Heterogeneity and characterisation of mitogenic and anti-complementary pectic polysaccharides from the roots of Glycyrrhiza uralensis Fisch et D.C.
Two anti-complementary polysaccharide fractions (GR-2IIa and GR-2IIb), isolated from the roots of Glycyrrhiza uralensis Fisch et D.C., each gave five anti-complementary polysaccharides (GR-2IIa-1-5 and GR-2IIb-1-5) on h.p.l.c.; likewise, GR-2IIc gave two anti-complementary and mitogenic polysaccharides (GR-2IIc-1-2A and -2IIc-2) by gel filtration and h.p.l.c. GR-2IIc-1-2A showed the most potent anti-complementary activity. GR-2IIa-1-5 and GR-2IIb-1-5 contained 40-85% and 50-90% of GalA, respectively, in addition to Rha, Ara, and Gal. GR-2IIc-1-2A and -2IIc-2 mainly comprised Glc, Gal, GalA, and GlcA in addition to Rha, Fuc, Xyl, Ara, and Man. Methylation analysis and digestion with endo-alpha-(1----4)-polygalacturonase indicated that all of the polysaccharides contained polygalacturonan regions which were frequently methyl-esterified. GR-2II-a, -2IIb, and -2IIc gave enzyme-resistant fractions of large and intermediate sizes, in addition to oligogalacturonides. Each large fraction from GR-2IIa and -2IIb consisted mainly of Ara, Gal, and GalA, whereas the intermediate fractions were composed of small proportions of 2-Me-Fuc, 2-Me-Xyl, and apiose (Api), in addition to Rha, Ara, Gal, and GalA. The large fraction from GR-2IIc mainly contained Rha, Man, Gal, and GalA in addition to Fuc, Ara, Xyl, and Glc, whereas the intermediate fraction consisted of 2-Me-Fuc, 2-Me-Xyl, and Api, in addition to Rha, Ara, GalA, Fuc, Xyl, Man, Gal, and Glc. Base-catalysed beta-elimination followed by ethylation indicated that all the polysaccharides except GR-2IIc-2 contained a 4-linked uronic acid attached to position 2 of 2,4-linked Rha. Single radial gel diffusion, using the beta-D-glucosyl-Yariv antigen, indicated that GR-2IIa-1 and GR-2IIc-2 contained relatively large proportions of (1----3,6)-beta-D-galactan moieties. The anti-complementary activities of GR-2IIa-3, GR-2IIa-4, and GR-2IIb-4 decreased after de-esterification followed by digestion with endo-alpha-(1----4)-polygalacturonase. The large fractions from GR-2IIa-2IIc showed more potent anti-complementary activities than the original polysaccharide fractions, whereas the intermediate fractions and oligogalacturonides were inactive. The large fraction from GR-2IIc had more potent mitogenic activity than GR-2IIc, whereas the intermediate fraction and oligogalacturonides from GR-2IIc were inactive.
Zhao
J F
JF
Oriental Medicine Research Center of the Kitasato Institute, Tokyo, Japan.
Kiyohara
H
H
Yamada
H
H
Takemoto
N
N
Kawamura
H
H
D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006035:Glycyrrhiza / Q000737:chemistry*; D008934:Mitogens / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D009005:Monosaccharides / Q000032:analysis; D010368:Pectins / Q000302:isolation & purification* / Q000494:pharmacology; D008517:Phytotherapy; D010946:Plants, Medicinal; D011096:Polygalacturonase / Q000378:metabolism
D000276:Adjuvants, Immunologic; D008934:Mitogens; D009005:Monosaccharides; D010368:Pectins; D011096:Polygalacturonase