Chromatographic and mass spectrometric characteristics of 20-dihydroaldosterone

The 20 alpha-reduced derivative of aldosterone, 20 alpha-dihydroaldosterone, was needed as reference compound in order to continue the studies on 18-hydroxylation in the Y-1 adrenal cell line. It was obtained by reduction of aldosterone with sodium borohydride. Analysis of the products of the reaction as methoxime trimethylsilyl (MO-TMS) derivatives by gas chromatography (GC) and GC-mass spectrometry (GC-MS) showed three possible forms of the compound. Their identification was confirmed by comparison with the products obtained by stereospecific reduction of aldosterone using 3 alpha,20 beta-hydroxysteroid dehydrogenase. Chromatographic behavior and mass spectra are given for the three forms of 20 alpha-dihydroaldosterone as the MO-TMS derivatives; that is, the 18-aldehyde, the 18,11 beta-hemiacetal, and the 11 beta:18,18:20 alpha-acetal. The possible origin of these different forms is discussed as a function of these results and of the results obtained by complementary analysis on high-performance liquid chromatography.