Seminars 2016

Title:Development of functional DNA materials by using acyclic scaffolds
Speaker:Professor Hiromu Kashida
Date: 8th December 2016
Time: 3.30pm to 5.00pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Shao Fangwei
Abstract:

Recently, DNA has been widely used as nano-materials due to its superb molecular recognition ability. However, DNA has little attractive characters as materials. If non-natural molecules are available as pseudo pairs, we can endow DNA with a wide variety of functions. We have developed pseudo base pairs by incorporating non-natural molecules into DNA through acyclic D-threoninol linker. For example, pairs of azobenzene derivatives strongly stabilized DNA duplex when they are introduced into DNA. In addition, these pairs showed high orthogonality to natural base pairs. Thus, azobenzene derivatives worked as a pseudo base pair although their chemical structures are much different from natural base-pairs. We have developed functional molecules into DNA as pseudo base pairs by using this design. In the presentation, I will introduce molecular designs and functions of several pseudo base pairs we have developed.

 

Title:Multicomponent Molecular Puzzles for Novel Photofunction Design
Speaker:Professor Toshikazu Ono
Date: 8th December 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Hajime Hirao
Abstract:

Multicomponent crystals or co-crystals formed with two or more different molecules have attracted much attention because of their promising applications for advanced materials such as novel optical, electronic and magnetic properties, but their collective behaviors in materials remain poorly understood. In this aspect, supramolecular chemistry and crystal engineering techniques play an important role in providing functional molecular assemblies and crystalline materials. Ultimate goals of such solid-state materials are highly emitting properties with (1) color-tunable (multi-color & white light) and (2) lifetime–controllable (fluorescence & phosphorescence) properties. Moreover, if possible, facile preparation is important factor of material design. For the sake of this purpose, we here report highly emitting multicomponent crystals by supramolecular assembly systems.

 

Title:A Greener Way for Catalytic Construction of Tetrasubstituted Chiral Carbon Stereocenters
Speaker:Professor Hiroyuki Morimoto
Date: 7th December 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Professor Shunsuke Chiba 

 

Title:Metal-Catalyzed Cross-Coupling of Alkyl Electrophiles
Speaker:Professor Gregory Fu
Date: 6th December 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Steve Zhou

 

Title:From Homonuclear Metal String Complexes to Heteronuclear Metal String Complexes
Speaker:Professor Peng Shie-Ming
Date: 6th December 2016
Time: 2.00pm to 3.30pm
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Soo Han Sen 
Abstract:

The study of metal string complexes with 1-D transition metal frameworks began in the early 1990s. Since these complexes provide great insight into multiple metal-metal bonds, and may have potential applications as molecular wires, this field of research has grown in the past 20 years. As such, the electronic structure of the simplest trinuclear complexes, the supporting ligand systems, and single molecular conductance of metal string complexes are discussed. This review will introduce the development of this field and summarize some important results in the newly designed heteronuclear metal string complexes (HMSCs). These molecules may be of great interest in studying the nature of heterometallic electronic effects and molecular electronic applications.

REFERENCES [1] Ismayilov RH, Wang WZ, Lee GH, Yeh CY, Hua SA, Song Y, Rohmer MM, Bénard M, S-M Peng Angew. Chem. Int. Ed., 2011, 50, 2045-2048. [2] M-C Cheng, C-L Mai, C-Y Yeh, G-H Lee and S-M Peng Chem. Commun. 2013, 49, 7938-7940. [3] M-J Huang, S-A Hua, M-D Fu, G-C Huang, C Yin, C-H Ko, C-K Kuo, C-H Hsu, G-H Lee; K-Y Ho, C-H Wang, Y-W Yang, I-C Chen, SM Peng, C-h Chen Chemistry-A European Journal 2014, 20(16), 4526-4531. [4] S-A Hua, M-C Cheng, C-h Chen, and S-M Peng European Journal of Inorganic Chemistry 2015, Micro Review, "From Homonuclear Metal String Complexes to Heteronuclear Metal String Complexes" 2015, 15, 2498.(Cover Picture)

 

Title:Nanoscience and metallo-supramolecular chemistry for DNA recognition and bioactivity
Speaker:Professor Michael Hannon
Date: 2nd December 2016 
Time: 2.30pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Xing Bengang
Abstract:

DNA occupies its familiar duplex form when it is ‘asleep’ and not being processed. When it is in action its structures are very different indeed. The recognition of DNA replication forks and other Y-shaped DNA and RNA junctions using nanosized metallo-supramolecular cylinder arrays [1-4] will be discussed together with work on new agents that recognise tetraplex DNAs found in gene promoter regions. We have shown that our cylinders bind strongly and preferentially to DNA fork structures and prevent DNA transactions in vivo, that they are taken up readily into cancerous cells and rapidly localise in cell nuclei, where they interfere with the processing of DNA leading to cell cycle arrest followed by apoptosis, without inducing genotoxicity or mutagenicity. The key challenge of how to build from in vitro biophysical observations to demonstrate what chemistry is happening in the cell, where and how quickly it is occurring and how that induces the biological response will be addressed. The talk will also explore the integration of this approach with other approaches from the field of nanoscience.

References 1 S. Phongtongpasuk, S. Paulus, J. Schnabl, R.K.O. Sigel, B. Spingler, M.J. Hannon, E. Freisinger, Angew Chem Int Ed., 2013, 52, 11513-11516 2 C. Ducani, A. Leczkowska, N. J. Hodges, M. J. Hannon, Angew Chem Int Ed., 2010, 49, 8942—8945 3 D. Boer, J. Kerckhoffs, Y. Parajo, M. Pascu, I. Usón, P. Lincoln, M. Hannon, M. Coll, Angew Chem Int Ed., 2010, 122, 2386-- 2389. 4 J. Malina, M.J. Hannon, V..Brabec, Scientific Reports, 2016, 6, Article number: 29674 .

 

Title:Regulatory pathway for plant epidermal cell differentiation via the homeobox gene GLABRA2
Speaker:Professor Takashi Aoyama
Date: 24th November 2016
Time: 2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Atsushi Goto
Abstract:

Root hairs and trichomes (hair-like structures on the shoot surface) of Arabidopsis thaliana are excellent subjects for studies on plant cell differentiation. A common network consisting of transcription factor genes has been found to play a pivotal role in regulating the differentiation of these cells. The homeobox gene GLABRA2 (GL2) acts as a bottleneck locating furthest downstream in the network. We focus on the role of GL2 as an output device of the conserved regulatory mechanism for plant epidermal cell differentiation.

 

Title:Chemical synthesis of correctly folded and misfolded glycoproteins for understanding oligosaccharide functions
Speaker:Professor Yasuhiro Kajihara
Date: 10th November 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Liu Xuewei  
Abstract:

Biosynthesis of glycoprotein in the Endplasmic Reticulum (ER), highmannose type oligosaccharide bearing three glucoses incorporated with nascent protein, work as a tag during glycoprotein folding process. The glycoprotein quality control system regulating the glycoprotein folding process consists of a pool of enzymes including calnexin/calreticulin (CNX/CRT), ERp57, glucosidases I and II and UDP-glucose: glycoproteins glucosyltransferase (UGGT), and those enzymes accelerate glycoprotein folding and prevent the accumulation of misfolded glycoproteins. CNX/CRT are chaperones and accelerate the folding of unstructured polypeptide chain. ERp57 is an oxido-reductase protein dedicated to the formation of disulfide bonds, and the glucosidases I and II (GI and GII) provide the de-glucosylation of the first, and the second as well as third glucose, respectively. Once glycoproteins are released from the chaperones, they go under the inspection of UGGT that re-glucosylates misfolded glycoproteins to send them back to CNX/CRT chaperones for additional folding attempts. Glucosylation/de-glucosylation of the highmannose type oligosaccharide of glycoproteins seems to be therefore a crucial step in the quality control cycle, determining which protein should be sent to the Golgi for further processing. In the Golgi apparatus, high-mannose type oligosaccharides are converted into acidic complex type sialyloligosaccharides. Nobody knows why this conversion is essential for glycoproteins. In order to understand glycoprotein quality control system and the function of sialyloligosaccharides, we have synthesized intentionally misfolded glycoproteins having high-mannose type oligosaccharides and erythropoietins having sialyloligosaccharides. In this presentation, I would like to discuss glycoprotein quality control system and the function of sialyloligosaccharides from the chemical point of view.

