Tannins and Related Compounds. XXV. A New Class of Gallotannins Possessing a (-)-Shikimic Acid Core from Castanopsis cuspidata var. sieboldii NAKAI. (1)

Abstract

A homologous series of (-)-shikimic acid gallates (I-V) has been isolated, together with 1, 6-di-O-galloyl-β-D-glucopyranoside (VI), 5-O-galloyl-D-hamamelose (VII), 2, 5-di-O-galloyl-D-hamamelose (VIII) and 2', 3, 5-tri-O-galloyl-D-hamamelose (IX), from the leaves of Castanopsis cuspidata var. sieboldii NAKAI. On the basis of spectroscopic analysis, enzymatic hydrolysis and methanolysis, their structures have been established as 3-O-gallate (I), 3-O-digallate (II), 3-O-trigallate (III), 3, 5-di-O-gallate (IV) and 3, 4-di-O-gallate (V) of (-)-shikimic acid.