Trapanins A and B, oligomeric hydrolyzable tannins from Trapa japonica Flerov.

Abstract

Trapanin A (6), a trimeric hydrolyzable tannin, and trapanin B (7), a tetrameric hydrolyzable tannin, were isolated from the leaves of Trapa japonica (Trapaceae), and their structrures were determined on the basis of spectroscopic and chemical data. The following tannins were also isolated from the leaves: cornusiin C (8) (trimer); cornusiin A (3), campothin B (4) and cornusiin D (5) (dimer); germin d (1), tellimagrandin I (2), pedunculagin, casuarictin and casuarinin (monomer).