chuanfeng
Date:19th March 2018
Time:2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Naohiko Yoshikai
Abstract:

Triptycene and its derivatives are a class of aromatic compounds with unique 3D rigid structures. Previously, we have proved that triptycene derivatives can be promising building blocks for the synthesis of novel artificial hosts. Consequently, a new class of triptycene-derived crown ethers including macrotricyclic polyethers and tris(crown ether) hosts, which are composed of rigid triptycene building blocks linked by flexible crown ether chains, have been developed. The specific structural feature makes the macrocyclic hosts show the diversified complexation properties with different kinds of guests, which also renders the host-guest systems based on these hosts to be easy responsive to multiple external stimuli. Recently, we have designed and synthesized a new class of chiral macrocyclic arenes composed of three 2,6- dihydroxyltriptycene subunits bridged by methylene groups, which we named as 2,6-helicarenes. It was found that the macrocycles not only exhibited highly enantioselective recognition towards chiral guests containing a trimethylamino group, but also showed controllable complexation towards various organic cationic guests, tropylium cation and even neutral electron-deficient molecules. In this lecture, I will present some of our recent results in controllable molecular recognition and self-assembly based on tritopic triptycene-derived crown ethers and helicarenes.

 

Title:Water oxidation chemistry of photosystem II and artificial systems
Speaker:Professor Gary Brudvig
Date:19th March 2018
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Assistant Professor Soo Han Sen
Abstract:

 

Photosystem II (PSII) uses light energy to split water into protons, electrons and oxygen. In this reaction, Nature has solved the difficult chemical problem of efficient four-electron oxidation of water to yield O2 without significant side reactions. In order to use Nature’s solution for the design of materials that split water for solar fuel production, it is important to understand the mechanism of the reaction. The X-ray crystal structure of cyanobacterial PSII provides information on the structure of the Mn and Ca ions, the redox-active tyrosine called tyrosine-Z, chloride and the surrounding amino acids that comprise the oxygen-evolving complex (OEC). The structure of the OEC in the intermediate oxidation states of the catalytic cycle, the binding of substrate water molecules to the OEC and the water oxidation chemistry of PSII will be discussed in the light of biophysical, spectroscopic and computational studies, inorganic chemistry and X-ray crystallographic information. These insights on the natural photosynthetic system are being applied to develop bioinspired materials for photochemical water oxidation and solar fuel production. Our progress on the development of synthetic water oxidation catalysts and their use in materials for artificial photosynthesis will be discussed.

 

 

Title:Redox Catalysis Strategies for Complex Molecules
Speaker:Professor Corey Stephenson
Date:28th February 2018
Time:3.30pm to 4.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract:

Single electron transfer (SET) processes – frequently utilized by Nature to activate its substrates – significantly enhance the reactivity of organic molecules. These SET reactions provide facile access neutral radicals – reactive intermediates that are particularly attractive for use in complex settings as a consequence of their general lack of reactivity with polar functional groups. The use of redox catalysis (e.g. photocatalysis and electrocatalysis) furthers the benefits of SET processes enabling the reduction of stoichiometric waste byproducts and toxic or hazardous reagents compared with classical approaches. The development of methodologies involving organic free radicals underpinned on practicality and mechanistic understanding with demonstrated applications in complex molecule synthesis (pharmaceuticals and natural products) exploiting batch and flow reactor designs will be presented in this talk.

 

 

Title:Iron(III)-Catalyzed Carbonyl-Olefin Metathesis and Oxygen Atom Transfer
Speaker:Professor Corinna Schindler
Date:28th February 2018
Time:2.30pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract:

 

The metathesis reaction between two unsaturated organic substrates is one of organic chemistry’s most powerful carbon-carbon bond forming reactions. The catalytic olefin-olefin metathesis reaction has led to profound developments in the synthesis of molecules relevant to the petroleum, materials and pharmaceutical industries. These reactions are characterized by their use of discrete metal alkylidene catalysts that operate by a well-established reaction mechanism. While the corresponding carbonyl-olefin metathesis reaction similarly enables the direct construction of carbon-carbon bonds, currently available methods are scarce and hampered by either harsh reaction conditions or the requirement of stoichiometric transition metal complexes as reagents. We have recently developed the first catalytic carbonyl-olefin ringclosing metathesis reaction that utilizes iron as an earth-abundant and environmentally benign transition metal. [1] , [2] Our reaction design accommodates a variety of substrates and is distinguished by its operational simplicity, mild reaction conditions, high functional group tolerance, and amenability to gram scale synthesis. [3]

[1] Ludwig, J.R.; Zimmerman, P.M.; Gianino, J.B.; Schindler, C.S. Iron(III)-catalyzed carbonyl-olefin metathesis. Nature 2016, 533, 374-379. [2] McAtee, C.C.; Riehl, P.S.; Schindler, C.S. Polycyclic Aromatic Hydrocarbons via Iron(III)-Catalyzed Carbonyl-Olefin Metathesis. J. Am. Chem. Soc. 2017, 139, 2960. [3] Ludwig, J.R.; Phan, S.; McAtee, C.C.; Zimmerman, P.M.; Devery, J., III; Schindler, C.S. Mechanistic Investigations of the Iron(III)-Catalyzed Carbonyl-Olefin Metathesis Reaction. J. Am. Chem. Soc. 2017, 139, 10832-10842.

