THE HEMICELLULOSE OF WHITE ELM (ULMUS AMERICANA) II. CONSTITUTION OF THE METHYL GLUCURONO-XYLAN

1958 ◽  
Vol 36 (11) ◽  
pp. 1467-1474 ◽  
Author(s):  
J. K. Gillham ◽  
T. E. Timell
Keyword(s):  
Glucuronic Acid ◽  
Degree Of Polymerization ◽  
Average Degree ◽  
Glycosidic Bond ◽  
Molar Ratio ◽  
Side Chain ◽  
Partial Hydrolysis ◽  
Ulmus Americana ◽  
Hydrolysis Of

The wood of white elm (Ulmusamericana) has been found to contain less xylan than most other hardwoods. Partial hydrolysis of the hemicellulose component yielded an aldotriouronic acid, a glucuronosyl xylose, 2-O-(4-O-methyl-α-D-glucopyranosyluronic acid)-D-xylopyranose, 4-O-methyl-D-glucuronic acid, and galacturonic acid.Hydrolysis of the fully methylated polysaccharide gave a mixture of 2-O- and 3-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-xylose, and 2-O-(2,3,4-tri-O-methyl-α-D-glucopyranosyluronic acid)-3-O-methyl-D-xylopyranose in a molar ratio of 6:124:1:14. The number-average degree of polymerization of the methylated hemicellulose was 133 and that of the native polymer 185. On the basis of this and other evidence it is suggested that the xylan is linear and contains 185 1,4-linked β-D-xylopyranose residues, every seventh of which carries a single terminal side chain of 4-O-methyl-D-glucuronic acid attached by an α-glycosidic bond through C2 of the xylose. The number of acid groups is larger than in other hardwood hemicelluloses so far studied.

CONSTITUTION OF A 4-O-METHYLGLUCURONOXYLAN FROM THE WOOD OF TREMBLING ASPEN (POPULUS TREMULOIDES MICHX.)

1961 ◽  
Vol 39 (5) ◽  
pp. 1059-1066 ◽  
Author(s):  
J. K. N. Jones ◽  
C. B. Purves ◽  
T. E. Timell
Keyword(s):  
Populus Tremuloides ◽  
Galacturonic Acid ◽  
Glucuronic Acid ◽  
Degree Of Polymerization ◽  
Average Degree ◽  
Quantitative Yield ◽  
Partial Hydrolysis ◽  
Trembling Aspen ◽  
Linear Framework ◽  
Hydrolysis Of

A 4-O-methylglucuronoxylan has been isolated in almost quantitative yield from the wood of trembling aspen (Populustretmuloides Michx.) The hemicellulose was electrophoretically homogeneous and had a number-average degree of polymerization of 212. Partial hydrolysis gave D-xylose, galacturonic acid, 4-O-methylglucuronic acid, and 2-O-(4-O-methyl-α-D-glucopyranosyluronic acid)-D-xylopyranose. Methanolysis and hydrolysis of the fully methylated polysaccharide, which contained 108 xylose residues per average molecule, gave 2-O-methylxylose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-xylose, and methyl 2-O-(2,3,4-tri-O-methyl-α-D-glucopyranosyluronic acid) -3-O-methyl-D-xylopyranoside in a mole ratio of 0.2:95:1:11. It is concluded that the hemicellulose contained a linear framework of approximately 200 (1 → 4)-linked β-D-xylopyranose residues and that, on the average, every ninth xylose unit carried a (1 → 2)-linked 4-O-methyl-α-D-glucuronic acid residue directly attached to the xylan backbone. The polysaccharide is evidently similar to the 4-O-methylglucuron-oxylans occurring in the wood of all arborescent angiosperms so far investigated.

