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.     

Polysaccharides from Lycium barbarum leaves: Isolation, characterization and splenocyte proliferation activity

The polysaccharides from the fruits of Lycium barbarum have received considerable attention in previous publication, but the polysaccharides from the leaves were rarely reported. In the present work, four water-soluble polysaccharide fractions: LBP-I, LBP-II, LBP-III and LBP-IV isolated from L. barbarum leaves were purified through DEAE-Sephadex A-25. LBP-II and LBP-IV respectively showed one symmetrical peak on HPGPC with average molecular weight of 9.39×10(4)Da and 4.18×10(5)Da. UV and IR analysis of the two fractions showed the characteristics of acidic polysaccharides combined with polypeptides or proteins. GC analysis showed LBP-IV was mainly composed of rhamnose, arabinose, xylose, glucose and galactose with molar ratio of 1.61:3.82:3.44:7.54:1.00, and the uronic acid content was 47.68% (w/w) determined by sulfuric acid-carbazole method. (1)H and (13)C NMR spectra of LBP-IV also showed the presence of carboxyl carbon and five anomeric carbons, and suggested there may be both α- and β-anomeric configurations in this fraction. Moreover, splenocyte proliferation activity assay showed that LBP-IV significantly enhanced the proliferation of splenocyte stimulated by ConA or LPS, indicating the fraction has the beneficial effect on immunostimulating activity.     

Synthesis, characterization, and lectin recognition of hyperbranched polysaccharide obtained from 1,6-anhydro-D-hexofuranose

1,6-Anhydro-D-hexofuranoses, such as 1,6-anhydro-β-D-glucofuranose (1), 1,6-anhydro-β-D-mannofuranose (2), and 1,6-anhydro-α-D-galactofuranose (3), were polymerized using a thermally induced cationic catalyst in dry propylene carbonate to afford hyperbranched polysaccharides (poly1-3) with degrees of branching from 0.40 to 0.46. The weight-average molecular weights of poly1-3 measured by multiangle laser light scattering varied in the range from (1.02 to 5.84) × 10(4) g·mol(-1), which were significantly higher than those measured by size exclusion chromatography. The intrinsic viscosities ([η]) of poly1-3 were very low in the range from 4.9 to 7.4 mL·g(-1). The exponent (α) in the Mark-Houkwink-Sakurada equation ([η] = KM(α)) of the polymers was 0.20 to 0.33, which is <0.5. The steady shear flow of poly1-3 in an aqueous solution exhibited a Newtonian behavior with steady shear viscosities independent of the shear rate. These viscosity characteristics were attributed to the spherical structures of hyperbranched polysaccharides in an aqueous solution. Poly1-3 contained a high portion of terminal units of 31-43 mol % nonreducing D-hexopyranosyl and D-hexofuranosyl units, in which the D-hexofuranosyl units were 20-44 mol %. Moreover, poly1 and poly2 showed a strong interaction to Concanavalin A due to the cluster effect or multivalent effect of numerous nonreducing saccharide units on their surfaces with binding constants in the range from 1.7 × 10(4) to 2.7 × 10(5) M(-1).     

Bibliography

Water-soluble polysaccharides isolated from the roots of Panax ginseng C. A. Meyer were completely fractionated into two neutral fractions (WGPN and WGPA-N) and six acidic fractions (WGPA-1-RG, WGPA-2-RG, WGPA-1-HG, WGPA-2-HG, WGPA-3-HG and WGPA-4-HG) by a combination of ethanol precipitation, ion-exchange and gel permeation chromatographies. The analytical results showed that WGPN was a starch-like glucan; WGPA-N was a mixture of starch-like glucan and arabinogalactan; WGPA-1-RG and WGPA-2-RG were composed of major neutral sugars and minor acidic sugars that belong to the type-I rhamnogalacturonan (RG-I)-rich pectins, while fractions WGPA-1-HG to WGPA-4-HG were mainly composed of galacturonic acid (GalA, 62.4–92.1%) and have been identified to be homogalacturonan (HG)-rich pectins with different degrees of methyl-esterification, ranging from 0% to 30%. High performance gel permeation chromatography (HPGPC) showed that the six acidic fractions were homogenous, with molecular weights approximately ranging from 3.5 × 10³ to 1.1 × 10⁵. Lymphocyte proliferation assays showed that both the neutral polysaccharides and acidic polysaccharides were potent B and T cell stimulators.     

