High-performance Gel Permeation Chromatography Research Articles

Submerged cultivation, characterization and in vitro antitumor activity of polysaccharides from Schizophyllum radiatum

Production of polysaccharides by white-rot-fungi in submerged cultivation has several advantages due to process control. This work deals with the submerged cultivation, extraction and antitumor activity of polysaccharides from a wild strain of Schizophyllum radiatum isolated from a tropical forest of Colombia. The mushroom was cultivated in laboratory conditions, and classified by classical and molecular taxonomy. Submerged cultivation was performed in a bioreactor of 5 L using a ligninolytic residue as substrate. The fermentation conditions were 30 ± 1 °C, pH 4.5, 300 rpm and 1.5 vvm of air for 4 days. The yields were 16.8 g/L (w/v) of biomass, and after extraction, 0.6 g/L of water-soluble exopolysaccharide (SEPS) and 2.01 % (w/w) of water-soluble intrapolysaccharide (SIPS) were obtained. In each extract total carbohydrate, glucans and protein contents were determined. Also, nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), high performance liquid chromatography with refraction index detection (HPLC-RI), high performance gel permeation chromatography (HPGPC) and Nuclear Magnetic Resonance (NMR) analysis were performed. Results indicated that SEPS and SIPS are heteropolysaccharides with amorphous structure and high molecular weights. Antitumor and immunostimulant activity was evaluated in different cancer cell lines. The results suggest these polysaccharides have direct and indirect antitumor activity activating immune cells such as macrophages. These findings enhance our knowledge about new sources of fungal metabolites that serve as adjuvant, cheaper and less harmful alternatives to cancer treatment.

Structural characterization and immunomodulatory activities of two polysaccharides from Rehmanniae Radix Praeparata

The structures and immunomodulatory activities of two polysaccharides (SDH-WA and SDH-0.2A) from Rehmanniae Radix Praeparata (RRP) were investigated. RRP crude polysaccharide was obtained by water extraction and purified. Ion chromatography, high-performance gel permeation chromatography, Fourier-transform infrared spectroscopy, methylation analysis, gas chromatography–mass spectrometry, and nuclear magnetic resonance were used to characterize the polysaccharides. The main chain of SDH-WA was →6)-α-D-Galp-(1→6)-α-D-Galp-(1→5)-α-L-Araf-(1→3,5)-α-L-Araf-(1→, terminal sugar residue α-L-Araf-(1→ linked to residue →3,5)-α-L-Araf-(1→ on the main chain by an O-3 bond. The other two terminal sugar residues α-D-Galp-(1→ and →6)-β-D-Galp were linked to the end of the main chain. The main chain of SDH-0.2A was →2,4)-α-L-Rhap-(1→4)-α-D-GalpA-(1→. Three branched chains α-D-Galp-(1→6)-α-D-Galp-(1→5)-α-L-Araf-(1→3,5)-α-L-Araf-(1→, →3,6)-β-D-Galp-(1→5)-α-L-Araf-(1→, and →4)-β-D-Galp-(1→5)-α-L-Araf-(1→ were linked to the main chain residue →2,4)-α-L-Rhap-(1→ by an O-2 bond. Three terminal sugar residues α-D-Galp-(1→, α-L-Araf-(1→, and →6)-β-D-Galp were linked to the end of the chain. Both polysaccharides showed no cytotoxic effects on and significantly promoted the phagocytic activity of RAW264.7 cells. They dose-dependently improved lysozyme activity and stimulated the production of TNF-α and IL-6 by RAW264.7 cells, but attenuated the secretion of lysozymes, TNF-α, IL-6, IL-1β, and nitric oxide by lipopolysaccharide-induced RAW264.7 cells. The present studies suggest that PRR polysaccharide is a valuable source with immunomodulating.

Structural characterisation and bioactivity of polysaccharides isolated from fermented Dendrobium officinale.

