Urinary sediments in sheep feeding on oestrogenic clover. III.* The identification of 4′-O-methyl equol as a major component of some sediments

Abstract

Chemical identification has been made of two types of sediment formed in the urine of sheep ingesting clovers high in formononetin. One type, described previously, consists of the calcium salt of the glucuronide of 4′-O-methyl equol (4′-methoxy-7-isoflavanol). The other contains unconjugated 4′-O-methyl equol associated with small amounts of equol, formononetin and biochanin A. This is the first report of the isolation of optically active 4′-O-methyl equol.

The present findings indicate that, under some conditions, at present undefined, 4′-O-methyl equol may replace equol as the main metabolite of formononetin.

When administered subcutaneously into mice, 4′-O-methyl equol is slightly less oestrogenic than equol, and its possible role in 'clover disease' of sheep is discussed.

____________________
*Part II, Aust. J. Agric. Res., 23: 693 (1972).