 

Title:Automated Glycan Assembly as Basis for Vaccine Development, Diagnostics and Material Science
Speaker:Professor Peter Seeberger
Date: 3rd November 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Liu Xuewei  
Abstract:

Pure glycans are key to enable biochemical, biophysical and immunological studies aimed at understanding the role of carbohydrates. Described is the development of a fully integrated platform for automated glycan assembly (AGA) based on solid-phase oligosacharide sythesis1 and carbohydrate arrays to address biological problems. Particular emphasis in this lecture will be placed on the new automated synthesis platform2 that has been commercialized. 3,4 Access to defined polysaccharides as long as 50-mers enables now biological as well as materials science investigations. 5,6 These synthetic polysaccharides can be combined much like “molecular LEGO” to create even larger oligosaccharide assemblies. Quality control of synthetic glycans can now be garanteed using ion mobility mass spectrometry to very low levels. 7 Carbohydrate arrays are used as diagnostics and in support of vaccine programs that are based on conjugates with synthetic oligosaccharides to screen blood sera.8 Particular emphasis in this lecture will be put on recent results concerning the discovery of glycan epitopes responsible for meat allergies. 8 Case studies of specific vaccines will provide an appreciation for the approach that is now advancing candidates toward clinical testing. 9-11 Fully synthetic vaccine candidates exploit iNKT cells for to induce a robust and protective immune response.12

1. Plante, O.J.; Palmacci, E.R.; Seeberger, P.H.; Science 2001, 291, 1523. 2. Castagner, B.; Kröck, L.; Esposito, D.; Wang, C.-C.; Bindschädler, P.; Seeberger, P.H.; Chem. Sci. 2012, 3, 1617. 3. www.glycouniverse.de 4. Seeberger, P.H.; Acc. Chem. Res. 2015, 48, 1450. 5. Hahm, H.S.; Hurevich, Seeberger, P.H.; Nature Comm 2016, 7, online. 6. Kottari, N.; Schuhmacher, F.; Seeberger, P.H.; manuscript in preparation 7. Hofmann, J.; Hahm, H.S.; Seeberger, P.H.; Pagel, K.; Nature 2015, 526, 241. 8. Geissner, A.; Fischer, J.; Biedermann, T.; Seeberger, P.H. in preparation. 9. Kamena, F.; Tamborrini, M.; Liu, X.; Kwon, Y.-U.; Thompson, F.; Pluschke, G.; Seeberger; P.H.; Nature Chem. Bio., 2008, 4, 238. 10. Schofield, L.; Hewitt, M.C.; Evans, K.; Siomos, M.A.; Seeberger, P.H.; Nature, 2002, 418, 785. 11. Martin, C.E.; Broecker, F.; Oberli, M.A.; Komor, J.; Mattner, J.; Anish, C.; Seeberger, P.H.; J. Am. Chem. Soc. 2013, 135, 9713. 12. Broecker, F.; Hanske, J.; Martin, C.; Baek, J.Y.; Wahlbrink, A.; Wojcik, F.; Hartmann, L.; Rademacher, C.; Anish, C.; Seeberger, P.H.; Nature Comm. 2016, 7, 11224. 13. Cavallari, M.; Stallforth, P.; Kalinichenko, A.; Rathwell, D.; Gronewold, T.M.A.; Adibekian, A.; Mori, L.; Landmann, R.; Seeberger, P.H.; De Libero, G.; Nature Chem. Bio. 2014, 10, 950.

 

Title:Nanodiamonds – a thrilling toolbox for scientists
Speaker:Dr Olga Shimoni
Date: 31st October 2016
Time: 2.30pm to 4.00pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Xing Bengang 
Abstract: 

Fluorescent nanodiamonds (NDs) have recently emerged as new promising imaging agents and therapeutic carriers for biological and medical applications. , In particular, there is a great interest in understanding surface properties of nanodiamonds and influence of various adsorbents and coatings for robust protocols employing nanodiamonds for bio-imaging. In this talk, I will highlight two recent results focused on interaction of nanodiamonds with biological and chemical species. In the 1st part of my talk, I will describe a robust and fast approach to coat nanodiamonds with coordination complex consisting of iron ions and tannic acid. We determine that coating of individual nanodiamonds with complexes pronouncedly enhance photoluminescence of single NV defects embedded in 60 nm nanodiamonds. In addition, the enhancement of photoluminescence is accompanied by a reduction of fluorescence lifetime providing a new opportunity for high resolution sensing. More importantly, we demonstrate an excellent signal-to-noise ratio in the ODMR signal, which is an important characteristic for single spin sensing applications. As the method utilizes biocompatible and FDA approved materials, the coating can be used with a range of bioapplications. In the second part, I will present our recent results on development of a new type of fluorescent NDs. Specifically, we will show the utilisation of commercially available NDs with NV centres and in-house fabricated NDs with silicon-vacancy (SiV) defects for application in bio-imaging. We further modify the surface of NDs with functional groups to attach biomolecules using standard organic chemistry procedures. Therefore, we demonstrate surface functionalisation of NDs to achieve selective intracellular targeting for intracellular imaging. In summary, our results provide an important stepping stone for the effective use of NDs for heavily sought after applications, showing that NDs are a promising biomedical research tool for cellular labelling, sensing and imaging.

1. Mochalin, V. N., O. Shenderova, D. Ho, and Y. Gogotsi (2012). Nat. Nanotechnol. 7(1): 11-23. 2. Shrand, A. M., S. A. C. Hens, and O. A. Shenderova (2009). Crit. Rev. Solid State Mater. Sci. 34(1-2): 18-74. 3. Bray, K.; Previdi, R.; Gibson, B. C.; Shimoni, O.; Aharanovich, I. (2015) Nanoscale 7 (11), 4869-4874.

 

Title:Photochemical Synthesis and Optical Properties of Nanoparticles
Speaker:Professor Masanori Sakamoto
Date: 28th October 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Loh Zhi Heng 
Abstract: 

Nano-sized metals and semiconductors exhibit different properties from those bulk and supposed to be applied to various fields of technology. Light is a powerful tool for synthesizing nanoparticles (NPs). In addition, spectroscopy is an effective means in order to study the formation process of NPs and their optical properties. I conducted a study on the formation processes and the optical functions of various NPs from the point of view of photochemistry. Geometric structure has a strong bearing on the properties of semiconductor NPs. Synthesizing NPs composed of two or more chemical species significantly expands available NP geometric structures and functionality. Heterostructured NPs (HNPs) are promising materials in photoelectric conversion systems, sensors, and catalysts. This is because of the combined effect of independent functional units, and/or efficient carrier transfer between phases. Understanding the relationship between geometry (shape, volume, and heterointerface area) and carrier dynamics in HNPs is important for controlling photo-generated carriers in HNPs for practical use. Synthesizing HNPs with preciously controlled sizes and shapes remains a significant challenge to achieving this. I synthesized a series of HNPs (heterotetrapod composed by the chalcopyrite CuInS2 (ch-CuInS2 ) core and CdS arms, phase-segregated CdS/CdTe heterostructured nanopencils, with controlled anisotropic structure and CdS/CdTe volume, etc., using the wet chemical synthesis method (Figure 1). We also investigated how geometry influences photo-induced charge separation in HNCs using femtosecond (fs)-laser flash photolysis.

References (1) M. Sakamoto, T. Tachikawa, M. Fujitsuka, and T. Majima, J. Am. Chem. Soc., 2009, 131, 6-7. (2) M. Sakamoto, T. Tachikawa, M. Fujitsuka, and T. Majima, Adv. Mater., 2008, 20, 3427-3432. (3) M. Sakamoto, K. Inoue, M. Saruyama, Y.-G. So, K. Kimoto, M. Okano, Y. Kanemitsu, and T. Teranishi, Chem. Sci., 2014, 5, 3831-3835. (4) M. Sakamoto, K. Inoue, M. Okano, M. Saruyama, S. Kim, Y. –G. So, K. Kimoto, Y. Kanemitsu, T. Teranishi, Nanoscale, 2016, 8, 9517-9520

 

Title:π-Conjugated Polymers Possessing Versatile Elements-Blocks by Post-element-transformation Technique
Speaker:Professor Ikuyoshi Tomita
Date: 27th October 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Atsushi Goto
Abstract: A new synthetic method of π-conjugated polymers possessing various elements-blocks by reactions of organometallic polymers possessing titanacyclopentadiene-2,5-dyl units is described. The macromolecular design of functional materials based on the present synthetic method will also be described.

 

Title:En Route to New Drug Discover & Jak1/TYK2 Inhibitors for Autoimmune Diseases
Speaker:Dr Wan Zhao Kui
Date: 21st October 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Professor Tan Choon Hong 
Abstract: New drug discovery is a complex process that requires various expertise and deep knowledge. The journey is at high risk, high cost and yet highly rewarding. This presentation will share with the audience a new drug discovery process and some key attributes in each stage. The discovery of a highly potent and efficacious Jak1/TYK2 inhibitor, that is now in Phase I clinical trial, will also be presented.

