17α-Dihydroequilin, or α-dihydroequilin, also known as estra-1,3,5(10),7-tetraene-3,17α-diol, is a natural estrogen found in horses that is closely related to equilin and equilenin. The compound, as the sodium salt of its sulfate ester, is present in the pharmaceutical drug Premarin, a conjugated estrogenic extract of the urine of pregnant mares, and is the third highest quantity constituent in the formulation (13.8%).

CAS：651-55-8
中文别名：17α-二氢马烯雌甾酮;
英文别名：7-Dehydro-17α-estradiol;Estra-1,3,5(10),7-tetraen-3,17α-diol;(9S,13S,14S,17R)-13-methyl-6,9,11,12,14,15,16,17-octahydrocyclopenta[a]phenanthrene-3,17-diol;α-dihydroequilin;α-Equilol;Estra-1,3,5(10),7-tetraene-3,17-diol, (17α)-;(17α)-Estra-1,3,5(10),7-tetraene-3,17-diol;
分子式：C18H22O2
分子量：270.366
精确质量：270.162
Psa：40.46
Logp：3.5293

UNII：48P73794OJ

密度：1.23g/cm3
沸点：457.798ºC at 760 mmHg
闪点：217.155ºC
折射率：1.637