 

Title:Chemistry Meets Biology: Towards Designer Protein Therapeutics?
Speaker:Dr Kuan Seah Ling
Date:13th February 2018
Time:2.30pm to 4.00pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Assistant Professor Shao Fangwei 
Abstract:

 

Protein therapeutics has seen an exponential growth in the last decades in oncotherapy. In particular, recombinant protein complexes such as antibodies and immunotoxins have emerged as eminent therapeutic candidates. However, the development of recombinant chimeras is often laborious and the activities of fused enzymes can be significantly reduced. Moreover, it is extremely challenging to use genetic engineering methods to prepare modular protein hybrids with functional synthetic components to reengineer their structures and functions. Consequently, the development of synthetic methodologies that could provide new avenues to expand our current arsenal of protein therapeutics is valuable. Our strategy focuses on developing integrative chemical platforms that allow rational design and customization of biotherapeutics to address specific systems, for instance, intracellular transport, molecular targeting, controlled release, etc. In this manner, we seek to overcome the limits of chemistry and biology in protein design and therefore, broaden the scope of the medical applications by merging the best of both worlds.

 

Title:Redox Active Low-coordinated Heavier Group 14 Elements Compounds
Speaker:Professor Takahiro Sasamori
Date:26th January 2018
Time:2.00pm to 3.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Rei Kinjo
Abstract:

Relative to π-electron systems between elements from the second row of the periodic table, those between heavier main group elements should exhibit higher HOMO and lower LUMO levels. Moreover, such π-electron systems and unsaturated species, i. e., low-coordinated species, of between heavier main group elements are expected to be good electron acceptors and donors, and they should also exhibit good electron transporting properties. With the ultimate goal to create unprecedented π-electron systems or unsaturated species of heavier main group elements in mind, we designed redox active low-coordinated species of heavier main group elements bearing ferrocenyl units.[1] Herein, our recent progress on the creation of ferrocenyl-based redox-active systems containing low-coordinated heavier group 14 elements will be presented.

[1] (a) Sasamori, T.; Suzuki, Y.; Tokitoh, N. Organometallics 2014, 33, 6696-6699. (b) Sakagami, M.; Sasamori, T.; Sakai, H.; Furukawa, Y.; Tokitoh, N. Bull. Chem. Soc. Jpn. 2013, 86, 1132-1143. (c) Yuasa, A.; Sasamori, T.; Hosoi, Y.; Furukawa, Y.; Tokitoh, N. Bull. Chem. Soc. Jpn. 2009, 82, 793- 805. (d) Suzuki, Y.; Sasamori, T.; Guo, J.-D.; Nagase, S.; Tokitoh, N. Chem. Eur. J. 2016, 22, 13784-13788

 

Title:Catalytic α-Amination of Acylpyrazoles and Catalytic Addition of Various Nucleophile to N-Unprotected α-Ketiminnoestersfor the Synthesis of Unnatural α-Amino Acid Derivatives
Speaker:Professor Takashi Ohshima
Date:17th January 2018
Time:11.00am to 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract:

Over the last few decades, the quest for environmentally benign chemical transformations has become an important topic in both industrial and academic research. Thus, in order to develop highly atom-economical and environmentally benign synthetic process, we have focused on the development of highly selective and practical direct catalytic reactions. In this lecture, I will present two newly developed catalyses for the synthesis of unnatural α-amino acid derivatives; (1) α-amination of carboxylic acid derivatives and (2) nucleophilic addition to N-unprotected α-ketiminnoesters. (1) α-Amination of carboxylic acid derivative is regarded as one of the most straightforward method for the synthesis of unnatural α-amino acids. While several elegant α-amination reactions have been developed, only limited examples using carboxylic oxidation state substrates were reported and the use of more than stoichiometric amount of strong base is usually inevitable. Recently, we developed a catalytic αamination under mild conditions using acylpyrazole as a pre-nucleophile. Under the optimized conditions using Cu(OTf)2 , α-amination reactions proceeded efficiently with wide functional group tolerance. Notably, the bidentate coordination mode of acylpyrazoles was amenable to highly chemoselective activation over ketone and much more acidic nitroalkyl functionality. (2) Nucleophilic addition to ketimines is also one of the most straightforward approaches to synthesize optically active tetrasubstituted amines. Recently, several direct catalytic additions to N-protected ketimines were reported including our Rh-catalysis. To obtain N-unprotected amines, however, they require additional deprotection steps, which limit their synthetic utilities. A prominent way to address these issues is using Nunprotected ketimines; however, there are only limited success using N-unprotected ketimines as an electrophile. Recently, we succeeded in the development of Zn-catalyzed direct asymmetric addition of terminal alkynes and 1,3-dicarbonyl compounds, to N-unprotected ketimines. Very surprisingly, Zn-catalyzed alkynylation selectively proceeded with N-unprotected ketimines over the N-PMP-protected ketimines and aldimines. Moreover, we also developed direct catalytic Mannich-type reactions to N-unprotected ketiminoesters for direct access to Nunprotected α- and/or β-tetrasubstituted amino acid esters.

