ANTICANDIDA ACTIVITY OF 4 ANTIFUNGAL BENZOTHIAZOLES

Anti-Candida activity of 6-amino-2-n-pentylthiobenzothiazole (I), benz ylester of (6-amino-2-benzothiazolylthio)acetic acid (II) and of 3-but ylthio-(1,2,4-triazolo)-2,3-benzothiazole (III) was followed and compa red to that of 2-mercaptobenzothiazole (IV). I and II exhibited good a ctivity against the C. albicans yeast form, similar to IV. They were i nhibitorily active against other Candida strains, IC50 values being of the order of 10(-5) M, which means better activity than IV. Compound I also exhibited inhibitory activity on germ-tube formation and myceli al growth in the C. albicans strains, while II, III and IV were not ac tive in these tests. III was the least active form of the compounds te sted, IC50 values being of the order of 10(-4) M. All the compounds te sted were highly active on a nystatin-resistant C. albicans mutant, wi th IC50s of the order of 10(-6) M-10(-5) M.