Further observations on the oestrogenic activity of synthetic polycyclic compounds

Abstract

In a former communication (Cook, Dodds, Hewett, and Lawson, 1934) we recorded the oestrogenic activity of a number of polycyclic aromatic and hydroaromatic compounds. The most active substances were found among a series of diols related to the carcinogenic hydro­carbon, 1 : 2 : 5 : 6-dibenzanthracene. We have now extended our investi­gation to seven new members of this series and have also examined a variety of diols of analogous structure, but containing other ring systems. Table I summarizes the results obtained in tests for oestrogenic activity carried out with 9: 10-dihydroxy-9: 10-dialkyl-9: 10-dihydro-1: 2: 5: 6- dibenzanthracenes. In none of the new compounds has the activity exceeded that of the most potent compound previously described, namely, the di- n -propyl derivative in this series. Among the straight-chain dialkyl compounds this di- n -propyl compound represents a peak of activity in a series of which the first (methyl) and higher ( n -amyl, n -hexyl) members are inactive. Two branched-chain compounds ( iso -propyl, iso -butyl) are fairly highly active, but show diminished activity by comparison with the corresponding straight-chain isomerides. This is particularly marked for the iso -propyl compound, which is about ten times less active than the n -propyl compound. In view of the high order of activity of the n -propyl compound, it is remarkable that the allyl compound has given negative results when injected into ovariectomized rats in 10 mg. doses.