Synthesis and biological activity of new metronidazole derivatives

The development of new antimicrobial and antiparasitic agents offers the possibility of generating structures of increased potency. To this end, three sulphonate ester derivatives of metronidazole were synthesized. Treatment of the tosylate analogue with NaSPh and NaN 3 gave the thiophenolate and azide derivatives, respectively. Oxidation of phenylthio derivative with m CPBA afforded the sulfonyl analogue. Similarly, cycloaddition of azido-metronidazole with various symmetric acetylene compounds furnished the 1,2,3-triazole analogues. Treatment of dimethyl dicarboxylate metronidazole derivative with guanidine hydrochloride in the presence of base resulted in the formation of the ring-expanded (fat) derivative, triazolo-diazepam derivative of metronidazole. Treatment of chlorometronidazole with silylated quinolones gave the quinolone analogues of metronidazole. The antigardiasis and antifungal activities of the synthesized compounds were investigated. In addition, all synthesized compounds were evaluated for their in vitro anti-HIV activity in MT-4 cells as non-nucleoside reverse transcriptase inhibitors. Graphical abstract