CHOLESTEROL CONVERSION TO Δ4-CHOLESTENONE BY CHOLESTEROL OXIDASE IN POLYPHASIC SYSTEMS : EXTENSION TO THE SELECTIVE OXIDATION OF 7Β-HYDROXYCHOLESTEROL

Article abstract of DOI:10.1016/S0040-4020(01)85893-2

The preparative use of cholesterol oxidase has been extended to polyphasic systems.The enzyme is active in microemulsions with the organic phase composed of mixtures of cyclohexane and chloroform.The kinetic data for oxidation of 7α- and 7β-hydroxycholesterol in microemulsion with the enzyme from Streptomyces are similar to those of cholesterol.The cholesterol oxidase is active in the two phase system aqueous buffer - butyl acetate and preparative enzymic conversion of 7β-hydroxycholesterol to Δ⁴-7β-hydroxycholestenone was performed in this medium.The enzymic conversion of cholesterol to Δ⁴-cholestenone was also performed in two liquis-solid systems, in buffer with cholesterol adsorbed on silica gel and in organic medium with cholesterol oxidase and catalase entrapped in Chromosorb.