Controlled Smith Degradation Research Articles

An acidic polysaccharide having activity on the reticuloendothelial system from the roots and rhizomes of Saposhnikovia divaricata.

An acidic polysaccharide, named saposhnikovan C, was isolated from the roots and rhizomes of Saposhnikovia divaricata Schischk. It was homogeneous as judged by electrophoresis and gel chromatography, and showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test. It is composed of D-galacturonic acid:L-rhamnose:L-arabinose:D-galactose in a molar ratio of 27:7:8:8, and its molecular mass was estimated to be 132000. About 30% of the D-galacturonic acid residues exist as the methyl esters. O-Acetyl groups were identified, and the content amounted to 3.3%. Methylation analysis, carbon-13 nuclear magnetic resonance, and controlled Smith degradation studies indicated the structural features. It has a pectin-like rhamnogalacturonan backbone with branched arabinan and galactan side chains.

Pectic substances. II. The location of O-acetyl groups and the Smith degradation of Zizyphus-pectin A.

The O-acetyl groups in Zizyphus-pectin A from the fruits of Zizyphus jujuba MILLER var. inermis REHD. were located at positions 2, 3, 6 of most of the D-galactopyranosyl residues in galactan side chains. A controlled Smith degradation study supported this conclusion and suggested the presence of continuous branching units in parts of arabinan side chains.

Plant mucilages. XXIX. Isolation and characterization of a mucous polysaccharide, "plantago-mucilage A," from the seeds of Plantago major var. asiatica.

A representative mucous polysaccharide, named Plantago-mucilage A, was isolated from the seeds of Plantago major L. var. asiatica DECAISNE (=Plantago asiatica L.). The final preparation was homogeneous as determined by ultracentrifugal analysis, glass-fiber electrophoresis, and gel chromatography. It was readily soluble in water and its solution gave an intrinsic viscosity value of 39.5. It was composed of L-arabinose, D-xylose, D-glucuronic acid, and D-galacturonic acid in the molar ratio of 4.0 : 10.8 : 3.3 : 0.7, and its molecular weight was estimated to be about 1500000. O-Acetyl groups were identified in it and their content amounted to be 4.8%. Reduction of carboxyl groups, methylation analysis, controlled Smith degradation, and partial acid hydrolysis studies showed that the mucilage possesses a main chain composed of β-1→4 linked D-xylopyranose residues having other D-xylopyranose side chains at position 3 and branches composed of O-α-(D-glucopyranosyluronic acid)-(1→3)-α-L-arabinofuranose and of O-α-(D-galactopyranosyluronic acid)-(1→3)-α-L-arabinofuranose at position 2 of the residual D-xylopyranose units.

STUDIES ON ANTITUMOR POLYSACCHARIDES, ESPECIALLY D-II, FROM MYCELIUM OF CORIOLUS VERSICOLOR

A water-soluble polysaccharide, D-II with marked antitumor activity was isolated from the cultured mycelium of Coriolus versicolor by extraction with hot-water, fractional precipitation with ethanol and ion-exchange chromatography. D-II strongly inhibited the growth of Sarcoma-180 transplanted subcutaneously in mice by intraperitoneal, intravenous, subcutaneous or intra-muscular administration at a dose of 5 mg/kg. The molecular weight was estimated to be 2,000,000 by gel-filtration or 6,500,000 by light scattering analysis. The chemical structure of D-II was then investigated by periodate oxidation, methylation analysis, Smith degradation, and a combination of controlled Smith degradation and methylation analysis. These studies proposed that D-II is composed of a unit structure of four D-glucose residues, and is a glucan consisting of β-D-1,3-linked main chain in which one for every three D-glucose residues is branched at C-6 with β-D-1,6-linkage.

Studies on antitumor polysaccharides, especially D-II, from mycelium of Coriolus versicolor.

