CONSTITUTION OF AN ACIDIC XYLAN FROM TAMARACK (LARIX LARICINA)

1960 ◽  
Vol 38 (12) ◽  
pp. 2402-2409 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Molecular Weight ◽  
Uronic Acid ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Degree Of Polymerization ◽  
Single Units ◽  
Larix Laricina ◽  
Glycosidic Bonds

An acidic xylan isolated from tamarack wood contained arabinose, xylose, and uronic acid (1:17:3) and was homogeneous on examination by electrophoresis and sedimentation. Molecular weight estimations by four different methods showed a degree of polymerization of 20. Methylation and periodate oxidation showed that the xylan consisted of ca. 16 β-D-xylopyranose units joined by 1 → 4 glycosidic bonds with the possible occurrence of one 1 → 3 linkage. To this unbranched structure were attached as side branches, three single units of 4-O-methyl-D-glucuronic acid through C2 and one unit of L-arabofuranose through C3.

CONSTITUTION OF A POLYURONIDE HEMICELLULOSE FROM WHEAT LEAF

1954 ◽  
Vol 32 (2) ◽  
pp. 186-194 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Uronic Acid ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Reducing Power ◽  
Degree Of Polymerization ◽  
Acid Anhydride ◽  
Alkaline Extraction ◽  
Wheat Leaf ◽  
Wheat Leaves ◽  
Acid Unit

Crude hemicellulose of mature wheat leaves has been prepared by alkaline extraction of leaf holocellulose. Purification by repeated complexing with Fehling′s solution yielded a polyuronide hemicellulose [Formula: see text] composed of D-xylose (88.5%), L-arabinose (6.90%), and uronic acid anhydride (5.27%). Methylation studies indicated a molecular structure comprising a main xylan chain of 30 an-hydro- D-xylose residues to which three L-arabinose residues and one D-glucuronic acid unit were attached as side chains by glycosidic linkages. Periodate oxidation data supported the proposed structure and the yield of formic acid indicated a molecule containing approximately 32 sugar residues. Estimations of the degree of polymerization of the molecule by measurements of viscosity and reducing power agreed with the foregoing values. The structure of the hemicellulose closely resembled that of one isolated previously from wheat straw.

THE CONSTITUTION OF A POLYURONIDE HEMICELLULOSE FROM WHEAT STRAW

1952 ◽  
Vol 30 (9) ◽  
pp. 698-710 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Wheat Straw ◽  
Uronic Acid ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Reducing Power ◽  
Molar Ratio ◽  
Acid Complex ◽  
Glycosidic Bonds ◽  
A Chain ◽  
End Group

The structure of a polyuronide hemicellulose from wheat straw containing xylose, arabinose, and hexuronic acid units has been investigated. Graded hydrolysis preferentially removed anhydro-L-arabinose units leaving a xylan to which uronic acid units were attached. Methylation and hydrolysis yielded 2,3,4-trimetliyl xylose (2.7%) indicating one nonreducing end group per 37 units; 2,3,5-trimethyl-L-arabinose, 2,3-dimethyl-D-xylose, and 2-methyl-D-xylose were found in a molar ratio 1:5:1. In addition, a methylated uronic acid complex was recovered which on extensive hydrolysis yielded an aldobiuronic acid. The latter, on reduction with sodium borohydride, yielded 2,3,4-trimethyl glucose (1 mole) and 2-methyl xylose (1 mole); the structure 2-methyl 3[2,3,4-trimethyl α-D-glucuronosido] D-xylose was therefore indicated for the methylated aldobiuronic acid.A structure for the hemicellulose is proposed which consists of approximately 32 anhydro-D-xylose units linked β 1,4- in a chain to which five anhydro-L-arabinose and three D-glucuronic acid units are attached as side groups by 1,3-glycosidic bonds. Results of periodate oxidation and estimation of reducing power support the proposed structure.

scholarly journals Structural studies on heparan sulphate from human lung fibroblasts. Characterization of oligosaccharides obtained by selective periodate oxidation of d-glucuronic acid residues followed by scission in alkali

