Antitumor Active Polysaccharides from the Chinese Mushroom Songshan Lingzhi,the Fruiting Body of Ganoderma tsugae

A systematic method of extraction, fractionation, and purification of polysaccharides from Songshan Lingzhi (Ganoderma tsugae) with antitumor activity was established.

Seven glycans with strong antitumor activities were obtained from 14 water-soluble, and 15 water-insoluble fractions: FI_o-a, FA-1, FII-1, FIII-2, and FIII-2-a, -b, and -c. FI_o-a and FA-1 were proteincontaining glucogalactans associated with mannose and fucose. FII-l was a (1→3)-β-D-glucan having a lower protein content. The water-insoluble fractions FIII-2-a, -b, and -c were extracted with alkali, and were found to be protein-containing (1→3)-β-D-glucans showing the strongest activity. Chemical properties .and structure of each antitumor polysaccharide were compared with three fungi of the Ganoderma family, Kofukitake (G. applanatum), Mannentake (G. lucidum), and Songshan Lingzhi (G. tsugae).     

Targeting and glycosylation of patatin the major potato tuber protein in leaves of transgenic tobacco

Patatin, the most abundant protein in the storage parenchyma cells of potato (Solanum tuberosum L.) tubers, is a vacuolar glycoprotein that consists of a number of closely related polypeptides and is encoded by a large gene family. To analyse the glycosylation pattern and the nature of the glycans on a single patatin polypeptide in a heterologous tissue we introduced a single chimaeric patatin gene into tobacco (Nicotiana tabacum L.) and studied its product in leaves. Patatin isolated from the leaves of transgenic tobacco plants is glycosylated at asparagine (Asn)⁶⁰, and Asn⁹⁰, but the third glycosylation site (Asn²⁰²) has no glycan. The two glycans are typical small complex glycans with xylose, fucose, mannose and N-acetylglucosamine in a ratio 1:1:3:2, the same ratio as found on patatin isolated from potato tubers. Expression of patatin in tobacco leaves was accompanied by the correct processing of the signal peptide, and the proper targeting of the glyco-protein to the vacuoles of mesophyll cells.Abbreviations Asn asparagine - ConA concanavalin A - EndoH endoglycosidase H - Fuc fucose - GlcNAc N-acetylglucosamine - HPLC high-performance liquid chromatography - Man mannose - PAGE polyacrylamide gel electrophoresis - SDS sodium dodecyl-sulfate - Ser serine - TFMS trifluoromethanesulfonic acid - Thr threonine - Xyl xylose     

STUDIES ON POLYSACCHARIDES FROM THREE EDIBLE SPECIES OF NOSTOC (CYANOBACTERIA) WITH DIFFERENT COLONY MORPHOLOGIES: COMPARISON OF MONOSACCHARIDE COMPOSITIONS AND VISCOSITIES OF POLYSACCHARIDES FROM FIELD COLONIES AND SUSPENSION CULTURES

Hot water-soluble polysaccharides were extracted from field colonies and suspension cultures of Nostoc commune Vaucher, Nostoc flagelliforme Berkeley et Curtis, and Nostoc sphaeroides Kützing. Excreted extracellular polymeric substances (EPS) were isolated from the media in which the suspension cultures were grown. The main monosaccharides of the field colony polysaccharides from the three species were glucose, xylose, and galactose, with an approximate ratio of 2:1:1. Mannose was also present, but the levels varied among the species, and arabinose appeared only in N. flagelliforme. The compositions of the cellular polysaccharides and EPS from suspension cultures were more complicated than those of the field samples and varied among the different species. The polysaccharides from the cultures of N. flagelliforme had a relatively simple composition consisting of mannose, galactose, glucose, and glucuronic acid, but no xylose, as was found in the field colony polysaccharides. The polysaccharides from cultures of N. sphaeroides contained glucose (the major component), rhamnose, fucose, xylose, mannose, and galactose. These same sugars were present in the polysaccharides from cultures of N. commune, with xylose as the major component. Combined nitrogen in the media had no qualitative influence on the compositions of the cellular polysaccharides but affected those of the EPS of N. commune and N. flagelliforme. The EPS of N. sphaeroides had a very low total carbohydrate content and thus was not considered to be polysaccharide in nature. The field colony polysaccharides could be separated by anion exchange chromatography into neutral and acidic fractions having similar sugar compositions. Preliminary linkage analysis showed that 1) xylose, glucose, and galactose were 1→4 linked, 2) mannose, galactose, and xylose occurred as terminal residues, and 3) branch points occurred in glucose as 1→3,4 and 1→3,6 linkages and in xylose as a 1→3,4 linkage. The polymer preparations from field colonies had higher kinematic viscosities than those from correspondingsuspension cultures. The high viscosities of the polymers suggested that they might be suitable for industrial uses.     

