Pectic Polysaccharides Research Articles

Pectin coating of titanium and polystyrene surfaces modulates the macrophage inflammatory response

Titanium has been used with success for bone anchoring of dental implants. However, when implant surfaces are exposed to the oral environment, the progression of peri-implantitis triggered by specific oral bacteria has been reported. Bacterial colonization of implants leads to prolonged immune cell activation and bone resorption. A new strategy to improve implant biocompatibility and prevent peri-implantitis is to develop pectin surface nanocoatings. These plant-derived polysaccharides are promising candidates for surface nanocoatings of titanium implants due to their osteogenic and anti-inflammatory properties. Therefore, the aim of the study was to evaluate the in vitro effect of nanocoating with plant-derived rhamnogalacturonan-I (RG-I) on pro- and anti-inflammatory responses of primary human monocyte-derived macrophages (HMDMs) induced by Escherichia coli LPS and Porphyromonas gingivalis bacteria. In the present study, two different types of surface materials, tissue culture polystyrene (TCPS) plates and titanium (Ti) discs, coated with pectic polysaccharides, potato unmodified RG-I (PU) and potato dearabinanated RG-I (PA), have been examined. The inflammatory responses of HMDMs after E. coli LPS/P. gingivalis stimulation were investigated through gene expression measurements of pro- and anti-inflammatory cytokines. The results showed that PU and PA decreased expression of the proinflammatory genes tumour necrosis factor-alpha (TNFA), interleukin-1 beta (IL1B) and interleukin-8 (IL8) in activated HMDMs cultured on TCPS/Ti surfaces. In contrast, the effects on anti-inflammatory interleukin-10 (IL10) gene expression were not significant. The results indicate that RG-Is should be considered as a candidate for organic nanocoatings of titanium implant surfaces in order to limit host proinflammatory responses and improve bone healing. DOI: http://dx.doi.org/10.5281/zenodo.1250541

Characterization, sulfated modification and bioactivity of a novel polysaccharide from Millettia dielsiana

Millettia dielsiana is a traditional herb medicine to treat rheumatic arthritis and gynecological diseases. In this study, a novel polysaccharide (MDP1) with a molecular weight of 139.54 kDa was isolated from Millettia dielsiana by DEAE-52 cellulose chromatography. Its sulfated derivative (S-MDP1) was prepared by the chlorosulfonic acid-pyridine method. Structural analysis indicated that MDP1 was a pectic polysaccharide and did not exhibit a triple helical conformation. In vitro, MDP1 and S-MDP1 had protective effect on H2O2-induced PC12 cells death. Immunological assay showed that MDP1 and S-MDP1 significantly stimulated NO production and phagocytic activity in RAW264.7 cells, and promoted lymphocyte proliferation. Anticoagulant assay indicated that S-MDP1 effectively prolonged activated partial thromboplastin time (APTT) and thrombin time (TT), but not prothrombin time (PT), and MDP1 prolonged APTT and TT weakly. These results implied that MDP1 and S-MDP1 had the potential to be used as antioxidant, immunomodulatory and anticoagulant agents.

Extraction, characterization and immunomodulatory property of pectic polysaccharide from pomegranate peels: Enzymatic vs conventional approach

Molecular characteristics, structural properties and immunostimulatory activities of polysaccharides from pomegranate peel were evaluated after 0.1 M HCl, Cellic CTec2 and buffer extractions. The isolated polysaccharides were mainly formed of neutral sugars (32.1%–51.1%) and uronic acids (19.9%–30.8%) as well as varying levels of proteins (15.0%–39.5%). Different levels of sugars including glucose (44.9%–68.1%), galactose (14.6%–19.4%), mannose (3.4%–18.1%), arabinose (3.1%–18.1%) and rhamnose (3.5–6.0%) constructed the structure of isolated polysaccharides. The average molecular weight (Mw) of polysaccharides differed notably and ranged from 422.5 × 103 to 18,631.8 × 103 g/mol. Polysaccharide molecules obtained using Cellic CTec2 enzyme induced RAW264.7 murine macrophage cells to release considerable amount of inflammatory mediators including nitric oxide, IL-1β, TNF-α, IL-6 and IL-10. The polysaccharide stimulation of macrophage cells initiated through NF-κB and MAPKs signaling pathways and activation of p-NF-κB, p-JNK, p-ERK and p-p38 proteins. The most potent immunostimulatory polysaccharides were consisted of (1 → 3)-linked glucose, (1 → 6)-linked galactose, (1 → 4)-linked mannose and (1 → 4)-linked arabinose residues with branching points at C6 and C3. These results indicated that the lower molecular weight of polysaccharides isolated with Cellic CTec2 enzyme could be one of the major determinant structural characteristics in stimulating macrophage cells.

