The use of steroid profiling in the resolution of pregnenolone metabolites from porcine testicular preparations.

The behaviour of 22 steroids has been examined by capillary gas chromatographic profiling, and the identities of the steroids confirmed by mass spectrometry and their relative retention times. Five pairs of steroids have been separated: 5 alpha-androstane-3 alpha,17 beta- and -3 beta,17 beta-diols; 5-androstene-3 beta,17 alpha- and -3 beta,17 beta-diols; pregnenolone and 3 beta-hydroxy-5,16-pregnadien-20-one; progesterone and 4,16-pregnadiene-3,20-dione; 17-hydroxypregnenolone and 5-pregnene-3 beta,20 beta-diol. 5 alpha-Androst-16-en-3 beta-ol and 5,16-androstadien-3 beta-ol (as trimethylsilyl-, tert.-butyl-dimethylsilyl- and chloromethyldimethylsilyl ethers) were only partially resolved but could be well separated on thin-layer plates of Kieselgel that had previously been dipped in AgNO3 solution. The profiling method was successfully applied to the separation of pregnenolone and its metabolites in porcine testicular incubation extracts.