GB823258A - Process for splitting steroid racemates - Google Patents

Abstract

Racemates of d,l-steroids containing at least one oxo group are split by subjecting the racemate to the action of an enzyme produced by the culture of a micro-organismnwhich reduces only the oxo group of the d-enantiomorph to a hydroxyl group, the l-form remaining unchanged, after which the reduced d-form and/or the l-form is isolated. The process may be effected using several different micro-organisms in the one operation; specified organisms are fungi of the genera Saccharomyces, e.g. S. cerevisae, and Streptomyces, e.g. S. coelicolor and S. lavendulae, and certain bacteria, e.g. Bacterium putrificus. The d,l-steroids may be saturated or unsaturated and of the cholestane, coprostane, cholane, spirostane, furostane, butanolide, cardanolide, testane and particularly the pregnane, androstane and estrane series, containing any of the usual substituents (halogen, hydroxyl, oxo, carboxyl and functional derivatives thereof) in the molecule. Many starting materials are specified, and detailed examples illustrate the splitting of dl-17a -hydroxycortexone into d-D 4-3-keto-17a ,20b ,21-trihydroxy pregnene and l-hydroxycortexone, and of dl-oestrone into d-oestradiol and l-oestrone.