Identification of 5alpha-androst-1-ene-3beta,17beta-diol in the fat of Sus scrofa L.: a "nutritional supplement" not found previously in the food supply.

5alpha-Androst-1-ene-3beta,17beta-diol (1) was detected in extracts from fat of Sus scrofa L. (pig) by comparison with the commercially available synthetic compound, using gas chromatography-mass spectrometry. This observation is unprecedented because 1 is currently sold as a nutritional supplement, yet has not been previously reported as naturally occurring in the food supply.

The in vitro biosynthesis of epitestosterone and testosterone from C19 steroid precursors in the testis of the lizard Tiliqua rugosa.

The metabolism of androgens in the testis of the lizard Tiliqua rugosa has been studied in vitro by incubating cellular homogenates with radiolabeled C19-steroid substrates. The identification 17 beta-oxidoreductase and 3 beta-hydroxysteroid dehydrogenase/isomerase activities. Aromatase, 5 alpha-reductase, and 17 alpha/beta-epimerase activities were not detected. The 17 alpha-oxidoreductase activity was temperature dependent (maximal at 32 degrees), while the 17 beta-oxidoreductase activity was temperature independent. Time yield and dual-label studies indicated that testosterone biosynthesis mainly involves the 4-ene pathway (via androstenedione), whereas the formation of epitestosterone uses both the 4-ene and 5-ene (via 5-androstene-3 beta, 17 alpha-diol) pathways. The function of alternative pathways in androgen biosynthesis is discussed, as is the role of temperature in the intratesticular regulation of androgen production.