Phenylpropanoid-substituted catechins from Castanopsis hystrix and structure revision of cinchonains

Two new and two known complex flavan-3-ols, containing an additional phenylpropanoid (C6–C3) unit in the molecule, have been isolated from the leaves of Castanopsis hystrix. The structures including absolute stereochemistry were elucidated on the basis of spectroscopic evidence and also by synthesis. In addition, comparison of the CD spectral data of these compounds with those of previously known complex flavan-3-ols, cinchonains, has led to the revision of their structures.