Production of an exopolysaccharide by Antarctic yeast

Psychrophilic Antarctic yeasts produce polysaccharides in different concentrations. According to morphological, cultural, physiological and biochemical characteristics, the best producer strain was identified as Cryptococcus flavus A₅₁. The highest values for viscosity (59.1 mPa s) and crude polysaccharide productivity (5.75 g/L) were obtained in a medium containing 5 % sucrose and 0.25 % (NH₄)₂SO₄, at 24 °C for 6 d. The chemical composition and sugar constituents of the crude exopolysaccharide were determined (92.5 % saccharides, 3.34 % protein, and 4.16 % ash). The monosaccharide composition of the exopolysaccharide obtained from C. flavus strain AL₅₁ was established (55.1 % mannose, 26.1 % glucose, 9.60 % xylose, 1.90 % galactose). The microbial biopolymer has a high molar mass and homogeneity: 82 % of it had M 1.01 MDa.     

Antitumor Protein-containing Polysaccharides from a Chinese Mushroom Fengweigu or Houbitake,Pleurotus sajor-caju (Fr.) Sings

Protein-containing polysaccharides extracted from fruiting bodies of a Chinese fungus named Feng Wei Gu, were fractionated and purified, and their antitumor activities were tested, out of which the following active fractions were obtained.

FI_o-a: A protein-containing xyloglucan, MW 280,000, polysaccharide: protein=76: 24 (w/w), polysaccharide consisting of Man: Gal: Xyl: Glc = 2: 12: 42: 42 (molar ratio). + 25.3°.

FA-2: A protein-containing mannogalactan, MW 120,000, polysaccharide: protein = 76 : 16 (w/w), consisting of Xyl : Man: Gal = 9 : 35 : 56 (molar ratio), + 98.5°.

FII-1: A Protein-containing xylan (62: 21 w/w). MW 200,000, +8.7°.

FIII-1a: A protein-containing glucoxylan (15: 71 w/w), +30.7°, MW 90,000, consisting of Glc : Xyl = 40 : 44 (molar ratio).

FIII-2a: A protein-containing xyloglucan, MW 70,000, polysaccharide: protein = 69: 3 (w /w), polysaccharide consisting of Xyl: Glc = 36 : 62 (molar ratio). + 38.6°.     

Mannose fermentation by an ethanologenic recombinant Escherichia coli

Summary Recombinant E. coli B (pLOI297) grows in Luria broth with mannose at a rate that is only about one-half of the rate with xylose and about one-quarter of the rate with glucose as carbon source. For a sugar concentration of about 2 % (w/v), the corresponding specific ethanol productivities (q_p) are 0.22, 0.45 and 0.70 g ethanol/g cell/h for mannose, xylose and glucose. At higher sugar concentrations (8–11 %), the sp. productivities are 0.12, 0.33 and 0.35 g ethanol/g cell/h for mannose, xylose and glucose. Using a synthetic softwood prehydrolysate medium, in which the mass ratio of mannose:xylose:glucose was approx. 1.0:0.6:0.4 (total sugar conc'n 4.5 %), the sp. productivities associated with glucose and xylose metabolism were decreased by about 50 % and 75 % respectively, whereas mannose metabolism appeared unaffected by the presence of the other sugars. In all cases, the sugar-to-ethanol conversion efficiency was >90 % of theoretical maximum     

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.     

