19-HYDROXY-Δ4-ANDROSTENE-3,17-DIONE AN INTERMEDIATE IN ESTROGEN BIOSYNTHESIS1

Abstract
Incubation of Δ4-androstene-3,17-dione-4-C14 with a human placental preparation yielded 19-hydroxy-Δ4-androstene-3,17-C14 in addition to estrone-C14. The 19-hydroxy steroid had previously been shown to be converted in good yield to estrone. This is the first direct demonstration of 19-hydroxylase in a tissue other than adrenal and more firmly establishes the 19-hydroxy derivative as an intermediate in the biosynthesis of estrogens from androgens.