Fast preparation of rhamnogalacturonan I enriched low molecular weight pectic polysaccharide by ultrasonically accelerated metal-free Fenton reaction

The recovery of pectic polysaccharides with high rhamnogalacturonan I (RG-I) branches from citrus canning processing water was achieved in a previous study aimed at reducing chemical oxygen demand and benefiting both process economics and the environment. However, the large molecular size and poor in vivo bioavailability of these polysaccharides limit the application of these pectic polysaccharides in functional foods. We report the development of an ultrafast and green approach to depolymerize pectic polysaccharides using an ultrasound-accelerated metal-free Fenton chemistry, relying on H2O2/ascorbic acid. The results show that ultrasound enhances the efficiency of H2O2/ascorbic acid system to degrade pectin into 7.9 kDa pectic fragments within 30 min through both chemical effects (increasing the amount of hydroxyl radicals and lowering activation energy of H2O2 decomposition) and mechanical effects (disaggregating polysaccharide clusters). The backbones of the resulting fragments mainly correspond to RG-I patterns (molar ratio galacturonic acid (GalA): rhamnose (Rha) ∼ 1.06:1) with a high degree of rhamnose branching. Free radicals preferentially act on the GalA backbone in the HG region and maintain the RG-I region. Antitumor activities, assessed using human breast cancer cells (MCF-7), suggest that the resulting fragments significantly inhibit cancer cell growth and that activity increases with decreasing molecular weight. The resulting ultralow molecular weight pectic fragments have potential application for the development of functional foods and antitumor drugs.

Pectic polysaccharides with different structural characteristics as inhibitors of pancreatic lipase

The effect of molecular weight (MW) and methoxylation degree (MD) of apple (A) and citrus (C1-C5) pectic polysaccharides (PPs) on both the digestion of emulsified lipids and the pancreatic lipase activity was evaluated by using a static in vitro digestion system and a simplified system, respectively. The first system consisted in the simulated digestion [composed of an initial (before digestion), oral, gastric, and intestinal phases] of a soybean oil-in-water emulsion containing PPs at initial concentrations of 0 (control) and 0.1% (w/w) of PPs with pancreatic lipase. The microstructure and particle size distribution of the soybean oil-in-water emulsions were characterized before (initial phase) and after (intestinal phase) the in vitro digestion process. During the intestinal phase the free fatty acid released were measured as well. The second system consisted of an acidic (H2SO4) back titration of Tris-HCl buffer after the hydrolysis of triacetin with pancreatic lipase, in the presence of PPs at concentrations of 0 (control) and 0.01% (w/v). Among tested PPs A [MW, 209 kDa; and MD, 73.3% (mol/mol)] was the most effective one in inhibiting the activity of pancreatic lipase in both the static in vitro digestion model (63% activity as compared to the control) and the simplified model (61% activity as compared to the control). From the contour plot, after mathematical modelling, MD of PPs had a greater influence as compared to MW on the inhibition of the activity of pancreatic lipase, with higher inhibition of enzymatic activity as the MD was increased.

Effect of the degree of esterification and blockiness on the complex coacervation of pea protein isolate and commercial pectic polysaccharides

The complex coacervation of pea protein isolate (PPI) with commercial pectic polysaccharides [high methoxy citrus pectin (P90, 90 representing DE), apple pectin (P78) sugar beet pectin (P62), low methoxy citrus pectin (P29)] of different degrees of esterification (DE) [and galacturonic acid content (GalA)] and blockiness (DB), was investigated. The maximum amount of coacervates formed at a biopolymer weight mixing ratio of 4:1 for all PPI-pectin mixtures, with the exception of PPI-P29 where maximum coacervation occurred at the 10:1 mixing ratio. The pH at which maximum interactions occurred was pH 3.4–3.5 (PPI: P90/P78) and 3.7–3.8 (PPI: P62/P29). PPI complexed with pectins with high levels of DE (low levels of GalA) and DB displayed greater interactions at optimal mixing conditions compared to pectin having lower levels of esterification and blockiness. The addition of P78 to PPI greatly increased protein solubility at pH 4.5.

