Homogeneous Polysaccharide Fractions Research Articles

Structural Properties of Homogeneous Polysaccharide Fraction Released from Wheat Germ by Hydrothermal Treatment

The work aimed to enhance the extraction of wheat germ polysaccharides (WGPs) by hydrothermal treatment and identify the structural properties of WGPs. Results showed that the extraction yield of crude WGPs reached 18.72% after steam explosion. A homogeneous polysaccharide fraction (steam explosion wheat germ polysaccharides, SEWGPs) was also released and purified by DEAE-cellulose-52 separation and Sephacryl S-500 HR gel filtration with a yield of 3.84%. The SEWGPs had an average molecular weight of 3.34 × 106 Da and was composed of glucose (32.62%), arabinose (28.27%), xylose (27.71%), and galactose (11.40%). Methylation and nuclear magnetic resonance results indicated that the main linkages of the SEWGPs contained →4)-α-D-Glcp(1→3)-β-D-Xylp(1→3)-α-L-Arap(1→4)-α- D-Glcp(1→3)-α-L-Arap(1→ or →3)-β-D-Xylp(1→4)-α-D-Glcp(1→3)-α-L-Arap(1→ 4)-α-D-Glcp(1→3)-α-L-Arap(1→, and the side chains were α-D- Galp(1→ and β-D-Xylp(1→ linked at the C6-position of →4,6)-α-D-Glcp(1→, respectively. Therefore, the steam explosion facilitated the detection of a more structural nature of WGPs and provided the industrial potential of WGPs as functional ingredients for food-making.

Novel polysaccharide from Chaenomeles speciosa seeds: Structural characterization, α-amylase and α-glucosidase inhibitory activity evaluation

Purification and structural characterization of a novel polysaccharide fraction from Chaenomeles speciosa seeds were investigated. After hot water extraction and ethanol precipitation, the crude polysaccharide was sequentially purified with Cellulose DEAE-52 and gel-filtration chromatography, and a highly purified polysaccharide fraction (F3) was obtained. The structure of F3 was characterized by high-performance gel permeation chromatography (HPGPC), high performance liquid chromatography (HPLC), ultraviolet-visible (UV), Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectrum, together with methylation, scanning electron microscopy (SEM), atomic force microscope (AFM), and Congo-red test analysis. The results indicated that F3 was a homogeneous polysaccharide fraction with a molecular weight of 8.65 × 106 Da, and it was composed of Rha, GlcA, Gal, and Ara in a molar ratio of 6.34:5.73:47.14:40.13. The backbone of F3 was consisted of →3,6)-Galp-(1→, and the side chains of F3 were composed of Araf-(1→, →4)-GlcpA-(1→, →4)-Galp-(1→ and →3)-Rhap-(1→. The hypoglycemic assays demonstrated F3 had good α-amylase and α-glucosidase inhibition activities, and their IC50 values were 6.24 mg/mL and 4.59 mg/mL respectively. Thus, the polysaccharide from Chaenomeles speciose could be applied as a potential natural source in retarding postprandial hyperglycemia effects.

Polysaccharide from tuberous roots of Ophiopogon japonicus regulates gut microbiota and its metabolites during alleviation of high-fat diet-induced type-2 diabetes in mice

Abstract Ophiopogonis Radix (Maidong in Chinese), the tuberous roots of Ophiopogon japonicus having polysaccharide as the main active ingredient, is a traditional Chinese herb and popularly used as functional food additive in China. Here, a homogeneous polysaccharide fraction (OJP-W1) was isolated and characterized from Ophiopogonis Radix collected from Sichuan (Chuan-Maidong). The therapeutic effects of OJP-W1 in diabetes symptoms, gut microbiota and metabolism of short-chain fatty acids (SCFAs) in high-fat diet (HFD)-induced type-2 diabetes mice were investigated. Results showed that OJP-W1 significantly ameliorated HFD-induced insulin resistance and glucose tolerance. Meanwhile, OJP-W1 regulated the gut microbiota dysbiosis in HFD-fed mice, as indicated by increasing Actinobacteria and Bifidobacterium, decreasing Proteobacteria and type-2 diabetes-enriched taxa (e.g. Desulfovibrionaceae, Dorea and Ruminococcaceae). In addition, OJP-W1 could improve the metabolic disorder of SCFAs in HFD-fed mice. This study indicated that OJP-W1 might serve as a novel functional food in preventing diabetes-associated gut microbiota dysbiosis and SCFA metabolic disorder.

