title: Microsomal 12alpha-hydroxylation of 7alpha-[12alpha, 12beta-2H2]hydroxy-4-cholesten-3-one.
abstract: The synthesis of 7alpha-[12alpha, 12beta-2 H2]hydroxy-4-cholesten-3-one is described. It was shown with different techniques that this compound was 12alpha-hydroxylated by the microsomal fraction of a rat liver homogenate without marked isotope effect, indicating that cleavage of the C--H bond is not the rate-limiting step in this hydroxylation. The rate of 12alpha-hydroxylation was decreased by about 20% when performed in a medium containing deuterated water. The findings were discussed with reference to the specific properties of the 12alpha-hydroxylating system and to the results of previous studies on rate-limiting step in microsomal hydroxylation of steroids.
mesh_terms: D000818:Animals; D002782:Cholestenes; D002783:Cholestenones / Q000138:chemical synthesis / Q000378:metabolism; D003903:Deuterium; D006900:Hydroxylation; D006914:Hydroxysteroids / Q000138:chemical synthesis / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D051381:Rats
chemical_list: D002782:Cholestenes; D002783:Cholestenones; D006914:Hydroxysteroids; D003903:Deuterium