A polysaccharide was purified in this study, which was acquired from the fermentation broth of Dendrobium officinale Kimura et Migo. We aimed to investigate the structural features and bioactivity of this polysaccharide. The polysaccharide was purified and the main polysaccharide fraction (i.e., DOP-1) was obtained. High-performance gel permeation chromatography (HPGPC) revealed that the molecular weight of DOP-1 was 447.48 kDa. Galactose, glucose and mannose were found to be present in DOP-1 via monosaccharide composition analysis, at a ratio of 1:1.79:6.71. Methylation and nuclear magnetic resonance spectroscopic analysis indicated that the backbone of DOP-1 was →4)-α-d-Glcp-(1 → 4)-α-d-Manp-(1 → 4)-α-d-Manp-(1 → 4,6)-α-d-Manp-(1→, and its repeating units were also preliminarily established. In vitro tests proved that DOP-1 not only protects RAW264.7 macrophages from the cytotoxic effect induced by lipopolysaccharide (LPS), but also inhibits cytokines (i.e., interleukin-6 and tumour necrosis factor-α) induced by LPS. DOP-1 demonstrated good scavenging activity in vitro toward 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals, as well as good metal chelating activity. Therefore, DOP-1 has potential antioxidant applications. The structural characteristics of DOP-1 support its favourable biological activities and lay a strong foundation for further exploration of its structure-activity relationships and activity development, providing experimental data for the development and utilisation of fermentation broth of D. officinale. © 2021 Society of Chemical Industry.

Pruning Influence on Chemical Composition of Spruce Wood (Picea abies (L.) Karst.)

The aim of the work was to investigate the influence of pruning on wood composition in different morphological parts of the Norway spruce (Picea abies (L.) Karst.) trees, including heartwood and sapwood compared to normal trees as a reference. Pruning intensity during that treatment was 35–41 % of the total length of the crown for the trees with the average and less than average diameter at breast height and 28 % for the trees with diameter at breast height higher than the average. Components composition of acetone soluble extractives was analysed by gas chromatography with long and short columns, and their molar mass distribution was analysed by gel permeation chromatography. The following was determined in the pre-extracted wood tissues: cellulose (acid hydrolysis – gas chromatography); lignin (Acetyl Bromide method) and hemicellulose and pectins composition (acid methanolysis – gas chromatography). Acetone-soluble wood extractives are a complex mixture of different groups of organic compounds, i.e. both lipophilic and polar substances. The high-performance gel permeation chromatography analysis revealed the dominance of triglycerides, steryl esters, fatty and resin acids in the obtained extracts. The amount of monosaccharides in the extracts was also substantial. The chemical composition of wood tissues of the reference and pruned trees was almost similar. Compared to the reference trees, the wood samples of the pruned trees showed increased amounts of resin acids in sapwood, high amounts of lignin and double amounts of fructose in both sapwood and heartwood. The analysis results can be explained by response of trees to their pruning as a defense mechanism against plant pathogens and must be a result of the current physiological activity of those trees, possibly related to differences in crown sizes.For citation: Pranovich A.V., Antonov O.I., Dobrovolsky A.A. Pruning Influence on Chemical Composition of Spruce Wood (Picea abies (L.) Karst.). Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 145–160. DOI: 10.37482/0536-1036-2021-3-145-160

Purification, Characterization and Immunomodulatory Activities of Polysaccharides fromMulberryLeaf Fermented withPhellinus igniarius

Phellinus igniariusis a rare and precious medicinal fungus, displaying an outstanding physiological effect, especially the immunomodulatory effects. Previous studies indicated that water-soluble crude polysaccharide (MPFP) was obtained from mulberry leaf fermented withPhellinus igniarius. In vitrocell assay revealed that MPFP showed higher immunomodulatory activity than that of mulberry leaves polysaccharide (MP) andPhellinus igniariusmycelial polysaccharide (PP). Therefore, in this study, structure and immunomodulatory activity of MPFP were measured, a novel polysaccharide named MPFP2-1 was separated through DEAE-52 cellulose column and SephadexG-100 gel-filtration chromatography. Monosaccharide composition analysis showed that MPFP2-1 was mainly composed of L-rhamnose and D-glucose with the molar ratio of 1.0:5.4. The average molecular weight was 50.3 kDa by high performance gel permeation chromatography (HPGPC). FT-IR spectrum showed that MPFP2-1 contained a characteristic absorption peak of polysaccharide. The NMR spectrum indicated MPFP2-1 contained 1 → 6 glucosidic bond.In vitroimmunomodulatory assay revealed that MPFP2-1 significantly enhanced the macrophages proliferation, stimulated the macrophages phagocytic capacity, as well as induced NO and TNF-a generation. We further discovered that MPFP2-1 stimulated iNOS and TNF-αprotein expression in RAW264.7 cells by western blotting. The results are in agreement with ELISA. All the results suggest that MPFP2-1 possesses potent immunomodulatory activity and could be taken forward as new products for medicines.

