Constituents of Morus alba L. Cell Cultures. (1). : Structures of Four New Natural Diels-Alder Type Adducts, Kuwanons J, Q, R, and V

Abstract

From callus tissues of Morus alba L., four new yellow pigments, kuwanons J (1), Q (2), R (3), and V (4), have been isolated. Chemical and spectroscopic evidence revealed that these compounds are stereochemically identical Diels-Alder type adducts of two 4-hydroxyprenylchalcone moieties bearing all the four possible patterns of hydroxylation at the 2 and/or 16'' positions.