A water-soluble polysaccharide, D-II with marked antitumor activity was isolated from the cultured mycelium of Coriolus versicolor by extraction with hot-water, fractional precipitation with ethanol and ion-exchange chromatography. D-II strongly inhibited the growth of Sarcoma-180 transplanted subcutaneously in mice by intraperitoneal, intravenous, subcutaneous or intra-muscular administration at a dose of 5 mg/kg. the molecular weight was estimated to be 2,000,000 by gel-filtration or 6,500,000 by light scattering analysis. The chemical structure of D-II was then investigated by periodate oxidation, methylation analysis, Smith degradation, and a combination of controlled Smith degradation and methylation analysis. These studies proposed that D-II is composed of a unit structure of four D-glucose residues, and is a glucan consisting of beta-D-1,3-linked main chain in which one for every three D-glucose residues is branched at C-6 with beta-D-1,6-linkage.

Plant mucilages. XXIV. The structural features of althaea-mucilage O, a representative mucous polysaccharide from the roots of Althaea officinalis.

Partial acid hydrolysis of Althaea-mucilage O, a representative mucous polysaccharide isolated from the roots of Althaea officinalis L., led to the isolation of five oligosaccharides. Analysis of their components, as well as reduction and methylation, and partial degradation studies showed that these oligosaccharides are O-α-(D-galactopyranosyluronic acid)-(1→2)-L-rhamnopyranose, O-β-(D-glucopyranosyluronic acid)-(1→3)-O-α-(D-galactopyranosyluronic acid)-(1→2)-L-rhamnopyranose, and the hexasaccharide, the nonasaccharide, and the dodecasaccharide composed of a repeating unit having the structure of the trisaccharide through position 4 of the D-galacturonic acid residue. The polysaccharide was also subjected to chromium trioxide oxidation, and to controlled Smith degradation. The configuration and the mode of branching were determined. The structural features of the mucilage are discussed.

Structures of the cell wall polysaccharides of Tremella fuciformis.

The cell wall fraction prepared from the yeast-like cells of Tremella fuciformis was frac-tionated by proteinase digestion, hot-water and alkaline extractions. The acidic polysac-charide, which may originate from the outer layer of the cell wall, was purified from the hot-water extract. It was composed of D-glucuronic acid, D-mannose and n-xylose (molar ratio, 0.5:3.8:1.0). The methylated polysaccharide yielded on acid hydrolysis 2, 3, 4-tri-O-methyl-D-xylose, 2, 3, 4, 6-tetra-O-methyl-, 2, 4, 6-tri-O-methyl-and 4, 6-di-O-methyl-n-mannose, and 2, 3, 4-tri-O-methyl-n-glucuronic acid (molar ratio, 1.0:0.8:2.7:2.3:0.5) together with a trace of 3, 4-di-O-methyl-D-xylose, suggesting that the polysaccharide consists of a backbone of (1→3)-linked D-mannose residues, some of which are substituted at the C-2 positions with single or short side chains of D-xylose, D-mannose and D-glucuronic acid residues. The alkali-insoluble residue of the cell wall was composed of D-glucose, D-glucuronic acid, D-mannose and D-xylose (molar ratio, 4.3:0.6:2.5:1.0). Methylation and periodate oxidation studies suggested it to comprise two polysaccharide moieties, i.e., β-D-glucan and glucurono-xylo-mannan, the structure of the latter resembling that of the cell surface acidic polysaccharide. The glucan moiety was shown by methylation and enzymatic degradation to have a branched structure consisting of β-(1→3)- and (1→6)-linkages (approx. ratio, 2:3). The controlled Smith degradation of the alkali-insoluble polysaccharide yielded an insoluble, degraded, predominantly (1→3)-linked gluco-mannan which may represent the backbone of the cell wall polysaccharide. On the basis of these findings, the constitution of the cell wall is discussed.

An arabinogalactan from extracellular polysaccharides of suspension-cultured tobacco cells.