Purification, in-depth structure analysis and antioxidant stress activity of a novel pectin-type polysaccharide from Ziziphus Jujuba cv. Muzaoresidue

Ziziphus Jujuba cv. Muzao has attracted researchers for a long time, while residue of jujuba after extracted by water still contains many bioactivities. This paper presents the first study on in-depth structure analysis and its antioxidant of a pectic polysaccharide (PZJRP) separated and purified from Ziziphus Jujuba cv. Muzao residue through alkali extraction. Results of structural and morphological characterization according to high-performance gel-permeation chromatography, methylation analysis and partial acid hydrolysis etc. showed that PZJRP was composed of rhamnose, arabinose, glucose, galactose and galacturonic acid. Main chain of PZJRP including 1,2,4-linked rhamnose and 1,4-linked galacturonic acid, branches attached to C-4 of rhamnose, which suggested that PZJRP was a pectin polysaccharide belongs to rhamngalacturonan I type (RG-I). Significant antioxidant activity of PZJRP was revealed by protecting RAW264.7 cells against H2O2-induced oxidative stress. These findings demonstrated the potential of PZJRP to be a functional thickener as a novel food additive.

Structure elucidation of arabinogalactoglucan isolated from Sedum sarmentosum Bunge and its inhibition on hepatocellular carcinoma cells in vitro

Sedum sarmentosum Bunge (SS) is clinically used as Chinese medicine for hepatitis related diseases treatment. The purpose of this study was to explore the chemical structures of polysaccharides from this plant. A neutral polysaccharide (SSWP) was isolated and purified by ion-exchange chromatography and Superdex-75 column. The obtained SSWP was a homogenous one with a molecular weight of 21.5 kDa according to the high-performance gel permeation chromatography. The major monosaccharide composition of SSWP was arabinose, glucose and galactose in a molar ratio of 2.4:1:1.8. The methylation analysis showed that SSWP consists mainly of Araf-(1→, →5)-Araf-(1→, →3,5)-Araf-(1→, →4)-Galp-(1→, →4)-Glcp-(1→. The NMR result and enzymatic digestion data comprehensively indicated that SSWP was a novel arabinogalactoglucan-type structure. The anticancer assay in vitro exhibited that SSWP could effectively inhibit 48.9% of Huh-7 cells growth at 50 μg/mL and arrest cells at S-phase, and induce tumor cells apoptosis. Together, polysaccharide from S. sarmentosum Bunge could be a potential natural antitumor agent.

Optimization of extraction process, characterization and antioxidant activities of polysaccharide from Leucopaxillus giganteus

Many literatures have been reported edible fungi with high protein, high carbohydrates, low fat and a variety of biological activities, while Leucopaxillus giganteus was rarely studied. In this study, in order to obtain high yield polysaccharides from L. giganteus, the best extraction process of polysaccharides was optimized by single factor and orthogonal experiments. The polysaccharide extracted by optimized method was characterized and its antioxidant activities were further investigated. The results showed that the optimum extraction conditions were as follows: ratio of material to water of 1:35, extraction temperature of 80 °C, extraction time of 4.5 h, ultrasound assisted and extraction times of 3. Under the optimal extraction conditions, the yield of polysaccharides from L. giganteus was 6.79 ± 0.15% (n = 3). High Performance Gel Permeation Chromatography showed that molecular weight of partially purified polysaccharide was about 92.4 KDa. The results of TGA and Congo red test indicated that polysaccharides from L. giganteus had great thermal stability and contained triple-helix structure. The antioxidant results in vitro suggested that the polysaccharide from L. giganteus had excellent antioxidant activity on DPPH· (91.76%), OH· (67.22%) and ABTS + (81.03%) at the concentration of 2 mg/mL. This result provided a theoretical basis for the polysaccharide from L. giganteus as a potential natural antioxidant in the future.