Physicochemical, molecular, emulsifying and rheological characterizations of sage (Salvia splendens) seed gum

The objective was to investigate the physicochemical, molecular, rheological, and emulsifying properties of water soluble-sage seed gum (WSG). WSG mainly comprised galacturonic acid and xylose. FTIR and NMR analyses confirmed the presence of pectic polysaccharides in WSG. Additionally, the molecular weight of WSG was higher than that of pectin standard. Compared to pectin standard solutions, WSG solutions exhibited higher shear thinning behavior and higher values of apparent viscosity (ηa,100) and consistency index (K) in steady shear measurements. According to the results of frequency sweep test, the dynamic moduli (G′ and G″) for WSG solutions were increased with increasing frequency and concentration. The changes in dynamic moduli of WSG solutions as a function of aging time at 4 °C indicated that WSG could form a more rigid network than pectin standard. According to the results of temperature sweep test, the dynamic moduli of WSG solutions were higher than those of pectin standard solutions. Emulsion capacity and stability analyses indicated that WSG (58 and 56%, respectively) had better emulsifying properties than pectin standard (46 and 37%). In conclusion, compared to pectin standard, superior rheological and emulsifying properties observed in WSG might be related to higher molecular weight and protein content, respectively.

Genetic and environmental factors contribute to variation in cell wall composition in mature desi chickpea (Cicer arietinum L.) cotyledons.

Chickpea (Cicer arietinum L.) is an important nutritionally rich legume crop that is consumed worldwide. Prior to cooking, desi chickpea seeds are most oftendehulled and cleaved to release the split cotyledons, referred to as dhal. Compositional variation between desi genotypes has a significant impact on nutritional quality and downstream processing, and this has been investigated mainly in terms of starch and protein content. Studies in pulses such as bean and lupin have also implicated cell wall polysaccharides in cooking time variation, but the underlying relationship between desi chickpea cotyledon composition and cooking performance remains unclear. Here, we utilized a variety of chemical and immunohistological assays to examine details of polysaccharide composition, structure, abundance, and location within the desi chickpea cotyledon. Pectic polysaccharides were the most abundant cell wall components, and differences in monosaccharide and glycosidic linkage content suggest both environmental and genetic factors contribute to cotyledon composition. Genotype-specific differences were identified in arabinan structure, pectin methylesterification, and calcium-mediated pectin dimerization. These differences were replicated in distinct field sites and suggest a potentially important role for cell wall polysaccharides and their underlying regulatory machinery in the control of cooking time in chickpea.

Structural studies of water-extractable pectic polysaccharides and arabinogalactan proteins from Picea abies greenery

Water-extractable arabinogalactan proteins (AGP) (the main constituent) and pectic polysaccharides were isolated from tree greenery of Picea abies. The carbohydrate part of AGP macromolecules consisted of AG-II, the side chains of which were represented by 1,6- and 1,3,6-β-d-Galp, T-α-l-Araf, 1,3- and 1,5-α-l-Araf, T-β-D-GlcpA and 1,4-β-D-GlcpA, T-α-l-Rhap, T-α-l-Fucp and 4-O-Me-α-l-Fucp residues. It was established that the unusual 4-O-Me-α-l-Fucp monosaccharide are located on the non-reducing ends of the side chains of carbohydrate part of AGP macromolecules, and are bound to 1,4-β-d-GlcpA residues by 1,4-bonds. The backbone of pectin macromolecules consisted mostly of 1,4-α-d-galactopyranosyluronan and RG-I, which side chains were represented by highly branched 1,5-α-l-arabinan. It was shown that RG-I is characterized mainly by short segments, which are alternated with the regions of the non-acetylated and non-methyl-esterified galacturonan. The study revealed that at least a part of the pectin is strongly associated with AGP. It was indicated that the RG-I segments are separated from the AGP-bound pectin by regions of 1,4-α-d-galactopyranosyluronane.