 

 

Title:Carbon Nanomaterial-Based Micromotors for Food Analysis
Speaker:Professor Alberto Escarpa
Date:15th January 2018
Time:2.00pm -3.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Martin Pumera
Abstract:

 

The utilization of self-propelled micromotors in (bio-)chemical assays has led to a fundamentally new approach where their continuous movement around the sample and the mixing associated effect, due to the generated microbubbles tail, greatly enhances the target-receptor contacts and hence the binding efficiency and sensitivity of the assay. This effect is a particularly important aspect to consider when low sample and reagent volumes are available, where other convection approaches are lower efficient to produce adequate interactions. Nevertheless, despite the great advances in the synthesis and movement of micromotors, they have to promote from their proof of concept into specific applications. Food safety constitutes one relevant example of unexplored areas which could be benefited from these new emerging micromotors-based approaches. On the other hand, carbon nanomaterials met in nanotechnology an enormous source of future diverse applications and they have been used for developing micromotors with excellent catalytic performances. In this talk, the analytical potency of these carbon nanomaterial-based micromotors in food analysis will be discussed towards selected examples of high significance in the field.

References R. Maria-Hormigos, B. Jurado-Sanchez, L. Vázquez, A. Escarpa, Chem. Mater. 2016, 28, 8962-8970 D. Rojas, B. Jurado-Sánchez, A. Escarpa, Anal. Chem., 2016, 88, 4153–4160 A. Molinero-Fernández, M. Moreno-Guzmán, M.A. López, A. Escarpa, Anal. Chem, 2017, 89, 10850–10857 R. María-Hormigos, B. Jurado Sánchez, A. Escarpa. Adv. Funct. Mater. 2017, (DOI:10.1002/adfm.201704256)

 

Title:Cyclization of Functionalized Alkynes
Speaker:Professor Yu Chen
Date:15th January 2018
Time:11.00am – 12.30pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Leung Pak Hing
Abstract:

 

Electrophilic cyclization of alkynes bearing versatile functional groups will be discussed. The cyclization reactions are catalyzed/mediated by transition metal catalysts or iodine monochloride, and in general are highly regioselective. The talk includes three topics: 1) synthesis of nitrogen-containing heterocycles using NH4OAc as nitrogen source; 2) preparation of poly-substituted isoxazoles and their application as intermediate compounds in the synthesis of other heterocycles; 3) ICl mediated synthesis of spiroconjugated molecules and dibenzocyclohepten-5-ones. These cyclization reactions start from readily available alkyne substrates, and consist of facile and user-friendly synthetic conditions. A variety of heterocyclic and carbocyclic compounds, including isoquinoline, isoxazole, pyrrole, indenone, and dibenzocyclohepten-5-one, are successfully prepared, which cover the interest of a broad spectrum of fields including synthetic and medicinal chemistry, as well as the materials science.

 

 

Title:Metal complexes in biology: development of metal-based probes
Speaker:Professor Hélène Bertrand
Date:10th January 2018
Time:10.30am – 12.00pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Leong Weng Kee
Abstract:

Inorganic complexes are increasingly used for biological applications, as metallodrugs or metalloprobes. At the Laboratoire des Biomolécules, we develop biologically active metal complexes and metal-based probes and their studies in a biological context. Innovative techniques to investigate their speciation, quantify them and determine their cellular location are used, leading to key information about their behavior inside cells. I will illustrate our approach with a focus on two recent projects:

(1) Nanometer-scale distance measurements by pulse electron paramagnetic resonance (EPR) techniques are powerful biophysical tools to study the structure, dynamics and functions of biomolecules and biological systems. 1 A commonly used approach is to measure the magnetic dipolar interactions between two nitroxides spin labels, introduced on the biomolecule by site-directed spin labelling, using pulse electron double resonance (PELDOR). Over the last decade, highspin metal centers (GdIII (S = 7/2) in particular) have been introduced as alternative paramagnetic centers for PELDOR measurements. 2 Despite MnII (S = 5/2) being very attractive for biological applications, MnII-based pulse-EPR distance measurements have been less explored. 3 We have developed synthetic model compounds incorporating two MnII spin-labels for the development of MnII-MnII PELDOR. 4