Isolation, purification and structural characterization of two pectin-type polysaccharides from Coreopsis tinctoria Nutt. and their proliferation activities on RAW264.7 cells.

Coreopsis tinctoria Nutt. (C.tinctoria) is an annual herb of the Compositae family with many health benefits, such as clearing heat, antioxidant and anticancer activity. In this paper, two polysaccharides were isolated from C.tinctoria, named CTAP-1 and CTAP-2, respectively. Structure of CTAP-1and CTAP-2 were elucidated by high-performance gel permeation chromatography, chemical derivative analyses, GC-MS and NMR techniques. Results reveal that they both CTAP-1 and CTAP-2 consisted of predominant amounts of galacturonic acid residues along with small amounts of arabinose, rhamnose and galactose.Both them contain homogalacturonan and rhammnogalcturan I regions in different ratio, suggesting their pectin-type features. The proliferation activities of CTAP-1 and CTAP-2 on RAW264.7 cells in vitro were detected. Results show both them have the significant proliferation effect on RAW264.7 cells when the concentration from 40 to 200µg/mL. Given their structural characteristics and proliferation activities, the pectins are expected to be potential natural immune modulators, which need further study.

Structural characterization of enzymatic modification of Hericium erinaceus polysaccharide and its immune-enhancement activity

In this study, the enzyme degradation of Hericium erinaceus polysaccharide (HEP) was successfully modified with endo-rhamnosidase to obtain the enzymatic hydrolysis of Hericium erinaceus polysaccharide product (EHEP). The gas chromatography–mass spectrometry (GC–MS), high performance gel permeation chromatography (HPGPC), Fourier transformed infrared spectrometry (FT-IR), scanning electron microscopy (SEM), atomic particle microscopy (AFM), nuclear magnetic resonance (NMR) and particle size distribution were used to characterize polysaccharides. In vitro, EHEP significantly enhanced the phagocytosis, NO, CD40 and CD86 by macrophage than HEP. In vivo, female Balb/c mice were injected respectively with EHEP and HEP after administrated with cyclophosphamide, once a day for 7 days. On days 11, the morphology and structure of jejunal sections, immunofluorescence of spleen and peritoneal macrophages were determined. These results indicated that the enzymatic hydrolysis product could enhance the activation of peritoneal macrophages, and enhance the immunomodulation function of HEP. This study demonstrated that enzymatic modification was an effective method to improve the activities of HEP, and could be developed as a potential technology for use in pharmaceutical and cosmeceutical industry.

Structural elucidation of fucoidans from Sargassum pallidum

The brown alga Sargassum pallidum has been used as a traditional Chinese medicine to treat a variety of diseases. Fucoidan is an important bioactive component in S. pallidum; however, its chemical structure has not been thoroughly investigated. In the present study, two fucoidan fractions (SPF-1 and SPF-2) from S. pallidum were obtained by extraction with hot-water, ethanol precipitation, anion-exchange, and size-exclusion chromatography. The structural characterizations of SPF-1 and SPF-2 were investigated using the high-performance gel permeation chromatography (HPGPC) and gas chromatography (GC), followed by periodate oxidation, Smith degradation, and methylation analysis. The results revealed the monosaccharide composition of SPF-1 and SPF-2 to be fucose, mannose, and galactose with small amounts of glucose, xylose, and rhamnose. The molecular weight of SPF-1 and SPF-2 was estimated to be 61.5 kDa and 167.6 kDa, respectively. The backbone of SPF-1 was mainly constituted by (1→3) linked Fuc, (1→3) linked Man, and (1→3,4) linked Man whereas the branches were composed of (1→3) linked Fuc. SPF-2 was a branched polysaccharide with a backbone consisted of (1→3) linked Fuc, (1→3) linked Gal, and (1→3,4) linked Gal and branches composed of (1→3) linked Fuc or Gal. In vitro bioassay revealed that SPF-2 showed higher cytotoxic activity than SPF-1 against P388 and A549 cells. These results provided an insight into the utilization and development of seaweed resources.

