Chemical characterisation of the released polysaccharide from the cyanobacterium Aphanothece halophytica GR02

The released polysaccharide from the halophilic cyanobacterium Aphanothece halophytica GR02 was separated into two main fractions byanion-exchange chromatography. The major fraction consisted of glucose,fucose, mannose, arabinose and glucuronic acid. Judging from thechromatography on Sepharose 2B, the major fraction was not furtherfractionated, and its apparent molecular weight was above 2.0 × 10⁶ Da.The minor fraction consisted of rhamnose, mannose, fucose,glucose, galactose and glucuronic acid, with traces of arabinose.Methylation and GC-MS spectrometry analyses of the major fractionrevealed the presence of 1-linked glucose, 1,3-linked glucose, 1,3-linkedfucose, 1,4-linked fucose, 1,3-linked arabinose, 1,2,4-linked mannose,1,3,6-linked mannose, 1-linked glucuronic acid and 1,3-linked glucuronicacid residues. The major fraction was thought to originate from capsularpolysaccharide. The released polysaccharides, obtained from cultures atdifferent age of culture, showed no striking variations in themonosaccharide composition and the relative proportions of themonosaccharides. However, the proportions of galactose and rhamnose inthe released polysaccharides, obtained from cultures under different salinity,were significantly different. The released polysaccharide also exhibitedgelling properties and strong affinity for metal ions.     

宁夏不同地区灵武长枣果实多糖的单糖成分分析

以宁夏4个不同地区(灵武、中宁、青铜峡、银川)成熟期的灵武长枣果实为研究对象,经水提醇沉法提取,采用DEAE-cellulose52和HW-55S分离纯化,并利用GC-MS法进行多糖的单糖组成分析。结果表明:多糖提取率最高的是灵武地区,达到1.795%;分离纯化后,4个地区的长枣多糖各得到1个中性(Ju-0)和3个酸性组分(Ju-1、Ju-2、Ju-3),其中Ju-2含量最高;GC-MS分析可知灵武长枣多糖含有阿拉伯糖、鼠李糖、核糖、岩藻糖、木糖、甘露糖、半乳糖、葡萄糖、葡萄糖醛酸、半乳糖醛酸10种单糖,不含果糖,以阿拉伯糖、核糖、半乳糖和2种糖醛酸为主,木糖含量最低。各地区多糖的单糖组成、含量各不相同,从各组分来看,四个地区多糖的Ju-0和Ju-1组分组成均以阿拉伯糖、核糖、半乳糖为主,四个地区多糖的组成差异主要在于Ju-2和Ju-3组分。从各地区单糖总量来看,灵武地区是阿拉伯糖含量最高,中宁、青铜峡、银川地区以葡萄糖醛酸含量为最高。     

The acidic polysaccharide from Palmaria decipiens (Palmariales,Rhodophyta)

Palmaria decipiens, one of the most abundant red seaweeds of the chilean Antarctic, was collected in King George Island. The hot water extract (26% yield) showed by acid hydrolysis to contain xylose, galactose and traces of glucose. Fractionation with cetrimide gave a soluble neutral xylan and an insoluble fraction. The insoluble fraction afforded an acidic polysaccharide that contained 4.8% of uronic acids, 2.8% of sulfate and 18.9% of protein. Polyacrylamide gel electrophoresis showed that it was homogeneous. The GLC and HPLC analysis of the total acidic hydrolysis products showed that the acidic polysaccharide was composed of the neutral sugars galactose and xylose in the molar ratio 8.2:1.0 and of galacturonic and glucuronic acid in the ratio 1.5:1.0. The second-derivative FT-IR spectrum showed the characteristic amide I, II and III bands of proteins. Alkaline cleavage with 0.1 M NaOH indicated the presence of a glycoprotein with O-glycosidic linkage.Results found in this work suggest that the acidic polysaccharide extracted from Palmaria decipiens is an acidic xylogalactan-protein complex.     

