[Physicochemical and biological characteristics of mycoheptin components A1 and A2].

Mycoheptin, an original antifungal polyenic antibiotic is a complex of several heptaen components. 2 heptaen components designated as mycoheptins A1 and A2 were isolated from the mycoheptin complex with the counter-current distribution technique in a system of methanol-chloroform-forate buffer, pH 8.3 (2:2:1). It was found that component A2 was the main one. Its content in the preparation is at least 80 per cent. The components were studied comparatively with respect to the elemental composition, UV and IR spectra, distribution coefficients in different solvent systems, specific rotation, biological activity and acute toxicity. Both components are original in the subgroup of "nonaromatic" heptaens. Mycoheptin A1 has a lower biological activity and toxicity but its chemotherapeutic efficiency is higher.