IN-VITRO SUSCEPTIBILITY OF FUNGI TO ACYCLIC INHIBITORS OF 2,3-OXIDOSQUALENE CYCLASES

In the present study we determine the antifungal properties of two acy clic inhibitors of 2,3-oxidosqualene cyclases: 22,23-epoxy-2-aza-2,3-d ihydrosqualene (EAS) and azasqualene alcohol (ASA). Fungistatic and fu ngicidal activity towards dermatophytes and other fungi involved in cu taneous and systemic infections was tested (48 isolates from 10 specie s). The tests were carried out by inoculating 10 mu l of mycelial homo genate in 1 ml of Sabouraud glucose liquid medium containing serial di lutions of 100 to 0.25 mu g ml(-1) of the substance. For each isolate, the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of both compounds were determined. EAS was more a ctive (MIC range 1.5-25 mu g ml(-1)) than ASA (MIC range 3-50 mu g ml( -1)). At the highest concentration tested, EAS also showed fungicidal action towards some isolates of Trichophyton mentagrophytes, T. terres tre, Epidermophyton floccosum, Microsporum canis and Scopulariopsis br umptii. The most sensitive species was T. mentagrophytes, the most res istant T. rubrum.