1980 ◽  
Vol 191 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Ingrid Sjöberg ◽  
Lars-Ȧke Fransson
Keyword(s):  
Uronic Acid ◽  
Glucuronic Acid ◽  
Human Lung ◽  
General Structure ◽  
Heparan Sulphate ◽  
Periodate Oxidation ◽  
Exchange Chromatography ◽  
Lung Fibroblasts ◽  
Human Lung Fibroblasts ◽  
Iduronic Acid

1. 3H- and 35S-labelled heparan sulphate was isolated from monolayers of human lung fibroblasts and subjected to degradations by (a) deaminative cleavage and (b) periodate oxidation/alkaline elimination. Fragments were resolved by gel- and ion-exchange-chromatography. 2. Deaminative cleavage of the radioactive glycan afforded mainly disaccharides with a low content of ester-sulphate and free sulphate, indicating that a large part (approx. 80%) of the repeating units consisted of uronosyl-glucosamine-N-sulphate. Blocks of non-sulphated [glucuronosyl-N-acetyl glucosamine] repeats (3–4 consecutive units) accounted for the remainder of the chains. 3. By selective oxidation of glucuronic acid residues associated with N-acetylglucosamine, followed by scission in alkali, the radioactive glycan was degraded into a series of fragments. The glucuronosyl-N-acetylglucosamine-containing block regions yielded a compound N-acetylglucosamine–R, where R is the remnant of an oxidized and degraded glucuronic acid. Periodate-insensitive uronic acid residues were recovered in saccharides of the general structure glucosamine–(uronic acid–glucosamine)n–R. 4. Further degradations of these saccharides via deaminative cleavage and re-oxidations with periodate revealed that iduronic acid may be located in sequences such as glucosamine-N-sulphate→iduronic acid→N-acetylglucosamine. Occasionally the iduronic acid was sulphated. Blocks of iduronic acid-containing repeats may contain up to five consecutive units. Alternating arrangements of iduronic acid- and glucuronic acid-containing repeats were also observed. 5. 3H- and 35S-labelled heparan sulphates from sequential extracts of fibroblasts (medium, EDTA, trypsin digest, dithiothreitol extract, cell-soluble and cell-insoluble material) afforded similar profiles after both periodate oxidation/alkaline elimination and deaminative cleavage.

THE STRUCTURAL ANALYSIS OF SOME ACIDIC XYLANS BY PERIODATE OXIDATION

1962 ◽  
Vol 40 (2) ◽  
pp. 348-352 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau
Keyword(s):  
Acid Hydrolysis ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Small Degree ◽  
Degree Of Polymerization ◽  
Borohydride Reduction ◽  
Mild Acid Hydrolysis ◽  
Degree Of Branching ◽  
Hydrolysis Of ◽  
Mild Acid

By determining the amount of formaldehyde produced on periodate oxidation of borohydride-reduced apple- and cherry-wood xylans the degree of polymerization was shown to be 155 and 100 respectively. Acid hydrolysis of the polyols obtained by periodate oxidation and borohydride reduction gave ethylene glycol in amounts indicating that these xylans have a small degree of branching. Mild acid hydrolysis of the polyols demonstrated that in these xylans D-glucuronic acid as well as 4-O-methyl-D-glucuronic acid was present and that some of the former occupied non-terminal positions.

Structure of the acidic capsular polysaccharide of Cryptococcus laurentii (NRRL Y-1401)

1982 ◽  
Vol 60 (2) ◽  
pp. 124-130 ◽  
Author(s):  
Malcolm B. Perry ◽  
Ann C. Webb
Keyword(s):  
Molecular Weight ◽  
Capsular Polysaccharide ◽  
Glucuronic Acid ◽  
Optical Rotation ◽  
Periodate Oxidation ◽  
Regular Structure ◽  
Cryptococcus Laurentii ◽  
Partial Acid Hydrolysis ◽  
Magnetic Resonance Studies ◽  
Structure Formula

The capsular polysaccharide produced by Cryptococcus laurentii (NRRL Y-1401) is composed of D-mannose (3 mol), D-glucuronic acid (1 mol), D-xylose (1 mol), and O-acetyl (~1 mol). Methylation, periodate oxidation, partial acid hydrolysis, optical rotation, and nuclear magnetic resonance studies showed that the polysaccharide is a high molecular weight branched polymer of regular structure having a repeating pentasaccharide unit with the structure:[Formula: see text]

