566-58-5Relevant 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.
ANDROGENIC MODULATION OF PROGESTERONE METABOLISM BY RAT GRANULOSA CELLS IN CULTURE
Duleba, Antoni J.,Takahashi, Hideyuki,Moon, Young S.
, p. 321 - 330 (2007/10/02)
Effects of androgens on progesterone accumulation, utilization of exogenous progesterone and accumulation of progesterone metabolites by rat granulosa cells in culture were studied.Androgen increased progesterone accumulation in cultures without exogenous progesterone and slowed the overall decline of progesterone concentration in cultures supplemented with exogenous progesterone.Both aromatizable testosterone and nonaromatizable 5α-dihydrotestosterone decreased progesterone utilization by granulosa cells by 12 to 30percent.This effect was observed irrespective of whether the cells were continuously exposed to androgens or only pre-exposed.In the same experiments, androgens decreased conversion of radiolabeled progesterone to 20α-hydroxy-4-pregnen-3-one by 11 to 50percent and to 5α-pregnane-3α,20α-diol by 26 to 49percent.Accumulation of 3α-hydroxy-5α-pregnan-20-one was not altered in 3 h incubations and was increased by up to 43percent in 24 h incubations by androgen treatment.It is suggested that androgens alter progesterone catabolism by granulosa cells by decreasing 20α-hydroxysteroid dehydrogenase activity and that this effect may contribute to overall stimulatory action of androgens on progesterone accumulation.