Characterization and in vitro antioxidant activities of polysaccharides from Pleurotus ostreatus

Two polysaccharide fractions (PSPO-1a and PSPO-4a) were isolated from the fruiting bodies of Pleurotus ostreatus using ethanol precipitation, anion-exchange chromatography and gel permeation chromatography. Both fractions were heteropolysaccharide containing protein and uronic acid. PSPO-1a was composed of mannose, glucose, galactose, xylose and rhamnose with a molar ratio of 2.47:0.91:1.00:1.66:3.87. PSPO-4a was composed of only three monosaccharides: rhamnose, mannose and galactose with a molar ratio of 0.92:2.69:1.00. The average molecular weight of PSPO-1a and PSPO-4a determined by HPLC were estimated to be 1.8 × 10(4)Da and 1.1 × 10(6)Da respectively. The in vitro tests revealed that two polysaccharides were natural potential antioxidant. Both polysaccharides presented stronger DPPH radical and superoxide anion radical scavenging activity with increasing concentrations, but less effective on scavenging hydroxyl radical. Compared with PSPO-4a, PSPO-1a was the more effective free-radical scavenger. In conclusion, the two polysaccharides may be useful as a naturally potential antioxidant agent for application in food and medicinal fields.     

Water-soluble endopolysaccharides from the fruiting bodies of <Emphasis Type="Italic">Laetiporus sulphureus</Emphasis> (Bull.:Fr.) Murr.

Endopolysaccharides represented by glucans, galactans, and glycoproteins were isolated from the fruiting bodies of the sulfur shelf (Laetiporus sulphureus (Bull.:Fr.) Murr.), which were obtained by the naturalplantation method. The study of the major 56-kDa polysaccharide, laetiporan A, the content of which accounted for 0.28% of the fruiting body weight, showed that it is a β-1,3-glucan containing mannose, galactose, fucose, xylose, and rhamnose residues at position C-6. An antioxidant effect of laetiporan A was discovered.     

Structure of polysaccharides from the Polyporus tumulosus cell wall

Cell walls of the Basidiomycete fungus Polyporus tumulosus (Cooke) were fractionated, and the polysaccharide content of the fractions investigated. The major constituents of the cell wall include four polysaccharides, chitin, a β-1, 3-glucan and the alkali soluble α-glucan and xylomannan.The glucan is highly dextrotatory with an [α]_D²¹ of + 221° and gave on partial acid hydrolysis and acetolysis an homologous series of oligosaccharides. The disaccharide was shown to be nigerose 3-0-α-D-glucopyranosyl-D-glucose. Periodate oxidation and methylation studies provided supporting evidence that the polysaccharide is an essentially unbranched polymer of 1,3-linked glucose residues.The other alkali-soluble polysaccharide, a xylomannan, is a polymer of mannose and xylose in the approximate molar proportions of 1.2:1. It has an [α]_D = + 56° and on partial acid hydrolysis and acetolysis gave an homologous series of 1,3-linked mannodextrins but no oligosaccharides containing xylose were obtained. An α-1,3-linked mannan was prepared from the xylomannan by degradation with mild acid or by degradation of the periodate-oxidased and reduced xylomannan. The structure therefore is visualised as having a backbone of 1,3-linked mannan, to which xylose residues are attached. Methylation studies showed that branching occurs at C-4 of the mannopyranose units; the presence of 2,3-di-o-methyl-d-xylose in the hydrolysate of the methylated polysaccharide indicated that some of the xylose residues are 1,4-linked. The possible structure of the fungal cell wall is discussed in the light of the results obtained.     

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.     

Pharmacological evaluation of tea polysaccharides with antioxidant activity in gastric cancer mice

Tea polysaccharides were fractionated by Sephadex G-100 gel permeation chromatography. The results showed that tea polysaccharides were mainly composed of TF-1, TF-2 and TF-3. The average molecular weights of TF-1, TF-2 and TF-3 determined by high-performance gel permeation chromatography (HPGPC) and high performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) were 231,568Da, 46,278Da and 7251Da, respectively. The monosaccharide composition of Renshen polysaccharides was evaluated by GC. TF-1 was composed of glucose, mannose, xylose with molar ratio of 1:3.2:1.4. TF-2 and TF-3 consisted of glucose, xylose and glucose, xylose, arabinose with molar ratios of 1:1.7 and 1:2.5:0.9, respectively. TF-1 contained mannose as main sugar component and TF-2 was rich in xylose, whereas TF-3 was rich in xylose. In addition, tea polysaccharides could decrease stomach malondialdehyde (MDA) level, serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels, increased serum immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-10 (IL-10) levels, and stomach antioxidant enzymes activities in gastric cancer mice.     

