OESTROGENIC, ANTI‐OESTROGENIC AND FERTILITY EFFECTS OF SOME TRIPHENYLETHANES AND TRIPHENYLETHYLENES RELATED TO ETHAMOXYTRIPHETOL (MER 25)

Five triphenylethylenes, a triphenylethane and a triphenylethanol, carrying methyl substituents ortho to one or both of the ring oxygen functions, have been examined for oestrogenic, and anti‐oestrogenic activity in mice, and three of the compounds, α‐[4‐(β‐diethylaminoethoxy)‐3, 5‐xylyl]‐α‐phenyl‐β‐4‐methoxyphenyl‐ethanol (IV), α′‐[4‐(β‐diethylaminoethoxy)‐3, 5‐xylyl]‐4‐methoxy‐bibenzyl (V) and α′‐[4‐(β‐diethylaminoethoxy)‐3, 5‐xylyl]‐4‐methoxy‐stilbene (VI), were tested for their effects on fertility in mice. Orthomethylation reduces oestrogenic and/or anti‐oestrogenic activity compared with the reported activities of non‐methylated analogues. The anti‐oestrogenic ethamoxytriphetol (MER 25) reduced fertility in mice whereas its inactive dimethylated analogue (IV) was ineffective. The weakly active anti‐oestrogens, V and VI, did not affect fertility in mice. 1976 British Pharmacological Society