Flavonol rhamnosylation indirectly modifies the cell wall defects of RHAMNOSE BIOSYNTHESIS1 mutants by altering rhamnose flux

Rhamnose is required in Arabidopsis thaliana for synthesizing pectic polysaccharides and glycosylating flavonols. RHAMNOSE BIOSYNTHESIS1 (RHM1) encodes a UDP-l-rhamnose synthase, and rhm1 mutants exhibit many developmental defects, including short root hairs, hyponastic cotyledons, and left-handed helically twisted petals and roots. It has been proposed that the hyponastic cotyledons observed in rhm1 mutants are a consequence of abnormal flavonol glycosylation, while the root hair defect is flavonol-independent. We have recently shown that the helical twisting of rhm1 petals results from decreased levels of rhamnose-containing cell wall polymers. In this study, we found that flavonols indirectly modify the rhm1 helical petal phenotype by altering rhamnose flux to the cell wall. Given this finding, we further investigated the relationship between flavonols and the cell wall in rhm1 cotyledons. We show that decreased flavonol rhamnosylation is not responsible for the cotyledon phenotype of rhm1 mutants. Instead, blocking flavonol synthesis or rhamnosylation can suppress rhm1 defects by diverting UDP-l-rhamnose to the synthesis of cell wall polysaccharides. Therefore, rhamnose is required in the cell wall for normal expansion of cotyledon epidermal cells. Our findings suggest a broad role for rhamnose-containing cell wall polysaccharides in the morphogenesis of epidermal cells.

Pectic polysaccharides as an acrylamide mitigation strategy – Competition between reducing sugars and sugar acids

The main route for acrylamide formation is the reaction between reducing sugars and asparagine. As foods pH modulates acrylamide formation, cooking under the lowest pH is a possible mitigation strategy, as long as it does not compromise the expected foods sensorial characteristics. Polymeric acid compounds, such as pectin or pectate, which are acidic polysaccharides, can provide acidity without significant interference in taste or colour. To prove this hypothesis, biscuits were prepared with tartaric acid (control to acidic effect), and galacturonic acid in monomeric (GalA), oligomeric, and polymeric forms (pectin or pectate). While 1% GalA leads to 95% increase in acrylamide, biscuits prepared with 5% pectin had a 67% decrease. Replacing sucrose with fructose increased the acrylamide levels in control biscuits above the benchmark level of 150 μg/kg recommended by EFSA for children. However, addition of pectin/pectate had an effective acrylamide mitigation by lowering its content below these indicative values.

Characteristics and intestinal immunomodulating activities of water-soluble pectic polysaccharides from Chenpi with different storage periods.

The traditional view considers that Chenpi (dried citrus peel) stored over the long-term has better health efficacies compared to fresh Chenpi, although the detailed mechanism responsible for this remains obscure. The three water-soluble pectic polysaccharides (CPP1, CPP5 and CPP10) were obtained from 1-, 5- and 10-year Chenpi, respectively, and their physicochemical characteristics and intestinal immunomodulating activities were investigated and compared. The results obtained showed that CPP5 and CPP10 demonstrated a lower dynamic viscosity and degree of methylesterification, as well as a higher molecular heterogeneity, compared to CPP1. Monosaccharide composition analysis indicated that CPP1 was composed of arabinose, galacturonic acid and galactose, and a small amount of rhamnose; however, CPP5 and CPP10 consisted of arabinose, galacturonic acid, galactose, glucose and xylose, and a small amount of rhamnose. With the extension of storage period of Chenpi, the content of soluble conjugate phenolic acids increased in the pectic polysaccharide. Furthermore, it was confirmed that the pectic polysaccharides extracted from the 5-year and 10-year Chenpi could significantly enhance the proliferation of bone marrow cells via activating the Peyer's patch cells in vitro. The present study demonstrates the differences in the pectic polysaccharides from Chenpi with different storage periods and also confirms that the pectic polysaccharides extracted from Chenpi stored over the long-term had more significant intestinal activities compared to that obtained from the fresh Chenpi. This phenomenon might partly explain why the Chenpi stored over the long-term has better healthcare effects. © 2018 Society of Chemical Industry.

Chamomile Wastes (Matricaria chamomilla): New Source of Polysaccharides

The chamomile (Matricaria chamomilla) is widely used as essential oil crop. Low amounts of oils in the plants lead to annual generation of significant wastes which are mainly discarded. The purpose of this study was to investigate chamomile wastes as source of polysaccharides as novel approach for valorization of chamomile waste biomass. Three wastes—generated by industrial steam distillation, hydrodistillation and extraction with 1,1,1,2-tetrafluoroethane of chamomile flowers, were investigated. The potential of wastes as source of polysaccharides was estimated by initial diluted acid extraction. Consecutive fractional extraction of the wastes with different extractants was performed in order to obtain information about the overall polysaccharides content and polysaccharide fractions present in the wastes. Different fractions of polysaccharides present in the chamomile wastes were extracted for the first time by consecutive fractional extraction. Their chemical composition and properties were investigated and was found that they were pectic type polysaccharides. The polysaccharides were subjected to differential thermal analysis and it was found that they start to decompose significantly after 230–240 °C. The present study explored the possibility for obtaining of polysaccharides by fractional extraction of chamomile wastes. For the first time also waste from extraction with 1,1,1,2-tetrafluoroethane of chamomile flowers was investigated. The overall yield of polysaccharides from steam-distilled, hydrodistilled wastes and residues after extraction with 1,1,1,2-tetrafluoroethane—11.66, 9.87 and 22.56%, respectively, suggested that waste chamomile biomass was a rich source of pectic type polysaccharides.