 

Title:Tailoring the structure of graphene oxide toward Application for composite functional materials
Speaker:Professor Yuta Nishina
Date: 3rd October 2016
Time: 1.00pm to 2.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Martin Pumera
Abstract: Graphene oxide (GO) has widely been employed in various fields, but its structure and composition has still not been fully controlled. Based on the formation mechanism of GO, we have developed general strategies to control the oxidation degree of graphene-like materials with two types of methods: oxidation of graphite by KMnO4 in H2SO4 (oGO), and reduction of highly oxidized graphene oxide by hydrazine (rGO). Even though the oxygen content was the same, oGO and rGO showed different properties in adsorption ability, oxidation ability, and electron conductivity, because of the difference in persisting graphitic structure and defects. These results will be a guideline for production of tailormade GO. Applications such as conductive films, electrodes for lithium-ion batteries, supercapacitors, and catalysts often require surface functionalizations to improve GO’s performances. Recently, adsorbents and membranes for water purification have also been recognized as promising applications of graphene-like materials. With our tailor-made GO, we developed catalyst, membrane, lubricant additive, and anode for Li-ion battery.

 

Title:New technology for full lamination of large LCD screens
Speaker:Professor Guo Hao
Date: 16th September 2016
Time: 2.30pm to 4.00pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Robin Chi 
Abstract: Liquid Crystal Display (LCD) screens have found widespread applications in our modern life: mobile phone, computer, TV, et al., to name a few. Full lamination is a key technology in production process of LCD screens. However, such a key technology is still limited to 20 inch (51 cm) LED displays. For larger LEDs, the qualified rate will be dramatically decreased. Our group has developed new material, technology, and equipment for full lamination of large LCD screens, with the largest size being up to 120 inches (305 cm). We wish to show the details in this lecture.

 

Title:Asymmetric Functionalization of Alcohols: Four Lewis Basic Functionalities Working Cooperatively
Speaker:Professor Marc Snapper
Date: 14th September 2016
Time: 11.00amt o 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Steve Zhou
Abstract: New reactions offer opportunities to shorten synthetic routes to important targets. We will describe our efforts to develop catalytic asymmetric silylation and sulfonylation of alcohols. Our initial rational selection strategies brought us to an effective, but slow imidazole catalyst. Subsequent computations studies then allowed us to identify a co-catalyst that accelerates significantly this asymmetric transformation. The net result is a selective and practical catalytic asymmetric functionalization of diols and polyols.

 

Title:Interactions of G-quadruplex DNA with dinuclear Pt(II) complexes
Speaker:Professor Janice Aldrich-Wright
Date: 14th September 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Shao Fangwei 
Abstract:

Contemporary platinum(II) anticancer drugs, such as cisplatin and carboplatin, covalently bind to DNA and exhibit many disadvantages including poor selectivity, acquired resistance, cross-resistance and severe side effects. 1 Research has focused on the development of complexes that do not demonstrate these clinical disadvantages; one example of this is the synthesis of complexes that can bind to Gquadruplex DNA (QDNA), in preference to B-DNA, in order to affect the reproduction of cancerous cells. 2 We have recently synthesized dinuclear (2,2':6',2''-terpyridine)-based complexes that are connected by thiol chains of varying length (examples in Figure below with IC50 in L1210 cells).3 These compounds have demonstrated potent cytotoxicity in cancerous cell lines and are thought to interact with Q-DNA through π-stacking interactions involving their terpyridine moieties. Small molecules that selectively bind to QDNA have been shown to stabilize these structures, and so Q-DNA represents a potential biological target for the suppression of telomerase activity. 4 Here the study of the binding of our platinum(II) complexes to Q-DNA, including the use of synchrotron radiation circular dichroism (SRCD), fluorescence, mass spectrometry and docking simulation techniques.

References: [1] Harper, B.W.; Krause-Heuer, A.M.; Grant, M.P.; Manohar, M.; Garbutcheon-Singh K.B.; Aldrich-Wright, J.R. Chem. Eur. J., 2010, 16, 7064- 7077. [2] Campbell, N.H.; Karim, N.H. A.; Parkinson, G.N.; Gunaratnam, M.; Petrucci, V.; Todd, A.K.; Vilar R.; Neidle, S. J. Med. Chem., 2011, 55, 209- 222. [3] Harper B.W.J.; and Aldrich-Wright, J.R. Dalton Trans., 2015, 44, 87-96. [4] Pages, B.J.; Ang, D.L. Wright E.P. and Aldrich-Wright, J.R. Dalton Trans., 2015, 44, 3505-3526.

 

Title:CATALYITC SELECTIVE OLEFIN TRIMERISATION
Speaker:Professor Randolf Kohn
Date: 9th September 2016
Time: 10.00am to 11.30am 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor So Cheuk Wai
Abstract:

Selective trimerisation of ethylene to 1-hexene with chromium or titanium based catalysts has become an important industrial process. 1 While a metallacyclic mechanism has become generally accepted many details on the active species are still controversial. Analogous selective trimerisation of α-olefins gives a range of isomeric trimer products suitable for mechanistic studies unavailable to ethylene trimerisation. However, most selective ethylene trimerisation catalysts are unable to trimerise α-olefins and following our initial description of an active system based on triazacyclohexane complexes of CrCl3 in 20002 no better catalysts have been reported until recently with activities of a few hundred turnovers. 3 We have now optimised the catalysis using triazacyclohexane complexes to achieve reliable selective α-olefin trimerisation at up to 5000 turnovers over a few hours. 4 We found that mainly the isomers shown above are formed and their ratio depends significantly on the N-substituents used in the triazacyclohexane ligand. Comparison of the GC-MS and 13C NMR spectra along with isotope labelling studies has now allowed us to identify and quantify all isomers (>1%) with their complete 13C NMR spectra for the trimer of 1-hexene and some other α-olefins. Selectively deuterium labelled -olefins show significant effects on the isomer ratios observed indicating the important role for H-transfer steps in the selectivity for some isomers. The results will be discussed with some DFT computational studies.

1. D.S. McGuinness, Chem. Rev., 2011, 111, 2321-2341. 2. R.D. Köhn, M. Haufe, G. Kociok-Köhn, S. Grimm, P. Wasserscheid, W. Keim, Angew. Chem., 112 (2000) 4519-4521; Angew. Chem., Int. Ed. Engl, 39 (2000) 4337-4339 3. A. Sattler, J. A. Labinger, J. E. Bercaw, Organometallics, 2013, 32, 6899-6902. 4. A.G.N. Coxon, R.D. Köhn, ACS Catal. 2016, 6, 3008−3016

 

Title:Modern Applications of Stable Isotopes to Quantitation and Tracing in Food Science
Speaker:Professor Michael Rychlik
Date: 5th September 2016
Time: 2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Li Tianhu
Abstract:Food components containing stable isotopes (so-called isotopologues) differ in their molecular mass but (essentially) not in their chemical and physical properties. Thus they undergo the same paths in chemical, physical and biochemical processes and can be differentiated by mass spectrometry. These properties make them perfect tools for following analytical procedures, biosynthesis in organisms and physiological pathways in humans. The most commonly used stable isotopes are deuterium, 13C and 15N. In food analysis, stable isotopes are applied in Stable Isotope Dilution Analysis (SIDA), which is one of the most accurate procedures up to date. SIDA is the golden standard in mycotoxin analysis and the number of other applications in food analysis is currently increasing. Assays for Alternaria and Fusarium mycotoxins along with vitamins such as the folate group will be presented. In all these cases, broad validation studies proved the superiority of SIDAs. In case of folates, stable isotopes can also be used as tracers for assessing the bioavailability of these micronutrients. In a combination of differently labeled folates, a double label isotope study was developed, in which deuterium and 13C-labels were used to differentiate oral doses of folates from analytical internal standards. In comparison with traditional short-term assays using the area-under-the curve approach of naturally occurring folates, new recommendations for the intake of folates were deduced.

 

Title:Excitons in Biological and Synthetic Molecular Aggregates
Speaker:Professor Jasper Knoester
Date: 23rd August 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Tan Howe Siang
Abstract:Self-assembled aggregates of dye molecules exhibit intriguing optical properties caused by their collective optical excitations, Frenkel excitons. The energetic, dynamic, and spatial properties of these excitons are responsible for special optical absorption, emission, and energy transport characteristics, which play an important role in optical materials as well as light-harvesting systems. The latter are abundant in natural photosynthetic systems, whose functioning is the topic of many scientific studies and may find applications in synthetic analogues. In this talk, I will introduce the topic of excitons in self-assembled molecular aggregates in general and light-harvesting antennae in particular. Next, I will discuss the modeling and experimental probing of the optical properties and dynamics of the excitons. The complexity of the systems considered and the resulting interplay between many degrees of freedom that govern the nature of the excitons, makes this an exciting and complex arena of research. Systems of particular interest during the talk will include nano-tubular aggregates, which occur in the photosynthetic apparatus of certain bacteria, but also can be created using synthetic dye molecules. Throughout the talk, connections between theory and experiment are made.

