Estrone (also known as oestrone) is a weak endogenous estrogen, a steroid and minor female sex hormone. Estrone is synthesized from cholesterol and secreted from gonads. Endoplasmic reticulum (ER) is the place that estrone undergoes primary metabolism. Estrone sulfate and estrone glucuronide are the conjugated product of estrone; and CYP450 can hydroxylate estrone into catechol estrogens. The enzyme catechol O-methyltransferase catalyzes the conversion of 2-hydroxyestrone into 2-methoxyestrone which is used to synthesize 2-methoxyestrone 3-glucuronide via the membrane-associated massive multimer UDP-glucuronosyltransferase 1-1. Estrone can also be reversibly converted into estradiol by estradiol 17-beta-dehydrogenase 1. This same enzyme can reversibly convert 16a-hydroxyestrone (synthesized from estrone via cytochrome P450 3A5) into estriol. Estriol is alternatively synthesized from estradiol via cytochrome P450 3A5.

Estrone Metabolism References