Tannins and Related Compounds. IV. Seven New Phenol Glucoside Gallates from Quercus stenophylla MAKINO (1)

Abstract

Along with gallic acid, ellagic acid, (+)-catechin and procyanidins B-1 and B-3, seven new gallates of phenol glucosides (compounds 1-7) have been isolated from the bark of Quercus stenophylla MAKINO (Fagaceae). On the basis of chemical and spectral evidence, the structures of compounds 1, 2, 4, 5 and 6 have been established respectively as 6"-O-gallate (1), 3"-O-gallate (2), 4', 6"-di-O-gallate (4), 4", 6"-di-O-gallate (5) and 3", 4", 6"-tri-O-gallate (6) of salidroside (p-hydroxyphenethyl alcohol 1-O-β-D-glucopyranoside). Similarly, compounds 3 and 7 have been characterized as 3', 4'-dihydroxyphenethyl alcohol 1-O-β-D-(6"-O-galloyl)-glucopyranoside (3) and 2, 4, 6-trimethoxyphenol 1-O-β-D-(6'-O-galloyl)-glucopyranoside (7), respectively.