Reticuloendothelial System-Activating Polysaccharides from Rhizomes of Panax japonicus. : I. Tochibanan-A and -B

Abstract

From rhizomes of Panax japonicus (Araliaceae), two polysaccharides named tochibanan-A and -B, which show reticuloendothelial-potentiating activity in the carbon clearance test in mice, were isolated. The structure of tochibanan-A (molecular mass : 23000) was elucidated as a linear β-1, 4-D-galactan. Tochibanan-B (molecular mass : 40000) consists of D-galactose (87.1%), L-arabinose, D-glucose and D-galacturonic acid and has a β-D-(1→4)-linked galactopyranosyl backbone possessing GalA-(1→6)-Gal, Ara-(1→5)-Ara, Gal, and Glc side chains. The structure around the branching points and the repeating unit were investigated and a possible structure of tochibanan-B is proposed.