CONSTITUTION OF A HEMICELLULOSE FROM WHEAT BRAN

1955 ◽  
Vol 33 (1) ◽  
pp. 56-67 ◽  
Author(s):  
G. A. Adams
Keyword(s):  
Oxalic Acid ◽  
Wheat Bran ◽  
Uronic Acid ◽  
Periodate Oxidation ◽  
Reducing Power ◽  
Degree Of Polymerization ◽  
Alkaline Extraction ◽  
Acidic Polysaccharide ◽  
Simultaneous Production ◽  
Hydrolysis Of

The hemicellulose prepared from wheat bran by alkaline extraction was an acidic polysaccharide containing arabinose (50.0%), xylose (38.5%), and uronic acid (9.0%). Graded hydrolysis with 0.02 N oxalic acid preferentially released 65% of the arabinose with only a small simultaneous production of xylose. Hydrolysis of the full methylated hemicellulose yielded 2,3,4-tri-O-methyl-, 2,3-di-O-methyl-, 2-O-methyl-, and free D-xylose; 2,3,5-tri-O-methyl-, 2,5-di-O-methyl-, and probably 3- and 5-O-methyl-L-arabinose. These data, together with those from periodate oxidation, strongly suggested that the molecule was a highly branched araboxylan. Viscosity measurements and reducing power determinations indicated a degree of polymerization of 300.

CONSTITUTION OF THE HEMICELLULOSE FROM MESTA FIBER (HIBISCUS CANNABINUS)

1963 ◽  
Vol 41 (9) ◽  
pp. 2346-2350 ◽  
Author(s):  
S. K. Sen
Keyword(s):  
Molecular Weight ◽  
Uronic Acid ◽  
Average Molecular Weight ◽  
Analytical Data ◽  
Degree Of Polymerization ◽  
Hibiscus Cannabinus ◽  
Molar Ratio ◽  
Alkaline Solutions ◽  
Number Average Molecular Weight ◽  
Hydrolysis Of

The chlorite holocellulose of mesta fiber (Hibiscus cannabinus) was extracted with alkaline solutions of successively increasing concentration and finally with alkaline borate solution. Hemicellulose fractions (I–IV) were thus obtained. Analytical data are recorded for each fraction.Partial acid hydrolysis of the mesta hemicellulose gave 2-O-(4-O-methyl-α-D-glucopyranosyl uronic acid)-D-xylopyranose. Methanolysis and hydrolysis of the fully methylated hemicellulose (fraction II) gave a mixture of 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-glucopyranosyl uronic acid)-3-O-methyl-D-xylopyranose in the approximate molar ratio of 1.6:34:1:6.4. The number-average molecular weight of the methylated polysaccharide was 18,400 ± 500 (degree of polymerization, 110 ± 3). The number-average molecular weight of the original hemicellulose (fraction II) was found to be 23,000 ± 500 (degree of polymerization, 164 ± 3). On the basis of this and other evidences it is suggested that the polysaccharide is composed of chains of 144 (1 → 4)-linked β-D-xylopyranose residues having approximately every seventh residue carrying a terminal 4-O-methyl-α-D-glucuronic acid residue linked through position 2. A small degree of branching in the backbone of D-xylose is indicated.

CONSTITUTION OF AN EXTRACELLULAR ACIDIC GLUCOMANNAN FROM SERRATIA MARCESCENS

1965 ◽  
Vol 43 (11) ◽  
pp. 2940-2946 ◽  
Author(s):  
G. A. Adams ◽  
Robert Young
Keyword(s):  
Fatty Acids ◽  
Serratia Marcescens ◽  
Moving Boundary ◽  
Glucuronic Acid ◽  
Periodate Oxidation ◽  
Chain Structure ◽  
Degree Of Polymerization ◽  
Vapor Pressure Osmometry ◽  
Straight Chain ◽  
Mannose Residue

