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-meth
yl-4-diazo-5-methanesulphonamid and 1,3-dimethyl-4-diazo-5-methanesulp
honamid) and the triazole (4-methyl-6-t-butylpyrazolo[3,4-d][1,2,3]tri
azole) were inactive at the highest dose tested (100 mu g/ml). The 4-m
ethyl-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 n
yl-5-methyl-7-(3,4-dichlorophenyl)pyrazolo[3,4-c] [1,2,5]thiadiazine-2
,2-dioxide and henyl-4H-pyrazolo[1,5-c][1,3,5]thiadiazine-4-one), and
an aminoisoxazole (3-methyl-5-aminoisoxazole-4-thiocyanate which induc
ed a remarkable and sometimes complete reduction in the growth rate of
the fungus. The structure-activity relationships are discussed.