The structures of two proanthocyanidins from Julbernadia globiflora

Abstract

By use of counter-current and steady state distribution techniques two biflavanoid proanthocyanidins have been isolated from J. globiflora. The compounds are stereoisomers, the structures being based on analysis of the ¹H n.m.r. and mass spectra. Definition of the point of attachment to the second flavanoid unit was made by the use of solvent-induced methoxy-shifts. From the mass spectra it is possible to distinguish between rings B and E of the 4,6″-linked biflavanoids.