 

Title:Microbial metabolic engineering for producing value-added products and designed probiotics
Speaker:Professor Yong-Su Jin
Date: 22nd August 2016
Time: 2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Li Tianhu 
Abstract: 

A third of foods we take every day are associated with microorganisms. Numerous value added products, such as biofuels, chemicals, and food ingredients are commercially produced by microorganisms. Moreover, we have more microorganisms in our body than human cells. These facts indicate how much microorganisms and their activities are crucial for maintaining and enhancing the quality of human life.

Recent advances in reading and writing DNA precisely have rapidly enabled sophisticated genetic perturbations in target microorganisms to alter their behaviors as designed. In this talk, I will present examples of our metabolic engineering endeavors to construct engineered yeast strains at different locations for various applications. Specifically, we have engineered yeast strains capable of producing value added products in bioreactors from mixed sugars prevalent in the hydrolysates of renewable biomass. In addition, we have developed an efficient genetic manipulation system for developing probiotic yeast strains capable of secreting target products in the human gut for preventing and curing diseases as well as altering gut microbiota.

While there are concerns about recombinant DNA technologies, I envision that the availability of safer genetic perturbation tools, such as Cas9/CRISPR-based genome engineering, and deeper and systems-level understanding of target pathways will deliver more and more engineered microorganisms in bioreactors, foods, and the human gut for various applications.

 

Title:Chemistry of Highly Reactive Diborane(4): Bond Cleavage and Complicated Mechanism
Speaker:Professor Makoto Yamashita
Date: 19th August 2016
Time: 2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Rei Kinjo 
Abstract: 

B2pin2 [bis(pinacolato)diborane(4)] is one of most widely used boron reagents in organic synthesis to achieve a variety of borylation reaction. In contrast to the rich chemistry in the development of organic reactions with B2pin2, new types of diborane(4) reagents are less explored. Recently, we reported easy and scalable synthesis of novel unsymmetrical diborane(4), pinB-BMes2 (1). This compound showed unique reactivity towards C O and C N triple bond in carbon monoxide and tert-butylisocyanide.1 In the former reaction, two CO molecules were incorporated into the product to construct characteristic -conjugation causing its pale yellow color. The latter reaction involved a cleavage of C N triple bond of isocyanide in the absence of transition metal reagent or catalyst. The strong Lewis acidity of 1 was originated from lowering LUMO level due to overlapping two vacant p-orbitals of pinB and BMes2 groups as supported by DFT calculation.2 The unsymmetrical diborane(4) 1 also exhibited reactivity toward C C triple bond of alkynes to form diborylalkenes having diarylboryl unit.3 By a careful control of reaction conditions, three possible isomers a-c were selectively synthesized. In the lecture, complicated mechanisms of these unique reactions and the related diborane(4) chemistry will also be presented.

References (1) Asakawa, H.; Lee, K.-H.; Lin, Z.; Yamashita, M., Nat. Commun. 2014, 5, 4245. (2) Asakawa, H.; Lee, K.-H.; Furukawa, K.; Lin, Z.; Yamashita, M., Chem. Eur. J. 2015, 21, 4267-4271. (3) Kojima, C.; Lee, K.-H.; Lin, Z.; Yamashita, M., J. Am. Chem. Soc. 2016, 138, 6662-6669.

 

Title:Syntheses and Properties of Cycloparaphenylenes
Speaker:Professor Shigeru Yamago
Date: 18th August 2016
Time: 1.30pm to 3.00pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Atsushi Goto 
Abstract: Cycloparaphenylenes (CPPs), which have the shortest sidewall structure of armchair carbon nanotube, have attracted considerable interest due to their unique structure as well as potential applications in molecular electronics. In this presentation, syntheses of CPPs and their derivatives and their unique physical properties will be presented. In particular, large scale synthesis and redox properties of CPPs will be emphasized.

 

Title:New Approaches for Selective Synthesis of Functional Organosilanes
Speaker:Professor Ryo Shintani
Date: 2nd August 2016
Time: 3.00pm to 4.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Steve Zhou
Abstract: 

Silicon-bridged π-conjugated compounds such as dibenzosiloles are widely found as a structural motif in various useful materials due to their optoelectronic properties. But the preparation of enantioenriched chiral dibenzosiloles and related compounds has been scarcely investigated. This is presumably due to the planar nature of these compounds except at the silicon atom, and the introduction of chirality at the silicon center, particularly in a catalytic asymmetric manner, is not a trivial task. In this context, we recently developed asymmetric syntheses of silicon-stereogenic dibenzosiloles and related compounds through a rhodium-catalyzed desymmetrization reaction of silicon-containing prochiral compounds. 1–3 During the course of this study, we also found new transformations that can be applied to the stereoselective synthesis of new types silicon-stereogenic silacycles: a rhodium-catalyzed intramolecular alkynylsilylation of alkynes4 and a palladium-catalyzed intramolecular 1,5-migration/amination cascade. 5

In addition to these catalytic asymmetric reactions directed toward the synthesis of silicon-stereogenic organosilanes, we are also interested in broadening the structural diversities of silicon-bridged π-conjugated compounds. Although dibenzosiloles and related compounds have been intensively investigated, even structurally simple compounds such as fused oligosiloles and their analogs are difficult to access with existing synthetic methods. In particular, no single report on the synthesis of quinoidal fused oligosiloles has ever been made as far as we are aware. In this context, we devised a rhodium-catalyzed stitching reaction between two different oligo(silylene-ethynylene)s for the first synthesis of quinoidal fused oligosiloles and the physical properties of these compounds were also investigated. 6

References (1) Shintani, R.; Takagi, C.; Ito, T.; Naito, M.; Nozaki, K. Angew. Chem., Int. Ed. 2015, 54, 1616. (2) Shintani, R.; Takano, R.; Nozaki, K. Chem. Sci. 2016, 7, 1205. (3) Shintani, R.; Misawa, N.; Takano, R.; Nozaki, K. manuscript in preparation. (4) Shintani, R.; Kurata, H.; Nozaki, K. Chem. Commun. 2015, 51, 11378. (5) Sato, Y.; Takagi, C.; Shintani, R.; Nozaki, K. manuscript in preparation. (6) Shintani, R.; Iino, R.; Nozaki, K. J. Am. Chem. Soc. 2016, 138, 3635.

 

Title:New Strategies for the Stereoselective Synthesis of Functionalised Heterocycles
Speaker:Professor Paul Clarke
Date: 27th July 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Roderick Bates 
Abstract: 

2,6-Disubstituted tetrahydropyran (THP) and piperidine rings form key structural motifs in many potent biologically active natural products and pharmaceuticals. In this lecture I will present our recent results into the synthesis of these important structural units.

In the first part of the lecture I will discuss a stereodivergent oxy-Michael approach to the synthesis of 4-hydroxy-2,6-cis- or 2,6-transsubstituted tetrahydropyran rings, which are present in natural products such as phorboxazole B (anti-tumour) and the diospongins (antiosteoporotic). Experimental and DFT calculations have been used to elucidate the mechanism of the stereodivergence – where a trifluoroacetic acid catalysed formation of 2,6-cis-tetrahydropyrans was mediated by a trifluoroacetate-hydroxonium bridge and proceeded via a chair-like transition state, and a TBAF mediated formation of 2,6-trans-tetrahydropyrans proceeded via a boat-like transition state, where the 4-hydroxyl group formed a crucial hydrogen bond to the cyclizing alkoxide.

The second part of the lecture will detail a new Maitland-Japp inspired route to the synthesis of spirocyclic piperidines, which are suitable for the use as fragments in 3D-compound libraries. 3Dfragments obeying the “rule of 3” are increasingly sought after in medicinal chemistry as they occupy sparsely explored areas of chemical space and can be further elaborated to product lead-like compounds. Our synthesis of spirocyclic piperidines generates these structures in good yields and in in novel areas of chemical space as defined by principle moments of inertia (PMI) analysis.

 

Title:Towards Artificial Photosynthesis–Highly Efficient Porphyrin-Based Organic Solar Cells
Speaker:Professor Zhu Xunjin
Date: 14th July 2016
Time: 2.30pm to 4.00pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Robin Chi 
Abstract: 

Photosynthesis is the source of energy for nearly all life on earth and nature systems selected chlorophyll as the centre piece of photosynthesis. Porphyrin is synthetic compound that mimic nature’s chlorophyll for solar energy conversion. Its nature occurring highly conjugated macrocycle exhibits unique optical properties with a very intense absorption in the visible region (namely a strong Soret band centered between 400-500 nm and moderate Q bands in the 550-650 nm spectral region), and therefore, is deeply colored. Impressively, porphyrin containing compounds has been demonstrated their effectiveness in dye-sensitized solar cell (DSSC) with the power conversion efficiency (PEC) of 13%. At the same time, solution-processed heterojunction (BHJ) organic solar cells (OSC) have been developed which are typically made of semiconducting conjugated polymers or small molecules. They are lightweight, low-cost, and flexible form solar cell. The natural photosynthesis implies that porphyrins and derivatives with unique properties (efficient light harvesting electron transport) could create comparably successful systems in BHJ OSC.

