Biotransformation of 24 alpha-methylcholesterol and 24 beta-methylcholesterol by yeast mutant GL7.
Incubation of 24 alpha- and 24 beta-methylcholesterols with yeast mutant GL7 afforded their corresponding C-22-desaturated products under the catalysis of sterol delta 22(23)-desaturase. The metabolites were identified to be 22-dehydro-24 alpha-methylcholesterol (2% yield from 24 alpha-methylcholesterol) and 22-dehydro-24 beta-methylcholesterol (51% yield from 24 beta-methylcholesterol) respectively on the basis of their chromatographic and spectral properties. It was concluded that the sterol delta 22(23)-desaturase prefers the 24 beta-methyl sterols and is highly stereospecific.
School of Pharmaceutical Sciences, Beijing Medical University, Beijing 100083, China.
Y J
YJ
Cui
L D
LD
Wang
R A
RA
Norton
J H
JH
Zheng
D A
DA
Guo
D001711:Biotransformation; D002784:Cholesterol / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D009154:Mutation; D010840:Phytosterols; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*
D010840:Phytosterols; C021273:campesterol; D002784:Cholesterol