An acidic glucomannan isolated from culture filtrate of Serratia marcescens contained D-glucose and D-mannose (3.5:1), D-glucuronic acid (5.5%), and "bound" fatty acids (7.4%). The polysaccharide, on examination by moving boundary electrophoresis and by sedimentation in the ultracentrifuge, was homogeneous. Degree of polymerization was estimated to be ca. 20 by vapor pressure osmometry. Isolation of nigerose (3-O-α-D-glucopyranosyl-D-glucopyranose) established the glycosidic linkage between the D-glucose units as α (1 → 3). Methylation and periodate oxidation data showed that the D-glucose and D-mannose units were joined by (1 → 3) linkages in a straight chain structure terminated at the non-reducing end by a unit of D-glucuronic acid which was attached to C3 of a D-mannose residue. The reducing end of the molecule was terminated by a D-glucose unit. The fatty acids, consisting mainly of hydroxymyristic acid and myristic acid, were attached to the molecule mainly by ester linkages.

The specific capsular polysaccharide of Streptococcus pneumoniae type 9V

1981 ◽  
Vol 59 (7) ◽  
pp. 524-533 ◽  
Author(s):  
Malcolm B. Perry ◽  
Virginia Daoust ◽  
Dennis J. Carlo
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Streptococcus Pneumoniae ◽  
Capsular Polysaccharide ◽  
Glucuronic Acid ◽  
Optical Rotation ◽  
Periodate Oxidation ◽  
Partial Hydrolysis ◽  
Part D ◽  
Magnetic Resonance Studies

The specific capsular polysaccharide produced by Streptococcus pneumoniae type 9V (American type 68) is composed of D-glucuronic acid (1 part), D-galactose (1 part), 2-acetamido-2-deoxy-D-mannose (1 part), D-glucose (2 parts), and O-acetyl (1.6 parts). Methylation, periodate oxidation, optical rotation, and nuclear magnetic resonance studies, and partial hydrolysis showed that the polysaccharide is an unbranched high molecular weight linear polymer of a partially O-acetylated pentasaccharide repeating unit having the structure indicated below.[Formula: see text]

Binding of lead and copper(II) cations to hemicelluloses of rye bran

1986 ◽  
Vol 51 (10) ◽  
pp. 2250-2258 ◽  
Author(s):  
Rudolf Kohn ◽  
Zdena Hromádková ◽  
Anna Ebringerová
Keyword(s):  
Uronic Acid ◽  
Equilibrium Solution ◽  
Glucuronic Acid ◽  
The Other ◽  
Carboxyl Groups ◽  
Stoichiometric Ratio ◽  
Molar Ratios ◽  
Free Ions ◽  
Uronic Acid Content ◽  
The Relationship

Several fractions of acid hemicelluloses isolated from rye bran were characterized by molar ratios of saccharides (D-Xyl, L-Ara, D-Glc, D-Gal) and 4-O-methyl-D-glucuronic acid and protein content. Binding of Pb2+ and Cu2+ ions to these acid polysaccharides was considered according to function (M)b = f([M2+]f), expressing the relationship between the amount of metal (M)b bound to 1 g of the substance and the concentration of free ions [M2+]f in the equilibrium solution and according to the association degree β of these cations with carboxyl groups of uronic acid at a stoichiometric ratio of both components in the system under investigation. Acid hemicelluloses contained only a very small portion of uronic acid ((COOH) 0.05-0.18 mmol g-1); the model polysaccharide, 4-O-methyl-D-glucurono-D-xylan of beech, was substantially richer in uronic acid content ((COOH) 0.73 mmol g-1). Consequently, the amount of lead and copper bound to acid hemicelluloses is very small ((M)b 0.017-0.025 mmol g-1) at [M2+]f = 0.10 mmol l-1. On the other hand, much greater amount of cations ((M)f 0.09-0.10 mmol g-1) was bound to the glucuronoxylan. The association degree β was like with the majority of samples (β = 0.31-0.38). The amount of lead and copper(II) bound to acid hemicelluloses from rye bran is several times lower than that bound to dietary fiber isolated from vegetables (cabbage, carrot), rich in pectic substances.

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