Hence, we developed a series of new acceptor-donor-acceptor (A-D-A) type small molecules based on porphyrin-core with peripheral aliphatic meso-substitutions, and applied them as donors in bulk heterojunction organic solar cells. The long pendant side-chains on both porphyrin-core and π-linkers can effectively strengthen the directional intermolecular π-π stacking through polymorphism associated with side-chain bending, and the blend films of those small molecules with [6,6]-phenyl-C71-butyric acid methyl ester are characteristics of bi-continuous, interpenetrating networks required for efficient charge separation and transportation. As a result, the engineering of porphyrin structure and self-assembly processing with 1,8-diiodooctane and solvent vapor annealing successfully led to impressive power conversion efficiencies higher than 9.2% for cells with the active layer of SM:PC71BM.

References: • H. Wang, L. G. Xiao, L. Yan, S. Chen, X. J. Zhu, X. B. Peng, X. Z. Wang, W. Y. Wong, W. K. Wong, Chem. Sci., 2016, Advance Article. • L. G. Xiao, H. D. Wang, K. Gao, L. S. Li, C. Liu, X. B. Peng, W. Y. Wong, W. K. Wong, X. J. Zhu, Chem.-Asian J. 2015, 10, 1513-1518. • S. Chen, L. G. Xiao, X. J. Zhu, X. B. Peng, W. K. Wong, W. Y. Wong, Chem. Commun. 2015, 51, 14439-14442.

 

Title:Combination of Light and Metal Complexes to fight Cancer
Speaker:Professor Gilles Gasser
Date: 13th July 2016
Time: 10.30am to 12.00pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Leong Weng Kee 
Abstract: 

The synergistic action of light, oxygen and a non-toxic photosensitizer has found applications since decades in medicine under the name of Photodynamic Therapy (PDT) for the treatment of skin diseases and, more recently, for the treatment of certain types of cancer. However, of the fourteen photosensitizers currently approved for the treatment of cancer in more than 10 countries, only three contain a metal ion. This fact is rather surprising considering that nowadays around 50% of conventional chemotherapies involve the use of cisplatin and other platinum-containing drugs. During this talk, we will present our recent results on the use of Ru(II) polypyridyl complexes to kill cancer cells and bacteria. Importantly, we will show that two-photon activation can be employed to efficiently eradicate multicellular tumor spheroids (i.e. mini-tumors).

 

Title:Combining field flow fractionation (FFF) with SERS for bio-analytical detection and nanodendrite-based SERS substrates
Speaker:Professor Hoeil Chung
Date: 7th July 2016
Time: 2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Ling Xing Yi 
Abstract: 

Asymmetrical flow field-flow fractionation (AF4) was evaluated as a potential analytical method for detection of a protective antigen (PA), an Anthrax biomarker. The scheme was based on the recognition of altered AF4 retention through the generation of the size-increased Au nanoparticle probes as a result of PA binding, in which a PA-selective peptide was conjugated on the probe surface. Further, an analytical scheme, incorporating field-flow fractionation (FFF)-based separation of target-specific polystyrene (PS) particle probes of different sizes and amplified SERS tagging, was demonstrated for simultaneous and sensitive detection of multiple microRNAs (miRNAs). For multiplexed detection, PS particles of three different diameters (15, 10, 5 μm) were used for the size-coding, and a probe single stranded DNA (ssDNA) complementary to a target miRNA was conjugated on an intended PS particle. After binding of a target miRNA on PS probe, polyadenylation reaction was executed to generate a long tail composed of adenine (A) serving as a binding site to thymine (T) conjugated Au nanoparticles (TAuNPs) to increase SERS intensity. The three size-coded PS probes bound with T-AuNPs were then separated in a FFF channel. In final, recently developed nanodendrite-based SERS substrates will be introduced.

 

Title:A Quantitative Approach to Polar Organic Syntheses
Speaker:Professor Herbert Mayr
Date: 1st July 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Roderick Bates
Abstract: 

Organic chemistry is generally organized by the concept of functional groups, and knowledge whether and how different functional groups react with each other is a key qualification of an organic chemist. Since the introduction of this concept, the number of functional groups has grown so tremendously that a new organizing principle appeared necessary. The basis for this approach was laid in the 1930s by C. Ingold who recognized that most organic reactions can be considered as combinations of electron-surplus (nucleophiles) with electron-deficient compounds (electrophiles). Numerous attempts to quantify nucleophilicity and electrophilicity have been reported since the 1950s, but most of them cover only a narrow group of compounds. The most comprehensive nucleophilicity and electrophilicity scales presently available have been created by my group in the past two decades. 1

By defining benzhydrylium ions 1, structurally related quinone methides 2, and benzylidene malonates 3 as reference electrophiles which differ by 32 orders of magnitude in reactivity (corresponding to relative reaction times of nanoseconds to 106 -times the age of the universe) and using the method of overlapping correlation lines it has become possible to directly compare nucleophiles of different functionality, which allows one to transfer knowledge from one field of chemistry into another. 2

It has been shown that equation (1), where electrophiles are characterized by one parameter (E) and nucleophiles are characterized by the solvent-dependent nucleophilicity parameter N and sensitivity parameter sN allows one to predict absolute rate constants with an accuracy of factor 10-100 in a reactivity range of more than forty orders of magnitude. lg k20°C = sN (E + N) (1)

For qualitative analyses, the sensitivity factor sN can be neglected, and as a rule of thumb one can expect electrophile-nucleophile combinations to take place at room temperature if (N + E) > –5. Since the diffusion limit is reached at k = 109 - 1010 M–1 s –1 , chemo-, regio- and stereoselectivity often break down when (N + E) > 10. As a consequence, most synthetically used reactions are characterized by -5 < (E + N) < 10.

Using the freely accessible data base, which presently comprises almost 1000 nucleophiles and 250 electrophiles1 one can examine the likeliness of designed synthetic transformations, derive suggestions for novel reactions, and examine the plausibility of patent claims. Analogous approaches to estimate rates of heterolytic cleavages and equilibrium constants (Lewis basicities) are described in refs 3 and 4, respectively.

eferences: (1) Data collection and download of a reactivity scales poster: http://www.cup.uni-muenchen.de/oc/mayr/ (2) Reviews: (a) H. Mayr, A. R. Ofial, Pure Appl. Chem. 2005, 77, 1807; (b) H. Mayr, B. Kempf, A. R. Ofial, Acc. Chem. Res. 2003, 36, 66. (c) H. Mayr, A. R. Ofial, J. Phys. Org. Chem. 2008, 21, 584. (3) N. Streidl, B. Denegri, O. Kronja, H. Mayr, Acc. Chem. Res. 2010, 43, 1537. (4) H. Mayr, J. Ammer, M. Baidya, B. Maji, T. A. Nigst, A. R. Ofial, T. Singer, J. Am. Chem. Soc. 2015, 137, 2580-2599.

 

Title:A Radical Solution to an Old Problem. Some New Perspectives for Organic Synthesis
Speaker:Professor Samir Zard
Date: 30th June 2016
Time: 11.00am to 12.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Associate Professor Shunsuke Chiba

 

Title:Chemistry of Stable Triply-bonded Silicon Compounds Disilynes and Stable Silyl Radicals: Beginning and Development
Speaker:Professor Akira Sekiguchi
Date: 15th June 2016
Time: 2.00pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Rei Kinjo
Abstract: 

The synthesis and isolation of compounds with a silicon-silicon triple bond was no more than a dream, one that was finally realized in 2004. The chemistry of disilynes also represented the beginning of a new area of main group chemistry research. The chemistry of stable silyl, germyl and stannyl radicals will be also reported together with their possible applications (for example, radical battery, etc). As one of the most important developments, the potential application of stable radicals and polysilynes in the design of new advanced materials will be presented.

 

Title:Nature and Intrinsic Strength of the Halogen Bond
Speaker:Professor Elfi Kraka
Date: 1st June 2016
Time: 2.30pm to 3.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Hajime Hirao
Abstract: 

 

Halogen bonding (XB) is defined as the non-covalent interaction formed between halogen atom X and a heteroatom A. Due to its unique features, XB has found extensive use in medicinal, supramolecular, and materials chemistry. In this way, XB has adopted an exceptional role among the noncovalent interactions. Despite the many investigations on XB carried out so far, there is no quantitative assessment on its intrinsic bond strength and a detailed description of its nature.

