Water-soluble polysaccharides of antarctic and cultured Phormidium species of the cyanophyceae

Hot water extraction of a Phormidium species from Antarctica and of a sample of Phormïdium foveolarum which had been cultured axenically led to the isolation of a water-soluble polysaccharide from both materials. Acidic hydrolysis of each gave a similar pattern of monosaccharides comprising arabinose, xylose, rhamnose, fucose, galactose, mannose and glucose, and both contained uronic acid. All attempts by a variety of methods to fractionate the Antarctic polysaccharide into more than a single entity were unsuccessful. Periodate oxidation, partial hydrolysis and methylation studies on this polysaccharide supported a highly branched molecule with 1,3-linked glucose and 1,4-linked galactose as dominant features.     

STRUCTURE OF EXTRACELLULAR POLYSACCHARIDES PRODUCED BY A SOIL CRYPTOMONAS SP. (CRYPTOPHYCEAE)1

The Hindak strain of a Cryptomonas species (Cryptophyceae) produces extracellular polysaccharides. Because there is no information on the structure of these compounds in the Cryptophyceae we conducted structural studies. Gas–liquid chromatographic analyses showed that the polysaccharide is composed of fucose, rhamnose, xylose, mannose, glucose, galactose, galacturonic acid, glucuronic acid, and traces of 3-O-methyl galactose. The polysaccharide was separated into two subtractions by ion-exchange chromatography. Fraction A consisted mainly of 1,3-linked galactose units and 1,4-linked galacturonic acid. Unlike fraction B, fraction A did not have xylose, 3-O-methyl galactose, or glucuronic acid. Also, its degree of branching was low compared to that of fraction B. Only traces of sulfate were present infraction A, but fraction B was 10–15% sulfated. Protein was approximately 1% in both fractions. These polysaccharides appear to be a novel type of polymer in algae.     

Partial structure of a polysaccharide from leaves of Welwitschia mirabilis

Gum-tears from the leaves of Welwitschia mirabilis contain a polysaccharide composed of arabinose, galactose and glucuronic acid as main constituents with xylose, fucose and rhamnose in smaller quantities. Periodate oxidation and permethylation studies indicated that the gum could consist of a framework of glucuronic acid residues linked 1 → 4 and galactose residues linked 1 → 6 and of short chains of arabinose, xylose, fucose and rhamnose linked 1 → 3 to both residues. All rhamnose and fucose and part of arabinose were found as non-reducing terminal units.     

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.     

Structural aspects of the exudate from the fruit of Chorisia speciosa St. Hil

Mature fruit of Chorisia speciosa yield an exudate (E-I) following mechanical injury. The polysaccharide contains rhamnose, arabinose, xylose, mannose, glucose, galactose and glucuronic acid in molar ratios of 20:11:1:3:2:40:23. The main chain of the structure is composed by beta-galactopyranosyl units linked (1 --> 3) and (1 --> 6) as indicated by NMR spectra and methylation data. Arabinosef and rhamnose are terminal residues. In order to compare E-I with the polysaccharides from the fruit mesocarp, the latter was submitted to different extractions. The water fraction contains rhamnose, arabinose, xylose, mannose, glucose, galactose and uronic acid in molar ratios of 18:4:1:2:3:44:28. It was treated with CTAB yielding a precipitate which was decomplexed with NaCl, giving four fractions. The fraction obtained using 0.15 M NaCl had a quantitative composition similar that of E-I.     

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.     

Chemistry of the polysaccharides of the diatom Coscinodiscus nobilis

The extracellular polysaccharide of Coscinodiscus nobilis, a member of the Coscinodiscaceae, contains a highly branched heteropolysaccharide(s) containing fucose, rhamnose, mannose, d-glucose, xylose, d-glucuronic acid, galactose (trace) and half ester sulphate. The positions of linkages between the monosaccharides have been established and evidence for the linkages between d-glucuronic acid and monosaccharides was obtained. The extracellular polysaccharide contained also a chrysolaminaran, but this may have been derived from dead cells. Fucose and mannose occur also in a separate polymer. The diatom contained polysaccharide material consisting of glucose, mannose, fucose and uronic acid residues.     

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.     

Glycoproteins of the opium poppy

Two carbohydrate-protein fractions were isolated from the water-soluble biopolymer from opium poppy capsules by chromatography on SP-Sephadex. The carbohydrate chains are composed of arabinose, rhamnose, xylose, mannose, glucose, galactose, galacturonic acid, glucuronic acid and 4-O-methyl glucuronic acid. Methylation analysis indicated a high degree of branching suggesting a very complex structure. Treatment of the glycoprotein with NaOH in the presence of NaBH₄ resulted in a significant decrease in the serine and threonine content. The carbohydrate side chains released contained the sugar alcohol, galactitol. These results indicate that polysaccharide chains are linked to protein via serine-O-galactoside linkages.     

