Characterization of an extracellular polysaccharide from a xanthomonas species

An extracellular polysaccharide containing glucose, mannose, D-manno-octulosonic acid (KDO), an unidentified component (X), and acetyl groups in the molar ratio of 1.3:3.8:1.6:1.1:2.9, was obtained from the incubated medium of a Xanthomonas species. The extracellular polysaccharide contained traces of phosphate and nitrogen but no lipid. Mild hydrolysis with 0.025M sulfuric acid released all of the KDO in the polysaccharide and a KDO-free product was obtained, which on hydrolysis with 0.05M sulfuric acid, gave mainly an oligosaccharide containing glucose, mannose, and X in molar ratio of 1:1:1. The reducing end-group of this oligosaccharide was X, and other hexose residues were linked (1 → 4). Compound X seems to be a 6-deoxyhexose that differs from fucose and rhamnose.     

Chemical structure of an acidic polysaccharide produced by serratia piscatorum

The acidic polysaccharide of Serratia piscatorum consists of L-rhamnopyranosyl, D-galactopyranosyl, and D-galactopyranosyluronic acid residues in the molar ratio of 2:1:1. Some of the D-galactopyranosyluronic acid residues are acetylated at O-2 or O-3, or both. Smith degradation and methylation analysis indicated that the L-rhamnopyranosyl, D-galactopyranosyl, and D-galactopyranosyluronic acid residues are substituted with glycosidic linkages at O-3, O-3, and O-4, respectively. Partial acid hydrolysis of the native polysaccharide gave four acidic oligosaccharides, each of which was isolated and characterized, suggesting the following tetrasaccharide repeating unit: →3)-L-Rhap-(1→4)-D-GalAp-(1→3)-L-Rhap-(1→3)-D-Galp-(1→.     

Isolation and chemical characterization of compounds isolated fromAspergillus flavus conidia

Three types of heterogenous preparations and four types of preparations of polysaccharide nature were obtained in studies aimed at the isolation of active compounds fromAspergillus flavus conidia bearing their biological stimulatory activity. Extraction with trichloroacetic acid at 0 °C yielded a preparation in which the protein component predominated over the polysaccharide moiety at a ratio of 3: 1. In the preparation isolated from the phenolic phase of the phenol—water mixture at 68 °C the protein polysaccharide ratio was 1 : 1. In the material extracted in the aquoues phase and in that obtained by extraction with acetic acid at 100 °C the polysaccharide portion highly predominated (8 : 1 and 7 : 1 respectively).     

Structural investigations of the extracellular polysaccharides elaborated by Beijerinckia mobilis

The extracellular mucilage from Beijerinckia mobilis, a member of the Azotobacteriaceae, after removal of contaminating protein, was separated into a neutral polysaccharide (N-2, 10%); a neutral, dialysable fraction (N-1, 5%), consisting of glucose and oligosaccharides containing glucose, arabinose, and rhamnose; and an acidic polysaccharide (85%). N-2 (mol. wt, 1900) was highly branched and comprised glucopyranose, mannopyranose, and arabinofuranose residues (1:1:1). The various linkages were determined. The acid fraction was a polymer of high molecular weight composed of L-guluronic acid (65%), D-glucose (15%), and D-glycero-D-mannoheptose (20%), together with acetic and pyruvic acids. From the results of methylation, periodate oxidation, and partial hydrolysis, a branched molecule with a backbone of guluronic acid and heptose, and side chains of glucose and guluronic acid is proposed. Pyruvic acid was found to be acetal-linked to 2?5% of the heptose residues. The similarities between this polysaccharide and that from the related species Azotobacter indicum are discussed.     

Mucilage from a fresh-water red alga of the genus Batrachospermum

The gelatinous polysaccharides of a Batrachospermum species have been extracted from the alga. The major polysaccharide is acidic and has been separated from neutral polysaccharides by chromatography on DEAE-cellulose. The constituent sugars of the acidic polysaccharide include d- and l-galactose, d-mannose, d-xylose, l-rhamnose, d-glucuronic acid, and two O-methyl sugars, which have been characterized as 3-O-methyl-l-rhamnose (l-acofriose and 3-O-methyl-d-galactose. Partial acid hydrolysis of this polysaccharide has given a complex mixture of neutral and acidic oligosaccharides. The two preponderant acidic oligosaccharides contained galactose and glucuronic acid in 1:1 ratio, suggesting the presence of a repeating sequence of these two residues as a major structural feature of the polysaccharide.     

