| Abstrakt: |
The loss of hydrogen from the C-21 position of 5β-pregnane-3α,21-diol-20-one (tetrahydrodeoxycorticosterone, THDOC) during reductive removal of the 21-hydroxy group by the anaerobic bacterium Eubacteriumlentumhas been shown to be selective for the pro-Sposition by the use of THDOC labelled with deuterium at the C-21 pro-Sand C-21 pro-Rpositions. The labelled substrates were obtained by using the bacterium Clostridiumparaputrificumto reduce chemically prepared C-21 labelled samples of pregn-4-en-21-ol-3,20-dione (deoxycorticosterone, DOC) at C-3 and C-4 (5). The stereochemistry of deuterium label introduced by chemical means at C-21 of DOC was determined by comparison with a sample of 21-(R)-DOC-21-d1produced by reduction of the corresponding aldehyde pregn-4-en-21-al-3,20-dione, 21-dby the enzyme 21-hydroxysteroid NAD oxidoreductase from beef liver. Keywords: Eubacterium, Clostridium, steroids, tetrahydrodeoxycorticosteroids. |
