80-91-1Relevant articles and documents
Substrate specificity and inhibitor sensitivity of rabbit 20α-hydroxysteroid dehydrogenase
Endo, Satoshi,Arai, Yuki,Hara, Akira,Kitade, Yukio,Bunai, Yasuo,El-Kabbani, Ossama,Matsunaga, Toshiyuki
, p. 1514 - 1518 (2013/10/08)
In this study, we examined the substrate specificity and inhibitor sensitivity of rabbit 20α-hydroxysteroid dehydrogenase (AKR1C5), which plays a role in the termination of pregnancy by progesterone inactivation. AKR1C5 moderately reduced the 3-keto group of only 5α-dihydrosteroids with 17β- or 20α/β-hydroxy group among 3-ketosteroids. In contrast, the enzyme reversibly and efficiently catalyzed the reduction of various 17- and 20-ketosteroids, including estrogen precursors (dehydroepiandrosterone, estrone and 5α-androstan-3β- ol-17-one) and tocolytic 5β-pregnane-3,20- dione. In addition to the progesterone inactivation, the formation of estrogens and metabolism of the tocolytic steroid by AKR1C5 may be related to its role in rabbit parturition. AKR1C5 also reduced various non-steroidal carbonyl compounds, including isatin, an antagonist of the C-type natriuretic peptide receptor, and 4-oxo-2-nonenal, suggesting its roles in controlling the bioactive isatin and detoxification of cytotoxic aldehydes. AKR1C5 was potently and competitively inhibited by flavonoids such as kaempferol and quercetin, suggesting that its activity is affected by ingested flavonoids.
A New Chiral Director for the Highly Diastereoselective Borane Reduction of Steroid-20-ones
Goendoes, Gyoergy,Dombi, Gyoergy,Orr, James C.
, p. 1055 - 1060 (2007/10/03)
The synthesis of a new chiral boroxazolidine was achieved which was used to control the stereochemistry of the borane reduction of the 20-keto group of steroids. The otherwise hardly accessible 20α-(20S)-alcohol can thus be prepared in a yield of 91 percent.
Mechanism of the D-Homoannulation of Pregnanediol Disulfate in Refluxing 3 N Hydrochloric acid
Yoshizawa, Itsuo,Itoh, Shinji,Nagata, Kyoko,Kawahara, Norio
, p. 3819 - 3828 (2007/10/02)
In order to elucidate the mechanism of D-homoannulation of pregnanediol 20-sulfate, solvolysis of -5β-pregnane-3α,20α-diol disulfate (3) in refluxing 3 N hydrochloric acid was investigated.The resulting D-homosteroids, 17percenta-methyl-D-homo-5β-androstane-3α,17aβ-diol (8) and 17α-methyl-17aβ-chloro-D-homo-5β-androstan-3α-ol (10), contained a quantitative amount of (13)C only at C-17, indicating that the ring-enlargement reaction of the 20α-ol sulfate proceeded with stereospecific migration of the C16-C17 bond.The same result was obtained from isomeric -5β-pregnane-3α,20β-diol disulfate (6).Based on these results,the D-homoannulation of pregnanediol 20-sulfate was concluded to proceed by a stepwise mechanism through the C-20 carbocation.The stereochemistry of this Wagner-Meerwein type rearrangement reaction is also discussed. Keywords --- 5β-pregnane-3α,20α-diol (pregnanediol); pregnanediol disulfate; 5β-pregnane-3α,20β-diol; D-homoannulation; stereochemistry; steroidal sulfate; acid hydrolysis; (13)C-NMR