With the aim of identifying more novel natural epothilone derivatives produced by the epothilones A and B producing strain Sorangium cellulosum strain So0157-2, a large-scale fermentation (5000 l) of the strain was carried out. As a result, five new epothilone variants (1-5) were isolated from the fermentation broth. Their structures were established as 3-alpha-D-arabinofuranosides of epothilones A (1), B (2), D (3), C(9) (4) and 8-demethyl epothilone A (5) by extensive NMR analysis and chemical methods. Bioassay results showed that compounds 1 and 2 had a weaker cytotoxic activity than did epothilone B.