Physicochemical properties of polysaccharides separated from Camellia oleifera Abel seed cake and its hypoglycemic activity on streptozotocin-induced diabetic mice

Two homogeneous polysaccharide fractions named SCP-1 (7.16 × 106 Da) and SCP-2 (2.00 × 104 Da) were purified by DEAE-52 cellulose and Sephadex G-200 column chromatography successively from Camellia oleifera Abel seed cake. They were characterized by Fourier transformed infrared (FT-IR), high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) spectroscopy and differential scanning calorimetry (DSC). The monosaccharide compositions of SCP-1 were d‑mannose, d‑glucose and l‑xylose with a molar ratio of 1.77:0.93:1 and that of the SCP-2 were d‑mannose, l‑rhamnose, d‑glucose and l‑xylose with a molar ratio of 5.27:1.21:0.16:1. Animal experiments suggested that the plasma glucose levels in hyperglycemia mice were reduced by 11.34%, 30.70%, 46.83% after administration of high, medium and low doses of SCP-1, and reduced by 16.67%, 23.93% and 33.00% after administration of high, medium and low doses of SCP-2, respectively. SCP-1 and SCP-2 also increased the activities of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD), as well as decreased the content of malondialdehyde (MDA) in the hyperglycemia mice. These results suggested that SCP-1 and SCP-2 possessed strong hypoglycemic activities in streptozotocin-induced model mice. In addition, the hypoglycemic activity of SCP-1 was stronger than that of SCP-2.

Cellulase-assisted extraction of polysaccharides from Malva sylvestris: Process optimization and potential functionalities

Enzyme-assisted extraction process of the water-soluble Malva sylvestris polysaccharides (MSPs) was optimized using response surface methodology (RSM). The highest yield (10.40%) of MSPs was achieved at 5.64% cellulase, 55.65°C temperature, 3.4h time, and 5.22 pH. Three homogeneous polysaccharide fractions (MSP-1, MSP-2, MSP-3) were purified by DEAE-cellulose and Sephadex G-100 chromatography, which were composed of galactose, glucuronic acid, arabinose, rhamnose and mannose in different molar ratios with molecular weight range of 2.6×105–8.8×105Da. The fractions could significantly increase antioxidant, antitumor and antimicrobial activities in a dose-dependent pattern. MSP-2 revealed stronger antioxidant activities than MSP-1 and MSP-3, including reducing power and scavenging activity of DPPH and OH radicals. The antiproliferative activity of MSP-2 (1.0mg/mL) on the growth of A549 and HepG2 cells was 45.1% and 53.2%, respectively. The Gram-positive bacteria (Bacillus cereus PTCC 1015 and Staphylococcus aureus PTCC 1112) compared with Gram-negative ones (Escherichia coli PTCC 1763 and Salmonella typhimurium PTCC 1709) showed less sensitivity against the various MSPs (3–15mg/mL).

Effects of the ultra-high pressure on structure and α-glucosidase inhibition of polysaccharide from Astragalus

A novel homogeneous polysaccharide fraction (APS) was extracted from Astragalus by hot water and purified by Sephadex G-100 and G-75 column. Its molecular weight was 693kDa. APS and APS with ultra-high pressure treatment exhibited significant inhibitory abilities on a-glucosidase, inhibition rate from high to low in order was 400MPa-APS, 300MPa-APS, 500MPa-APS and APS. The inhibition ​percentage of 400MPa-APS (1.5mg/mL) was 49% (max.). This suggested that the inhibitory activity of APS on a-glucosidase was improved by ultra-high pressure treatment. FT-IR, SEM, CD spectra, atomic force microscope and Congo red test analysis of APS and 400MPa-APS showed ultra-high pressure treatment didn’t change the preliminary structure but had an effect on its advanced structure.