Optimization of antioxidant and antiglycated activities of polysaccharides from Arthrocnemum indicum leaves

Central composite design was performed to optimize uronic acid rate, esterification degree, total antioxidant ability and antiglycation capacity of carbohydrates from Arthrocnemum indicum leaves. Three independent variables were opted: extraction temperature, time and ratio (solvent/material). The optimal settings were: extraction temperature of 80°C, time of 288min and (solvent/solid) ratio of 40mL/g. Under these settings, uronic acid rate and esterification degree were 49.29%, 30.24%, respectively, whereas total antioxidant activity and antiglycation capacity was 35.81mg ascorbic acid equivalents/g matter and 69.81%, respectively. Colorimetric assays showed that total sugar and uronic acid contents for polysaccharide were 71.78% and 49.24%, respectively. Furthermore, Preliminary structure study was performed via various methods including FT-IR, NMR and UV–vis analysis. SEC analyzes revealed that polysaccharide had an average molecular weight of 2179kDa. Moreover, GC–MS analyzes showed that extracted polysaccharide was a pectic polysaccharide which formed of arabinose, mannose, galactose, rhamnose, glucose and xylose in the molar percentage of 66.68%, 3.93%, 12.71%, 6.31%, 6.08% and 4.29%, respectively. This results revealed that extracted polysaccharide can be employed as source of natural antioxidants and as possible antiglycated agents.

Active proton efflux, nutrient retention and boron-bridging of pectin are related to greater tolerance of proton toxicity in the roots of two Erica species

Background and aimsTolerance to soil acidity was studied in two species of Ericaceae that grow in mine-contaminated soils (S Portugal, SW Spain) to find out if there are interspecific variations in H+ tolerance which might be related to their particular location. MethodsTolerance to H+ toxicity was tested in nutrient solutions using seeds collected in SW Spain. Plant growth and nutrient contents in leaves, stems and roots were determined. Viability tests and proton exchange were studied in roots exposed, short-term, to acidic conditions. Membrane ATPase activity and the cell-wall pectic polysaccharide domain rhamnogalacturonan-II (RG-II) were analysed to find out interspecific differences. ResultsVariation in survival, growth and mineral composition was found between species. The H+-tolerant species (Erica andevalensis) showed greater concentration of nutrients than E. australis. Very low pH (pH 2) produced a significant loss of root nutrients (K, P, Mg) in the sensitive species. Root ATPase activity was slightly higher in the tolerant species with a correspondingly greater H+ efflux capacity. In both species, the great majority of the RG-II domains were in their boron-bridged dimeric form. However, shifting to a medium of pH 2 caused some of the boron bridges to break in the sensitive species. ConclusionsVariation in elements linked to the cell wall-membrane complex and the stability of their components (RG-II, H+-ATPases) are crucial for acid stress tolerance. Thus, by maintaining root cell structure, active proton efflux avoided toxic H+ build-up in the cytoplasm and supported greater nutrient acquisition in H+-tolerant species.

Gastroprotective activity of a pectic polysaccharide fraction obtained from infusion of Sedum dendroideum leaves

BackgroundSedum dendroideum, popularly known in Brazil as balsam, is traditionally used as a wound healing agent, to treat gastritis, and several other health problems. Some studies have shown that plant polysaccharides may have gastroprotective properties. PurposeConsidering the popular use of S. dendroideum and the gastroprotective activity of polysaccharides, the objective of this work was to obtain, to characterize, and to evaluate the gastroprotective activity of a polysaccharide fraction from this plant. MethodsPolysaccharides of S. dendroideum were extracted with water by infusion, fractionated by freeze-thawing process and dialyzed at a 100 kDa cut-off membrane, and characterized by monosaccharide composition and NMR analysis. The gastroprotective activity of the pectic polysaccharide fraction RSBAL was evaluated in the ethanol-induced ulcer model in rats, followed by determination of the mucus and glutathione levels in the gastric tissue. ResultsRSBAL was constituted by a homogalacturonan and a homogalacturonan branched by side chains of arabinans and type II arabinogalactans. It reduced ethanol-induced gastric ulcers in rats, preserving mucus and glutathione levels in the stomach. ConclusionThis study demonstrated that polysaccharides could be related to the pharmacological activity of S. dendroideum.

