• Archives of Pharmacal Research
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• 제20권6호
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• pp.525-528
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• 1997

Steroid $9{\alpha}$.-hydroxylase is a key enzyme system in steroid nucleus degradation in company with ${\Delta}$-dehydrogenase. To examine $9{\alpha}$-hydroxylase activity during microbial transformation of steroids, 9(11)-dehydro-$17{\alpha}$-methyl-testosterone was adopted as a stable substrate for preventing the rupture of steroid nucleus. Using Nocardia restrictus ATCC 14887 capable of introducing a $9{\alpha}$-hydroxyl group into steroids, $9{\alpha}$,$11{\alpha}$-oxido-$17{\beta}$-hydroxy-$17{\alpha}$-methyl-4-androstene-3-one and $9{\alpha}$-hydroxyl group into steroids,$9{\alpha}$,$11{\alpha}$-oxido-$17{\beta}$-hydroxy-$17{\alpha}$-methyl-1,4-androstadiene-3- one were obtained. These microbiologically transformed products could be used as reference compounds in the enzyme assay.