Characterization, antioxidant activities, and inhibition on α-glucosidase activity of corn silk polysaccharides obtained by different extraction methods

The polysaccharides (CSPw, CSPc, CSPa, and CSPu) were prepared by hot water extraction, acid-assisted extraction, alkaline-assisted extraction, and ultrasound-assisted extraction from corn silk, respectively. High performance gel permeation chromatography (HPGPC), fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) results indicated that the extraction methods had an obvious impact on the molecular weight, structure, and morphology of the CSPs. Among the four polysaccharides, CSPu showed the highest inhibitory α-glucosidase activity, which might be related to its smaller molecular weight. Furthermore, kinetics analyses revealed that CSPu had significant inhibition of α-glucosidase in a non-reversible and competitive manner. Fluorescence quenching analysis illustrated that the interaction mechanism of CSPu and α-glucosidase was claimed as a static quenching mechanism. Isothermal titration calorimetry (ITC) analysis showed that the main driving forces for the interaction of CSPu with α-glucosidase was hydrogen bonding and the binding interactions of them occurred spontaneously.

Changes in Physical and Chemical Properties of Thermally and Oxidatively Degraded Sunflower Oil and Palm Fat.

Deep-fat frying is an important process used worldwide for the preparation of foods. Due to oxidation, hydrolysis, decomposition and oligomerization, numerous polar compounds are formed. These compounds change the physical, nutritional and sensory properties of the oil or fat. The standard methods of the German Society for Fat Science for the assessment of the quality of frying fats are time consuming and cost intensive. Therefore, alternative cost-effective and sensitive rapid methods, which ideally allow the quantitative determination of the quality of frying fats “in-line” in the deep-frying pan are needed. Sunflower oil and palm fat were thermally and oxidatively degraded in a beaker at atmospheric pressure under intensive stirring for 76 h at 175 °C. To evaluate the development of the physical properties during heat treatment, the viscosity and dielectric constant of these oils were measured. The temperature in a deep-frying pan can vary within a wide range (160–190 °C), and the viscosity and dielectric constant show a strong temperature dependence. Therefore, it was necessary to measure the temperature dependence of the viscosity and dielectric constant of the different degraded oils. Additionally, their chemical properties were characterized by high-performance gel permeation chromatography and Fourier-transform infrared spectroscopy (FTIR). The determination of the dielectric constant, which is directly correlated with the concentration of polar compounds, seems to be the best method for the assessment of the quality of used frying oils.

Biotechnological production, characterization and in vitro antitumor activity of polysaccharides from a native strain of Lentinus crinitus

This work deals with the submerged cultivation, extraction and antitumor activity of polysaccharides from Lentinus crinitus. The fungus was isolated from a tropical forest (Antioquia, Colombia), cultivated in laboratory conditions, and classified by classical and molecular taxonomy. Then, it was cultivated in a bioreactor of 5 L using a ligninolytic residue as substrate. The fermentation conditions were 30 ± 1 °C, pH 4.5, 300 rpm and 1.5 vvm for 4 days. The yields of fermentation were 20 g/L of biomass. After extraction, 0.65 g/L of water-soluble exopolysaccharide (LEPS) and 3.3 mg/100 g of water-soluble intrapolysaccharide (LIPS) were obtained. In each extract total carbohydrate, glucans and protein contents were determined. Also, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffractometry (XRD), high performance liquid chromatography with refraction index detection (HPLC-RI) and high performance gel permeation chromatography (HPGPC) analysis for characterization were performed. The antitumor activity was evaluated and polysaccharides not only showed anti-proliferative activity in breast cancer cells but also they activate J774 macrophages as evidenced by the increase of nitric oxide and tumor necrosis factor-α (inducers of tumor cell apoptosis). Our findings suggest that polysaccharides can activate macrophages to release nitric oxide (NO) and tumor necrosis factor alpha (TNF-α), which directly blocks cancer cell growth. These findings enhance our knowledge about new sources of fungal metabolites that serve as coadjuvant, cheap and less harmful alternatives to cancer treatment.

