Components of Root Bark of<i>Cudrania tricuspidata</i>; 3.^1,2. Isolation and Structure Studies on the Flavonoids

Abstract

A new isoprene substituted flavanone (1), named cudraflavanone A, was isolated from the root bark of Cudrania tricuspidata (Carr.) Bur. together with three known flavonoids, cycloartocarpesin (2), populnin (3), and quercimeritrin (4). The structure of 1 was determined on the basis of the spectral evidence and the total synthesis. The structure of euchrestaflavanone C (5) which had been isolated from Euchresta japonica Hook, f. ex Regel was also determined on the basis of the total synthesis.