Characterization and immunomodulatory activities of sulfated polysaccharides from Capsosiphon fulvescens

Sulfated polysaccharides isolated from Capsosiphon fulvescens and fractionated using ion-exchange chromatography were investigated to determine their chemical and molecular characteristics and biological activities. The crude and fractionated polysaccharides (F(1), F(2), and F(3)) consisted mostly of carbohydrates (28.9-67.0%), uronic acids (1.6-9.2%) and sulfates (5.2-13.4%) with various amounts of proteins (2.1-53.7%). Their monosaccharide levels were significantly different including rhamnose (20.8-65.2%), xylose (13.0-37.1%) and mannose (11.6-65.1%). The polysaccharides contained one or two subfractions with molecular weights (M(w)) ranging from 401.7×10(3) to 6232×10(3)g/mol. These polysaccharides (the crude and fraction F(2)) strongly stimulated macrophage cells, RAW264.7 cell line, producing considerable amounts of NO, PGE(2) and cytokines which suggested that they could be strong immunostimulators. The main backbone of the most immunoenhancing polysaccharide (F(2)) was suggested by GC-MS and NMR to be the following:     

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.     

Synthesis and antitumor activity of s-tetrazine derivatives

Fifty-five compounds of s-tetrazine derivative including hexahydro-, 1,6-dihydro, 1,4-dihydro-, 1,2-dihydro- and aromatic s-tetrazine were prepared. Their antitumor activities were evaluated in vitro by MTT method for P-388 cell and SRB method for A-549 cell. The results show that there are 9 compounds which in 10(-6) microM have more than 50% inhibition rate to A-549 cancer cell growth, and 7 compounds in 10(-6) microM have more than 50% inhibition rate to P-388 cancer cell growth. The IC(50) of compound 3q for P-388, Bel-7402, MCF-7 and A-549 are 0.6 microM, 0.6 microM, 0.5 microM and 0.7 microM, respectively. So s-tetrazine derivative is a kind of compound which possesses potential antitumor activities and is worth to research further.     

Biological activity of Brassica rapa L. polysaccharides on RAW264.7 macrophages and on tumor cells

Polysaccharides are a type of natural macromolecule widely existing in nature, and its pharmacological activity has attracted wide research attention. In this study, Brassica rapa L. polysaccharides were taken as the research object, and a preliminary study of the immune activity and mechanism of the antitumor activity of these polysaccharides in vitro was carried out. Five polysaccharides, namely, BRP, BRNP-1, BRNP-2, BRAP-1, and BRAP-2, were compared in terms of their ability to inhibit the growth of three types of cancer cells, namely, A549, AGS, and HepG2. The most effective polysaccharides were screened out, and their mechanism was studied. Immunoassay results showed that the five polysaccharides not only promoted the growth of RAW264.7 cells but also stimulated their endocytic/pinocytosis activity and released NO, TNF, IL-6 cytokines, especially BRP. In vitro antitumor experiments showed that BRP has a significant inhibitory effect (*P < 0.05) on the growth of A549 cells, especially at high concentrations (500–2000 μg/mL). BRP can also induce A549 cells to release reactive oxygen species, cause mitochondrial membrane potential, and effect the expression of Bax, caspase-9, caspase-3, p53, and B-cell lymphoma 2. Immunological experiments showed that the five groups of polysaccharides are not cytotoxic to normal cells and have immunostimulatory effects. Mitochondria represent one of the more important endogenous pathways in the apoptotic process. The results suggested that BRP participates in mitochondria mediated apoptosis and induces A549 cell apoptosis. This study lays a theoretical foundation for further research on the mechanisms of BRP immunoregulation and antitumor activity in vitro and in vivo.     

超滤分离和鉴定三种香菇多糖

用热水从香菇子实体中浸提出香菇多糖,采用两种超滤陶瓷膜将粗多糖分级成三部分Le1,Le2和Le3。所有的这三种多糖都由两组分所组成,采用凝胶过滤色谱测定了多糖分子量,13CNMR和IR光谱测定显示多糖Le1为含α糖甙键的多糖,多糖Le3为含β糖甙键的多糖。采用气相色谱法测定了三种多糖的单糖组成,结果显示三种多糖都由葡糖糖,阿拉伯糖,木糖,甘露糖和半乳糖组成,Le1,Le2和Le3中阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖的摩尔比分别为0.15∶0.52∶1.00∶1.20∶7.20、0.21∶0.68∶1.00∶1.02∶11.56、0.29∶0.42∶1.00∶0.85∶16.20。三种多糖Le1,Le2和Le3的平均分子量分别为4.02×104、2.16×105和8.93×105。     

Induction of NGF synthesis in astrocytes by onjisaponins of Polygala tenuifolia, constituents of kampo (Japanese herbal) medicine, Ninjin-yoei-to.

