Chemical constituents of the leaves of Campylospermum elongatum
AbstractThe leaves ofCampylospermum elongatumhave furnished the cyano-glycoside (lithospermoside), nine isomeric biflavonoid derivatives among which five are I3–II6linked (robustaflavone; 4′-O-methyl robustaflavone; 4′,4″′-di-O-methyl robustaflavone; 7,4′,4″-tri-O-methyl robustaflavone; 4′,7″-di-O-methyl robustaflavone) and four I3–II8linked (amentoflavone; 7-O-methyl amentoflavone; 7,7″-di-O-methyl amentoflavone; 7, 4′,7″-tri-O-methyl amentoflavone) and a flavone glycoside, 4″-O-methyl-7-O-β-d-galactosylapigenin. All structures were established from a complete spectroscopic analysis (MS, IR, 1D, and 2D NMR, including HSQC, HMBC, and NOESY) as well as by comparing the obtained spectroscopic data with literature. This is the first report on the characterization of 4′-O-methyl-7-O-β-d-galactosylapigenin from the genuscampylospermumand thus has important chemotaxonomic implications.