Conversion of acid S, produced by the organism {i Polyangium cellulosum {b var. {i fulvum {b into acid F

摘要

A process for the conversion of the major antifungal antibiotic, acid S (ATCC NO. 25532) isolated from the fermentation of Polyangium cellulosum var. fulvum into the minor antibiotic, acid F, from the same fermentation is described wherein acid S is methylated with diazomethane to provide acid S methyl ester which is then oxidized with silver carbonate on celite to obtain the corresponding keto ester S, which is subsequently reduced with sodium borohydride to give a mixture of acid S methyl ester and acid F methyl ester. These esters are readily separated by preparative thin layer chromatography and the acid F methyl ester is hydrolyzed with sodium hydroxide solution to provide acid F.