The extracellular polysaccharides of Rhizobium japonicum: Compositional studies

The extracellular polysaccharides of seven strains of Rhizobium japonicum were investigated by using a gas-chromatographic scheme developed for determination of the various sugars present. These polysaccharides were more heterogeneous in their composition than those of any other species of Rhizobium yet examined. Five strains (1809, 110, 123, 127, and 709) produced polysaccharides containing the same constituents, although in varying relative amounts: glucose (36–44%), galactose (7–25%), mannose (18–20%), 4-O-methylgalactose (5–13%), galacturonic acid (12–16%), and acetyl groups (4–8%). The sugars of the polysaccharide of strain 1809 were all of the d series. These are the first bacterial polysaccharides reported to contain 4-O-methylgalactose and the first Rhizobium polysaccharides in which galacturonic acid has been found. In contrast to this, the polysaccharide of strain 129 consisted of glucose (7%), galactose (51%), mannose (5%), xylose (5%), glucuronic acid (5%), and pyruvic acid (2%). The polysaccharide of strain 711 contained glucose (34%), galactose (13%), mannose (27%), and pyruvic acid (6%).     

Structural analysis of a pectic polysaccharide from the leaves of Diospyros kaki

A pectic polysaccharide DL-2A with a molar mass of 8.5 x 10(5), was obtained from the boiling water extract of Diospyros kaki leaves. It had [alpha]20D -21.8 degrees (c 0.22, H2O) and consisted of rhamnose, arabinose, galactose, xylose and galacturonic acid units in the molar ratio of 0.4:3.4:2.4:1.0:0.8, along with traces of glucuronic acid. About 16.7% of galacturonic acid existed as the methyl ester. A combination of linkage analyses, periodate oxidation, partial acid hydrolysis, selective lithium-degraded reaction, ESIMS, 1H- and 13C- NMR spectral analyses revealed its structural features. It was found that DL-2A possessed an alpha-(1-->4)-galacturonan backbone with some insertions of alpha-1,2-Rhap residues. The side-chains of arabino-3,6-galactan were attached to the backbone via O-4 of Rhap residues and O-3 of GalAp residues, while 4-linked xylose residues (forming short linear chains) were directly linked to O-4 of rhamnose residues, not as part of the xylogalacturonan. These novel structural features enlarge the knowledge on the fine structure of pectic substances in the plant kingdom.     

Water-soluble polysaccharides from Ginkgo biloba leaves.

The water-soluble polysaccharides from dried Ginkgo biloba leaves were isolated after exhaustive extraction with organic solvents. The polysaccharide mixture could be separated into a neutral (GF1) and two acidic (GF2 and GF3) polysaccharide fractions by ion exchange chromatography. According to the Mr distribution GF1 and GF3 seemed to be homogenous, whereas GF2 could be further fractionated into two subfractions (GF2a and GF2b) by gel permeation chromatography. GF1 (Mr 23,000) showed the structural features of a branched arabinan. The main chain was composed of 1,5-linked arabinose residues and three in 12 arabinose molecules were branched via C-2 or C-3. GF2a (Mr 500,000) consisted mainly of 1,2,4-branched mannose (29%), 1,4-linked glucuronic (32%) and galacturonic (8%) acid as well as terminal rhamnose (25%). After removal of ca 70% of the terminal rhamnose the remaining polysaccharide showed a decrease in 1,2,4-branched mannose and an increase in 1,2-linked mannose indicating that at least half of the rhamnose residues were linked to mannose via C-4. GF3 (Mr 40,000) consisted of 1,4-linked galacturonic (30%) and glucuronic (16) acid, 1,3,6-branched galactose (15%), 1,2-linked (5%) and 1,2,4-branched (3.5%) rhamnose as well as 1,5-linked arabinose (11%). Rhamnose (5%) and arabinose (10%) were present as terminal groups. Mild acid hydrolysis selectively cleaved arabinose and the remaining polysaccharide showed an increased amount of 1,6-linked and terminal galactose and a decreased quantity of 1,3,6-branched galactose. These results indicated that the terminal as well as the 1,5-linked arabinose were mainly connected to galactose via C-3. The GF3 polysaccharide appeared to be a rhamnogalacturonan with arabinogalactan side chains.     

