Antifungal, antibacterial, antiviral and cytotoxic activity of novel thio- and seleno-azoles.

A series of pentaatomic heterocyclic compounds containing sulphur or selenium in position 2, were tested for cytotoxicity, antiviral and antimicrobial activities. Generally, selenium-containing compounds were more toxic than the corresponding sulphur-containing ones (30-75 times more toxic) and, furthermore, the biological activity against some microorganisms was also enhanced. In particular, some selenium-containing derivatives exerted an inhibitory activity on plant pathogenic fungi at doses markedly lower than the toxic ones, showing an interesting selectivity of action. In this case the tested compounds appeared more active than ketoconazole, the control used, with an almost comparable degree of cytotoxicity.