Antimicrobial activities of N-arylsulfonylthioureas (23 compounds) and the corresponding isothioureas (28 compounds) were examined against bacteria and fungi parasitic to animals and influenza A2/Adachi virus in vitro. Remarkable activities were not observed in these compounds, but some thioureas showed MIC of 12.5μg/ml against Trichophyton asteroides and Trichophyton interdigitals, and some isothioureas MIC of 25μg/ml against Mycoplasma gallisepticum. N-Phenyl-N'-(p-tolylsulfonyl) thiourea and S-butyl-N-methyl-N'-(p-tolylsulfonyl) isothiourea showed the inhibitory activity against the virus but not the virucidal activity. Fifty % inhibitory concentrations (Index) of these two compounds were 74 (13.5) and 40 (17.7) μg/ml, respectively.
