Synthesis and Comparative Antibacterial Studies of some Benzylidene Monosaccharide Benzoates

Abstract

Methyl a-D-glucopyranosıde on reactıon wıth benzaldehyde followed by dırect dlmolar‘ benzoylation afforded 4,6-O-benzylidene-protected 2,3-di-O-benzoate in good yield. Regioselective monobenzoylation of methyl a-D-mannopyranoside employing dibutyltin oxide method furnished 3-O-benzoate 5. Compound 5, on treatment with excess benzaldehyde followedl by direct benzoylation, provided 2,3-di—O-benzoate in high yield. In vitro antibacterial activity studies of the synthesized compounds along with the precursor materials (1-7) were evaluated against ten bacterial pathogens. The structure activity relationship study revealed that the benzoyl mannopyranosides (5-7) exhibited more antibacterial inhibitory property as compared to that of glucopyranosides (2-3).