Estrogenic properties of six compounds derived from Eucommia ulmoides Oliv. and their differing biological activity through estrogen receptors α and β

► Six novel estrogenic compounds have been identified in Eucommia ulmoides. ► The six compounds can activate ER-dependent transcription of estrogen target genes. ► These compounds exhibit significant difference in ER subtype (α vs. β) selectivity. ► Proliferation effect on breast cancer cells mediated by the genomic action of ERα.