Structural studies of the capsular polysaccharide of Klebsiella type 52

The structure of the capsular polysaccharide from Klebsiella Type 52 has been investigated. Methylation analysis, characterization by gas-liquid chromatography-mass spectrometry of oligosaccharide derivatives obtained on partial hydrolysis of the methylated polysaccharide with acid, and specific degradation of the methylated polysaccharide by successive treatments with base and acid followed by characterization of the product, were the principal methods used. The polysaccharide is composed of hexasaccharide repeating-units containing D-glucuronic acid, D-galactose, and L-rhamnose, in the ratios 1:3:2. A structure for these units, disregarding the anomeric natures of the sugar residues, is proposed.     

Structural studies of the Rhizobium trifolii extracellular polysaccharide

The structure of the extracellular polysaccharide of Rhizobium trifolii has been investigated. Methylation analysis, sequential degradations by oxidation and elimination of oxidized residues, uronic acid degradation, and degradation by oxidation of the acetylated polysaccharide with chromium trioxide in acetic acid were the main methods used. It is proposed that the polysaccharide is composed of heptasaccharide repeating-units having the following structure:

An unusual feature is that some of the repeating units are incomplete and lack the terminal β-d-galactopyranosyl group. The polysaccharide contains O-acetyl groups (somewhat more than 1 mol. per unit), linked to O-2 and O-3 of 4-O-substituted d-glucopyranosyl chain-residues. A previous finding that the polysaccharide contains 2-deoxy-d-arabino-hexose (2-deoxy-d-glucose) residues is erroneous.     

An Escherichia coli antimicrobial effect of arabinoglucomannan from fruit of Bryonia lacinosa

Extraction of the pulp of ripe berries of Bryonia lacinosa with 1% aqueous acetic acid yielded a polysaccharide material, having d-glucose, d-mannose and l-arabinose in the molar ratio of. 5.00:3.01:4.00. Hydrolysis of the fully methylated polysaccharide furnished 2,3,4,6-tetra-O-methyl-d-glucose, 2,3-di-O-methyl-d-glucose, 2,3,6-tri-O-methyl-d-mannose, 2,3-di-O-methyl-d-mannose and 2,3,5,-tri-O-methyl-l-arabinose in 1:4:2:1:4 molar ratio. Partial hydrolysis of the polysaccharide furnished; mannobiose, epicellobiose, 6-O-β-l-arabinofuranosyl-d-glucose, 6-O-α-mannopyranosyl-d-mannose and epimaltose along with the component monosaccharides. On metaperiodate oxidation studies, 100 g of the polysaccharide liberated 0.055 mol of HCOOH consuming 0.7127 mol of periodate, indicating about 8.33% of the end groups. On the basis of the above results, a structure for the repeating unit of the polysaccharide has been proposed. The polysaccharide was tested for the microbial activity and was found to be active against Escherichia coli with a minimum dose of 6.25 mg/mL.     

Structure of a polysaccharide from the lipopolysaccharide of Vibrio vulnificus CECT4602 containing 2-acetamido-2,3,6-trideoxy-3-[(S)- and (R)-3-hydroxybutanoylamino]-l-mannose

A polysaccharide was isolated by GPC after mild acid treatment of the lipopolysaccharide of Vibrio vulnificus CECT4602 and found to contain l-Rha, d-GlcpNAc and 2-acetamido-2,3,6-trideoxy-3-(3-hydroxybutanoylamino)-l-mannose (l-RhaNAc3NHb). GLC analysis of the trifluoroacetylated (S)-2-octyl esters derived by full acid hydrolysis of the polysaccharide showed that ∼80% of the 3-hydroxybutanoic acid has the S configuration and ∼20% the R configuration. The following structure of the polysaccharide was established by ¹H and ¹³C NMR spectroscopies, including 2D ROESY and ¹H/¹³C HMBC experiments:      

