Sterols of fungi responsible for superficial skin and nail infection.

Two groups of fungi isolated from human skin and nail are the dermatophytes Epidermophyton, Microsporum and Trichophyton species and the non-dermatophytes Hendersonula toruloidea and Scytalidium hyalinum. Examination of the sterol composition of these fungi by gas chromatography-mass spectrometry (GC-MS) identified five new sterols from dermatophytes, namely cholesterol, campesterol, episterol, fecosterol and sitosterol. These sterols, with ergosterol and brassicasterol, were also identified from extracts of H. toruloidea and S. hyalinum. Sterol patterns produced by GC-MS with selected ion recording of ten ions were analysed by principal components analysis using the SIMCA statistical package. The dermatophyte genera and species were not differentiated using this method, the similarity in sterol content reflecting the close taxonomic relationship of this group. H. toruloidea and S. hyalinum had similar sterol contents to each other, reinforcing the opinion that these fungi are related, although H. toruloidea form 3 was distinguished from forms 1 and 2.