Composition and properties of pectin polysaccharides of St. John’s wort Hypericum Perforatum L.

Three fractions of acidic water-soluble polysaccharides (concentration of glucuronic acid 10?C65%) were obtained from the above-ground part of St. Johns wort Hypericum perforatum L. by serial extraction with water and 0.7% aqueous solution of ammonium oxalate. Enzymatic hydrolysis of these polysaccharides using endo-polygalacturonase indicates that their carbohydrate chains contain the units of galacturone formed by 1,4-??-linked residues of non-substituted D-galacturonic acid. The extracted polysaccharides have been purified by means of gel filtration. It has been shown that water-soluble polysaccharides obtained by extraction with water manly contain the residues of galactose, mannose, glucose, and arabinose (the concentration of glucuronic acid being 10?C27%) while the polysaccharide fraction extracted using 0.7% aqueous solution of ammonium oxalate is presented by pectin polysaccharides. Only the residues of galacturonic acid (55?C72%) have been identified among glucuronic acids in its composition using chromatography/mass spectrometry of trimethylsilyl derivatives. In addition, this fraction contains the residues of the neutral monosaccharides which are typical for pectins: arabinoses, galactoses, rhamnoses, and glucose; there are also minor concentrations of residues of xylose and mannose. IR spectra of pectin polysaccharides of St. John??s wort have absorption bands in the ranges 1740, 1640?C1620, 1236?C1200, and 1200?C1000 cm^?1 which are typical for pectins. It has been demonstrated that aqueous solutions of pectin polysaccharides of St. John??s wort (2 mg/mL) have pronounced antioxidant activity (44% of the activity of trolox taken for 100%).     

Chemical characterization of the hyphal walls of the basidiomyceteArmillaria mellea

Purified hyphal walls ofArmillaria mellea were analyzed and shown to contain glucose (59.0%), mannose (6.9%), galactose (4.2%), xylose (0.2%), ribose (traces), glucosamine (6.7%), protein (10.5%), and some lipid material (8.0%). The mucilaginous surface polysaccharide (fraction I) consisted mainly of (1–3), (1–4), and (1–6)β-glucan chains with mannose, galactose, xylose, and ribose. Fraction II was made mostly of (1–3)-linkedα-glucan. Fraction III contained mainly (1–3)-linkedβ-glucan with small amounts of mannose and galactose, and fraction IV was an alkali-insolubleβ(1–3)-glucan in close association with chitin.     

Analytical and structural features of the gum exudate from Combretum hartmannianum schweinf.

The gum exudate from Combretum hartmannianum is water-soluble, forms very viscous solutions, and contains galactose (22%), arabinose (43%), mannose (10%), xylose (6%), rhamnose (4%), glucuronic acid (6%), 4-O-methylglucuronic acid (2%), and galacturonic acid (7%). The acidic components produced on hydrolysis of the gum were 6-O-(β-D-glucopyranosyluronic acid)-D-galactose, and two saccharides that had the same chromatographic mobility, and contained mannose and galacturonic acid, and galactose and 4-O-methylglucuronic acid, respectively. Methylation and methanolysis of the gum indicated the presence of terminal uronic acid, rhamnose, xylose, galactose, arabinofuranose, and arabinopyranose. Controlled, acid hydrolysis indicated the presence of (1→3)-linked arabinopyranose side-chains and (1→6)-linked galactose residues. C. hartmannianum gum, when subjected to two Smith-degradations, yielded Polysaccharides I and II, both of which contained galactose, arabinose, and mannose. Insufficient crude gum was available for a complete structural study, but the molecule was shown to contain long, sparsely branched chains of (1→6)-linked galactose residues, to which are attached (1→3)-linked arabinose and (1→3)-linked mannose side-chains.     

