Isolation fo 15alpha-hydroxypregnenolone and 15alpha-hydroxydehydroisoandrosterone from human pregnancy urine

Biosynthesis of estetrol in human pregnancy: Potential pathways

Estetrol (E4) has emerged as a novel and highly promising estrogen for therapeutic use. E4 is a weak natural estrogen produced only in pregnancy. Because of its novelty, there is considerable interest by clinicians in how it is produced in pregnancy. Although the fetal liver plays a key role in its production, the placenta is also involved. A current view is that estradiol (E2) formed in the placenta enters the fetal compartment and is then rapidly sulfated. E2 sulfate then undergoes 15α-/16α-hydroxylation in the fetal liver thereby forming E4 sulfate (phenolic pathway). However, another pathway involving 15α,16α-dihydroxy-DHEAS formed in the fetal liver and converted to E4 in the placenta also plays a significant role (neutral pathway). It is not known which pathway predominates, but both pathways appear to be important in E4 biosynthesis. In this commentary, we summarize the well-established pathways in the formation of estrogens in the nonpregnant and pregnant female. We then review what is known about the biosynthesis of E4 and describe the 2 proposed pathways involving the fetus and placenta.

Urinary steroids from a newborn human infant. Identification of 2 alpha-hydroxy-4-pregnene-3,20-dione, 3 beta,15 beta-dihydroxy-5-pregnen-20-one and 3 beta,15 alpha-dihydroxy-5-pregnen-20-one

Urinary steroids from healthy newborn human infants were analyzed by gas-liquid chromatography and gas-liquid chromatography-mass spectrometry. The identification of 2 alpha-hydroxy-4-pregnene-3,20-dione and the characterization of its 2 beta-isomer is recorded here for the first time. Mass spectrometric evidence supporting the identification of 3 beta,15 beta-dihydroxy-5-pregnen-20-one and 3 beta,15 alpha-dihydroxy-5-pregnen-20-one is also presented. Furthermore, the following 15-hydroxylated steroids were also found and identified: 3 beta,15 epsilon,16 epsilon-trihydroxy-5-androsten-17-one, 5-androstene-3 beta,15 alpha,16 alpha,17 beta-tetrol, 3 beta,15 beta,17-trihydroxy-5-pregnen-20-one and 5-pregnene-3 beta,15 epsilon,17,20 epsilon-tetrol. The origin of these 2- and 15-hydroxylated urinary steroids is discussed in relation to current knowledge of 4-pregnene-3,20-dione and 3 beta-hydroxy-5-pregnen-20-one metabolism during the human perinatal period.