(2) Metal-CO complexes can be designed as multimodal probes,5 combining fluorescence, IR-modality, but also, as shown very recently, X-fluorescence properties. ReL(CO)3X complexes (with L a ligand with low-lying π*-orbitals) display a single molecular core enabling multimodal imaging, both at the sub-cellular and tissue levels. 6 One of the interests of the IR modality is the possibility of direct quantification in a biological context. 7 X-fluorescence offers direct imaging of the metal center and is a promising powerful technique in the study of metal complexes in biological environments. Development of new ReL(CO)3X probes8 and their study in multimodal bio-imaging will be presented.

References: 1. Schiemann, O.; Prisner, T. F. Q. Rev. Biophys. 2007, 40 (1), 1-53 2. Goldfarb, D. Phys. Chem. Chem. Phys. 2014, 16, 9685-9699 3. Akhmetzyanov, D.; Plackmeyer, J.; Endeward, B.; Denysenkov, V.; Prisner, T. F. Phys. Chem. Chem. Phys. 2015, 17, 6760-6766 4. Demay-Drouhard P., Chamoreau L.-M., Guillot R., Policar C., Bertrand H. C., Eur. J. Org. Chem. 2017, 131-137; Demay-Drouhard P., Ching H. Y. V., Akhmetzyanov D. Guillot R., Tabares L. C., Bertrand H. C., Policar C., ChemPhysChem, 2016, 17 (13), 2066-78; Ching, H. Y. V.; Demay-Drouhard, P.; Bertrand, H. C.; Policar, C.; Tabares, L. C.; Un, S., Phys. Chem. Chem. Phys. 2015, 17, 23368–23377; Ching H. Y. V., Mascali F. C., Bertrand H.C., Bruch E. M., Demay-Drouhard P., Rasia R. M., Policar C., Tabares L. C., Un S., J. Phys. Chem. Lett., 2016, 7 (6), 1072–1076 5. Clède S., Policar C., Chem Eur. J., 2015, 21 (3), 942-958 6. Clède S., Cowan N., Lambert F., Bertrand H. C., Rubbiani R., Patra M., Sandt C., Trcera N., Gasser G., Keiser J., Policar C., ChemBioChem, 2016, 17, 1004 –1007 7. Clède S., Lambert F., Saint-Fort R., Plamont M.-A., Bertrand H., Vessières A., Policar C., Chem. Eur. J., 2014, 20 (28), 8714-8722 8. Bertrand H. C., Clède S., Guillot R., Lambert F., Policar C., Inorg. Chem., 2014, 53 (12), 6204 – 6223

 

Title:Medicinal Chemistry in Pharmaceutical Drug Discovery
Speaker:Dr Mahmood Ahmed
Date:9th January 2018
Time:10.30am – 12.00pm
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Professor Shunsuke Chiba
Abstract:This introductory lecture will describe the critical role of Medicinal Chemistry in Pharmaceutical Drug Discovery. After describing the overall Drug Discovery & Development process, the talk will introduce the concept of Medicinal Chemistry and it’s essential role across all key aspects of Drug Discovery. These encompass Target Validation, Hit Identification, Hit-to-Lead and Lead Optimisation to deliver a clinic-ready Drug Candidate. A Case History will be used to further exemplify Medicinal Chemistry principles.

 

Title:New Mechanistic Insights into PARP1-mediated DNA Damage Response
Speaker:Professor Qian Chemgmin
Date:5th  January 2018
Time:11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Conference Room 
Host:Associate Professor Xing Bengang 
Abstract:PARP1 is a major poly(ADP-ribose) transferase that plays an important role in DNA damage repair. PARP1 has been shown to be a DNA singlestrand and double-strand break sensor protein that helps rapidly recruit many downstream DNA repair proteins to damaged DNA sites in a poly(ADP-ribose) dependent manner. Here I will talk about a new mechanism of PARP1-mediated DNA damage response. We recently identified and provided the structural evidence that PARP1 interacts with Timeless - a classic subunit of the replication fork protection complex. We demonstrated that rapid and transient accumulation of Timeless at laser-induced DNA damage sites requires PARP1 but not poly(ADPribosyl)ation and that Timeless is co-trapped with PARP1 at DNA lesions upon PARP inhibition. Furthermore, we show that Timeless and PARP1 interaction is required for efficient homologous recombination repair. Our study provides implications for understanding the mechanism of the clinically active PARP inhibitors and raise a new possibility to develop alternative PARP1-targeted therapy for cancer treatment.