Isolation of vitamin K2(35) from Nocardia restrictus and Corynebacterium simplex. A natural electron acceptor in microbial steroid ring A dehydrogenations.

Isooctane extraction of cells from Nocardia restrictus and Corynebacterium simplex followed by chromatographic separation gave yellow crystals which were identified as vitamin K2(35) by its ultraviolet absorption, nuclear magnetic resonance spectrum, and mass spectrometry. The purified vitamin K2(35) was found to stimulate steroid 1,2-dehydrogenase obtained from cell free extracts of N. restrictus, C. simplex, Cylindrocarpon radicicola, and Septomyxa affinis as well as 4,5alpha-dehydrogenase and 4,5beta-dehydrogenase obtained from N. restrictus. Evidence is presented to show that vitamin K2(35) can act as an efficient electron acceptor in steroid ring A dehydrogenations which may be coupled to other systems during microbial transformations of steroids.