Chemical structure and antioxidant activity of a new exopolysaccharide produced from Micrococcus luteus

An exopolysaccharide (EPS) reaching a maximum of 13 g/L was isolated from Micrococcus luteus by ethanol precipitation. The crude EPS was purified by chromatography on DEAE-cellulose and Sephacryl S-200, affording a polysaccharide active fraction (AEP) with a molecular weight of ∼137 kDa. AEP was investigated by a combination of chemical and chromatographic methods including FTIR, HPLC, periodate oxidation, methylation and GC–MS. Data obtained indicated that AEP was composed of mannose, arabinose, glucose and glucuronic acid in a molar ratio of 3.6:2.7:2.1:1.0, respectively. The main backbone consists of mannose units linked with (1→6)-glycosidic bonds and arabinose units linked with (1→5)-glycosidic bonds. There is a side chain consisting of mannose units linked with (1→6)-glycosidic bonds at C3, when all glucose and most of glucuronic acid are found in the side chain. The in vitro antioxidant assay showed that AEP possesses DPPH radical-scavenging activity, with an EC₅₀ value of 180 μg/mL.     

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.     

猴头菌子实体和菌丝体多糖的分离纯化与理化特征的比较*

人工栽培的猴头菌子实体和固体培养的菌丝体分别经热水提取,浓缩、醇析后得子实体粗多糖（HFP）和菌丝体粗多糖（HMP）,HFP的得率和多糖含量均高于HMP;两者再经透析、Sevag法脱蛋白、乙醇分级沉淀、SephadexG-100柱层析纯化,得子实体纯多糖hfp-1和菌丝体纯多糖 hmp-2,经HPLC检测hfp-1和hmp-2为单一均匀多糖。气相色谱分析表明hfp-1的单糖组成为阿拉伯糖、甘露糖、半乳糖和葡萄糖,摩尔比为：0.12：0.04：1.00：0.71;hmp-2的单糖组成为阿拉伯糖、木糖、甘露糖、半乳糖和葡萄糖,摩尔比为：0.25：0.41：0.31：1.00：0.29。紫外光谱分析表明组成中不含核酸和蛋白质,红外光谱分析二者均有多糖特征吸收峰,hfp-1有β-型连接的吸收峰,hmp-2无明显的β-型连接的吸收峰;经HPLC进行分子量测定,hfp-1的分子量为54000,hmp-2的分子量为68000。猴头菌子实体多糖和菌丝体多糖在化学组成上有一定的差异。     

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.     

In vitro antioxidant activities of a water-soluble polysaccharide derived from Dendrobium nobile Lindl. extracts

A water-soluble polysaccharide (DNP), isolated from the aqueous extracts of the stem of Dendrobium nobile Lindl., was found to have an average molecular weight (Mw) of about 8.76 × 10⁴ Da. Monosaccharides analysis revealed that DNP was composed of rhamnose, arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1.00:2.80:2.20:30.76:117.96:31.76. The evaluation of antioxidant activity in vitro revealed that DNP is a novel potential antioxidant. The NMR spectra suggested that the main structure of DNP was possible as     

Purification,structural characterization and antioxidant property of an extracellular polysaccharide from Aspergillus terreus

The marine fungus Aspergillus terreus produces an extracellular polysaccharide, YSS, when grown in potato dextrose-agar medium. YSS was isolated from the fermented liquids using ethanol precipitation, anion-exchange and size-exclusion chromatography. YSS was mainly composed of mannose and galactose in a molar ratio of 7.68:1.00, its average molecular weight was estimated to be about 18.6 kDa. On the basis of chemical and spectroscopic analyses, including one- and two-dimensional nuclear magnetic resonance (1D and 2D NMR) spectroscopy, structure of YSS may be represented, at an average, as a backbone of mannan with two types of branches. The mannan backbone is mainly composed of (1→2)-linked α-mannopyranose with small amounts of (1→6)-linked α-mannopyranose residues. The branches consist of terminal β-galactofuranose residues, and disaccharide units of (1→6)-linked α-mannopyranose. The branches are linked to C-6 of (1→2)-linked α-mannopyranose residues of backbone. The antioxidant activity of YSS was evaluated with the scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals in vitro, and the results indicated that YSS had good antioxidant activity, especially scavenging ability on DPPH radicals. The investigation demonstrated that YSS is a novel branched galactomannan with antioxidant activity, and differs from previously described extracellular polysaccharides.     