The effect of a kampo medicine, Ninjin-yoei-to (NYT; Ren-shen-yang-rong-tang in Chinese) on nerve growth factor (NGF) secretion from the cultured rat astrocytes was examined in vitro. When rat embryo astrocytes were cultured in the presence of NYT for 24 h, the amount of NGF in the medium was significantly increased in a dose dependent manner. Among 14 kinds of component herbs in NYT, the roots of Polygala tenuifolia and roots of Panax ginseng extracts increased NGF levels from the astrocytes. Saponin fraction from the roots of P. tenuifolia enhanced the production of NGF, however phenolic glycoside fraction showed no effect. Onjisaponins A, B, E, F and G as major saponins of the root of P. tenuifolia strongly increased the NGF level, whereas ginsenosides Rb1 and Rg1 did not affect the NGF level. Onjisaponin F also induced ChAT mRNA level in rat basal forebrain cells. These results indicate the possibility that NYT and/or onjisaponins in P. tenuifolia may have potential therapeutic effects for the treatment of Alzheimer disease patients.     

Molecular origin of two polysaccharides of Campylobacter jejuni 81116

The nature of the polysaccharide molecules of the human enteric pathogen Campylobacter jejuni has been the subject of debate. Previously, C. jejuni 81116 was shown to contain two different polysaccharides, one acidic (polysaccharide A) and the other neutral (polysaccharide B), occurring in a 3 : 1 ratio, respectively. The aim of this study was to determine the molecular origin of these polysaccharides. Using a combination of centrifugation, gel permeation chromatography, chemical assays, and (1)H-NMR analysis, polysaccharide B was shown to be derived from lipopolysaccharide and polysaccharide A from capsular polysaccharide. Thus, C. jejuni 81116 produces both lipopolysaccharide-like molecules and capsular polysaccharide.     

Characterization of acetylated 4-O-methylglucuronoxylan isolated from aspen employing 1H and 13C NMR spectroscopy

Water-soluble hemicelluloses were extracted from milled aspen wood (Populus tremula) employing microwave oven treatment at 180 degrees C for 10 min. The final pH of this extract was 3.5. From this extract oligo- and polysaccharides were isolated and subsequently fractionated by size-exclusion chromatography. The structures of the saccharides in three of the fractions obtained were determined by 1H and 13C NMR spectroscopy, using homonuclear and heteronuclear two-dimensional techniques. The polysaccharides present in the two fractions eluted first were O-acetyl-(4-O-methylglucurono)xylans. The average degree of acetylation of the xylose residues in these compounds was 0.6. The structural element -->4)[4-O-Me-alpha-D-GlcpA-(1-->2)][3-O-Ac]-beta-D-Xylp-(1 --> could also be identified. On the average, these two xylans were composed of the following (1-->4)-linked beta-D-xylopyranosyl structural elements: unsubstituted (50 mol%), 2-O-acetylated (13 mol%), 3-O-acetylated (21 mol%), 2,3-di-O-acetylated (6 mol%) and [MeGlcA alpha-(1-->2)][3-O-acetylated] (10 mol%). Most of the 4-O-methylglucuronyl and acetyl substituents in the isolated polysaccharides survived the microwave oven treatment. The third fraction, eluted last, contained acetylated xylo-oligosaccharides, with minor contamination by an acetylated mannan. In the case of these xylo-oligosaccharides, the average degree of acetylation was 0.3.     

Efficient purification of antiproliferative polysaccharides from Hypsizigus marmoreus with radial flow chromatography