Structural studies on an antitumor polysaccharide from Microellobosporia grisea

The structure of the antitumor polysaccharide from the actinomycete Microellobosporia grisea has been investigated. By methylation and periodate-oxidation studies, the polysaccharide was shown to consist of (nonreducing)d-mannosyl groups, (1→4)-linkedd-glucosyl residues, and 3,6-branched, (1→4)-linkedd-glucosyl residues in the approximate molar ratios of 2:1:1. Periodate oxidation of the polysaccharide, followed by borohydride reduction and mild hydrolysis with acid yielded glycerol, erythritol, 2-O-β-d-glucopyranosyl-d-erythritol, and 5-O-β-d-glucopyranosyl-2,4-bis(hydroxymethyl)-1,3-dioxane, which were isolated in the molar ratios of 2.0:0.14:0.74:0.35. Partial hydrolysis of the polysaccharide gave α-d-Man p-(1→6)-d-Glcp, β-d-Glcp-(1→4)-d-Glcp, α-d-Man p-(1→3)-d-Glcp, and β-d-Glcp-(1→4)-[α-d-Man p-(1→3)-]-d-Glcp. From these results, it is proposed that the polysaccharide is mainly composed of tetrasaccharide repeating-units having the following structure.     

Structure of the 3-deoxy-d-manno-octulosonic acid-containing polysaccharide (K6 antigen) from escherichia coli LP 1092

The acidic polysaccharide (K6) antigen from Escherichia coli LP 1092 contains d-ribose and 3-deoxy-d-manno-octulosonic acid in the molar ratio of 2:1, respectively. Spectroscopic data (¹³C- and ¹H-n.m.r.), methylation analyses, and periodate oxidation indicate that the polysaccharide is composed of the foregoing components essentially in the following trisaccharide sequence: →2)-β-d-Ribf-(1→2)-β-d-Ribf-(1→7)-α-d-KDO-(2→The polysaccharide also contains O-acetyl substituents (～0.2–0.3 mol per KDO residue).     

Studies on a novel polysaccharide gel from the fruit of Thaumatococcus daniellii (Benth)

T. daniellii gel contains residues of L-arabinose, D-xylose, D-glucuronic acid, and 4-O-methyl-D-glucuronic acid in the ratios 1.00:7.20:1.91:0.66, together with nitrogen (1?%) and ash (3.1 %). The ash-free gel contains 76% of pentose and 24% of uronic acid; 25% of the uronic acid occurs as the 4-O-methyl derivative. All of the uronic acid residues in the polysaccharide are susceptible to periodate oxidation. Methylation studies suggest that the uronic acids occur as terminal side-substituents to a xylan back-bone and that the polysaccharide is highly branched. Enzymolysis with β-D-glucuronidase liberates a substantial part of the uronic acid, but does not completely depolymerise the gel.     

Isolation and characterization of a heteropolysaccharide from the corm of Amorphophallus campanulatus

A water-soluble polysaccharide isolated from the aqueous extract of the corm of Amorphophallus campanulatus was found to contain d-galactose, d-glucose, 4-O-acyl-d-methyl galacturonate, and l-arabinose in a molar ratio 2:1:1:1. Structural investigation of the polysaccharide was carried out using acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies (¹H, ¹³C, DQF-COSY, TOCSY, NOESY, ROESY, HMQC, and HMBC). On the basis of the above-mentioned experiments the structure of the repeating unit of the polysaccharide was established as:This molecule showed splenocyte activation.     

A mucilage from Hibiscus moscheutos leaves

A mucilage, Hibiscus-mucilage ML, from leaves ofHibiscus moscheutos was found to be peptidoglycan with a molecular weight ofca 1800000. Its intrinsic viscosity in aqueous solution was 26.1. The major constituent is a partially acetylated, acidic polysaccharide composed ofL-rhamnose:D-galactose:D-glucose:D-galacturonic acid:D-glucuronic acid in a molar ratio of 18:12:1:12:11. Chemical and physico-chemical studies indicated its main structural features. It had considerable hypoglycemic activity when administered to mice.     

