Abstract
Six new phenol glucoside gallates (3-5, 7, 9 and 10) have been isolated from Castanopsis cuspidata var. sieboldii NAKAI (Fagaceae), together with the known compounds, dehydrodigallic acid (1), cretanin (2), chesnatin (11) and chestanin (8). On the basis of spectroscopic evidence and the result of tannase hydrolysis, the structures of compounds 3-5 have been established to be the mono- (3) and digallates (4 and 5) of crenatin (6). Similarly, compounds 7, 9 and 10 have been characterized as the monogallate (7) of 3, 4-dihydroxyphenethyl alcohol 4-O-β-D-glucopyranoside and the monogallates (9 and 10) of 8. In addition, the structure of chesnatin (11), in which the orientation of the dehydrodigalloyl group had been unknown, was determined by detailed carbon-13 nuclear magnetic resonance examination.