Composition and antioxidant activity of the polysaccharides from cultivated Saussurea involucrata

Polysaccharides from cultivated Saussurea involucrata (CSIP) were purified, two major fractions (CSIP1-2 and CSIP2-3) were investigated for their molecular weights, monosaccharide compositions and in vitro antioxidant activities. The results suggested that the molecular weights of CSIP1-2 and CSIP2-3 were approximately 163.5 kDa and 88.6 kDa, respectively. CSIP1-2 was composed of glucose, galactose, xylose, rhamnose, arabinose and galacturonic acid with a molar ratio of 1.651:0.39:0.062:8.331:1.759:40.426. CSIP2-3 was composed of glucose, galactose, xylose, rhamnose, arabinose and galacturonic acid with a molar ratio of 0.762:0.657:0.112:5.587:0.318:44.655. Different scavenging activities on superoxide radical, DPPH radical and hydroxyl radical were observed in CSIP1-2 and CSIP2-3 at tested concentrations.     

Chemical characteristics and antioxidant activity of exopolysaccharide fractions from Microbacterium terregens

The Gram-positive bacterial strain isolated from soil was identified as the non-pathogenic Microbacterium terregens. The exopolysaccharide (CPS) produced from M. terregens was obtained by isopropanol precipitation (13.72 g L^?1 growth medium), The resulted exopolysaccharide was purified by chromatography on DEAE-cellulose and Sephacryl S-200 columns, when two polysaccharide fractions termed CPSI and CPSII were obtained. Structure features of CPSI and CPSII were investigated by a combination of chemical and chromatographic analyses, such as acid hydrolysis, methylation analysis, periodate oxidation–Smith degradation, HPLC, GC–MS, and IR. The results indicated that CPSI and CPSII were composed of glucose: mannose in a ratio of 2.7:1 and 3.2:1 with molecular weights 80 and 150 kDa, respectively. It has a backbone of (1 → 4)-linked β-glucose residues, which occasionally branches at O-6. The branches were composed of (1 → 4)-linked β-mannose residues. The antioxidant activity of the CPS, CPSI and CPSII was evaluated in-vitro by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay (RSA). CPSI fraction showed the highest antioxidant activity among the three fractions, with an IC₅₀ value of 230 μg mL^?1. The effect of molecular weight of the polysaccharide on the improvement of the antioxidant potential seems to be significant.     

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 properties and antiinflammatory activity of a galactomannoglucan from Arecastrum romanzoffianum

A galactomannoglucan (GMG) with an estimated weight-average molar mass of 1.5 × 10⁵ was obtained from an aqueous extract of the mesocarp of fruits of Arecastrum romanzoffianum (Cham.) Becc. by fractionation by Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that GMG has a chain of (1 → 4)-linked β-d-mannopyranosyl residues, a chain of (1 → 3)-linked β-d-galactopyranosyl residues, a chain of (1 → 4)-linked α-d-glucopyranosyl residues, repeating units of β-d-galactopyranosyl-(1 → 4)-β-d-mannopyranosyl and β-d-mannopyranosyl-(1 → 4)-α-d-glucopyranosyl and terminal residues of d-galactopyranosyl and d-glucopyranosyl which comprised galactose, mannose and glucose in the molar ratio of 10:37:53. The polysaccharide exhibited significant antiinflammatory activity against carrageenan-induced mouse paw oedema.     

Chemical properties and adjuvant activity of a galactoglucomannan from Acrocomia aculeata

A galactoglucomannan (GGM) with an estimated weight-average molar mass of 3.5 × 10⁵ was obtained from an aqueous extract of the mesocarp of fruits of Acrocomia aculeata (Jacq.) Lodd. by fractionation by Sephacryl S-300 HR and Sephadex G-25. Chemical and spectroscopic studies indicated that GGM has a main chain of (1 → 4)-linked β-d-mannopyranosyl residues attached to an initial chain of (1 → 3)-linked β-d-galactopyranosyl residues and a terminal chain of (1 → 4)-linked α-d-glucopyranosyl residues which comprised galactose, glucose and mannose in the molar ratio of 18:22:60. The adjuvant potential of the polysaccharide on the cellular immune response against ovalbumin antigen was investigated using in vivo assays.     

Structural characterization of extracellular polysaccharides produced by the marine fungus Epicoccum nigrum JJY-40 and their antioxidant activities