Effect of ageing on the combustion of single base propellants

This paper shows how the combustion properties of single base nitrocellulose propellants are affected by degradation by ageing. A single base gunpowder sample containing methyl centralite and ethyl centralite as stabilizers was artificially aged by 10, 20 and 25 years. Closed vessel experiments were performed to evaluate the burning rate, the dynamic vivacity, the maximum pressure, the force, and the covolume of the gases produced. The propellant degradation was characterized by the Bergmann-Junk test, heat flow calorimetry test (HFC), high performance liquid chromatography (HPLC) and gel permeation chromatography (GPC). Gel permeation chromatography was especially useful to describe the degradation process. The results found for the burning rate suggest the existence of two phases during ageing: intensification and passivation. The intensification phase occurs while the propellant samples maintain the chemical stability and the passivation phase was observed for the unstable samples.

Purification, characterization and in vitro antioxidant activity of a polysaccharide AAP–3–1 from Auricularia auricula

The objective was to investigate the in vitro antioxidant activity of a novel polysaccharide AAP–3–1 from Auricularia auricula. AAP–3–1 was isolated from the fruiting bodies of A. auricula by hot water extraction and ethanol precipitation and was purified by DEAE FF ion exchange chromatography and Superdex 200 gel filtration chromatography. The molecular weight and monosaccharide composition were determined by high performance gel permeation chromatography and high–performance liquid chromatography, respectively. Ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy were used for structural characterization. The results showed that AAP–3–1 is a heteropolysaccharide and is mainly composed of mannose and glucose in a molar ratio of 1.4:1 with a molecular weight of 320.9 kDa. AAP–3–1 exhibited antioxidant activity in a concentration–dependent manner and the scavenging rates at 1.6 mg/mL on superoxide anions and hydroxyl and 1,1–diphenyl–2–picrylhydrazyl radicals were 88.13%, 93.03% and 68.31%, respectively. AAP–3–1 effectively ameliorated 2,2′–azobis–2–methyl–propanimidamide–induced oxidative stress in HepG2 cells by inhibiting reactive oxygen species generation, decreasing the content of malondialdehyde, and increasing the activities of superoxide dismutase, glutathione peroxidase and catalase. The results indicated that the antioxidant mechanism of AAP–3–1 was associated with both non–enzymatic and enzymatic defense systems.

Isolation and analysis of a novel protoglycan from zizyphus jujuba cv. jinsixiaozao

Chinese jujube (Zizyphus jujuba Miller) is a well-known oriental medicinal plant that has various biological activities. In this study, a novel water-soluble proteoglycan (ZSG4b) was isolated from Zizyphus jujuba cv. Jinsixiaozao and its effect on the complement system was investigated. ZSG4b was extracted with hot water and purified by DEAE-Sepharose CL-6B and Sepharose CL-6B column chromatography. It was eluted as a single symmetrical narrow peak on high-performance gel-permeation chromatography (HPGPC) and the average molecular weight was estimated to be 1.4 × 105 Da. ZSG4b contained 83.5% glycan and 9.7% protein. Gas chromatography analysis result indicated that the glycan portion of ZSG4b was composed mainly of rhamnose, arabinose, mannose and galactose in a molar ratio of 13.8:4:3:8. It also contains 29% uronic acid as determined by m-hydroxybiphenyl method. The presence of galacturonic acid was estimated by the increase of galactose content in the carboxyl-reduced ZSG4b. The amino acid composition showed that it was rich in aspartic acid, glutamic acid, serine, threonine and leucine; the molar content of these five amino acids constituted 62.8% of the total amino acids. The β-elimination reaction demonstrated that the protein and glycan were linked by O-linkage. ZSG4b exhibited high anti-complement activity which was increased in accordance with the concentration below 120 μg/mL in vitro.

