Regioselective synthesis, characterization and antimicrobial evaluation of S-glycosides and S,N-diglycosides of 1,2-Dihydro-5-(1H-indol-2-yl)-1,2,4-triazole-3-thione.

Abstract Glycosylation of 1,2-Dihydro-5-(1 H -indol-2-yl)-1,2,4-triazole-3-thione with 2,3,4,6-tetra- O -acetyl-α- d -glucopyranosyl bromide, 2,3,4,6-tetra- O -acetyl-α- d -galactopyranosyl bromide and 2-acetamido-3,4,6-tri- O -acetyl-2-deoxy-α- d -glucopyranosyl chloride was investigated in the presence of Et 3 N and K 2 CO 3 as acid scavengers. A regioselective S-glycosides were obtained by using Et 3 N whereas, using K 2 CO 3 gave a mixtures of two hybrids having two glycosidic bonds. The two products of each mixture were separated and characterized as S , N 1 - and S , N 2 -bis(glycosylated) derivatives. The structures of the newly synthesized compounds were elucidated by 1 H NMR, 13 C NMR, 2D NMR and mass spectra. The compounds were screened for their antibacterial and antifungal activities. Some compounds exhibited strong inhibition activity compared with the reference drugs (chloramphenicol and baneocin).