The increasing commercial significance of natural polysaccharides for use in medicinal products is stimulating the development of efficient and easy scale‐up techniques for polysaccharide purification. In this research, the crude polysaccharides from submerged cultivation broth of Hypsizigus marmoreus were purified using radial flow chromatography (RFC), and the antiproliferative activity of the purified fractions was evaluated in vitro. DEAE Sepharose CL‐6B was selected to be packed in the RFC column based on its good resolution, physical stability, and low cost. Compared with axial flow chromatography (AFC), an efficient chromatographic process with significantly less time and buffer consumption but yielding higher polysaccharide recovery and resolution was established in RFC, which could clearly purify the crude polysaccharides into different fractions. An acceptable linear scale‐up effect of RFC from 100 to 500 mL was successfully achieved without loss of resolution and enhancement of time consumption. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assays in cell cultures indicated that the purified polysaccharide fractions possess moderate antiproliferative activities in three different human cancer cell lines, but have significantly lower cytotoxicity in normal human cell lines in vitro. Among the polysaccharide fractions, the main purified acidic fraction W‐I could be considered as a novel potential antitumor agent candidate for several tumors, especially for human alveolar epithelial tumors. This research confirmed for the first time that RFC would be a new fast and efficient tool for purification of polysaccharides into different fractions, both at laboratory and commercial scales. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:872–878, 2014     

Studies on the uronic acid-containing glycoproteins of Fusarium sp. M7-1: III. The primary structures of the acidic polysaccharides of the glycoproteins.

Two O-glycosidically linked acidic polysaccharides, AP I and AP II, were released, respectively, from glycoproteins GP I and GP II of Fusarium sp. M7-1 by alkaline borohydride treatment and purified by gel filtration chromatography. They were found to be apparently homogeneous on gel filtration chromatography and analytical ultracentrifugation. Their molecular weights were estimated to be 8.2 x 10(4) and 3.1 x 10(4), respectively. The various oligosaccharide fragments obtained from AP I and AP II by acetolysis and partial acid hydrolysis were purified by gel filtration chromatography and HPLC. Their primary structures were resolved mainly by NMR spectrometry in combination with methylation mass spectrometry. Analyses of the acetolysis and partial acid hydrolysis products and the 1H-NMR spectrum of AP I and AP II showed that they are analogues. Thus, we propose that the main parts of the acidic polysaccharides have the following structures. [formula: see text] *X, unidentified oligosaccharide chains. The numbers on the left and the numbers in parentheses outside the brackets indicate the approximate number of side chains of AP I and AP II, respectively, the saccharide sequences of which are not specified.     

A polysaccharide from Armillaria mellea exhibits strong in vitro anticancer activity via apoptosis-involved mechanisms

Armillaria mellea is a famous traditional Chinese medicinal and edible fungus. In this study, we purified a water-soluble polysaccharide (AMP) from the fruiting bodies of this fungus. AMP contained 94.8% carbohydrate, 2.3% uronic acid and 0.5% protein. Its molecular weight was determined as 4.6×10(5)Da, as determined by high-performance gel-permeation chromatography (HPGPC). Gas chromatography (GC) analysis indicated that AMP was mainly composed of d-glucose. In vitro assay, AMP exhibited a potent tumor growth inhibitory effect on A549 cells, and induced cell cycle disruption in the G0/G1 phase, accompanied by an increment of apoptotic cells. Furthermore, AMP induced the disruption of mitochondrial membrane potential, thus leading to cytochrome c release from mitochondria and activation of caspase-3 and -9. Taken together, our results demonstrate that AMP possesses strong antitumor activities through the mitochondria dependent pathway and activation of caspase cascade through cytochrome c release.     

Development and application of a rapid and efficient CZE method coupled with correction factors for determination of monosaccharide composition of acidic hetero-polysaccharides from Ephedra sinica

Introduction – Ephedrine alkaloids cannot account for all the effects of Ephedra sinica and the polysaccharides are also demonstrated to be one of the main bioactive constituents of E. sinica. However, no work has been reported on the analysis of monosaccharide composition of purified polysaccharides isolated from the stem of E. sinica. Objective – To develop a rapid and efficient capillary zone electrophoresis (CZE) method based on pre‐column derivatisation with 1‐phenyl‐3‐methyl‐5‐pyrazolone for the simultaneous determination of neutral and acidic sugars of purified polysaccharides from E. sinica. Methodology – Three polysaccharides (ESP‐A3, ESP‐A4 and ESP‐B4) were isolated and purified by ion exchange and gel‐filtration chromatography from the stem of E. sinica. The effects of background electrolyte pH and concentration, applied voltage and temperature on the separation were investigated. Meanwhile, factors affecting the hydrolysis of ESP‐B4 with sulphuric acid were investigated by changing the hydrolysis time, acid concentration and hydrolytic temperature to achieve complete hydrolysis. The standard curves coupled with correction factors were used to calculate molar ratios. Results – The optimal CZE method coupled with correction factors was successfully applied to the determination of molar ratios of three purified polysaccharides and their corresponding partial acid hydrolysis products. ESP‐A3, ESP‐A4 and ESP‐B4 were all typical acidic hetero‐polysaccharides and consisted of xylose, arabinose, glucose, rhamnose, mannose, galactose, glucuronic acid and galacturonic acid, and their corresponding molar ratios were 6.8:7.5:1.0:14.0:13.7:22.3:10.2:3.8 for ESP‐A3, 1.2:4.1:1.0:5.1:1.6:17.3:3.1:2.2 for ESP‐A4, and 1.0:4.5:1.0:2.0:1.0:5.5:1.5:50.0 for ESP‐B4. Conclusion – The results provided scientific evidence for the further study of the structure and bioactivity of complex acidic E. sinica polysaccharides. Copyright © 2010 John Wiley & Sons, Ltd.     

