2-hydroxyestradiol

2-Hydroxyestradiol

Names
IUPAC name (8R,9S,13S,14S,17S)-13-Methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-2,3,17-triol
Other names 2-OHE2; Estra-1,3,5(10)-triene-2,3,17β-triol
Identifiers
CAS Number	362-05-0
3D model (Jmol)	Interactive image
ChemSpider	216475
PubChem	247304
InChI InChI=1S/C18H24O3/c1-18-7-6-11-12(14(18)4-5-17(18)21)3-2-10-8-15(19)16(20)9-13(10)11/h8-9,11-12,14,17,19-21H,2-7H2,1H3/t11-,12+,14-,17-,18-/m0/s1
SMILES C[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@@H]2O)CCC4=CC(=C(C=C34)O)O
Properties
Chemical formula	C18H24O3
Molar mass	288.39 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

2-Hydroxyestradiol (2-OHE2), also known as estra-1,3,5(10)-triene-2,3,17β-triol, is an endogenous steroid, catechol estrogen, and metabolite of estradiol, as well as a positional isomer of estriol.

Transformation of estradiol to 2-hydroxyestradiol is a major metabolic pathway of estradiol in the liver.CYP1A2 and CYP3A4 are the major enzymes catalyzing the 2-hydroxylation of estradiol. Conversion of estradiol into 2-hydroxyestradiol has also been detected in the uterus, breast, kidney, brain, and pituitary gland, as well as the placenta, and may similarly be mediated by enzymes. Although estradiol is extensively converted into 2-hydroxyestradiol, circulating levels of 2-hydroxyestradiol and levels of 2-hydroxyestradiol in various tissues are very low. This may be due to rapid conjugation (O-methylation, glucuronidation, sulfonation) of 2-hydroxyestradiol followed by urinary excretion.

2-Hydroxyestradiol has approximately 7% and 11% of the affinity of estradiol at the ERα and ERβ, respectively. The steroid is only very weakly estrogenic, and is able to antagonize the estrogenic effects of estradiol, indicating that its intrinsic activity at the estrogen receptor is less than that of estradiol and hence that it possesses the profile of a selective estrogen receptor modulator.