Estradiol(redirected from Femring)
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C18H24O2, a female sex hormone of the estrogen group with the structural formula
Estradiol occurs as colorless crystals with a melting point of 176°–178°C. Poorly soluble in water, it dissolves better in organic solvents. It is optically active, with a specific rotation of [α]D= +81°.
Estradiol was first isolated in 1935 from the follicular fluid of the ovaries of swine by the American biochemist E. Doisy. Of all the estrogens, it has the highest physiological activity, but it is rapidly inactivated in the body. Longer-acting preparations of estradiol (estradiol dipropionate and estradiol benzoate) are obtained by the esterization of estradiol with various organic acids. Estradiol has important physiological functions (seeESTROGEN).