Antiestrogenic properties of substituted benz[a]anthracene-3,9-diols

The antiestrogenic potency of benz[a]anthracene-3,9-diol, as well as its 7- and 12-methyl derivatives, was evaluated by measuring he inhibition in the onset of estrus brought about by this compound in ovariectomized rats treated with 17beta-estradiol. At a dose of 0.5 mg and 7,12-dimethyl derivative caused a decrease in the percentage of rats in estrus from 78 to 44%. This decrease is identical with that caused by 0.05 mg of nafoxidine.