We have systematically analyzed XB in dependence of X and A. For the quantification of the intrinsic strength of the X … A interaction we have used new quantum chemical tools, which in combination with Coupled Cluster calculations provide for the first time a direct insight into the nature and strength of halogen bonding. Calculated binding energies between 1 and 45 kcal/mol reflect the large variation in XB. An outlook is given on how to utilize XB as a building block for crystal engineering, materials science, and drug design.

 

 

Title:Development and Application of Dirac-exact Relativistic Methods for the Calculation of Molecular Properties
Speaker:Professor Dieter Cremer
Date: 1st June 2016
Time: 1.30pm to 2.30pm 
Venue:SPMS Research & Graduate Studies Office Conference Room
Host:Assistant Professor Hajime Hirao
Abstract: 

The NESC method, originally developed by Dyall and improved by Zou, Filatov and Cremer [1-5], is a first principles 2-component approach (positron components are eliminated) fully equivalent to the exact 4-component approach based on the Dirac equation. In view of the fact that NESC provides the exact 2-component relativistic description of one-electron systems, it is an ideal starting point for developing a repertoire of methods, by which routinely first and second order response properties can be calculated. Previously, we have pointed out the relationship between IORA (infinite order regular approximation) and NESC and have used this for a rapid iterative solution of the NESC equations. [1] In this work, we present algorithm and methods for the calculation of molecular geometries, dipole moments, hyperfine structure constants, vibrational frequencies, force constants, electric polarizabilities, infrared intensities, and other response properties.[2-5] We also discuss the impact of spin-orbit coupling on molecular properties. Applications are presented for mercury containing molecules and some other molecular systems containing transition metals, which require a relativistic treatment. A simple way is sketched how to obtain a quantitative characterization of the bond strength involving heavy atoms with strong relativistic effects.

[1] Zou, W., Filatov, M., Cremer, D. Theor. Chem. Acc. 130:633–644, 2011. [2] Zou, W., Filatov, M., Cremer, D. J. Chem. Phys. 134:244117.1-11, 2011. [3] Zou, W., Filatov, M., Cremer, D. J. Chem. Theory Comput. 8:2617, 2012. [4] Zou, W., Filatov, M., Cremer, D. J. Chem. Phys. 137:084108, 2012. [5] Filatov, M., Zou, W., Cremer, D. J. Chem. Phys. 139:014106, 2013. [6] Filatov, M., Zou, W., Cremer, D. J. Chem. Phys. 139, 014106 (2013). [7] Zou, W., Filatov, M., Cremer, D. J. Chem. Phys, 142, 214106.1-11 (2015).

 

Title:Chlorin–Polyoxometalate and Chlorin–Gold Nanorod Complexes for Efficient Photosensitization
Speaker:Professor Il Yoon
Date: 10th May 2016
Time: 11.00am to 12.30pm 
Venue:SPMS CBC Building Level 2, Conference Room
Host:Associate Professor Zhao Yanli
Abstract: 

Photodynamic therapy (PDT) is a promising non-invasive cancer treatment based on activation of photosensitizer (PS) upon light irradiation for a generation of reactive oxygen species (e.g. singlet oxygen, 1O2) to destroy the tumors.[1] The development of desirable PS as well as delivery systems of PS (e.g. gold nanoparticles (GNPs), gold nanorod (GNR) and polyoxometalate (POM)) has attracted much attention for highly selective targeting of tumor sites.[2]

Recently, we have developed water soluble ionic liquid type PSs and GNPs, in which the GNPs used as a drug delivery vehicle reveals significantly enhanced PDT activity compared with the free PSs.[3] We prepared 4:1 supramolecular complexed ionic salt between pyridinium chlorin and polyanionic [α-SiMo12O40]4− exhibits significantly enhanced photodynamic activity against A549 cell lines because of increased singlet oxygen photogeneration through high cellular penetration and localization of the chlorin molecules on the ionic salt into the cancer cell (Fig1a).[4] Confocal laser scanning microscopy images clearly represent a higher uptake and photodynamic effect of this supramolecular complex corresponding to the lower IC50 value compared to the free chlorin.

In addition, GNR‒PS complex was prepared using anionic PS (sodium salt of purpurin-18) and cationic poly(allylamine hydrochloride) by layerby-layer method, and was characterized by transmission electron microscopy, UV-vis spectroscopy, and zeta potential (Fig1b).[5] The GNR‒PS complex is a promising agent for a synergistic (photothermal and photodynamic) therapy (PTT/PDT), in which PTT generates heat as well as operates the PS release which maximize the following PDT activity. The combined dual therapy, PTT followed by PDT, exhibits a significantly higher photocytotoxicity result based on synergistic effect of hyperthermia from PTT as well as singlet oxygen photogeneration from PDT.

1. Bonnet in Chemical Aspects of Photodynamic Therapy, Gordon and Breach Science Publishers, Netherlands, 2000. 2. P. K. Jain, X. Huang, I. H. El-Sayed, M. A. El-Sayed, Acc. Chem. Res. 2008, 41, 1578–1586. 3. (a) B. Lkhagvadulam, J. H. Kim, I. Yoon, Y. K. Shim, BioMed Res. Int. 2013, V2013, Article ID 720579; (b) B. Lkhagvadulam, J. H. Kim, I. Yoon, Y. K. Shim, J. Porphyrin Phthalocyanines 2012, 16, 331–340 (highlighted as a cover of April issue). 4. I. Yoon, J. H. Kim, J. Z. Li, W. K. Lee, Y. K. Shim, Inorg. Chem. 2014, 53, 3‒5. 5. S. B. Kim, T. H. Lee, I. Yoon, Y. K. Shim, W. K. Lee, Chem. Asian J. 2015, 10, 563‒567.

 

Title:From Aziridines to Alkaloids: Total Synthesis of (±)-Alstonerine
Speaker:Professor Donald Craig
Date: 21st April 2016
Time: 11.00am to 12.30pm 
Venue:SPMS CBC Building Level 2, Conference Room
Host:Associate Professor Roderick Bates 
Abstract: 

This lecture will describe the development of synthesis methods based on ring-opening of activated aziridines by sulfur-stabilised carbanionic nucleophiles. Bifunctional sulfone-containing nucleophiles possessing appended acetal groups give sulfonyl-substituted tetrahydropyridines on acid treatment of disubstituted aziridine ring-opening adducts, and these heterocycles enter into highly regio- and stereoselective substitution reactions when combined with soft carbon nucleophiles in the presence of Lewis acids. Trisubstituted aziridines possessing additional hydroxymethyl or vinyl groups show complete regioselectivity in stereospecific ring-opening reactions, and this reactivity is harnessed in a total synthesis of the naturally-occurring macroline-related indolic alkaloid (±)-alstonerine.

 

Title:NANOOPTICS WITH FAST ELECTRONS
Speaker:Professor Mathieu Kociak
Date: 20th April 2016
Time: 11.00am to 12.30pm 
Venue:SPMS CBC Building Level 2, Conference Room
Host:Assistant Professor Ling Xing Yi
Abstract: 

How light behaves and interacts with matter at the nanometer scale is a fascinating subject. Indeed, at this scale, both the electromagnetic field and the electron wave functions may be subject to confinement. This is why the optical properties of nano-objects will in general depend drastically on their shape, size and local environment. This is the case for surface plasmons on metallic nanoparticles, which can be viewed as classical electromagnetic standing waves, or for the excitons in quantum emitters (such as Quantum Dots), where the confinement now affects the excitons wavefunction.

The typical sizes at which confinement becomes crucial range from few angströms (for excitons) to tens or hundred of nanometers (for plasmons). It is thus important to develop tools able to probe optical and structural properties at these scales. Of course, regular optical microscopies and spectroscopies are not able to deliver such spatial resolutions. Recently, electron spectroscopies such as Electron Energy Loss Spectroscopy (EELS) and Cathodoluminescence (CL) used in a Scanning Electron Microscope (STEM) have been shown to address this issue. In this presentation, I will thus present how recent technical and conceptual developments in EELS and CL have allowed to explore various aspects of nano-optics (plasmonics, photonics, quantum optics) at the scale relevant for plasmons and quantum emitters: few nanometers.

 

Title:Biomass valorization by heterogeneous catalytic materials in industry
Speaker:Dr. Yashodhan Bhawe
Date: 4th April 2016
Time: 11.00am to 12.30pm 
Venue:SPMS MAS Executive Classroom 1
Host:Assistant Professor Soo Han Sen 
Abstract: 

The global requirement of reduction in greenhouse gas emissions forces us to devise alternatives to fossil fuels as a source for both fuels and a large spectrum of chemicals. The objective of my talk is to discuss / propose some existing technologies on biomass conversion. I will discuss existing commercial & lab scale processes for value addition to biomass. In order to more effectively convert biomass into chemicals, catalysts would be required. I will provide a quick tour through one such class of catalysts that I have worked on previously - microporous materials & zeolites. I will discuss one reaction, the conversion of methanol-to-olefins, as an example of a classical use of such microporous materials. Then I will discuss the isomerization of glucose to fructose over Lewis acidic microporous materials as an example of the classes of reactions being worked on for using microporous materials in the growing biomass sector. 