Characterization and biological activity of Taishan Pinus massoniana pollen polysaccharide in vitro.

Taishan Pinus massoniana pollen polysaccharide (TPPPS) improves cellular and humoral immune responses of animals and is a novel potential immunomodulator. However, the components of TPPPS have not been recognized. To investigate the composition of TPPPS, crude polysaccharide was obtained from Taishan P. massoniana pollen through water extraction and ethanol precipitation. Three homogeneous polysaccharide fractions (TPPPS1, TPPPS2, and TPPPS3) were purified from TPPPS by DEAE-cellulose column chromatography. The average molecular weights of the three polysaccharides were 56, 25, and 128 kDa, respectively. Results of high-performance liquid chromatography (HPLC) showed that TPPPS comprised mannose, ribose, xylose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose. The biological activity assays showed that TPPPS2 and TPPPS3 significantly promoted spleen lymphocyte proliferation, and that TPPPS3 showed better effect than TPPPS2. TPPPS3 enhanced the secretion of cytokine IL-2 and TNF, whereas TPPPS2 mainly elevated IL-2 secretion. By contrast, TPPPS1 exhibited other effects, and it induced the highest amount of NO production, thereby indicating that TPPPS1 had the best antioxidant activity. TPPPS3 at 50 μg/mL significantly inhibited the proliferation of subgroup B Avian Leukosis virus (ALV-B) through virus adsorption interference in vitro. Results indicated that TPPPS comprised three main components, among which, TPPPS1 mainly showed antioxidant effects, whereas TPPPS2 and TPPPS3 played key roles in immunomodulation, especially TPPPS3. Further studies on the use of a reasonable proportion of TPPPS1-3 may facilitate the development of an effective immunomodulator.

A novel water-soluble β-(1→6)- d-glucan isolated from the fruit bodies of Bulgaria inquinans (Fries)

A low molecular-weight polysaccharide named BIWP2 was purified from the fruit bodies of Bulgaria Inquinans (Fries) via hot-water extraction, followed by freeze-thawing and gel filtration chromatography on Sephadex G-75. Monosaccharide composition analysis revealed that BIWP2 contained exclusively glucose. High performance size exclusion chromatography (HPSEC) showed that it was a homogeneous polysaccharide fraction. Its molecular weight was estimated to be 2.6 KD and the polydispersity index ( M w/ M n) was calculated to be 1.4. Periodate oxidation, methylation, and NMR analyses indicated that BIWP2 was a linear β-(1→6)- d-glucan without side chains. This is the first time to report a linear β-(1→6)- d-glucan with low molecular weight in non-lichenized ascomycete.

Kinetics of polysaccharide degradation during ethanol-alkali delignification of giant reed—Part 2. Minor carbohydrates and uronic acids

The degradation kinetics of the minor neutral carbohydrates (composed of arabinosyl, galactosyl and mannosyl residuals) and uronic acid moieties of the agrofibre crop Arundo donax L. (giant reed) under conditions of ethanol-alkali delignification has been studied. Based on properties of multi-component reaction system, the degradation of arabinan, galactan and mannan (expressed as homopolymers) was accurately described in terms of two simultaneous irreversible first-order reactions, corresponding to two kinetically homogeneous polysaccharide fractions. The first and more reactive fraction accounted for about 30, 73 and 4% of total arabinan, galactan and mannan, respectively, and is rapidly lost during the first pulping period. The respective values of apparent activation energy were estimated as 65, 45 and 82 kJ mol −1. The second fraction slowly degraded during pulping with two-order lower rate (activation energy of 88–98 kJ mol −1). The degradation of uronic acids as well as the formation of hexenuronic acids was accurately described in terms of three simultaneous first-order reactions, corresponding to three kinetically homogeneous fractions. The overall rate of hexenuronic acid formation during ethanol-alkali pulping was found to be one-order lower of the overall rate of uronic acids degradation.