EQUILENIN

Description

Equilenin is a steroidal estrogen originally isolated from the urine of pregnant mares. It was discovered by French researchers A. Girard and co-workers in 1932. The naturally occurring form is the (+)-isomer shown here. It should not be confused with equilin, in which the B ring of equilenin is monohydrogenated.
Among equilenin’s claims to fame is that it was the first complex natural product to be totally synthesized in the laboratory. The feat was accomplished in 1939 by W. E. Bachmann, Wayne Cole, and A. L. Wilds at the University of Michigan (Ann Arbor). The next year, the trio followed up with the total synthesis of the three non-natural stereoisomers of equilenin.
Equilenin, equilin, and several other conjugated equine estrogens (CEEs) are the components of Premarin*, a drug introduced by Wyeth (Philadelphia; now part of Pfizer) in 1941–42. Premarin is a hormone therapy primarily used to treat hot flashes, vaginal burning and dryness experienced by postmenopausal women who have undergone hysterectomies. But Premarin’s many adverse side effects caused it to be replaced by estradiol (Molecule of the Week for November 4, 2013) in some parts of the world.
CEEs are also used to treat some cancers; but ironically, equilenin and other CEEs are also suspected of causing cancer.
*From pregnant mare urine.

The Uses of EQUILENIN

Equilenin is a naturally occuring estrogenic steroidal hormone (1,2) isolated from urine of pregnant mares (3). Not found in human urine. Component of conjugated estrogenic hormones. Estrogen. This compound is a contaminant of emerging concern (CECs). Drinking water contaminant candidate list 3 (CCL 3) compound as per United States Environmental Protection Agency (EPA), environmental, and food contaminants.

The Uses of EQUILENIN

Estrogenic steroidal hormone isolated from urine of pregnant mares. Occurs naturally in the d-form. Not found in human urine. Component of conjugated estrogenic hormones. Estrogen.

What are the applications of Application

Equilenin solution is an estrogenic steroid that is usually found in pregnant horses

Definition

ChEBI: Equilenin is a 3-hydroxy steroid that is estrone which carries two double bonds at positions 6 and 8. It is found in the urine of pregnant mare's and extensively used for estrogen replacement therapy in postmenopausal women. It has a role as a mammalian metabolite and an antioxidant. It is a 3-hydroxy steroid and a 17-oxo steroid.

Purification Methods

Crystallise (+)-equilenin from EtOH (solubility is 0.63% at 18o, 2.5% at 78o), aqueous EtOH or *C6H6 (Norite) and dry it in a vacuum. It sublimes on melting and at 170-180o/0.01mm. The acetate crystallises from MeOH with m 165-167o and [ ] D +71o (c 1, CHCl3). [Bachmann et al. J Am Chem Soc 62 824 1940, Beilstein 8 III 1522, 1523, 1525, 8 IV 1420.]