Antifungal effects of aminosulphoxide and disulphide derivatives.

2-Benzenesulphinyl-(1,4)-naphtoquinone and 14 derivatives were synthesised and were used to evaluate their cytotoxicity against a human myelomonocyte cell line and their antifungal activity against two yeast, i.e. Candida albicans and C. tropicalis and against two filamentous fungi such as Aspergillus niger and Fusarium oxysporum and against one dermatophyte, namely Trichophyton tonsurans. The cytotoxicity and antifungal activities were investigated in comparison with amphotericin B as reference drug. No compound was significantly more toxic than amphotericin B at 0.2 microg ml(-1). The best results of antifungal activity were obtained with GFL 10, GFL 13 and GFL 30 on C. tropicalis, F. oxysporum and T. tonsurans. For C. albicans and A. niger, there was no difference between amphotericin B and the other molecules. The sterol quantitation, the time-kill curves were carried out for these three compounds in order to confirm their action in ergosterol synthesis. Time-kill curves showed a fungistatic activity. For C. tropicalis GFL 10, GFL 13 and GFL 30 increased the growth delay better than amphotericin B, in contrast to F. oxysporum. As for T. tonsurans, GFL10 and GFL13 gave a delay, but the effect of GFL 30 was a bit less marked.