RETRODIHYDROCHALCONES AND HOMOISOFLAVONES ISOLATED FROM THAI MEDICINAL PLANT DRACAENA-LOUREIRI AND THEIR ESTROGEN AGONIST ACTIVITY

Biological evaluation of the extract prepared from the stem wood of Dr acaena loureiri, a Thai folkloric medicine called ''Chan-daeng'', reve aled a significant capacity to inhibit [H-3]-estradiol binding to the estrogen receptor. During the course of separation, two novel (1 and 2 ) and two known retrodihydrochalcones (3 and 4), in addition to three known homoisoflavones (5, 6, and 7), were isolated, The structures of compounds 1 and 2 were established by NMR and MS studies by correlatin g their spectroscopic properties with those of 3 and 4. Each isolate w as assessed for its estrogenic activity. Compounds 1 and 6 exhibited a ctivity comparable to that of genistein and daidzein.