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SCIENCE TECHNOLOGY Professor of Chemistry Department of Chemistry Tel 868 662 2002 ext. 83538 E-mail gurdial.singhsta.uwi.edu PROF. GURDIAL SINGH 120 My research encompasses a number of areas of organic chemistry. These are generally targeted at obtaining solutions to a range of diseases that are prevalent in humans and to date have no general treatments. The approach my team are employing entails the attainment of a sound understanding of the mechanisms involved that are the cause of the disease states. I am also interested in developing new methods that solve significant problems in the energy sector and in Green chemistry. Synthesis of cell surface epitopes of TUBERCULOSIS MYCOBACTERIUM My research team members are engaged in developing new methodology for the synthesis of galacto- and arabinofuranoside 1 2 synthesis targeted at the synthesis of naturally occurring oligosaccharide found on the cell surface of the TB organisms.Our strategy involves synthesis of 1-O-unprotected sugars for use as glycosyl acceptors in the preparation of 15-linked oligofurano- sides having free anomeric centres. While this approach could potentially lead to the formation of several glycosylation products if successful it would dramatically simplify the synthesis of oligofuranosides and possibly have general application in glycosylation. The team has been partially successful in this strategy in that we have prepared arabinosaccharides in 35-40 per cent yields with total selectivity.As a result of these findings we have undertaken density functional theory calculations in order to understand the equilbria that occur and are involved in these reactions. At present we are actively investigating applying this approach for the synthesis of furanosides of the ribo- and xylo- sugars. Carbohydrate Ionic Liquids My research team members and I have recently patented 2008 Ionic Liquids USA Patent 12126 639 our research in the area of carbohydrate based ionic liquids. The synthesis of these new classes of ionic liquids is outlined in the scheme below. We are actively pursuing the utilisation of these stable ionic liquids for the enantiomeric synthesis of secondary and tertiary alcohols. Supported Enzymes for Oligosaccharide Synthesis In order to develop more efficient synthesis of complex oligosac- charides we have successfully immobilised transferase enzymes and are investigating their employment for the efficient synthesis of saccharides utilising both unprotected and partially protected sugars. We have observed that we obtain rate enhancement of glycosylation reactions using these supported enzymes along with good chemical yields. Our target is the synthesis of the important hexasaccharide Globo-H. This antigen occurs on prostate cancer cells and can serve as a target for immune recog- nition. Our strategy will substantially shorten the synthesis of this important saccharide. To date we have prepared the three disaccharides in 100 mg quantities required as part of the conver- gent synthesis for this target. Synthesis of Glycosylcyanohydrins as Insect Antifeedants A distinctive group of natural products found in higher plants e.g. yams and cassava that exhibit a definite relationship to their biosynthetic precursors are the cyanogenic glycosides.A character- istic feature of the cyanogenic glycosidese.g.zierin 1is their ability to release hydrocyanic acid by hydrolysis and this process is often initiated by enzymes when the tissues which contain them are damaged by mechanical or other means. The penultimate step in the biosynthetic pathway involves transglycosylation with UDPG. Development of Novel Treatments for Dengue Viruses The dengue virus is the most important human pathogen that is borne by arthropods. Over the last decade the incidence of epidemics as a result of contracting dengue fever is estimated at up to 100 million cases annually. Furthermore the most severe form of the disease dengue hemorrhagic fever DHF has emerged in the same period resulting in 500000 cases worldwide. Every year these infections result in death in ca. 33 per cent of the reported cases. To date the sole method available to prevent dengue infections is the control of Aedes aegypti the mosquito vector. This approach has proved to be expensive and mostly unworkable with serial infections occur- ring in most of the tropical regions of the world where multiple dengue viruses circulate. In order to investigate the efficacy of new vaccines we are involved in the synthesis of the saccharide GlcNAc-Fuca1-6-b1-4GlcNAc-Manb1-4Mana1-6a1-3Man using 13-propanediylphosphate coupling protocols. Peptides Oxidation of Methane The efficient transformation of methane to methanol is chemically a difficult reaction to perform due to the C-H bond strength being