摘要

Thin-layer chromatography with microbiological detection (direct bioautography) of amphotericin B has never been reported. The combination of these methods can be used advantageously, especially when not only chemical identification of samples is required, but also when antifungal activity is of interest. In this paper a fast and easy-to-perform method is introduced in which major (R(F) 0.46) and minor (R(F) 0.31) components can be separated from amphotericin B, which itself is not a homogenous substance but mixture of polyenes. Thin-layer chromatography is performed on silica gel layers with chloroform methanol borate buffer 4:5:1 (v/v) as optimized mobile phase, and the microbiological activity of amphotericin B can be measured sensitively by direct bioautography. Candida albicans (ATCC 90028) and Saccharomyces cerevisiae (ATCC 9763) fungus strains were tested. Among the detection methods investigated, direct bioautography with Candida albicans proved to be the most sensitive, with a detection limit of 0.8 ng per spot. For densitometric evaluation of plates with (385 nm) ten times more substance is required, and with a UV lamp (366 nm) as much as 50 ng AmB per spot is needed to visualize the main component.