POLYPHENOLS IN SALIX SPECIES .1. POLYPHEN OLS FROM THE BARK OF SALIX RORIDA LACKSCHEWITZ

Chemical characteristics of polyphenols from the bark of willow specie s grown in Japan were investigated. The bark of four willow species (S alix rorida Lackschewitz, Salix hinuyanagi Kimura, Salix gilgiana Seem ., and Salix gracilistyla Mig.) contained 13-17% of phenolics, 12-18% of flavanols, and 6-10% of tannins. Among the willow barks analysed, S . rorida contained the largest amount of tannins. From the bark of S. rorida, 1-(4-Hydroxyphenyl)-propane-3-ol (1), 1-(4-Hydroxyphenyl)-prop ane-3-yl beta-D-glucoside (2), catechin (3), gallocatechin (4), catech in-(4 alpha-8)-catechin (5), and gallocatechin-(4 alpha-8)-catechin (6 ) were identified. Polymeric fractions from the bark of S. rorida were proanthocyanidin polymers with prodelphinidin and procyanidin type fl avanol units, and the configurations of their heterocyclic rings were 2,3-trans and 2,3-cis in the extender units and 2,3-trans in the botto m units. In addition, it also was found that they have an abundance of prodelphinidin units, and that the main components of them are proant hocyanidin octamers.