Synthesis of Two Tetrasaccharide Pentenyl Glycosides Related to the Pectic Rhamnogalacturonan I Polysaccharide.

The synthesis of two protected tetrasaccharide pentenyl glycosides with diarabinan and digalactan branching related to the pectic polysaccharide rhamnogalacturonan I is reported. The strategy relies on the coupling of N-phenyl trifluoroacetimidate disaccharide donors to a common rhamnosyl acceptor. The resulting trisaccharide thioglycosides were finally coupled to an n-pentenyl galactoside acceptor to access the two protected branched tetrasaccharides.

Two complement fixing pectic polysaccharides from pedicel of Lycium barbarum L. promote cellular antioxidant defense

Purification, characterization and biological activities of polysaccharides from Lycium barbarum pedicel were investigated in this study. Two polysaccharides, PLBP-I-I and PLBP-II-I, were obtained from water extracts by anion exchange chromatography and gel filtration. Structural elucidation based on IR, 1H NMR, and 13C NMR spectra indicated that these two fractions were typical pectic polysaccharides, with homogalacturonan and rhamnogalacturonan type I regions and arabinogalactan side chains, and some of the galacturonic acid units were methyl esterified. Both fractions exhibited potent complement fixating activity and pro-antioxidant defense capacity, and those two fractions showed different activities. The higher complement fixation activity was obtained in fraction PLBP-I-I, while the higher pro-antioxidant defense capacity was obtained in fraction PLBP-II-I, which may be due to the structural differences between those two fractions. Thus, the pedicel of L. barbarum could be used as a potential source for natural immunomodulator and antioxidant.

Structural characterization and immunomodulatory activity of a pectic polysaccharide (CALB-4) from Fructus aurantii

A purified polysaccharide, designated CALB-4, was acquired from Fructus aurantii that is the traditional edible/medicina plant in China. The present study was performed to characterize the CALB-4 and to evaluate its immunomodulatory activities on human peripheral blood mononuclear cells (PBMCs). The structure of CALB-4 was characterized by partial acid hydrolysis, periodate oxidation, Smith degradation, and methylation analysis combined with gas chromatography–mass spectrometry (GC–MS), Infrared Spectroscopy (IR) and scanning electron microscopy (SEM). The results indicated that CALB-4 was elucidated as a pectic polysaccharide and its main chain is composed of Man, Gal UA and Gal, interspersed with Ara, Rha, Man and Gal. Furthermore, immunological tests showed that CALB-4 exhibits the immunoenhancement effects. The mechanism for this action might be attributed to the increase of the cytoplasmic concentration of pro-IL-1 via the up-regulation of several mitogen-activated protein kinases (MAPKs) and the nuclear translocation of p65. This study clarified that CALB-4 could be as an efficacious biological response modifier in immunotherapy.

Characteristics and immune-enhancing activity of pectic polysaccharides from sweet cherry (Prunus avium)

Two water soluble polysaccharides components PAPS-1 and PAPS-2 with homogeneously distributed molecular weight were obtained from Prunus avium. PAPS-1 and PAPS-2 contained GalA: Ara: Gal: Rha: GluA: Glu in 49.38: 32.39: 10.68: 4.66: 1.94: 0.48 and 77.18: 14.91: 3.39: 3.46: 0.93: 0.19 M ratios respectively, as well as trace amount of mannose and fucose. Infrared spectroscopy (IR), nuclear magnetic resonance (NMR) and methylation analysis indicated that both fractions were type I rhamnogalacturonan (RG-I) pectic polysaccharides with glycan side chains constituted mainly of arabinose with minor amount of galactose. Galacturonic acid methylation and sugar acetylation was found in both PAPS-1 and PAPS-2. Both PAPS-1 and PAPS-2 significantly induced the NO release from RAW264.7 cells and the expression of several immune-related molecular (TNFα, IL6, IL10, GCSF, iNOS, COX-2) was induced in RAW264.7 cells.