细菌素Paracin 1.7的纯化与性质研究

摘要：【目的】分离纯化（Lactobacillus paracasei）HD1.7所产生的细菌素并分析其特性。【方法】细菌素Paracin 1.7的纯化采用色谱技术,其分子量检测采用十二烷基磺酸钠－聚丙烯酰胺凝胶电泳（SDS-PAGE）,利用琼脂扩散法测定细菌素活力。【结果】Paracin 1.7分离于我国传统发酵食品酸菜发酵液中,其产生菌为副干酪乳杆菌。 Paracin 1.7可以抑制其它微生物的生长,为细菌素。该菌在稳定期可产生大量Paracin 1.7。经过阳离子交换层析、凝胶过滤层析以及高效液相色谱（HPLC）,对该细菌素进行了初步纯化,并经Tricine-SDS-PAGE检测其分子量大约为11 kDa。Paracin 1.7抑菌谱较广,其抑菌范围包括Proteus, Bacillus, Enterobacter, Staphylococcus, Escherichia, Lactobacillus, Microccus, Pseudomonas, Salmonella, Saccharomyces,其中有些为食品源致病菌。该细菌素在酸性及高温下稳定,对几种蛋白质酶敏感。该细菌素对敏感菌株的作用方式为抑菌。在4oC保存4个月后,Paracin 1.7的抑菌活性保持稳定。【结论】基于细菌素Paracin 1.7的性质,该细菌素可用作食品防腐剂。     

虫草多糖的分离、纯化和初步药效活性研究

以虫草发酵菌丝体为原料提取虫草多糖并对多糖进行结构鉴定和初步药效活性研究。采用水提醇沉和离子交换纤维素进行分离得到两种虫草多糖,HPLC测定相对分子质量,紫外光谱、红外光谱、部分酸水解、甲基化分析和高效液相色谱等方法研究单糖组成及连接方式,四甲基偶氮唑盐微量酶反应比色法（MTT）检测虫草多糖的活性。经分离得到中性（CPSl）、酸性（CPS2）两种成分,相对分子质量分别为2．56×10^4,9．91×10^;单糖组成：CPSln,（葡萄糖）：n（甘露糖）：n（半乳糖）：n（阿拉伯糖）=46：36：18：l;CPS2／n,（葡萄糖）：n,（甘露糖）：n（半乳糖）：n（半乳糖酸）：n（木糖）：n（阿拉伯糖）：n（鼠李糖）=30：25：14：4：3：3：1。红外谱揭示均含-a-键。CPSl主链含（1→6）糖苷键的高度分支的葡甘露半乳聚糖,另有少量葡萄糖分支点在2,3,4位。CPS2主链含葡萄糖（Glc）、甘露糖（Man）、半乳糖（Gal）,分支点主要在3位,侧链含多种单糖。CPSl和CPS2都对顺铂（CDDP）损伤的vero细胞有一定保护作用。     

The isolation, preliminary study of structure and physiological activity of water-soluble polysaccharides from squeezed berries of Snowball tree Viburnum opulus

Water-soluble polysaccharide fractions VO1-VO4 were isolated from the squeezed berries of snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of alpha-1,4-linked residues of D-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of beta-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of alpha-arabinofuranose at a Gal: Ara ratio of 3:1. Some polysaccharides from V. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides from V. opulus.     

The isolation, preliminary structural studies, and physiological activity of water-soluble polysaccharides from the squeezed berries of the snowball treeViburnum opulus

Water-soluble polysaccharide fractions VO1–VO4 were isolated from the squeezed berries of the snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of α-1,4-linked residues ofD-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of β-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of α-arabinofuranose at a Gal : Ara ratio of 3 : 1. Some polysaccharides fromV. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides fromV. opulus.