TANNINS AND RELATED-COMPOUNDS .122. NEW DIMERIC, TRIMERIC AND TETRAMERIC ELLAGITANNINS, LAMBERTIANINS A-D, FROM RUBUS-LAMBERTIANUS SERINGE

Chemical examination of the leaves of Rubus lambertianus SERINGE (Rosa ceae) has led to the isolation of four new ellagitannins. which were c haracterized on the basis of chemical and spectroscopic evidence to be dimers [lambertianins A (6) and B (7)], a trimer [lambertianin C (8)] and a tetramer [lambertianin D (10)], all having sanguisorbic acid es ter group(s) as linking unit(s) between glucopyranose moieties. Furthe rmore, HPLC analyses of fifteen Rubus species collected in Japan and T aiwan revealed that the trimer (8) and the tetramer (10), together wit h sanguiin H-6 (1), occur widely in these species.