3H-[1,2]Dithiolo[3,4-b]pyridine-3-thione and its derivatives - Synthesis and antimicrobial activity

A series of 2-substituted isothiazolo[5,4-b]pyridine-3(2H)-thiones isothiaz olo[5,4-b]pyridin-3(2H)-ones, N-substituted 2-sulfanylnicotinamides and the corresponding carbothioamide derivatives were synthesized and evaluated fo r their antimicrobial activity against several strains of Gram + and Gram - bacteria and fungi. Chemical syntheses were resumed into a comprehensive c yclic route that enables the reversible conversion for each derivative of t he series considered. Among the tested compounds the N-(aralkyl)-2-sulfanyl nicotinamides show the highest fungitoxicity (MIC = 1.25-5 mug/ml). The bes t activity towards Gram-positive bacteria was in the range of 2.5-5 mug/ml. Activity against Gram-negative bacteria was generally very poor for all co mpounds. (C) 2000 Elsevier Science S.A. All rights reserved.