Isolation and structural elucidation of a low-molecular-weight polysaccharide from the roots of Panax ginseng C. A. Meyer

A low-molecular-weight polysaccharide named MCGP-L was extracted and purified from the roots of Mountain cultivated ginseng (Panax ginseng C. A. Meyer). The polysaccharide MCGP-L was purified by molecular exclusion chromatography using the Sephadex G-25 column. The average molecular weight of MCGP-L was estimated to be 3 × 103 kDa. Monosaccharide composition analysis showed MCGP-L was composed of three kinds of monosaccharide: D-glucose, D-galactose and D-mannose. The physicochemical properties and structural characteristics of MCGP-L were investigated by the combination of chemical and instrumental analysis such as methylation analysis, High Performance Gel-Permeation Chromatography (HPGPC), High Performance Liquid Chromatography (HPLC) and Nuclear Magnetic Resonance (NMR). The backbone of MCGP-L was composed of (1→4)-linked-α-D-Glcp residues and with branch chain substituted at O-6 position of (1→4,6)-linked-α-D-Glcp. The branch chain consists of →6)-α-D-Galp-(1→, →2)-α-D-Manp-(1→ and β-D-Glcp-(1→.

Characterization and inhibitory activities on α-amylase and α-glucosidase of the polysaccharide from blue honeysuckle berries

An acidic heteropolysaccharide HEP-2 was obtained from blue honeysuckle berry extracts after purification using Sepharose 6B and Sephadex G-200 column chromatography. The molecular weight of HEP-2, determined with high-performance gel permeation chromatography, was 3.01 × 106 Da. Fourier transform infrared spectroscopy, gas chromatography and nuclear magnetic resonance analyses revealed the presence of α-, β-pyranose ring and six sugar residues in HEP-2. Amorphous aggregates of HEP-2 with irregular shape and lacking the triple helical structure were detected using the Congo red test, scanning electron and atomic force microscopy, and X-ray diffraction studies. Rheological characterization showed typical shear-thinning behavior and viscoelastic property of the polysaccharide. HEP-2 exerted significant inhibitory effects on α-amylase and α-glucosidase and displayed competitive inhibition kinetics. The collective results support the potential utility of HEP-2 as a hypoglycemic agent for enzyme-targeted treatment of diabetes or functional food.

Extraction, structural characterization, and immunobiological activity of ABP Ia polysaccharide from Agaricus bisporus

The extraction, purification, immunobiological activities, and structure of Agaricus bisporus polysaccharides (ABP) were investigated. Especially we purified and identified the polysaccharides with the highest in vitro immunobiological activity. The extraction conditions of ABP were optimized using single factor and orthogonal experiment. ABP Ia was screened after double purification with DEAE-52 and Sephadex G-200 and showed the best immunoregulatory activity. UV spectra analysis and high-performance gel permeation chromatography results indicated that the ABP Ia fraction did not contain any proteins or nucleotides and was a homogeneous polysaccharide with a relative molecular weight of 784 kDa. Gas chromatography mass spectroscopy results showed that ABP Ia was a heteropolysaccharide consisting of ribose, rhamnose, arabinose, xylose, mannose, glucose, and galactose at a molar ratio of 2.08:4.61:2.45:22.25:36.45:89.22:1.55. FT-IR and periodic acid oxidation analysis indicated that ABP Ia was an α-pyran polysaccharide composed of 1 → 2 and 1 → 4 glycosidic bonds, as well as a possible 1 → 3 glycosidic bond. Furthermore, atomic force microscopy revealed that ABP Ia polysaccharide chains twisted to form a rod-like architecture and, at a 5% concentration, aggregated into a tight structure similar to the shape of a stone forest. These findings identify ABP Ia as a potential functional food ingredient or pharmaceutical for immunoregulation.