The in vitro antifungal activity of several N2-phenyl-3(2H)-isothiazolones substituted at C4 of the phenyl moiety with heterocyclic nucleus or groups of different physico-chemical properties against four human pathogenic fungi was determined by broth macrodilution method; results were compared with those obtained with itraconazole and ketoconazole. These isothiazolones showed moderate to high activity against some or all tested strains and in comparison with the reference drugs, 5-chloro-2-(4-nitrophenyl)isothiazol-3-one (1g), 5-chloro-2-phenylisothiazol-3-one (1c), 4-[4-(5-chloro-3-oxo-3H-isothiazol-2-yl)phenyl]-1,4-dihydrotriazol-5-one (1s) and 2-(4-nitrophenyl)isothiazol-3-one (2g) against Aspergillus niger, 5-chloro-2-(4-nitrophenyl)isothiazol-3-one (1g) and 4-[4-(5-chloro-3-oxo-3H-isothiazol-2-yl)phenyl]piperazine-1-carboxamide (1q) against Trichophyton mentagrophytes had comparable activity, compounds 1g and 2g showing higher activity against Microsporum canis. Antifungal activity was favored by the presence of chlorine at C5 of the isothiazolone and/or the presence of nitro group or heterocyclic nucleus at C4 of the phenyl ring and proper hydrophilicity of the molecule.

• MeSH
• Antifungal Agents chemistry   pharmacology   MeSH
• Ascomycota drug effects   MeSH
• Itraconazole pharmacology   MeSH
• Ketoconazole pharmacology   MeSH
• Microbial Sensitivity Tests MeSH
• Thiazoles chemistry   pharmacology   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• 3-isothiazolone MeSH Browser
• Antifungal Agents MeSH
• Itraconazole MeSH
• Ketoconazole MeSH
• Thiazoles MeSH