THE CONSTITUTION OF A METHYL GLUCURONOXYLAN FROM KAPOK (CEIBA PENTANDRA)

1959 ◽  
Vol 37 (5) ◽  
pp. 922-929 ◽  
Author(s):  
A. L. Currie ◽  
T. E. Timell
Keyword(s):  
Galacturonic Acid ◽  
Uronic Acid ◽  
Glucuronic Acid ◽  
Molar Ratio ◽  
Side Chain ◽  
Partial Hydrolysis ◽  
Alkaline Extraction ◽  
Branching Points ◽  
Seed Hairs ◽  
Hydrolysis Of

The seed hairs of kapok (Ceibapentandra) on alkaline extraction have yielded a hemicellulose composed of xylose and uronic acid residues. Partial hydrolysis of the polysaccharide gave 2-O-(4-O-methyl-α-D-glucopyranosyluronic acid)-D-xylopyranose, 4-O-methyl-D-glucuronic acid, and, probably, galacturonic acid. Hydrolysis of the fully methylated hemicellulose yielded a mixture of 2-O- and 3-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-xylose, and 2-O-(2,3,4-tri-O-methyl-α-D-glucopyranosyluronic acid)-3-O-methyl-D-xylopyranose in a molar ratio of 1.1:38:1:6. The number-average D.P. of the native and the methylated polysaccharides was 177 and 124, respectively. On the basis of this and other evidence it is suggested that the average hemicellulose molecule contains approximately 180 1,4-linked β-D-xylopyranose residues, one eighth of which carry a single terminal side chain of 4-O-methyl-D-glucuronic acid, attached through an α-glycosidic bond to C2 of the xylose. The xylan framework contains, on the average, slightly less than two branching points per macromolecule, most of them probably originating from C3. The number of acid side chains and branches is twice as large as that of the otherwise similar 4-O-methyl glucuronoxylan present in the seed hairs of milkweed floss.

CONSTITUTION OF AN ARABOGALACTAN FROM JACK PINE (PINUS BANKSIANA LAMB)

1957 ◽  
Vol 35 (9) ◽  
pp. 1010-1019 ◽  
Author(s):  
C. T. Bishop
Keyword(s):  
Methyl Ether ◽  
Pinus Banksiana ◽  
Jack Pine ◽  
Degree Of Polymerization ◽  
Average Degree ◽  
Water Soluble ◽  
Molar Ratio ◽  
Hydrolysis Of ◽  
Homogeneous Hydrolysis

A water soluble arabogalactan isolated from jack pine was shown to have a molar ratio of arabinose to galactose of 1:13, and a number average degree of polymerization of 53 ± 3. Fractionation data and electrophoresis indicated that the arabogalactan was homogeneous. Hydrolysis of the methyl ether of the polysaccharide yielded 2,3,5-tri-O-methyl-L-arabinose (4 moles); 2,3,4,6-tetra-O-methyl-D-galactose (12–13 moles); 2,3,4-tri-O-methyl-D-galactose (19 moles); 2,6-di-O-methyl-D-galactose (1 mole); and 2,4-di-O-methyl-D-galactose (14 moles). Some features of the structure of the arabogalactan are discussed on the basis of these results.

THE STRUCTURE OF THE EXTRACELLULAR POLYSACCHARIDE OF AZOTOBACTER INDICUM

1963 ◽  
Vol 41 (11) ◽  
pp. 2826-2835 ◽  
Author(s):  
V. M. Parikh ◽  
J. K. N. Jones
Keyword(s):  
Glucuronic Acid ◽  
Extracellular Polysaccharide ◽  
Molar Ratio ◽  
Linear Molecule ◽  
Partial Hydrolysis ◽  
Major Fraction ◽  
Sodium Metaperiodate ◽  
Unit Reduction ◽  
Hydrolysis Of

The extracellular polysaccharide of the Azotobacter indicum has been shown to be a mixture of two polymers of which the acidic polymer was a major fraction. The acidic polymer contained D-glycero-D-mannoheptose in the molar ratio of 1:1:1 plus traces of mannose. It consumed 1 mole of sodium metaperiodate per mole of an average anhydroaldose unit and released 0.95 moles of formaldehyde per anhydroheptose unit. Reduction of the oxidized polymer followed by hydrolysis yielded D-glucose, glycerose, glycolaldehyde, and glycerol. Complete fission of the methylated polymer yielded 2,3-di-O-methyl-D-glucuronic acid, 2,4,6,-tri-O-methyl α-D-glucose and 3,4,6,7-tetra-O-methyl D-glycero-D-mannoheptose. Partial hydrolysis of the methylated polymer produced a methylated aldotriouronic acid composed of 1 mole each of 2,3-di-O-methyl-D-glucuronic acid, 2,4,6-tri-O-methyl-D-glucose and 3,4,6,7-tetra-O-methyl D-glycero-D-mannoheptose. A methylated aldobiouronic acid was also produced and was shown to be composed of 2,3-di-O-methyl-D-glucuronic acid and 2,4,6-tri-O-methyl D-glucose.On the basis of these results it is proposed that the polysaccharide is a linear molecule composed of repeating units of D-glucuronic acid, D-glucose, and D-glycero-D-mannoheptose.

