Antifungal screening of seven new azole derivatives

Two strains of the dermatophyte Epidermophyton floccosum were treated with seven new synthetic azole derivatives to determine their possible antifungal activity. Among these, two diazopyrazoles (1-phenyl-3-methyl-4-diazo-5-methanesulphonamid and 1,3-dimethyl-4-diazo-5-methanesulphonamid) and the triazole (4-methyl-6-t-butylpyrazolo[3,4-d] [1,2,3]triazole) were inactive at the highest dose tested (100 micrograms/ml). The 4-methyl-6-phenyl-pyrazolo[3,4-d] [1,2,3]triazole produced only a partial inhibition of growth, whereas the most active compounds were the two thiadiazines (6H-3-phenyl-5-methyl-7-(3,4-dichlorophenyl)pyrazolo[3,4-c] [1,2,5]thiadiazine-2,2-dioxide and 7-methyl-2-phenyl-4H-pyrazolo[1,5-c] [1,3,5]thiadiazine-4-one), and an aminoisoxazole (3-methyl-5-aminoisoxazole-4-thiocyanate), which induced a remarkable and sometimes complete reduction in the growth rate of the fungus. The structure-activity relationships are discussed.