Abstract
Of the 7 carotane sesquiterpenes of Ferula jaeschkeana Vatke evaluated, three jaeschkeanadiol esters (compounds 3, 5, and 6) showed contraceptive efficacy when administered orally on days 1-7 post coitum in rats. In ovariectomized immature female rats, however, the active compounds exhibited estrogenic activity and were devoid of antiestrogenic activity. Using a competitive protein binding assay, the compounds 3, 5, and 6 showed relative binding affinity of 0.01%, 5.75%, and 0.75% of 17β-estradiol, respectively, for rat uterine cytosol estrogen receptors.
