20α,22R-Dihydroxycholesterol
- 20α,22R-Dihydroxycholesterol, or (3β)-cholest-5-ene-3,20,22-triol is an endogenous, metabolic intermediate in the biosynthesis of the steroid hormones from cholesterol. Cholesterol ((3β)-cholest-5-en-3-ol) is hydroxylated by cholesterol side-chain cleavage enzyme (P450scc) to form 22R-hydroxycholesterol, which is subsequently hydroxylated again by P450scc to form 20α,22R-dihydroxycholesterol, and finally the bond between carbons 20 and 22 is cleaved by P450scc to form pregnenolone ((3β)-3-hydroxypregn-5-en-20-one), the precursor to the steroid hormones.
- CHAUDHURI AC, HARADA Y, SHIMIZU K, GUT M, DORFMAN RI (March 1962). “Biosynthesis of pregnenolone from 22-hydroxycholesterol”. The Journal of Biological Chemistry. 237 (3): 703–4. doi:10.1016/S0021-9258(18)60359-X. PMID 13878470
- Hume R, Kelly RW, Taylor PL, Boyd GS (May 1984). “The catalytic cycle of cytochrome P-450scc and intermediates in the conversion of cholesterol to pregnenolone”. European Journal of Biochemistry. 140 (3): 583–91. doi:10.1111/j.1432-1033.1984.tb08142.x. PMID 6723652.
