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.

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.

Partial hydrolysis of acyl 1,6-anhydro-β-D-glucopyranose

1984 ◽  
Vol 49 (8) ◽  
pp. 1780-1787 ◽  
Author(s):  
Štefan Kučár ◽  
Juraj Zámocký ◽  
Juraj Zemek ◽  
Dušan Anderle ◽  
Mária Matulová
Keyword(s):  
Acid Hydrolysis ◽  
Hydrazine Hydrate ◽  
Hydrogen Chloride ◽  
Ester Group ◽  
The Other ◽  
Hydroxyl Group ◽  
Partial Hydrolysis ◽  
Substantial Influence ◽  
Hydrolysis Of ◽  
Derivatives Of

Partial hydrolysis of per-O-acetyl- and per-O-benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose with methanolic hydrogen chloride and hydrazine hydrate was investigated. The acyl group at C(3) is of substantial influence on the course of hydrolysis. The esterified hydroxyl group at C(3) was found to be most stable on acid hydrolysis with methanolic hydrogen chloride when compared with that at C(2), or C(4); on the other hand, this ester group is the most labile upon hydrolysis with hydrazine hydrate. Selectivity of the respective ester groups towards hydrolysis made it possible to prepare all variations of acetyl and benzoyl derivatives of 1,6-anhydro-β-D-glucopyranose.

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.

Alkaloids of the Australian Apocynaceae: Kopsia longiflora Merr. III. Preliminary Degradation of the Alkaloids

1962 ◽  
Vol 15 (1) ◽  
pp. 130 ◽  
Author(s):  
WD Crow ◽  
M Michael
Keyword(s):  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Alkaline Hydrolysis ◽  
The Other ◽  
Partial Hydrolysis ◽  
Residual Oxygen ◽  
Methoxycarbonyl Group ◽  
Additional Oxygen Atom ◽  
Hydrolysis Of ◽  
Aromatic Ether

Graded alkaline hydrolysis of the monoacid tertiary bases kopsiflorine (C23H28O5N2), kopsilongine (C24H30O6N2), and kopsamine (C24H28O7N2) shows that they contain two methoxycarbonyl groups. All but one of the residual oxygen atoms are accounted for as aromatic ether linkages. One of the methoxycarbonyl groups is responsible for the deactivation of the other nitrogen atom (N(a)) present, since anew basic centre is generated by partial hydrolysis and subsequent decarboxylation of the acid produced. The alkaloids are tentatively formulated as blocked indoline bases containing a urethane grouping at N(a). The fourth alkaloid, kopsinine (C21H26O2N2) is similarly formulated, but in this case N(a) is weakly basic, the urethane methoxycarbonyl group and the additional oxygen atom being absent.

CONSTITUTION OF THREE HEMICELLULOSES FROM THE WOOD OF ENGELMANN SPRUCE (PICEA ENGELMANNI)

1963 ◽  
Vol 41 (6) ◽  
pp. 1389-1395 ◽  
Author(s):  
A. R. Mills ◽  
T. E. Timell
Keyword(s):  
Glucuronic Acid ◽  
Water Soluble ◽  
Partial Hydrolysis ◽  
Side Chains ◽  
Engelmann Spruce ◽  
Linear Framework ◽  
Single Side ◽  
Hydrolysis Of ◽  
Picea Engelmanni

An arabino-4-O-methylglucuronoxylan (10:70:12), a water-soluble galactoglucomannan (1:1:3), and an alkali-soluble galactoglucomannan (0.2:1:3) have been isolated in yields of 8.0, 1.0, and 8.1% from the wood of Engelmann spruce (Picea engelmanni). The xylan consisted of a linear framework of (1 → 4)-linked β-D-xylose residues to which were directly attached single side chains of (1 → 2)-linked 4-O-methyl-α-D-glucuronic acid and (1 → 3)-linked α-L-arabinofuranose residues. The galactoglucomannans were both composed of a backbone of (1 → 4)-linked β-D-mannose and β-D-glucose residues, some of which carried directly attached side chains of (1 → 6)-linked α-D-galactopyranose residues. Partial hydrolysis of the water-soluble galactoglucomannan yielded, among other oligosaccharides, a trisaccharide composed of galactose, glucose, and mannose residues. It is concluded that the main polysaccharides in the wood of Engelmann spruce are the same as those in most other gymnosperms. In the bark of this tree, the water-soluble galactoglucomannan is replaced by one or several polysaccharides of an entirely different composition.

THE CONSTITUTION OF A HEMICELLULOSE FROM SUGAR MAPLE (ACER SACCHARUM)

1959 ◽  
Vol 37 (5) ◽  
pp. 893-898 ◽  
Author(s):  
T. E. Timell
Keyword(s):  
Acer Saccharum ◽  
Galacturonic Acid ◽  
Sugar Maple ◽  
Glucuronic Acid ◽  
Linear Chain ◽  
European Beech ◽  
Partial Hydrolysis ◽  
White Birch ◽  
Yellow Birch ◽  
Hydrolysis Of

Partial hydrolysis of the main hemicellulose constituent of sugar maple (Acersaccharum) has yielded D-xylose, D-galacturonic acid, 4-O-methyl-D-glucuronic acid, and 2-O-(4-O-methyl-α-D-glucosyluronic acid)-D-xylose. 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-glucosyluronic acid)-3-O-methyl-D-xylose in a mole ratio of 3:111:1:12. The number-average degrees of polymerization of the native and the methylated polysaccharide were 205 and 149, respectively. These data indicate that the hemicellulose is composed of a linear chain of 1,4-linked β-D-xylose residues and that on the average every tenth residue of the chain carries a terminal 4-O-methyl-D-glucuronic acid residue attached through its C2. The structure of the polysaccharide is similar to that of the main hemicellulose component of European beech, white birch, and yellow birch.

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.

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.

Sign in / Sign up

Export Citation Format

Share Document