Eleven polysaccharides have been isolated from the hot water extracts of several Oriental crude drugs. They showed remarkable reticuloendothelial system (RES)-potentiating activity. The effect of the polysaccharides on the RES was demonstrated by a modification of the in vivo carbon clearance test using ICR-SPF male mice. Structural features of the immunologically active polysaccharides were elucidated by chemical and spectral procedures. Saposhnikovans A, B, and C were obtained from the roots and rhizomes of Saposhnikovia divaricata. The ''A'' has α-1→4-linked D-galacturonan backbone bearing α-1→5-linked L-arabino-β-3,6-branched D-galactan side chains, and the ''C'' possesses a pectin-like rhamnogalacturonan backbone carrying α-3,5-branched L-arabinan and β-3,4-branched D-galactan side chains. A neutral polysaccharide (MVS-I) and two acidic polysaccharides (MVS-IIIA and -IVA) were isolated from the seeds of Malva verticillata. MVS-I has a backbone consisting of β-1→3-linked D-glucan and D-galactan bearing α-1→5-linked L-arabinan and β-1→4-linked D-galactan side chains. The basic structure of both MVS-IIIA and MVS-IVA consists of α-1→5-linked L-arabino-β-3,6-branched D-galactan. In addition, both the substances have 1→3-linked L-arabinopyranosyl residues with β-1→4-linked D-xylan and α-1→4-linked D-galacturonan units. An arabinoxylan, named cinnaman AX, was obtained from the barks of Cinnamomum cassia. It possesses β-1→4-linked D-xylan backbone carrying side chains composed of both α-L-Araf-(1→3)-β-L-Arap and α-L-Araf-(1→4)-β-D-Xylp-(1→3)-β-L-Arap units at position of 3 of ca. 70 % of xylose residues. The rhizomes of Curcuma longa afforded four highly active substances, named ukonans A, B, C, and D. These polysaccharides have a common structural unit of α-L-arabino-β-3,6-branched D-galactan with α-1→3-linked L-arabinopyranosyl residues, β-3,4-branched D-xylan, α-1→4-linked D-glucan, and rhamnogalacturonan units. Deacetylated product of Plantago-mucilage A, the mucous polysaccharide isolated from the seeds of Plantago asiatica, also showed remarkable activity. This substance has β-1→4-linked D-xylan backbone bearing side chains composed of ̄-D-Xylp and of α-D-GlcpA-(1→3)-α-L-Araf at position 3.
|Journal of Pharmacobio-Dynamics
|Published - 1990 Jan 1
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