Tannins of Stachyurus Species. III. Stachyuranins A, B and C, Three New Complex Tannins from Stachyurus praecox Leaves

抄録

Three new complex tannins, stachyuranins A (1), B (2) and C (3), were isolated from the leaves of Stachyurus praecox (Stachyuraceae), and their structures, each consisting of a catechin or gallocatechin residue and a monomeric hydrolyzable tannin moiety, were assigned. Structures 1 and 2 lack a C-C linkage between glucose C-1 and the aroyl group at glucose O-2, suggesting that they may be biogenetic precursors of complex tannins with the C-C linkage.