Some structural features of the heteropolysaccharides of Candida bogoriensis

1968 ◽  
Vol 46 (21) ◽  
pp. 3407-3411 ◽  
Author(s):  
P. A. J. Gorin ◽  
J. F. T. Spencer
Keyword(s):  
Main Chain ◽  
Glucuronic Acid ◽  
Structural Features ◽  
Side Chain ◽  
Partial Hydrolysis ◽  
Exocellular Polysaccharides ◽  
Hydrolysis Of

The two exocellular polysaccharides of Candida bogoriensis contain D-mannose, D-fucose, L-rhamnose, D-glucuronic acid, and D-galactose residues. The main heteropolymer (> 80%) has an α-D-(1 → 3)-linked mannan main-chain as shown by successive Smith degradations. Partial hydrolysis of the heteropolymers provided several methylpentose-containing oligosaccharide fragments corresponding to possible side-chain components.

THE STRUCTURE OF A SYNTHETIC GLUCAN: I. GENERAL STRUCTURAL FEATURES

1962 ◽  
Vol 40 (6) ◽  
pp. 1196-1200 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau
Keyword(s):  
Petroleum Ether ◽  
Acid Hydrolysis ◽  
Direct Evidence ◽  
Periodate Oxidation ◽  
Structural Features ◽  
Degree Of Polymerization ◽  
Molar Ratio ◽  
Partial Hydrolysis ◽  
Large Numbers ◽  
Hydrolysis Of

Only D-glucose was obtained on acid hydrolysis of the glucan. Periodate oxidation released formaldehyde, which was believed to arise from C6 of D-glucofuranose units. From the additional formaldehyde liberated from the borohydride-reduced glucan the degree of polymerization was estimated to be about 165. Complete hydrolysis of the derived polyalcohol gave glycerol, erythritol, D-glucose, and D-xylose. Partial hydrolysis gave glycerol, erythritol, and at least seven non-reducing oligosaccharides. Direct evidence for the existence of relatively large numbers of 1 → 6 and 1 → 4 linkages was found, together with smaller numbers of 1 → 2 linkages. The methylated glucan was freely soluble in chloroform – petroleum ether (5:95), and hydrolysis gave tetra, tri, di, and mono-O-methyl-D-glucoses in a 6:6:3:1 molar ratio.

THE ALDOBIOURONIC ACIDS OF HEMICELLULOSE B OF OAT HULLS

1956 ◽  
Vol 34 (3) ◽  
pp. 338-344 ◽  
Author(s):  
E. L. Falconer ◽  
G. A. Adams
Keyword(s):  
Glucuronic Acid ◽  
The Other ◽  
Partial Hydrolysis ◽  
Oat Hulls ◽  
Hydrolysis Of

Partial hydrolysis of hemicellulose B from oat hulls yielded two aldobiouronic acids, which were identified as 2-O-(4-O-methyl-α-D-glucopyruronosyl)-D-xylose and 2-O-(α-D-glucopyruronosyl)-D-xylose respectively. In addition, two aldotriouronic acids were isolated, one yielding on hydrolysis xylose and 4-O-methyl-glucuronic acid, and the other, xylose, galactose, and glucurone.

STRUCTURE OF A GALACTURONAN FROM SUNFLOWER PECTIC ACID

1966 ◽  
Vol 44 (11) ◽  
pp. 1275-1282 ◽  
Author(s):  
V. Zitko ◽  
C. T. Bishop
Keyword(s):  
Galacturonic Acid ◽  
Periodate Oxidation ◽  
Degree Of Polymerization ◽  
Critical Assessment ◽  
Molar Ratio ◽  
Aqueous Methanol ◽  
Pectic Acid ◽  
Potassium Borohydride ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of

