Pectic polysaccharides from roots of Glycyrrhiza uralensis: possible contribution of neutral oligosaccharides in the galacturonase-resistant region to anti-complementary and mitogenic activities.
Digestion with endo-alpha-(1-->4)-polygalacturonase liberated the enzyme-resistant region (PG-1c) as an active site of the anti-complementary and mitogenic pectic polysaccharide (GR-2IIc) from Glycyrrhiza uralensis. Partial acid hydrolysis of PG-1c resulted in acidic oligosaccharides, and methylation analysis and GC-MS analysis of the acidic oligosaccharides suggested that PG-1c comprised a rhamnogalacturonan core such as -->2)-Rha-(1-->4)-GalA-(1-->2)-Rha-(1-->4)-GalA-(1-->-->4)-GalA-(1-->4) as the acidic moiety. Degradation of uronic acids by lithium decreased the anti-complementary and mitogenic activities of PG-1c. Although the products from PG-1c were still active, the methylglycoside of alpha-L-Rha-(1-->4)-alpha-D-GalA-(1-->2)-alpha-L-Rha-(1-->4)-alpha-D-Gal A did not show both activities. The products obtained by the lithium degradation from PG-1c gave fractions containing various neutral oligosaccharide-alditols. Among these fractions the longest and the short oligosaccharide-alditol fractions had relatively potent anti-complementary activity, whereas all oligosaccharide-alditol fractions expressed weak but significant mitogenic activity. GC-MS analysis indicated that the short oligosaccharide-alditol fraction contained various kinds of di- to tetrasaccharide-alditols. However, malto-oligosaccharide-alditols, and malto-, isomalto-, and laminari-oligosaccharides did not show anti-complementary and/or mitogenic activities, and these results suggested that certain neutral carbohydrate chains in PG-1c were responsible for the expression of mitogenic activity as well as anti-complementary activity of PG-1c.
Kiyohara
H
H
Oriental Medicine Research Center of the Kitasato Institute, Tokyo, Japan.
Takemoto
N
N
Zhao
J F
JF
Kawamura
H
H
Yamada
H
H
D000818:Animals; D002240:Carbohydrate Sequence; D002478:Cells, Cultured; D003169:Complement Inactivator Proteins / Q000494:pharmacology*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D051379:Mice; D008807:Mice, Inbred BALB C; D008934:Mitogens / Q000494:pharmacology*; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000737:chemistry*; D011096:Polygalacturonase / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*
D003169:Complement Inactivator Proteins; D008934:Mitogens; D011134:Polysaccharides; D011096:Polygalacturonase