 

Title:Play with Molecules at Surfaces
Speaker:Professor Wu Kai
Date: 29th March 2016
Time: 11.00am to 12.30pm 
Venue:SPMS MAS Executive Classroom 2
Host:Assistant Professor Zhao Yanli
Abstract: 

 

Controlling molecular assemblies at surfaces is one of the major challenges in surface chemistry. Surface molecular assemblies are primarily balanced by various weak interactions. Therefore, a slight change in the building block structure or an input of small external energy would drastically change the balance and the assembling structures. In this presentation, I’ll first focus on the utilization of hydrogen and halogen bonds as well as metal-ligand coordination to control two-dimensional molecular porous networks and to construct defect-free molecular fractal assemblies at surfaces. Afterwards I’ll show with examples that the surface molecular assembly strategy can be effectively exploited to tweak the reactions and properties of molecules at surfaces.

 

 

Title:Development of New Coupling Reaction Using Alkenyl Esters and Its Mechanistic Studies
Speaker:Professor Fumitoshi Kakiuchi
Date: 8th March 2016
Time: 11.00am to 12.30pm 
Venue:SPMS CBC Conference room
Host:Assistant Professor Naohiko Yoshikai
Abstract: 

Transition metal-catalyzed functionalization of carbon-hydrogen bonds is one of the most attractive research subjects in organic synthesis. Various catalytic C–H functionalization methods have been developed. To date, a variety of C–C bond formation such as alkylation, alkenylation, alkynylation, arylation, acylation can be achieved using C–H bonds. Among these reactions, catalytic alkenylations of C–H bonds in aromatic compounds have widely been studied because these reactions can become powerful tools for synthesis of styrene derivatives which can be found in many molecules of biological, pharmaceutical, and industrial interest. In this seminar, I will present developments of a new strategy of C–H alkenylation with alkenyl esters, ethers, and carbonates using ruthenium catalysts. I will also discuss mechanistic studies of C–H alkenylation using alkenyl acetates.

 

Title:Remote spectroscopy below the diffraction limit
Speaker:Professor Hiroshi Uji-i
Date: 8th March 2016
Time: 11.00am to 12.30pm 
Venue:SPMS MAS Executive Classroom 2
Host:Associate Professor Edwin Yeow 
Abstract: 

 

Metal nanowires can be used as wave-guides for propagating surface plasmon polaritons (SPPs), allowing the spatial confinement and transfer light energy over micrometer distance through the structures below sub-diffraction limited diameter. SPPs confined at the surface of single crystalline metal nanowires, such as wet-chemically synthesized silver nanowires, can propagate over tens of microns before energy is lost by Ohmic damping. Alternatively, the use of surface plasmoncs allows us to concentrate light energy in nanometer regions, such as a nanogap between metal nanoparticles, leading to a massive enhancement of electromagnetic filed that can be used for surface enhanced Raman scattering (SERS) or fluorescence (SEF) spectroscopy/microscopy.

In this contribution, we introduce a noble nanoscopic techniques using a combination of these two concept, that of SERS/SEF detection of (bio)molecules and that of sub-diffraction limit SPPs wave-guiding. Specifically, we demonstrate that SPPs launched along a silver nanowire (50 ~ 100 nm diameter) can remotely excite SERS [1,2] and SEF [3] in the vicinity of the nanowire surface due to the SPPs wave-guiding effect. The ability to transfer SERS/SEF excitation over several microns, through sub-diffraction limited structures, will be discussed with respect to potential application toward super-resolution endoscopy [1] and tip-enhanced Raman microscopy [4].

References: [1] G. Lu, H. De Keersmaecker, L. Su, B. Kenens, S. Rocha, E. Fron, C. Chen, P. Van Dorpe, H. Mizuno, J. Hofkens, J. A. Hutchison, H. Uji-i. Advanced Materials, 2014. 26, 5124-5128. [2] J. A. Hutchison, S. P. Centeno, H. Odaka, H. Fukumura, J. Hofkens, H. Uji-i, Nano Lett., 2009, 9, 995 - 1001. [3] L. Su, G. Lu, B. Kenens, S. Rocha, E. Fron, H. Yuan, C. Chen, P. Van Dorpe, M. B. J. Roeffaers, H. Mizuno, J. Hofkens, J. A. Hutchison, H. Uji-i, Nature Commun. 2015, DOI: 10.1038/ncomms7287. [4] Y. Fujita, R. Chiba, G. Lu, N. Horimoto, S. Kajimoto, H. Fukumura, H. Uji-i, Chem. Commun. 2014. 50, 9839-9841.

 

 

Title:Stereoselective C-H functionalization by Dynamic Kinetic Asymmetric Transformation for the control of axial chirality in natural products
Speaker:Professor Francoise Colobert
Date: 4th March 2016
Time: 2.30pm to 4.00pm
Venue:SPMS MAS Executive Classroom 2
Host:Associate Professor Shunsuke Chiba 

 

Title:The Use of Continuous Flow Technology for Organic Synthesis
Speaker:Professor C. Oliver Kappe
Date: 18th February 2016
Time: 2.00pm to 3.30pm 
Venue:SPMS MAS Executive Classroom 1
Host:Associate Professor Roderick Bates 
Abstract: 

 

Continuous flow processes form the basis of the petrochemical and bulk chemicals industry where strong competition, stringent environmental and safety regulations, and low profit margins drive the need for highly performing, cost effective, safe and atom efficient chemical operations. In contrast to the commodity chemical industry, however, the fine chemical industry primarily relies on its existing infrastructure of multipurpose batch or semi-batch reactors. Fine chemicals, such as drug substances and active pharmaceutical ingredients (APIs), are generally considerably more complex than commodity chemicals and usually require numerous, widely diverse reaction steps for their synthesis. These requirements generally make versatile and reconfigurable multipurpose batch reactors the technology of choice for their preparation.

However, the advantages of continuous flow processing are increasingly being appreciated also by the pharmaceutical industry and, thus, a growing number of scientists, from research chemists in academia to process chemists and chemical engineers in pharmaceutical companies, are now starting to employ continuous flow technologies on a more routine basis.

In this lecture, contributions from our research group in the field of continuous flow processing will be highlighted. Emphasis will be given to highly atom efficient and process intensified chemical transformations useful for the synthesis of APIs or key intermediates that are often too hazardous to be executed in a batch reactor. These involve azide, diazomethane and nitration chemistry, selective precious metal-free olefin and nitrogroup reductions, and flow photochemistry applications.

 

 

Title:Application Oriented Organic Synthesis: Our Group Efforts in Total Synthesis and Medicinal Chemistry
Speaker:Professor D. Srinivasa Reddy
Date: 17th February 2016
Time: 11.00am to 12.30pm 
Venue:SPMS CBC Building Level 2, Conference Room
Host:Associate Professor Roderick Bates
Abstract: 

Our research group at NCL, Pune focuses mainly on total synthesis of biologically active compounds and medicinal chemistry with an ultimate aim of discovering drugs. We have accomplished the synthesis of almost 20 natural products which include cell-adhesion inhibitors, antibacterial, anti-inflammatory, anti-cancer agents, sex pheromones and insect repellents. In the medicinal chemistry front, several programs have been initiated with collaborations from academia and industry. In particular, significant progress has been made using a new concept called “Silicon-switch approach”. This is a relatively new concept in drug discovery and very few companies and academic groups are working on this. We have identified several molecules in three different series which can be taken forward towards further development. Our findings in pre-clinical species with the silinezolid series suggest that silicon incorporation is highly useful in improving brain exposures. I will discuss about the highlights our efforts towards societal importance.

References: 1. Kishor L. Handore and D. Srinivasa Reddy, Total Synthesis of (±)-Nardoaristolone B and Its Analogues, Org. Lett., 2014, 16, 4252. 2. Rahul D. Shingare, R. Velayudham, Jalindar R. Gawade and D. Srinivasa Reddy, First total synthesis of Hunanamycin A, Org. Lett. 2013, 15, 4556. 3. Enantiospecific Synthesis of Both Enantiomers of the Longtailed Mealybug Pheromone and their Evaluation in a New Zealand Vineyard, Remya Ramesh, Vaughn Bell, Andrew M. Twidle, Rajesh Gonnade and D. Srinivasa Reddy, J. Org. Chem., 2015, 80, 7785. 4. D. Srinivasa Reddy, B. Seetharamsingh and Remya Ramesh, Patent WO 2013/054275; US20140296133; EP2766373.