Two extracellular polysaccharides, ENP1 and ENP2, were isolated from the fermentation liquid of the marine fungus Epicoccum nigrum JJY-40 by anion-exchange chromatography and gel-filtration chromatography, and their structures were investigated using chemical and spectroscopic methods including methylation analysis and NMR spectroscopy. The results demonstrated that ENP1 was composed of mannose, glucose, and galactose in the molar ratio of 5.0:2.1:1.0, and the main chain of the polysaccharide consisted of (1?→?2)-linked mannose, (1?→?3)-linked mannose, terminal mannose, (1?→?6)-linked glucose, (1?→?4)-linked glucose, and (1?→?4)-linked galactose. ENP2 was composed of mannose, galactose, glucose, and glucuronic acid in a molar ratio of 12.4:11.2:8.3:1.0, and its glycosidic linkage patterns included terminal mannose, (1?→?6)-linked glucose, (1?→?4)-linked galactose, and (1?→?3)-linked mannose. The two polysaccharides had a partially branched structure with branch point located at C-3 position of (1?→?6)-linked glucose residue. The molecular weights of ENP1 and ENP2 were 19.2 kDa and 32.7 kDa, respectively. Antioxidant properties of the two polysaccharides were evaluated with hydroxyl, superoxide, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and lipid peroxidation inhibition in vitro, and results showed that ENP2 and ENP1 had good antioxidant activities, especially ENP2. ENP2 could be effective as a potential antioxidant.     

Preliminary studies on the composition and rheological properties of the extracellular polysaccharide synthesized by Pseudomonas PBI (NCIB 11264).

A microorganism isolated from a carbohydrate-rich industrial effluent synthesized an exocellular slime polysaccharide composed of glucose and galactose in a molar ratio of 7.45 +/- 0.68 : 1, and two non-carbohydrate substituents acetate (3--4%) and pyruvate (5--9%). Contamination by rhamnose and mannose was detectable in crude polysaccharide samples. Solutions of the polysaccharide were pseudoplastic, but not thixotropic, and formed gels in the presence of certain trivalent cations.     

Purification,structural features,antioxidant and moisture-preserving activities of an exopolysaccharide from Lachnum YM262

A water-soluble exopolysaccharide, designated as LEP-2a, was isolated from Lachnum YM262 and purified by DEAE-Cellulose 52 and Sepharose CL-6B chromatographic columns. LEP-2a was a homogeneous polysaccharide, with a molecular weight of 1.52 × 10⁵ Da. It was composed of mannose and galactose in a molar ratio of 20.6:1.0. Its structural features were investigated and elucidated by methylation analysis, periodate oxidation and Smith degradation, FT-IR and NMR spectroscopy. Based on obtained data, the backbone of LEP-2a consisted of 1,2-linked-α-d-mannose, 1,3-linked-α-d-mannose, 1,2,6-linked-α-d-mannose and 1,3-linked-β-d-galactose and the side chains were attached to the backbone at O-6 position of 1,2,6-linked-α-d-mannose. In vitro antioxidant activity assay proved that LEP-2a possessed significant scavenging activities on superoxide, hydroxyl and DPPH radical. Furthermore, LEP-2a had strong in vitro moisture-absorption and -retention capacities as compared to chitosan and glycerol. These results suggested that LEP-2a might have a good potential to be applied as a multifunctional cosmetic additive in cosmetics.     

Flash Extraction,Characterization, and Immunoenhancement Activity of Polysaccharide from Hippophae rhamnoides Linn

Hippophae rhamnoides L. polysaccharide was optimized with flash extraction by response surface design. The optimum process conditions were: rotation rate 5000 r/min, extraction time 15 s, extraction temperature 90 °C and liquid-to-material ratio 38 mL/g, the extraction yield was 15.28±0.02 %. HRP-1 and HRP-2 obtained by 40 % and 60 % graded alcohol precipitation were characterized. The results indicated that HRP-1 and HRP-2 both composed of mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose with different molar ratio and the molecular weights were 380.59 kDa and 288.24 kDa, respectively. In addition, the in vitro antioxidant and immunoenhancement activities of HRP-1 and HRP-2 were analyzed, and the two fractions showed good free radical scavenging activity against ⋅OH, ABTS⋅⁺, DPPH⋅, and extremely strong immunomodulatory activity against RAW264.7 cells. Indicating that flash extraction is suitable for extraction of HRP, the structural study of HRP provides a scientific theoretical basis for the development of Hippophae rhamnoides.     

Isolation and Sugar Composition of Blood Group H-Like Substance from Seeds of Euonymus Sieboldiana

Blood group H-like polysaccharides were isolated from seeds of Euonymus Sieboldiana by a procedure that included fractionation with (NH₄)SO₄, heat treatment, chromatography on DEAE-cellulose and gel filtration on Bio-Gel P-150. One of the highly purified polysaccharide fractions was composed of arabinose, mannose, glucose, rhamnose, galactose and fucose. Arabinose and mannose were the main components, and their molar ratio was calculated as about 3: 1 by gas chromatographic analysis. An analytical ultracentrifugal experiment revealed that the finally purified H-like substance was close to an homogeneous preparation with a small disperse fraction. This heteropolysaccharide inhibited the haemagglutination of human group O red blood cells and eel anti-H serum minimally at 0.004 mg/ml, reacted also with the eel anti-H serum on an immunodiffusion plate to form sharp precipitin line(s).     

