Nimisha Ganesh

Learn More
The cell wall O-polysaccharides of pathogenic Brucella species are homopolymers of the rare sugar 4,6-dideoxy-4-formamido-α-D-mannopyranose. Despite the apparent simplicity of the polysaccharide it appears to be a "block copolymer" composed of A and M polysaccharide sequences expressed as a single molecule. The simultaneous presence of both in the cell wall(More)
Monoliths of nanoporous gold (np-Au) were modified with self-assembled monolayers of octadecanethiol (C18-SH), 8-mercaptooctyl α-D-mannopyranoside (αMan-C8-SH), and 8-mercapto-3,6-dioxaoctanol (HO-PEG2-SH), and the loading was assessed using thermogravimetric analysis (TGA). Modification with mixed SAMs containing αMan-C8-SH (at a 0.20 mole fraction in the(More)
Members of the genus Brucella have cell wall characteristics of Gram-negative bacteria, which in the most significant species includes O-polysaccharide (OPS). Serology is the most cost-effective means of detecting brucellosis, as infection with smooth strains of Brucella leads to the induction of high antibody titers against the OPS, an unbranched(More)
Nitrogen adsorption/desorption isotherms are used to investigate the Brunauer, Emmett, and Teller (BET) surface area and Barrett-Joyner-Halenda (BJH) pore size distribution of physically modified, thermally annealed, and octadecanethiol functionalized np-Au monoliths. We present the full adsorption-desorption isotherms for N(2) gas on np-Au, and observe(More)
Nanoporous gold (NPG), made by dealloying low carat gold alloys, is a relatively new nanomaterial finding application in catalysis, sensing, and as a support for biomolecules. NPG has attracted considerable interest due to its open bicontinuous structure, high surface-to-volume ratio, tunable porosity, chemical stability and biocompatibility. NPG also has(More)
A ring-expansion methodology for the preparation of aryl septanosides, arabinofuranosyl and glucopyranosyl septanoside disaccharides, and azido septanosides is reported. A cyclopropanated adduct of the oxyglycal upon reaction with phenols, sugars, and azide led to the formation of ring-expanded septanoside derivatives. The ring expansion was found to be(More)
A new route to synthesize septanoside derivatives from protected 2-hydroxyglycals is reported. Ring expansion of a pyranoside to a septanoside was achieved through key reactions of a cyclopropanation, ring opening, oxidation, and reduction. Methyl septanoside derivatives, namely, methyl alpha-D-glycero-D-talo-septanoside and methyl(More)
A standard HPLC was adapted to polymer supported oligosaccharide synthesis. Solution-based reagents are delivered using a software-controlled solvent delivery system. The reaction progress and completion can be monitored in real time using a standard UV detector. All steps of oligosaccharide assembly including loading, glycosylation, deprotection, and(More)
Oxyglycals, derived from lactose and maltose, were expanded to trisaccharides through a ring expansion method. Trisaccharides with 6-7-5 and 6-7-6 ring sizes were prepared through the ring expansion method, with high diastereoselectivities, in each step of their synthesis. The NOE and ROESY NMR spectroscopies were used to assess the dipolar couplings within(More)
The C epitope of Brucella O-polysaccharide (O-PS) has so far lacked definitive structural identity. Revised structures for this antigen revealed a unique capping perosamine tetrasaccharide consisting of a sequence of 1,2:1,3:1,2 interresidue linkages. Here, using synthetic oligosaccharide glycoconjugates, the α-1,3 linkage of the O-PS is shown to be an(More)