7a-O-methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoliata

From the roots of Derris trifoliata an isoflavonoid derivative (1), a modified rotenoid with an open ring-C, representing a new sub-class of isoflavonoids (the sub-class named rotenoloid) was isolated and characterised. The structure was determined on the basis of spectroscopic evidence.