Characterization of anti-complementary acidic heteroglycans from the seed of Coix lacryma-jobi var. ma-yuen

The anti-complementary polysaccharides, CA-1 and CA-2, were purified from the seed of Coix lacryma-jobi L. var. ma-yuen. CA-1 consists of rhamnose, arabinose, xylose, galactose, galacturonic acid and glucuronic acid in molar ratios of 1.8:43.8:10.8:33.2:3.2:7.2, and CA-2 consists of rhamnose, arabinose, xylose, mannose, galactose, glucose, galacturonic acid and glucuronic acid in molar ratios of 2.4:37.0:11.8:1.7:35.6:2.9:2.6:6.0. CA-1 and CA-2 contained 8 ∼ 11% protein. Their M_rs were estimated to be 160 000 in CA-1 and 70 000 in CA-2 by gel filtration. CA-2 showed more potent anti-complementary activity than CA-1 in low dose.Methylation analysis of CA-1, its carboxyl-reduced products (reduced CA-1a and CA-1b) and CA-2 were carried out by the use of GC/MS and the results suggested that CA-1 has a very complicated and highly branched structure, and CA-2 is also composed of the same glycosidic linkages as CA-1 in different molar proportions. The results of exo α-L-arabinofuranosidase treatment and partial acid hydrolysis suggested that CA-1 and CA-2 contained arabino 3,6-galactan moiety and most of the arabinose was present as an α-L-furanosyl residues in the non-reducing terminals and (1 → 5)-linked side chains which mostly attached to the O-3 of (1 → 6)-linked galactopyranosyl residues. The results also suggested that CA-1 and CA-2 contained rhamnogalacturonan moiety which has a main chain consisting of (1 → 4)-linked galacturonic acid and (1 → 2)-linked rhamnose, and arabino 3,6- and 4-galactan might be attached to the rhamnosyl residue at the O-4. All glucuronic acid residues were present at the non-reducing terminals.     

2-O-methyl-d-xylose containing sheath in the cyanobacterium Gloeothece sp. PCC 6501

The sheath of the unicellular cyanobacterium Gloeothece sp. PCC 6501 was isolated from cell homogenates by differential and sucrose gradient centrifugation, followed by lysozyme treatment and hot sodium dodecyl sulfate extraction. The sheath contains a major fraction of carbohydrate consisting of galactose, glucose, mannose, rhamnose, 2-O-methyl-d-xylose, xylose, glucuronic and galacturonic acids, but only traces of fatty acids and phosphate. A protein content of about 2% (of fraction dry weight) could not be removed by the detergent treatment.Abbreviation SDS sodium dodecyl sulfate     

STRUCTURE OF THE CAPSULAR AND EXTRACELLULAR POLYSACCHARIDES PRODUCED BY THE DESMID SPONDYLOSIUM PANDURIFORME (CHLOROPHYTA)1

The filamentous desmid Spondylosium panduriforme (Heimerl) Teiling var. panduriforme f. limneticum (West & West) Teiling (Desmidiaceae), strain 072CH-UFCAR, is surrounded by a well-defined, mucilaginous capsule consisting of a capsular polysaccharide (CPS). This microalga also produces an extracellular polysaccharide (EPS), which can be isolated from the culture medium. Analysis of the carbohydrate composition of the two polymers by gas chromatography showed that they were different. Both were composed, of galactose, fucose, xylose, arabinose, rhamnose, and glucose but in different amounts. For example, glucuronic acid accounts for 24% of the EPS material but only traces were found in the CPS. Significant differences were also found during methylation analysis. Fucose appeared to have a higher degree of branching in the EPS than in the CPS. These branches were located on C-3 and could be the position for the attachment of the glucuronic acid units in the EPS. The glucuronic acid was present as 1→4-linked and terminal units. A possible explanation for the formation of the EPS is suggested.     