高效液相色谱法测定金钱菇多糖的单糖组成

采用高效液相色谱法,测定金钱菇多糖的单糖组成.用超声辅助提取金钱菇多糖,通过1-苯基-3-甲基-5-吡唑酮(PMP)衍生水解后的单糖,高效液相色谱法检测衍生物.结果表明：金钱菇多糖由甘露糖(Man)、核糖(Rib)、鼠李糖(Rha)、葡萄糖(Glc)、半乳糖(Gal)、木糖(Xyl)组成,其摩尔为1．00∶0．90∶0．91∶28．03∶1．58∶0．11.该方法快速、简便、重现性好,可用于测定金钱菇多糖的单糖组成.     

Cell wall formation in zoospores of Allomyces arbuscula

Carbohydrate composition was determined in isolated cell walls of meiospores of Allomyces arbuscula after incubation for 15 min (encysted meiospores: cysts), 150 min (germlings: cysts + rhizoids) and 24 h (cysts + rhizoids + hyphae). The principal constituent in all cell wall samples is chitin, accounting for about 75% of the recovered carbohydrates. In addition, cell walls of all stages examined contain polysaccharides which release galactose, glucose, mannose, arabinose, xylose, fucose, and rhamnose on acid hydrolysis. While different developmental stages show minor quantitative changes in chitin, the ratio of galactose to glucose decreases sharply during differentiation of ungerminated cysts into germlings with rhizoids and hyphae. The increase in glucose is accompanied by a decrease in the amount of xylose and/or fucose and of galactose.List of Abbreviation TFA trifluoroacetic acid     

Sulfated polysaccharides from marine green algae Ulva conglobata and their anticoagulant activity

Sulfated polysaccharides from the green algae Ulva conglobata were isolated and prepared by extraction in hot water, precipitation with ethanol and purification by ion-exchange and size-exclusion column chromatography. The characterizations of the sulfated polysaccharides were defined, and containing 23.04–35.20% sulfate ester groups, 10.82–14.91% uronic acid and 3.82–4.51% protein. Gas chromatography analysis shows that the sulfated polysaccharides from Ulva conglobata are mainly consisted of rhamnose with variable contents of glucose and fucose, trace amounts of xylose, glactose and mannose. The anticoagulant properties of the sulfated polysaccharides were compared with those of heparin by studying the activated partial thromboplastin time using normal human plasma. The sulfated polysaccharide from Ulva conglobata collected in Qingdao, China is the most potent among the sulfated polysaccharides tested. The mechanism of anticoagulant activity mediated by the sulfated polysaccharides is due to the direct inhibition of thrombin and the potentiation of heparin cofactor II.     

Conditions of cultivation,composition, and biological activity of mycelium of <Emphasis Type="Italic">Flammulina velutipes</Emphasis> (Fr.) P. Karst

A study is made on a strain of higher basydiomycete Flammulia velutipes (Fr.) P. Karst. The conditions of maximum biomass production by Flammulia velutipes were studied. Soluble and insoluble fractions were isolated from mycelium. The composition of cultured mycelium and aqueous extracts from mycelium were investigated. These objects mainly contained carbohydrates (65.3 and 84.0% in insoluble and soluble fractions, respectively, and 56% mycelium), proteins (7.5–10.0% in fractions and 17.5% in mycelium), as well as an insignificant amount of mineral substances. The main carbohydrate component of fractions was glucose (53.6–78.8%); galactose and mannose were also present, as well as fucose and xylose in insignificant amounts. The aqueous extracts from mycelium demonstrated immunomodulating activity. They rendered a stimulating effect on the functional activity of macrophages—central cells of the reticluoendothelial system. The soluble fraction had a more pronounced effect than the insoluble fraction.     

