A new coumestan from Tephrosia calophylla

Abstract

A new coumestan, tephcalostan (1) has been isolated from the whole plant of Tephrosia calophylla BEDD. together with two known flavonoids, 7-O-methylglabranin (2) and kaempferol 3-O-β-D-glucopyranoside (3). The structure of tephcalostan was elucidated as 5′-(R)-8,9-methylenedioxy- 5′-isopropenyl-4′,5′-dihydrofurano-[2′,3′:2,3] coumestan by extensive one-and two-dimensional (1D- and 2D-)-NMR techniques including 1H-1H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) experiments. © 2003 Pharmaceutical Society of Japan.