What is "coumestrol"

n. (cx organic compound English) A coumestan with estrogenic activity, found in soybeans and other foods.

Coumestrol is a natural organic compound in the class of phytochemicals known as coumestans. Coumestrol was first identified as a compound with estrogenic properties by E. M. Bickoff in ladino clover and alfalfa in 1957. It has garnered research interest because of its estrogenic activity and prevalence in some foods, including soybeans, brussels sprouts, spinach and a variety of legumes. The highest concentrations of coumestrol are found in clover, Kala Chana, a type of chick pea, and Alfalfa sprouts.

Coumestrol is a phytoestrogen, mimicking the biological activity of estrogens. Phytoestrogens are able to pass through cell membranes due to their low molecular weight and stable structure, and they are able to interact with the enzymes and receptors of cells. Coumestrol interacts with the ER-β estrogen receptor and has approximately the same binding affinity for the receptor as 17β-estradiol, but much less affinity than 17α-estradiol, although the estrogenic potency of coumestrol at both receptors is much less than that of 17β-estradiol. Estrogenic activity is 30-100 times greater than isoflavones.

The chemical shape of coumestrol orients its two hydroxy groups in the same position as the two hydroxy groups in estradiol, allowing it to inhibit the activity of aromatase and hydroxysteroid dehydrogenase. These enzymes are involved in the biosynthesis of steroid hormones, and inhibition of these enzymes results in the modulation of hormone production.