Composition and properties of the extracellular polysaccharide produced by arthrobacter stabilis NRRL B-3225

The extracellular polysaccharide produced by Arthrobacter stabilis NRRL B-3225 contains d-glucose, d-galactose, pyruvic acid, O-succinyl, and O-acetyl in the approximate molar ratio of 6:3:1:1:1.5. Succinyl is linked as its half-ester, making it a readily removable, acidic function that imparts versatility to the polysaccharide both for fundamental research and for commercial use. The viscosity of aqueous, salt-free solutions of both native and deacylated polymer is relatively low, but atypical of anionic polysaccharides, increases rapidly in the presence of salts, acids, or alkali.     

Preparation and anticoagulant activity of a fucosylated polysaccharide sulfate from a sea cucumber Acaudina molpadioidea

A fucosylated polysaccharide sulfate, AMP-2, was purified by DEAE-Sepharose Fast Flow and Sephadex G-100 columns in successive steps from a special sea cucumber in southeastern China. HPLC and cellulose acetate membrane electrophoresis experiments confirmed AMP-2 was a homogenous carbohydrate with a relative molecular weight of ca. 2.4 × 10⁴ Da, and methylation analysis indicated that polysaccharide was composed of 1-substituted-Galp, 1,4-disubstituted-GalNp, 1,2-disubstituted-FucSp, 1,4,6-trisubstituted-Glcp in a molar ratio of ca. 0.5:2.0:1.0:3.0, together with a small amount of different substituted Manp. Sulfated derivative and carboxymethylated derivative were prepared using dry pyridine and chlorosulfonic acid, and chloroacetic acid, respectively. Anticoagulant activities in vitro investigation showed that sulfated derivative showed a stronger ability than native polysaccharide and carboxymethylated derivative, which might be caused by their different percentages and types of functional groups in their structures.     

Chemical and n.m.r.-spectroscopic investigation of the capsular polysaccharide of klebsiella serotype k41

The structure of the repeating unit of the capsular polysaccharide from Klebsiella type 41 has been investigated by methylation analysis of the original and the carboxyl-reduced polymer, uronic acid degradation, Smith degradation, and graded acid hydrolysis. Proton- and ¹³C-n.m.r. spectroscopy of the original polysaccharide and of the fragments obtained by various methods confirmed some structural features and allowed determination of the anomeric configuration of the glycosidic linkages. This polysaccharide is shown to have the following heptasaccharide repeating-unit:

This is the first polysaccharide antigen K of the Klebsiella series found to have seven sugar residues in its repeating unit, and to contain a galactose residue in its furanose form.     

Structural studies of the capsular polysaccharide from Klebsiella type 1

The structure of the capsular polysaccharide from Klebsiella type 1, which is composed of D-glucose, D-glucuronic acid, L-fucose, and pyruvic acid (1:1:1:1), has been investigated. Methylation analysis, n.m.r. spectroscopy, graded hydrolysis, and periodate-oxidation studies were the principal methods used. These studies demonstrated that the polysaccharide consists of the following trisaccharide repeating-unit:

     

Structural studies of the capsular polysaccharide from streptococcus pneumoniae type 1

The capsular polysaccharide from Streptococcus pneumoniae type 1 is composed of D-galactopyranosyluronic acid residues and 2-acetamido-4-amino-2,4,6-trideoxy-D-galactopyranosyl residues. The latter sugar, previously unknown in Nature, was not isolated but was identified from the products obtained on deamination of the polymer. Using n.m.r. spectroscopy, methylation analysis, and Smith degradation as the principal methods of structural investigation, it is concluded that the polysaccharide is composed of trisaccharide repeating-units having the structure: →3)-α-Sugp-(1→)-α-D-GalpA-(1→3)-α-D-GalpA-(1→, in which Sug denotes the new sugar.     

Structural studies of an acidic polysaccharide from Ocimum basilicum seeds

An acidic polysaccharide isolated from the seeds of Ocimum basilicum by DEAE-cellulose fractionation was ～92% pure, having an associated glucan impurity (～8%). The polysaccharide is composed of d-xylose, l-arabinose, l-rhamnose, and d-galacturonic acid in the molar ratios 15:9:7:12, together with traces or galactose and glucose. Methylation analysis indicated that the polysaccharide contained a (1→4)-linked xylan backbone carrying branch-points at C-2 and C-3 of the xylosyl residues, and revealed the structural features of the side chains. Periodateoxidation and Smith-degradation studies support the results of methylation analysis.