Pattern of estetrol conjugation in the human

Estetrol: A unique steroid in human pregnancy

“…Although [19]; (9) YoungLai et al [20]. not calculated in that study, the data are consistent with a metabolic half-life of 12-15 h. Further analysis of the excretion products from that study indicated that E 4 was predominantly glucuronidated on Ring D [22].…”

Transfer of N-acetylglucosamine from uridine diphosphate N-acetylglucosamine to 3,15α-dihydroxyestra-1,3,5(10)-trien-17-one by human adult and fetal kidney homogenates

“…The solvent systems are shown in Table I. The preparation of alumina and Sephadex columns has been described previously (Emerman et al, 1967;Jirku and Levitz, 1969). Thin-layer chromatography was carried out on silica gel G. The solvent system was chloroform-ethanol (7:4, v/v), the plate being developed twice to effect the separation of 15a-OHEiGNAc from 15a-OHEi-3 sulfate.…”

“…To characterize the product the aqueous phase was centrifuged and the supernatant was flash evaporated. The residue was chromatographed on Sephadex (Jirku and Levitz, 1969). Additional characterization of the N-acetylglucosaminide was obtained from chromatography in system 8 (HBV 2) and 9 (HBV 2-3).…”

“…principally in the form of JY-acetylglucosaminides. The Nacetylglucosaminides are found as single conjugates and as double conjugates, the second conjugating moiety being sulfate (Jirku and Levitz, 1969. Considering that only two other laboratories have isolated and identified steroid Nacetylglucosaminides (Layne et al, 1964;Arcos and Lieberman, 1967), these conjugates are novel.…”

Estetrol and Mammary Gland: Friends or Foes?

“…The hepatic metabolism of E4 is slow in both humans and rodents and is similar across the two species. E4 metabolites are produced through conjugation, mainly methylation, (de) hydroxylation, glucuronidation and sulfation, they are inactive [32,38] and are rapidly excreted in urine [32,[38][39][40]. The principal urine metabolite is the Ring D-monoglucuronide, but E4 can also be excreted in an unconjugated form that cannot be reciprocally converted back into E2 or E3 [35,36].…”