The structures of two proanthocyanidins from Julbernadia globiflora
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.