Novel Oxadiazole Thioglycosides as Potential Anti- Agents.

The glycosylation of 1,3,4-oxadiazole-2-thiones has been performed with peracetylated β-pyranosyl bromide in the presence of potassium carbonate. Deprotection of acetylated thioglycosides was necessary for increasing their antibacterial effects. The structures of nucleosides were confirmed by H NMR, C NMR and HRMS. The anomeric protons of nucleosides c were assigned to the doublet, confirming the β-configuration. The synthesized compounds were tested for their antimicrobial activity against (Gram-negetive) strain in comparison with Ampicillin as a reference drug which is normally used for treating such infections. The synthetic compounds showed different inhibition zones against tested bacterial strain. Thioglycoside derivatives of 1,3,4-oxadiazole-2-thiones (c set) were more active against ATCC 23055 than "parent" 1,3,4-oxadiazole-2-thiones (a set), confirming the relation between glyco-conjugation and increasing of antiproliferative activity of antibiotic agents. The best result belonged to nucleoside bearing 2-furyl moiety in its heterocyclic nucleus (c). The existence of -PhNO group as Ar in structures of a set and their corresponding sugar derivatives decreased the antibacterial activity of them in comparison with the rest of synthetic compounds.