GAS CHROMATOGRAPHIC IDENTIFICATION OF THE URINARY OXOPREGNANE DERIVATIVES IN THE PREGNANT RABBIT

Abstract

SUMMARY The oxosteroid metabolites of the pregnant rabbit were identified by gas chromatography using a combination of chromatographic runs involving examination of the free and acetylated material on QF-1, the alcohols on SE-30 and the trimethylsilyl ethers on neopentyl glycol adipate (NGA). The oxidized material was run on QF-1 and NGA. The ketonic fraction consisted mainly of pregnanes, some of which were 20-oxosteroids (3α-hydroxy-5β-pregnan-20-one, 3α,6α-dihydroxy-5α-pregnan-20-one and its 5β-epimer, and 3α-hydroxy-5β-pregnane-11,20-dione), and two of which were 20α-ol-3-ones (20α-hydroxypregn-4-en-3-one and 20α-hydroxy-5β-pregnan-3-one). The detection of the latter two compounds directs attention to the catabolic pathway for pregnanediol which involves initially reduction of the 20-ketone.