 

Title:Disordered matter: a tribute to Jacques Friedel and Pierre Gilles de Gennes
Speaker:Professor Etienne Guyon
Date: 4th February 2016
Time: 11.00am to 12.30pm 
Venue:SPMS CBC Building Level 2, Conference Room
Host:Professor Francois Mathey

 

Title:Heterocyclic Metal Carbenes in Unusual Environments
Speaker:Professor Jun Okuda
Date: 26th January 2016
Time: 2.30pm to 4.00pm 
Venue:SPMS CBC Building Level 2, Conference Room
Host:Associate Professor Shunsuke Chiba
Abstract:

 

More than fifty years ago, Nobel laureate E. O. Fischer in Munich reported the first stable metal carbene complex. More recently, Nheterocyclic carbenes have been established as a versatile ligand family in numerous synthetic and catalytic applications. Three new systems will be discussed which illustrate the utility of heteroatom substituted carbenes: 1. Using N-heterocyclic carbenes, highly reactive zinc hydride ZnH2 can be stabilized and the chemistry of the resulting zinc hydride complexes studied. 2. Artificial metalloenzymes that show olefin metathesis activity have been developed by attaching via a linker group in the N-heterocyclic carbene ligand of a Grubbs-Hoveyda type catalyst to a cysteine in an engineered protein. 3. Dihydroxy carbene C(OH)2 is an unstable species but its deprotonated form has been stabilized by special titanium tris(anilide) fragments and the reactivity of the formal CO2 dianion investigated.

 

 

Title:π-Conjugated Pyrrolic Macrocycles: Rare Classes of Non-Aromatic and Anti-Aromatic
Speaker:Professor Chang Hee Lee
Date: 20th January 2016
Time: 10.30am to 12.00pm   
Venue:SPMS CBC Building Level 2, Conference Room
Host:Associate Professor Atsushi Goto
Abstract:

The ‘proton-coupled electron transfer (PCET) processes’ which are among the most important phenomena that serve to control a variety of che mical and biological transformations. While extensively studied in a variety of natural systems and a number of discrete metal complexes, PCET mechanisms are less well codified in the case of purely organic compounds. We found that a planar, a 24 π-electron antiaromatic naphthorosarin displays unique redox reactivity upon protonation. Specifically, treatment with acid (i.e., HI) yields a 26 π-electron aromatic trip rotonated mono cationic species; it is produced spontaneously via an intermediate, but stable, 25 π-electron nonaromatic triprotonated mono radical dication.

The second topic is the development of molecular receptors possessing high affinity and selectivity for various anionic guests utilizing various m olecular scaffolds. The calix[4]pyrroles have been shown to bind anions in organic polar media and the encapsulation of the binding domain of t he calix[4]pyrrole greatly enhances the binding affinity. We have designed and synthesized various calix[4]pyrrole-based ion/molecular recepto rs. The guest binding studies indicated that the synthesized systems have shown many interesting properties. Also, picket calix[4]pyrroles have been synthesized and studied for selective recognition of anions through fluorescent dye displacement assay (FDDA).

References 1. Recent Advencements in Calix[4]pyrrole-Based Anion Receptor Chemistry, Indrajit Saha, Jeong Tae Lee, Chang-Hee Lee, Eur. J. Org. Chem. 2015, 3859-3885 (Review). 2. Protonation-coupled Redox Reaction in Planar Antiaromatic meso-Pentafluorophenyl-substituted Phenylene Bridged Annu lated Rosarins. M. Ishida, S.-J. Kim, C. Preihs, K. Ohkubo, J. M. Lim, B. S. Lee, V. M. Lynch, V. V. Roznyatovskiy, P. K. Panda, C .-H. Lee, S. Fukuzumi, D. Kim, J. L. Sessler, Nature Chemistry, 2013, 5, 15-20. 3. 5-Substituted dipyrranes: synthesis and reactivity, D. T. Gryko, D. Grykoa and Chang-Hee Lee, Chem. Soc. Rev., 2012, 41, 37 80-3789. 4. p-Extended isomeric and expanded porphyrins, V. V. Roznyatovskiy, Chang-Hee Lee, J. L. Sessler, Chem. Soc. Rev., 2013, 42, 1921-1933. 5. A dicationic calix[4]pyrrole derivative and its use for the selective recognition and displacement-based sensing of pyrophos phate, Punidha Sokkalingam, D. S. Kim, H. Hwang, J. L. Sessler and Chang-Hee Lee, Chem. Sci., 2012, 3, 1819-1824. 6. Controlling Cesium Cation Recognition via Cation Metathesis within an Ion Pair Receptor, S. K. Kim, G. I. Vargas-Zúñiga, B. P . Hay, N. J. Young, L. H. Delmau, C. Masselin, Chang-Hee Lee, J. S. Kim, V. M. Lynch, B. A. Moyer and J. L. Sessler, J. Am. Che m.Soc. 2012, 134, 1782-1792.

 

Title:Effect of phytochemicals on free radicals formation and BDNF in humans
Speaker:Professor Boris Nemzer
Date: 19th January 2016
Time: 2.00pm to 3.30pm  
Venue:SPMS CBC Building Level 2, Conference Room
Host:Associate Professor Li Tianhu
Abstract: 

 

Epidemiological studies of last decade describing the different protective mechanisms of herbal ingredients which able to inhibit oxidative stress and improve nitric oxide production, are responsible for protective effects of cardiovascular system. Aim of this study was to compare different types of herbal formulations characterized with antioxidant activity on their effects to inhibit generation of reactive oxygen species (ROS) and on in vivo circulating NO concentrations.

22 healthy in the age of 40±10 years old volunteers consumed single dose of different herbal formulations with different content of biologically active ingredients such EGCG, quercetin, anthocyanins, proanthocyanins and vitamin C. Antioxidative capacities of herbal formulations were characterizes by ORAC-5 assay. Formation of ROS was performed in capillary blood of volunteers before and 1, 2, 3h after of single dose herbal formulations administration. Electron spin resonance spectrometer E-SCAN analysis of bioavailable NO concentration and TNF-alpha dependent inflammatory response assay have been used.

In this study we found the different capacity of formulated herbal blends to inhibit in vivo generation of ROS, to elevate circulating NO concentration and to inhibit inflammatory response of human blood cells due to the different mechanism of action of their bioactive ingredients.

The possible interaction between brain-derived neurotrophic factor (BDNF) and oxidative stress markers (OSM) has not been investigated enough. This study aimed to provide phytochemical composition, antiradical activity and perform to assess the effect of whole coffee fruits extract (WCFE) on blood levels of BDNF in healthy humans. A single dose of WCFE significantly decreased a cellular and mitochondrial ROS formation, inhibited generation of extracellular NADPH oxidasedependent superoxide (O2-) and peroxidase-dependent hydrogen peroxide (H2O2). WCFE increased BDNF plasma level in patients by an average of 137% with respect to baseline (range 65-222%; P=0.001 v. placebo). WCFE could be used to inhibit ROS formation and other oxidative stress markers and for modulation of BDNF-depend health conditions to support an optimal health in humans.

 

 

Title:The Frame-Guided Assembly
Speaker:Professor Liu Dongsheng
Date: 8th January 2016
Time: 11.00am to 12.30pm 
Venue:SPMS CBC Building Level 2, Conference Room
Host:Assistant Professor Shao Fangwei
Abstract: 

How to precisely control the shape and size of final assemblies, especially using same amphiphilic molecules and under the same environmental conditions, is always a challenge in molecular assembly. Inspired by the cytoskeletal/membrane protein/lipid bilayer system that determines the shape of eukaryotic cells, we proposed and ‘the Frame Guided Assembly’ (FGA) strategy to prepare heterovesicles with programmed geometry and dimensions. This method offers greater control over self-assembly: with same molecular system, the size of final assemblies could be tuned at 1 nm level and their shape could vary from spherical to cubic, and even given sized two dimensional sheets. Most importantly, the principle of the FGA could be applied to various materials such as bock copolymers, small molecules including surfactants and lipids, which is a general rule in self-assembly. Scheme 1. Schematic illustration of the Frame Guided Assembly.

References [1] Zhao, Z., Chen, C., Dong, Y., Yang, Z., Fan, Q., * Liu, D., *: Angew. Chem. Int. Ed. 2014, 53, 13468-13470. [2] Zhou, C., Wang, D., Dong, Y., Xin, L., Sun, Y., Yang Z., Liu, D.,*: Small 2015, 11(9-10), 1161-1164. [3] Dong, Y., Sun, Y., Wang, L., Wang, D. , Zhou, T., Yang, Z., Chen, Z., Wang, Q., Fan, Q., Liu, D.,*: Angew. Chem. Int. Ed. 2014, 53(10), 2607-2610.