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.     

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.     

Hemicellulosic polymers from the leaves of coffea arabica

Polysaccharide fractions from leaves of Coffea arabica var. Mundo Novo were obtained by extraction with 24% potassium hydroxide solution and were found to contain rhamnose, arabinose, xylose, mannose, galactose, glucose, glucuronic acid and 4-O-methylglucuronic acid in different proportions. 2-Acetamido-2-deoxygalactose was detected in all fractions. The structures of the carbohydrate portions were analysed by methylation and Smith degradation. A high amount of 2,3,5-tri-O-methylarabinose and 2,3,4-tri-O-methylxylose units, which are related through end groups, suggested a large degree of branching in the polysaccharide fractions. Glucose was present mainly as (1 → 4)-linked residues, as indicated by the presence of 2,3,6-tri-O-methylglucitol in the hydrolysates of the methylated fractions. A greater proportion of monomethylxylitol in acidic fraction B-IV indicated that it was more branched than the others. The glucose and galactose residues are 4,6- and 3,4-di-O-substituted, respectively. Three successive Smith degradations gave mainly glycerol with some erythritol and threitol. In the linkage of carbohydrate—protein, the presence of O-glycosyl linkages between arabinose and hydroxyproline was indicated. A phenolic compound was detected in all polysaccharide fractions from leaves of the coffee tree and is probably derived from chlorogenic acid.     

An arabinogalactan from the skin of Opuntia ficus-indica prickly pear fruits

The cold-water extract from the skin of Opuntia ficus-indica fruits was fractionated by anion-exchange chromatography. The major fraction, which was purified by size exclusion chromatography, consisted of a polysaccharide composed of galactose and arabinose residues in the ratio 6.3:3.3, with traces of rhamnose, xylose and glucose, but no uronic acid. The results of methylation analysis, supported by (13)C NMR spectroscopy, indicated that this polysaccharide corresponded to an arabinogalactan having a backbone of (1-->4)-linked beta-D-galactopyranosyl residues with 39.5% of these units branched at O-3. The side-groups consisted either of single L-arabinofuranosyl units or L-arabinofuranosyl alpha-(1-->5)-linked disaccharides. This polysaccharide is thus an arabinogalactan that can be classified in the type I of the arabinogalactan family.     

藏药蕨麻多糖的光谱性质及单糖组成分析

本研究对藏药蕨麻多糖进行了分离提纯,并测定其水溶性多糖含量为99.4%;通过紫外光谱与红外光谱分析表明,蕨麻多糖为分子量较小的α-吡喃糖,并含有氨基糖;蕨麻多糖的水解单糖经过NMP衍生后进行毛细管电泳分析,测得其单糖组成为木糖、阿拉伯糖、葡萄糖、鼠李糖、甘露糖、岩藻糖、半乳糖、葡萄糖醛酸和半乳糖醛酸,含量分别为3.945、77.445、17.568、17.646、3.942、2.165、65.268、13.037μg/mg和33.484μg/mg,与GC-MS的定性分析结果一致。     

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。     

RELATIVE INCREASE OF DEOXY SUGARS DURING MICROBIAL DEGRADATION OF AN EXTRACELLULAR POLYSACCHARIDE RELEASED BY A TROPICAL FRESHWATER THALASSIOSIRA SP. (BACILLARIOPHYCEAE)1

The aim of this study was to characterize the extracellular polysaccharides (EPS) released by a freshwater Thalassiosira sp. (Bacillariophyceae) and evaluate their degradation by heterotrophic microbial populations from the same habitat of Thalassiosira sp., a tropical eutrophic reservoir. The EPS were purified by anion exchange column chromatography, the monosaccharide composition was determined by GC, and the linkages of the monosaccharides by GC‐MS. The EPS is a mannose‐rich heteropolysaccharide composed of two different acidic fractions. Both of these fractions are composed of mannose, rhamnose, fucose, xylose, galactose, glucose, glucuronic acid, and N‐acetyl glucosamine but with different proportions. N‐acetyl galactosamine occurs only in fraction 1 and galacturonic acid only in fraction 2. We monitored the concentrations of the monosaccharides in the EPS during its degradation using pulse amperometric detection in an HPLC. The decay patterns of the monosaccharides were varied and the deoxy sugars, fucose and rhamnose, were degraded at a slower rate than the other components, increasing their relative concentrations and the hydrophobic feature of the EPS. The possibility of a selective degradation, which enhances the stickiness of the EPS, promoting transparent exopolymeric particles and aggregate formation, is discussed based on the literature data.     