Characterization and antioxidant activity of Ginkgo biloba exocarp polysaccharides

Ginkgo biloba exocarp polysaccharide (GBEP) was obtained by hot water extraction, the crude polysaccharide was deproteinized by Sevag method and fractionized by a DEAE Sepharose fast flow anion-exchange column. Five fragments were obtained, including neutral polysaccharide (GBEP-N) and four acidic polysaccharides (GBEP-A1, GBEP-A2, GBEP-A3 and GBEP-A4). GBEP-N and GBEP-A3 were further purified by Superdex 200 gel column chromatography. The resulted two fractions GBEP-NN, and GBEP-AA were characterized by FT-IR, and HPGFC (high pressure gel filtration chromatography). Monosaccharide composition was determined by RP-HPLC method of precolumn derivatization with 1-phenyl-3-5-pyrazolone. GBEP-NN was mainly composed of rhamnose, arabinose, mannose, glucose and galactose, while GBEP-AA was mainly made up of mannose, rhamnose, glucuronic acid, galacturonic acid, galactosamine, glucose, galactose, xylose, arabinose, and fucose. The crude GBEP exhibited certain antioxidant activity. At the concentration of 5 mg/mL, the hydroxyl radical scavenging effect of GBEP was 90.52%, greater than 77.37% for the positive control ascorbic acid.     

Chemical composition of extracellular polysaccharides of cowpea rhizobia

The extracellular polysaccharides (EPS) of six strains of cowpea rhizobia were examined. The strains (MI50A, M6-7B, IRC253) produced polysaccharides containing glucose, galactose and mannose in a molar ratio of 2:1.1:1, 1:1.3:3.1 and 1:1.3:3.5 respectively. Two strains (513-B and Ez-Aesch) produced polysaccharides containing galactose and mannose in a molar ratio of 2:3. Mannose was the only sugar detected in the EPS of strain IRC291. Pyruvate, acetate, glucuronic acid and galacturonic acid were not detected in any strain.Abbreviations EPS Extracellular polysaccharide - YEMA yeast-extract mannitol agar - YEMB yeast extract mannitol broth     

Localization of mucilaginous polysaccharides in mulberry leaves

Mulberry tree leaves were shown to have mucilaginous polysaccharides. The extracted water-soluble mucilage was separated into three fractions via a cetylpyridinum chloride complex and purified by anion-exchange chromatography. Five acidic polysaccharides were separated from these fractions, one of which was a major polysaccharide (Mp-3) that was structurally analyzed and used for antibody preparation. The Mp-3 polysaccharide contained rhamnose, galactose, glucose, galacturonic acid, and glucuronic acid in a molar ratio of 1 : 0.2 : 0.5 : 2.3 : 1.5 as constituent monosaccharides. Methylation and gas chromatography-mass spectrometry analysis indicated that the polysaccharide was a rhamnogalacturonan mainly consisting of 1,2,3-linked rhamnose residues, 1,3,4- and 1,4-linked uronic acid residues, and terminal uronic acid residues. Its molecular weight was estimated to be 5.5 x 10(5). Immunohistological observation revealed that the Mp-3 polysaccharide is specifically localized in inner epidermal cells situated in adaxial leaves, and electron microscopy showed that its subcellular location is between the plasma membrane and the cell wall. In young leaves, numerous secretory vesicles were present in a shrunken cytoplasm that was surrounded by fibers. In mature leaves, more than 20% of total epidermal cells were these inner cells in which polysaccharide deposition was significantly increased. The deposits appeared as a rounded electron-dense mass throughout the inner cells by electron microscopy.     

A simple procedure for the synthesis of alpha-32P-nucleoside triphosphates.

Chemical analysis of grapefruit (Citrus paradisi) pectic polysaccharides demonstrated that galacturonic acid constitutes 78% by weight of the total carbohydrates found. The remaining 22% was accounted for by a number of sugars which include galactose, glucose, arabinose, xylose, and mannose and, by weight, galactose accounted for almost 50% of the total neutral sugar components found in these pectic polysaccharides. Treatment of pectic polysaccharides with galactose oxidase followed by reduction of oxidized galactose residues with tritiated potassium borohydride resulted in the labeling of pectic polysaccharides. Analysis of the labeled polysaccharides demonstrated that of the total radioactivity incorporated more than 90% was recovered in the galactose residues. These results clearly demonstrate the successful utilization of the galactose oxidase/tritiated potassium borohydride method in labeling plant pectic polysaccharide.     

