Neutral C19-steroids and steroid sulfates in human pregnancy IV. Isolation and identification of unconjugated dehydroepiandrosterone and 16α-hydroxydehydroepiandrosterone from pooled cord blood

Identification of unconjugated dehydroepiandrosterone (D) and 16α-hydroxydehydroepiandrosterone (16α-OH-D) isolated from 500 ml of cord plasma obtained from mixed arterial and venous cord blood collected after vaginal delivery at term is presented. The identification is based upon in vitro placental conversion of D and 16α-OH-D to 17β-estradiol and estriol respectively, further on formation of D acetate and 16α-OH-D diacetate and their thiosemicarbazones, and finally on reduction of the acetates and repeat acetylation. All acetates were doubly labelled and chromatographed to constant 3 H/ 14 C ratios. Constant ratios were also obtained in recrystallizations of D acetate and 16α-OH-D diacetate after reversed isotope dilution.