A note on the formation of microbial polysaccharide from wheat straw decomposed in the absence of soil

C hapman , S.J. & L ynch , J.M. 1984. A note on the formation of microbial polysaccharide from wheat straw decomposed in the absence of soil. Journal of Applied Bacteriology 56 , 337–342.
The proportions of neutral sugars in fresh and decomposed wheat straw polysaccharide were similar, irrespective of the oxygen concentration used during breakdown. Polysaccharide extracted by hot water from the decomposed straw was composed mainly of galactose, glucose and mannose with smaller quantities of arabinose, xylose, rhamnose, fucose and ribose. The presence of these sugars indicates a mainly microbial origin for the polysaccharide but with some soluble hemi-cellulose breakdown products. The polysaccharide precipitable with 70% (v/v) ethanol accounted for 0.5% (w/w) of the degraded straw. The extracted polysaccharide was shown to increase the aggregate stability of Mount St Helens volcanic ash.     

Studies of the polysaccharides from sunflower heads

Extraction of sunflower heads with ammonium oxalate afforded water-soluble pectin material and water-insoluble glycoprotein material, the carbohydrate portion of which consisted of galacturonic acid and xylose residues; the pectin material defied fractionation with cetylpyridinium chloride. Extraction with hydrochloric acid (pH 1.5) afforded water-soluble and water-insoluble polysaccharide materials. The former, when fractionated with cetylpyridinium chloride, gave a glycoprotein, the carbohydrate moiety of which was composed of galacturonic acid, galactose (major), glucose, arabinose, and xylose, and also a rhamnan. The latter was a glycoprotein, the carbohydrate portion of which consisted of galactose (major), glucose, xylose, and rhamnose residues. Extraction of the sunflower heads with water also gave glycoprotein material, which was fractionated by paper electrophoresis into a glyco-protein, the carbohydrate moiety ofwhich was composed of galacturonic acid (minor), galactose, glucose, xylose, arabinose, and rhamnose (major) residues, and a heteropolysaccharide composed of galactose (major), glucose, xylose, and arabinose residues.     

Production and composition of extracellular polysaccharide from cell suspension cultures of Mentha

A suspension culture of Mentha was established from callus which formed on the tips of young shoots of a Mentha hybrid (M. arvenis × M. spicata). Changes in growth parameters during a culture cycle were recorded. The general appearance of cells during division and growth, including the changes in cell form, was also represented.Suspension-cultured cells of Mentha hybrid released a large amount of extracellular polysaccharides (ECP) mainly at the logarithmic phase of the growth cycle. The ECP contained galacturonic acid as major components and arabinose, galactose, glucose, xylose, rhamnose and mannose as minor components. The ratio of the uronic acid content to total sugar content in the ECP was below 40% at day 7, but increased up to 90% at day 21. The relative contents of xylose and glucose in the ECP decreased during the culture period, while the arabinose content increased and those of rhamnose, mannose and galactose remained constant.The IR spectrum suggested that the ECP were low-methoxylated pectic polysaccharides. The presence of lignin and related compounds in the ECP was not detected. The protein content of the ECP was about 10% and the main amino acids were alanine, proline, hydroxyproline, valine, asparticacid and serine, in that order.     

Chemical Studies on the Cell Walls of Leptospira biflexa Strain Urawa and Treponema pallidum Strain Reiter

The preparation and chemical poperties of the cell walls of Leptospira biflexa Urawa and Treponema pallidum Reiter are described. Both cell walls are composed mainly of polysaccharides and peptidoglycans. The data of chemical analysis indicate that the cell wall of L. biflexa Urawa contains rhamnose, arabinose, xylose, mannose, galactose, glucose and unidentified sugars as neutral sugars, and alanine, glutamic acid, α,ε-diaminopimelic acid, glucosamine and muramic acid as major amino acids and amino sugars. As major chemical constituents of the cell wall of T. pallidum Reiter, rhamnose, arabinose, xylose, mannose, galactose, glucose, alanine, glutamic acid, ornithine, glycine, glucosamine and muramic acid have been detected. The chemical properties of protein and polysaccharide fractions prepared from the cells of T. pallidum Reiter were also partially examined.