Synthesis, characterization, in silico and in vitro studies of novel glycoconjugates as potential antibacterial, antifungal, and antileishmanial agents

In the present work, several new glycoconjugates (8a-e) were generated from glycopyranosyl-alpha-trichloroacetimidates (sugar-OTCA) as glycosyl donors and dimethyl-l-tartrate as an aglycone acceptor in good to excellent yields. In the synthetic protocol, various monosaccharides were transformed into pentaacetylated derivatives and then into glycopyranosyl-alpha-trichloroacetimidates. Afterward, the sugar-OTCA was reacted with dimethyl-l-tartrate using Schmidt's trichloroacetimidate protocol to give the desired products. The newly synthesized glycoconjugates were characterized by FT-IR, H-1, and C-13-NMR spectroscopic analytical methods. All the target compounds (8a-e) were tested in vitro against various strains of bacteria and fungi at different concentrations. The results revealed that the target compounds had encouraging antibacterial and antifungal potential. The antileishmanial activity of the target compounds against Leishmania tropica promastigotes was also investigated. The in vitro results were further supported by the in silico docking study that indicated minimum values of the docking scores and binding energies for the resulting complexes obtained by the favorable interactions between the target compounds (8a-e) and the selected strains of bacteria and fungi. The docking results proposed promising antibacterial and antifungal activities of the target compounds (8a-e) against the selected bacterial and fungal species.