A C-methylbiflavone from Cephalotaxus harringtonia K. Koch
Abstract
6-C-Methyl-7-O-methylamentoflavone (1) isolated from the leaves of Cephalotaxus harringtonia K. Koch (Cephalotaxaceae) has been identified on the basis of the spectral data of its hexamethyl ether (1a) and its penta-acetate (1b). The location of the C-methyl group was first deduced from 1H n.m.r. studies with a lanthanide shift reagent and confirmed by a synthesis of the hexamethyl ether (1a).