The distribution of oestrogenic isoflavones in the genus Trifolium

Abstract

Of 100 Trifolium species tested prior to and during early flowering, 14 had isoflavone contents comparable with that of subterranean clover, and seven of these were closely related taxonomically. Intervarietal variation in isoflavone content was found in self-fertilized species containing isoflavones, but not in the cross-fertilized T. pratense L. In all species the isoflavones genistein, biochanin A, and formononetin were in glycosidic forms. The same isoflavone glycosides were represented in all species containing isoflavones in quantity. No species contained significant quantities of coumestrol, and many of the common naturalized species were virtually free of known oestrogens.