Compositional features of carbohydrate compound from rhizoma ligustici wallichii and ethanol extract of danshen and its bioactivity

Water extraction was applied to prepare carbohydrate compound of rhizoma ligustici wallichii. Four main fractions, fraction-I, fraction-II, fraction-III, and fraction-IV, were obtained by membranes of 1.0 × 10⁻⁴ mm pore size and normal molecular-weight cut-off of 50 kDa. The resulting four preparations were further analysed by capillary gas chromatography method. Thin layer chromatography (TLC) analysis showed that carbohydrate compound of rhizoma ligustici wallichii was composed of five types of monosaccharides, namely glucose, rhamnose, mannose, galactose and arabinose. Gas chromatography (GC) analysis showed that fraction I of rhizoma ligustici wallichii was composed of four types of monosaccharides, namely glucose, mannose, galactose and arabinose at a molar ratio of 521:1:4.6:3.3. Furthermore, the protective effect of the Rhizoma ligustici wallichii polysaccharides and ethanol extract of danshen against ischemia-reperfusion (IR) induced renal injury were evaluated. The findings imply that carbohydrate compound of the Rhizoma ligustici wallichii and ethanol extract of danshen play a causal role in IR-induced renal injury probably by the radical scavenging and antioxidant activities. Moreover, ethanol extract of danshen displayed stronger renoprotective effect than that of carbohydrate compound of the Rhizoma ligustici wallichii.     

Characterization of a neutral polysaccharide with antioxidant capacity from red wine

A neutral fraction (PS-SI) (0.3 g/L) with MW of 74 kDa, which contained galactose, arabinose, mannose, and glucose in the molar ratio of 1.0:0.6:0.4:0.2 was obtained by treatment of the whole polysaccharide extracted from red wine with cetrimide, followed by gel permeation chromatography. Spectroscopic and methylation analyses indicated that PS-SI is a mixture of neutral polysaccharides, consisting mainly of β (1→3)-linked galactopyranosyl residues, with side chains of galactopyranosyl residues at positions O-6. Arabinofuranosyl residues linked α (1→5), α-mannopyranosyl and glucosyl residues appear to be components of different polysaccharides. The in vitro antioxidant capacity of fractions of wine polysaccharide was studied by hydroxyl radical scavenging and ORAC assays. Fraction PS-SI presented the strongest effect on hydroxyl radicals (IC₅₀ = 0.21).     

Structure of acidic polysaccharide from cell wall of Propionibacterium acnes strain C7

The structure of polysaccharide prepared by lysozyme digestion from the cell wall of Propionibacterium acnes strain C7 was examined. The polysaccharide fraction was composed of glucose, galactose, mannose, galactosamine, and diaminomannuronic acid in a molar ratio of 1:1:0.3:1:2. By Smith degradation of the polysaccharide, diaminouronic acid-containing fractions were obtained, and the configuration of diaminouronic acid was identified as 2,3-diacetamido-2,3-dideoxymannuronic acid [Man(NAc)2A] by means of 1H-NMR and 13C-NMR spectroscopic analyses. The results of analyses involving methylation and partial acid hydrolysis led to the conclusion that the polysaccharide has the repeating unit----6)Gal(alpha 1----4)Man(NAc)2A(beta 1----6)Glc(alpha 1----4)Man(NAc)2A (beta 1----3)GalNAc(beta 1--. In addition, a portion of the galactose residues were substituted at C-4 by alpha 1----2 linked mannotriose.     

Isolation and structural characterization of a polysaccharide FCAP1 from the fruit of Cornus officinalis

A water-soluble polysaccharide, FCAP1, was isolated from an alkaline extract from the fruits of Cornus officinalis. Its molecular weight was 34.5 kDa. Monosaccharide composition analysis revealed that it was composed of fucose, arabinose, xylose, mannose, glucose, and galactose in a molar ratio of 0.29:0.19:1.74:1:3.30:1.10. On the basis of partial acid hydrolysis and methylation analysis, FCAP1 was shown to be a highly branched polysaccharide with a backbone of β-(1→4)-linked-glucose partially substituted at the O-6 position with xylopyranose residues. The branches were composed of (1→3)-linked-Ara, (1→4)-linked-Man, (1→4,6)-linked-Man, (1→4)-linked-Glc, and (1→2)-linked-Gal. Arabinose, fucose, and galactose were located at the terminal of the branches. The structure was further elucidated by a specific enzymatic degradation with an endo-β-(1→4)-glucanase and MALDI-TOF-MS analysis. Oligosaccharides generated from FCAP1 indicated that FCAP1 contained XXXG-type and XXG-type xyloglucan fragments.