A xylogalacturonan whose level is dependent on the size of cell clusters is present in the pectin from cultured carrot cells

A substantial level of xylose was detected in the pectic polysaccharides that had been extracted from carrot (Daucus carota L.) calli and purified by gel-permeation and ion-exchange chromatography. The results of the removal of neutral sugar chains and -elimination indicated that the xylose was not included in the neutral sugar chains but was directly bound to a polygalac-turonic-acid backbone. Methylation analysis confirmed that the xylose was directly linked to galacturonic acid at position 2 or 3, as a terminal residue. The amount of xylose was positively correlated with the size of cell clusters in several lines of cultured carrot cells.Abbreviations EC embryogenic callus - 4-GalA 4-linked galacturonic acid - NC non-embryogenic callus - T-Xyl terminal xylose - 3,4-GalA 3,4-linked galacturonic acid - 2,4-GalA 2,4-linked galacturonic acid Part of this work was supported by a research grant from the Science and Technology Agency of Japan and a Grand-in-Aid from the Ministry of Education, Science and Culture, Japan. The authors are grateful to Dr. Koichi Kakegawa of the Forestry and Forest Products Research Institute for his encouragement throughout this research.     

Some structural features of a new sulphated heteropolysaccharide from Padina pavonia

An acid-extractable, water-soluble, polysaccharide sulphate, isolated from Padina pavonia, comprised variable proportions of glucuronic acid, galactose, glucose, mannose, xylose, and fucose in addition to a protein moiety. Partial acid hydrolysis and autohydrolysis of the free acid polysaccharide yielded several oligosaccharides. Evidence from periodate oxidation studies indicated that the inner polysaccharide portion is composed of (1 → 4)-linked β-D-glucuronic acid, (1 → 4)-linked β-D-mannose and (1 → 4)-linked β-D-glucose residues. The heteropolymeric partially sulphated exterior portion is attached to the inner part and comprises various ratios of (1 → 4)-linked β-D-galactose, β-D-galactose-3-sulphate residues, (1 → 4)-linked β-D-glucose residues, (1 → 2)-linked α-L-fucose 4-sulphate residues and (1 → 3)-linked β-D-xylose residues.     

Structural features of the sulphated polysaccharide from a green seaweed,Caulerpa taxifolia

A sulphated heteropolysaccharide was isolated from a green seaweed, Caulerpa taxifolia, by extraction with acid and purified via its copper complex. Methylation analysis of both the sulphated and desulphated polysaccharides revealed the presence of 1,4-linked xylose, 1,6-linked galactose, 1,4,6-linked mannose and non-reducing galactose end group units which are all devoid of sulphate groups. In addition 1,4-linked galactose units sulphated at C-3 are also present. Quantitative periodate oxidation showed a consumption of 1.30 and 1.60 moles of oxidant per anhydrosugar unit in the sulphated and desulphated polysaccharides respectively. The oxo-polysaccharides after reduction and hydrolysis revealed the presence of glycerol, erythritol and unoxidized galactose in the mol ratio 11.6:5.1:4.9 and 11.2:5.0:1.0 respectively, besides threitol (3.9 mol) in the desulphated polysaccharide.     

Studies on the Non-starchy Polysaccharides of the Endosperm of Buckwheat

Water soluble polysaccharides from the buckwheat endosperm was fractionated by salting out and a DEAE-cellulose column (phosphate form) chromatography and the main component (polysaccharide A₁) was isolated as an ultracentrifugally and electrophoretically pure preparation.

The content of polysaccharide A₁ in the buckwheat endosperm was 0.1~0.2%.

Its water solution showed high viscosity and [α]_d was +39.4°. The molecular weight was 240,000~260,000.

Polysaccharide A₁ consisted of xylose, mannose, galactose and glucuronic acid. The hydrolysis of methylated polysaccharide A₁ gave 2,3,4-tri-O-methyl-xylose, 2,3,4,6-tetra-O-methyl-galactose, 2,4,6-tri-O-methyl-galactose, di-O-methyl-mannose and 4-O-methyl- and 5-O-methyl-glucuronic acid. These results suggested that the main chain of this polysaccharide consisted of glucuronic acid, mannose and galactose and the former two occupied branching position with xylose and galactose residues as nonreducing end.