2 ACIDIC POLYSACCHARIDES HAVING RETICULOENDOTHELIAL SYSTEM-POTENTIATING ACTIVITY FROM THE RAW ROOT OF REHMANNIA-GLUTINOSA

Two acidic polysaccharides, called rehmannan FS-I and rehmannan FS-Il, were isolated from the raw root of Rehmannia glutinosa LIBOSCHITZ. Th ey were homogeneous on electrophoresis and gel chromatography, and the ir molecular masses were estimated to be 5.8 x 10(4) and 6.6 x 10(4), respectively. Rehmannan FS-I is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid: D-glucuronic acid in the molar ratio of 68:40:4:84:3; rehmannan FS-II is composed of L-arabinose: D-galacto se: L-rhamnose: D-galacturonic acid in the molar ratio of 18:15:4:33, in addition to small amounts of O-acetyl groups. About two-thirds (reh mannan FS-I) and about one half (rehmannan FS-IT) of the hexuronic aci d residues exist as methyl esters. Methylation analysis of the carboxy l-reduced derivatives and nuclear magnetic resonance studies indicated that their structural features include mainly both arabino-3,6-galact an and rhamno-galacturonan type structural units. Both polysaccharides showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test.