Fractions of sunflower pectic acid containing 89.8%, 94.2%, and 91.4% of D-galacturonic acid were carboxyl reduced as their methyl or ethylene glycol esters by potassium borohydride. Critical assessment of the effects of three different solvents (water, 80% aqueous dimethyl sulfoxide, and 80% aqueous methanol) on the efficiency of reduction showed that the latter solvent was best. The reductions caused a decrease in the degree of polymerization from 270 to 21. Measurement of the rates of hydrolysis of partially reduced pectic acids containing 90%, 41.6%, 19.9%, 11.0%, and 0.65% of D-galacturonic acid showed that the rate of hydrolysis was directly related to the proportion of galacturonosidic linkages present. Methylation and hydrolysis of the carboxyl-reduced pectic acid fractions yielded 2,3,4,6-tetra-O-methyl-D-galactose and 2,3,6-tri-O-methyl-D-galactose in an approximate molar ratio of 1:20. Results of the periodate oxidation of the carboxyl-reduced pectic acid supported the conclusion inferred from the methylation results that the pectic acid was a linear polymer of 1 → 4 linked α-D-galacturonic acid units.

scholarly journals Studies of the polysaccharide fraction from the lipopolysaccharide of Pseudomonas alcaligenes

1974 ◽  
Vol 139 (3) ◽  
pp. 633-643 ◽  
Author(s):  
James A. Lomax ◽  
George W. Gray ◽  
Stephen G. Wilkinson
Keyword(s):  
Gel Filtration ◽  
Periodate Oxidation ◽  
Side Chain ◽  
Partial Hydrolysis ◽  
Methylation Analysis ◽  
Mild Acid Hydrolysis ◽  
Pseudomonas Alcaligenes ◽  
Crude Polysaccharide ◽  
Hydrolysis Of ◽  
Mild Acid

Studies of the lipopolysaccharide of Pseudomonas alcaligenes strain BR 1/2 were extended to the polysaccharide moiety. The crude polysaccharide, obtained by mild acid hydrolysis of the lipopolysaccharide, was fractionated by gel filtration. The major fraction was the phosphorylated polysaccharide, for which the approximate proportions of residues were; glucose (2), rhamnose (0.7), heptose (2–3), galactosamine (1), alanine (1), 3-deoxy-2-octulonic acid (1), phosphorus (5–6). The heptose was l-glycero-d-manno-heptose. The minor fractions from gel filtration contained free 3-deoxy-2-octulonic acid, Pi and PPi. The purified polysaccharide was studied by periodate oxidation, methylation analysis, partial hydrolysis, and dephosphorylation. All the rhamnose and part of the glucose and heptose occur as non-reducing terminal residues. Other glucose residues are 3-substituted, and most heptose residues are esterified with condensed phosphate residues, possibly in the C-4 position. Free heptose and a heptosylglucose were isolated from a partial hydrolysate of the polysaccharide. The location of galactosamine in the polysaccharide was not established, but either the C-3 or C-4 position appears to be substituted and a linkage to alanine was indicated. In its composition, the polysaccharide from Ps. alcaligenes resembles core polysaccharides from other pseudomonads: no possible side-chain polysaccharide was detected.

CONSTITUTION OF A DEGRADED POLYSACCHARIDE FROM WHEAT BRAN

1957 ◽  
Vol 35 (2) ◽  
pp. 108-114 ◽  
Author(s):  
J. Schmorak ◽  
C. T. Bishop ◽  
G. A. Adams
Keyword(s):  
Acid Hydrolysis ◽  
Wheat Bran ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Glycosidic Bond ◽  
Cellulolytic Enzyme ◽  
Acidic Polysaccharide ◽  
Hydrolysis Of ◽  
End Group ◽  
Acid Unit

Graded acid hydrolysis of a soluble wheat bran hemicellulose containing L-arabinose (50%), D-xylose (38.5%), and D-glucuronic acid (9.0%) preferentially removed the L-arabinose giving an insoluble acidic polysaccharide in approximately 25% yield by weight. Methylation studies, periodate oxidation data, and hypoiodite end group estimations showed that the degraded polysaccharide was composed of repeating units of 7-8 D-xylopyranose residues joined by β,1 → 4 linkages. To this repeating unit, one D-glucuronic acid unit was attached by a 1 → 2 glycosidic bond. The cellulolytic enzyme of Myrotheciumverrucaria, which is specific for β,1 → 4 glycosidic linkages, hydrolyzed the degraded polysaccharide although it had no effect on the parent hemicellulose

Sign in / Sign up

Export Citation Format

Share Document