2-hydroxyestron

2-Hydroxyestron (2-OHE1), also known as estra-1,3,5 (10) -trien-2,3-diol-17-one, is a naturally occurring endogenous catechol estrogen and a major metabolite of estrone and estradiol. It is irreversibly formed from estrone in the liver and to a lesser extent in other tissues through 2-hydroxylation mediated by cytochrome P450 enzymes, mainly the subfamilies CYP3A and CYP1A. 2-OHE1 is the most common catechin estrogen in the body. It is not significantly uterotrophic in bioassays, while other hydroxylated estrogen metabolites, including 2-hydroxyestradiol, 16α-hydroxyestrone, estriol (16α-hydroxyestradiol), 4-hydroxyestradiol and 4-hydroxyestrone.