The Structure of the Carbohydrate Moietv of a Glycopeptide GP-I-a from Rhizopus Saccharogenic Amylase

The structure of the carbohydrate moiety of GP–I–a, one of three glycopeptides obtained from Rhizopus saccharogenic amylase, was determined by using enzymatic and chemical techniques.

Six residues (all of the residues in GP–I–a) of mannose and one residue of N-acetylglucosamine were released in that order when GP–I–a was digested successively with purified α-mannosidase and β-N-acetylglucosaminidase.

Exhaustive methylation of GP–I–a gave 3,6-di-O-methyl derivative from the N-acetylglucosamine residues, and 2,3,4,6-tetra-O-methyl, 3,4,6-tri-O-methyI and 2,4-di-O-methyl derivatives from the mannose residues in an approximate ratio of 3: 1:2.

After one step of the Smith degradation of GP–I–a, a residual glycopeptide (F–1) consisted of one mole each of asparagine and glycine and two moles each of mannose and N-acetylglucosamine was obtained. Exhaustive methylation of F–1 gave 3,6-di-O-methyl derivative of N-acetylglucosamine, and 2,3,4,6-tetra-O-methyl and 2,3,4-tri-O-methyl derivatives of mannose in a ratio of 1.00: 0.91.

Partial acetolysis of 1→6 linkages in GP–I–a yielded mannose, 3-O-mannosylmannose and a smaller glycopeptide which was resistant to the acetolysis.

From these and other evidences, the following structure was determined for GP–I–a.     

侧耳属食用菌多糖的研究进展

侧耳多糖是从侧耳属食用菌子实体、菌丝体、发酵液或菌糠中提取的一种活性代谢产物。从侧耳多糖的提取方法、结构以及生理作用等方面进行了综述,并对其应用前景进行了展望,旨在进一步发掘和利用侧耳属食用菌的食用价值和药用价值,扩大其在食品和医药领域的应用范围。     

Detection of the lipid-linked precursor oligosaccharide of N-linked protein glycosylation in Drosophila melanogaster

The presence of a glycan of the same molecular size as the lipid linked precursor oligosaccharide (Glc₃Man₉GlcNAc₂) of the N-linked protein glycosylation pathway in mammalian cells has been detected in a glycolipid fraction of cultured Drosophila melanogaster cells. Oligosaccharide sequencing studies were consistent with the existence of a glucosylated high mannose containing structure, which may be the common precursor for N-linked protein glycosylation in insect cells.     

Structural basis for langerin recognition of diverse pathogen and mammalian glycans through a single binding site

Langerin mediates the carbohydrate-dependent uptake of pathogens by Langerhans cells in the first step of antigen presentation to the adaptive immune system. Langerin binds to an unusually diverse number of endogenous and pathogenic cell surface carbohydrates, including mannose-containing O-specific polysaccharides derived from bacterial lipopolysaccharides identified here by probing a microarray of bacterial polysaccharides. Crystal structures of the carbohydrate-recognition domain from human langerin bound to a series of oligomannose compounds, the blood group B antigen, and a fragment of β-glucan reveal binding to mannose, fucose, and glucose residues by Ca²⁺ coordination of vicinal hydroxyl groups with similar stereochemistry. Oligomannose compounds bind through a single mannose residue, with no other mannose residues contacting the protein directly. There is no evidence for a second Ca²⁺-independent binding site. Likewise, a β-glucan fragment, Glcβ1-3Glcβ1-3Glc, binds to langerin through the interaction of a single glucose residue with the Ca²⁺ site. The fucose moiety of the blood group B trisaccharide Galα1-3(Fucα1-2)Gal also binds to the Ca²⁺ site, and selective binding to this glycan compared to other fucose-containing oligosaccharides results from additional favorable interactions of the nonreducing terminal galactose, as well as of the fucose residue. Surprisingly, the equatorial 3-OH group and the axial 4-OH group of the galactose residue in 6SO₄-Galβ1-4GlcNAc also coordinate Ca²⁺, a heretofore unobserved mode of galactose binding in a C-type carbohydrate-recognition domain bearing the Glu-Pro-Asn signature motif characteristic of mannose binding sites. Salt bridges between the sulfate group and two lysine residues appear to compensate for the nonoptimal binding of galactose at this site.