The structure of an arabinogalactan, separated from extracellular polysaccharides of cultured tobacco cells, has been investigated by methylation analysis of the original polysaccharide and of the products obtained after mild acid hydrolysis and after controlled Smith degradation. The arabinogalactan consists of L-arabinose, D-galactose and L-rhamnose in the molar ratio of 47:45:8. The arabinogalactan has a main chain of (1→3)-linked D-galactopyranosyl residues, half of which are substituted at the 6-position. Most of the side chains consist of three (1→6)-linked D-galactopyranosyl residues, to which L-arabinose residues are attached at C-3. The L-arabinofuranosyl and pyranosyl residues are present as end groups, and L-arabinopyranosyl residues are attached to C-5 of L-arabinofuranosyl residues. Non-reducing terminal L-rhamnopyranosyl residues are also present.

Plant mucilages. XV. The main structural features of the backbone chain of paniculatan.

Paniculatan, the mucous polysaccharide isolated from the inner barks of Hydrangea paniculata SIEB., was found to be composed of L-rhamnose : D-galactose : D-galacturonic acid : D-glucuronic acid : 4-O-methyl-D-glucuronic acid in the approximate molar ratio of 4 : 4 : 3 : 2 : 5. The mucilage has been subjected to the reduction of carboxyl groups and to controlled Smith degradation. As the results of methylation analysis of these products and the original polysaccharide, possible structures of the backbone chain were proposed. The chain is composed of 1→2 linked L-rhamnopyranose residues having branches at position 4 and 1→4 linked D-galactopyranosyluronic acid residues having branches at position 3 in the approximate molar ratio of 2 : 1.

Activation of the Alternative Complement Pathway by Water-Insoluble Glucans of Streptococcus Mutans: The Relation between Their Chemical Structures and Activating Potencies

Water insoluble, sticky glucan was synthesized by reacting glucosyltransferase obtained from the sulture filtrate of cariogenic Streptococcus mutans OMZ 176 on sucrose. This glucan (OMZ 176 glucan), that consisted of the backbone chains of consecutive alpha-1, 3 glucosidic linkages (65%) and the side chain of alpha-1, 6 glucosidic bonds (35%), showed an ability to activate the alternative pathway of the complment system in human serum. Water soluble glucans synthesized from the reaction of glycosyltransferases of S. mutans strain AHT, FA-I, and Ingbritt with sucrose, that have a high content of alpha-1,6 and a low content of alpha-1, 3 glucosidic linkages, were less effective to activate the complement system. Sephadex (G-25) and Dextran (T-2,000 and T-40), that consisted exclusively of alpha-1, 6 glucosidic linkages, did not significantly activate the complement system. Controlled Smith degradation products of OMZ 176 glucan, composed of the alpha-1, 3 linked glucose backbone chain alone, lost its activity. From these results it was concluded that both backbone chain of alpha-1, 3 glucose units and branched alpha-1, 6 glucose units were essential for the OMZ 176 glucan to activate the alternative pathway of the human complement system.

Studies on uronic acid materials : Part XXVIII. Some structural features of Acacia drepanolobium gum

Linkage analysis of Fraction A of A. drepanolobium gum yielded 3- O-β- L-arabinopyranosyl- L-arabinose, 3- O-β- L-arabinofuranosyl- L-arabinose, 3- O-β- D-galactopyranosyl- D-galactose, 6- O-β- D-galactopyranosyl- D-galactose, and the β- D-(1→3)- and β- D-(1→6)-linked trisaccharides. The O-methyl derivative of degraded gum A was analysed, after methanolysis, by gas-liquid partition chromatography. After paper-chromatographic separation of a hydrolysate of methylated, degraded gum A, the resulting O-methyl sugars were characterised. Degraded gum A was subjected to a Smith degradation, and the product was examined by linkage and methylation analysis. Degraded gum A was subjected to a controlled Smith degradation, and the product was shown to contain arabinitol. This shows that at least some of the reducing galactose residues of degraded gum A are substituted at both C-3 and C-6. The structural evidence obtained shows that, although A. drepanolobium gum Fraction A and A. arabica gum are very similar, some differences do exist between these two gums.