
%0 Journal Article
%A Shutt, DA 
%A Braden, AWH 
%T The significance of equol in relation to the oestrogenic responses in sheep ingesting clover with a high formononetin content
%J Australian Journal of Agricultural Research
%D 1968/08/01
%V 19
%N 4
%P 545-553
%K 
%R https://doi.org/10.1071/AR9680545
%U https://www.publish.csiro.au/paper/AR9680545 
%X Equol (7,4'-dihydroxyisoflavan), a metabolite in sheep of the dietary isoflavone formononetin, was found to be oestrogenic in mice. By subcutaneous administration it had about one-quarter of the activity of genistein. Equol (35&ndash;68 &#181;g/100 ml) was found in the peripheral blood of sheep 4&ndash;24 hr after first feeding with red clover (Trifolium pratense) pellets, and represented 9&ndash;68&#37; of the "free" and 23&ndash;72&#37; of the conjugated "phyto-oestrogens" in the plasma. In ewes grazing red clover, equol was found in the plasma (50 &#181;g/100 ml) and in the uterine tissue (46 &#181;g/uterus) and represented in both instances more than 70&#37; of the extracted "phyto-oestrogen". It is concluded that equol is probably of major importance in relation to the oestrogenic activity found in sheep ingesting clover with a high formononetin content. In guinea-pigs, equol (32&ndash;71 &#181;g/100 ml) was found in plasma samples 4&ndash;16 hr (day 3) after feeding with red clover pellets. Another probable metabolite of formononetin, referred to as metabolite "A" and tentatively identified as demethylated angolensin (2,4-dihydroxyphenyl-p-hydroxyphenylethylketone), was also noted in the plasma of sheep and guinea-pigs after ingesting red clover. 
