Mannan changes induced by 3-methyl-5-aminoisoxazole-4-thiocyanate, a new azole derivative, on Epidermophyton floccosum

• Published in: Fungal genetics and biology Vol. 36; no. 1; pp. 47 - 57
• Main Authors: Mares, D., Romagnoli, C., Tosi, B., Benvegnù, R., Bruni, A., Vicentini, C.B.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2002
• Subjects: Antifungal Agents - pharmacology; Azole derivatives; Cell Wall - drug effects; Cell Wall - metabolism; Cell Wall - ultrastructure; ConA–FITC; Electron microscopy; Epidermophyton - drug effects; Epidermophyton - growth & development; Epidermophyton - metabolism; Epidermophyton - ultrastructure; Epidermophyton floccosum; Fluorescence; Isoxazoles - pharmacology; Mannans - metabolism; Microscopy, Electron; Microscopy, Electron, Scanning; Thiocyanates - pharmacology; Uvitex; Wall mannans; Uvitex; Azole derivatives; ConA–FITC; Epidermophyton floccosum; Fluorescence; Wall mannans; Electron microscopy
• ISSN: 1087-1845; 1096-0937
• DOI: 10.1016/S1087-1845(02)00003-8

The antifungal activity of 3-methyl-5-aminoisoxazole-4-thiocyanate, a new azole derivative, was studied on the dermatophyte Epidermophyton floccosum. The compound strongly inhibited the in vitro growth of two different strains of the fungus and even induced profound morphogenetic anomalies. Optical and electron microscopy showed that such treatment targets the endomembrane system, particularly the plasmalemma, causing abnormal extrusion of the wall mannans. This results in improper arrangement of the different parietal materials; the walls are thus weak and subject to subapical rupture which terminates cell growth and elongation of the hypha. The morphological results and the preliminary biochemical data on fungal sterols suggest that this compound employs an action mechanism similar to that of other azoles used in therapy.