Molecular Weight Polysaccharide Research Articles

Optimizing the sensitivity and resolution of hyaluronan analysis with solid-state nanopores

Hyaluronan (HA) is an essential carbohydrate in vertebrates that is a potentially robust bioindicator due to its critical roles in diverse physiological functions in health and disease. The intricate size-dependent function that exists for HA and its low abundance in most biological fluids have highlighted the need for sensitive technologies to provide accurate and quantitative assessments of polysaccharide molecular weight and concentration. We have demonstrated that solid state (SS-) nanopore technology can be exploited for this purpose, given its molecular sensitivity and analytical capacity, but there remains a need to further understand the impacts of experimental variables on the SS-nanopore signal for optimal interpretation of results. Here, we use model quasi-monodisperse HA polymers to determine the dependence of HA signal characteristics on a range of SS-nanopore measurement conditions, including applied voltage, pore diameter, and ionic buffer asymmetry. Our results identify important factors for improving the signal-to-noise ratio, resolution, and sensitivity of HA analysis with SS-nanopores.

Chitosan‐capped silver nanoparticles: A comprehensive study of polymer molecular weight effect on the reaction kinetic, physicochemical properties, and synergetic antibacterial potential

AbstractThe search for novel efficient antibacterial agents is attracting a great attention due to the unregulated use of common antibiotics and development of multidrug‐resistant bacteria strains. This paper proposes an eco‐friendly approach to obtain stable chitosan‐capped silver nanoparticles with controlled physicochemical and biological properties using reducing and stabilizing capacity of chitosan. The study of the influence of chitosan characteristics on the kinetic of Ag+ reduction showed that an increase in polysaccharide molecular weight led to a decrease in their reducing ability. The synthesized silver nanoparticles were characterized by UV and FTIR spectroscopy, TEM, XRD, DLS. The relationships between physicochemical characteristics of the formed silver nanoparticles and the type of used chitosan, as well as synthesis temperature, were determined. It has been demonstrated that spherically‐shaped (13–27 nm) and positively‐charged (zeta‐potential 26.1–29.5 mV) silver nanoparticles with a single symmetric SPR band at 408–418 nm are stable during 6 months in a colloidal form, and can be produced with the assistance of low‐molecular weight chitosan (20–30 kDa) at 95°C. The synthesized silver nanoparticles enhanced the antibacterial activity of kanamycin and ampicillin against both gram‐negative and gram‐positive bacteria. These results revealed the prospects for the application of chitosan‐capped silver nanoparticles to create new effective antibacterial systems (gels, films, etc).

Screening and characterization of an acid polysaccharide with antioxidant activity in vitro and in vivo from Dendrobium aurantiacum var. denneanum (Kerr)

Aim: We aimed to monitor an acid polysaccharide with antioxidant activity. Materials and Methods: Three acidic polysaccharides (DAP-A40, DAP-A60, and DAP-A80) were extracted from D. aurantiacum imbricate by alkaline aqueous solution extraction and ethanol precipitation. The structure characterization and antioxidant activity in vitro and in vivo were examined. Results: The molecular weight (MW) of three polysaccharides was 1.70 mol5 Da, 5.78 mol4 Da, and 1.36 mol4 Da, respectively, by high-performance gel chromatography. The consequences of infrared spectrum displayed that three polysaccharides enclosed uronic acid and sulfuric acid groups. DAP-A40 and DAP-A60 were collected of α-configuration pyranose. DAP-A80 was composed of β-configuration pyranose. Antioxidant test exhibited that DAP-A80 had outstanding antioxidant activity. The half-maximal inhibitory concentration of DAP-A80 in dipping power and scavenging the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), DPPH, and OH radicals was 163.5 μg/mL, 613.2 μg/mL, 583.2 μg/mL, and 365.1 μg/mL, respectively. The grades of correlation analysis showed that the ability of DAP-A80 to scavenge ABTS, DPPH, and OH radicals was negatively connected with the MW of polysaccharides and certainly correlated with the content of sulfate group. The results of in vivo experiments exposed that DAP-A80 might knowingly decline the formation of malondialdehyde. High levels of DAP-A80 could evocatively upsurge the activity of superoxide dismutase and GSH-Px in mouse serum. Conclusion: DAP-A80 has an antioxidant effect and can be reconnoitered as a health medicine and food.

The effect of Moringa oleifera polysaccharides on the regulation of glucocorticoid-induced femoral head necrosis: In vitro and in vivo

One of the common challenges in using glucocorticoid in the long term is the development of femoral head necrosis. To address this challenge, the use of glucocorticoid suppressors like plant polysaccharides has been considered. In this study, Moringa oleifera polysaccharide was isolated through hot water–ethanol precipitation method and purified by DEAE-Sepharose fast flow column. Then, they were characterized by FT-IR, NMR, methylation, and chromatography assays. The polysaccharide biocompatibility was investigated by MTT assay and its effect on osteoblasts was evaluated by controlling gene expression. Also, the effect of polysaccharide on dexamethasone-induced femoral head necrosis in rats was assessed by hydroxyproline, hexosamine and morphometric parameters. The results show that 2 Da molecular weight polysaccharide is mainly composed of Rha, Ara, Fru, Xyl, Man and Gal in the molar ratio of 1.7:2.1:3.4:5.9:5.8:1.3. Meanwhile, MTT results on osteoblasts cells showed polysaccharide biocompatibility, while significantly reducing the negative effects of glucocorticoid. Likewise, polysaccharide significantly reduced the levels of apoptosis and intracellular ROS of glucocorticoid-induced femoral necrosis. Moreover, the results of gene expression indicated a decrease in the expression of TNF-α and IL-6 genes using polysaccharide, which is very effective in preventing apoptotic activity. Also, Polysaccharide increased bone density, bone volume per tissue volume, trabecular thickness, and the hexosamine to hydroxyproline ratio in the rat serum in the presence of glucocorticoids, which are very effective in the process of femoral head necrosis. Furthermore, polysaccharide significantly increases the OCN, RUNX2 and COL-1 genes expression in cartilage tissue, which is in line with the result of morphometric parameters. Overall, this study suggests that the use of polysaccharide could result in the treatment of femoral head necrosis.

Structure Characterization and Antioxidant Activity of Polysaccharides from Amomum villosum extracted with Alkaline Solution

In this study, A. villosum was used as the raw material, and the crude polysaccharides of A. villosum were extracted by 0.1 mol/L NaOH solution. After the protein was removed by the Sevag method, the polysaccharides of A. villosum were obtained. The extraction rate of polysaccharides was 3.97%, the total sugar content was 37.10%, the uronic acid content was 65.66%, the protein content was 4.36%, and the molecular weight of polysaccharide was 95.46 kDa. The results of high-performance liquid chromatography showed that A. villosum polysaccharides were mainly composed of arabinose, xylose, galactose and galacturonic acid. Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), X-ray diffraction(XRD), thermogravimetric analysis(TGA) results showed that it was an amorphous structure, had a pyran ring, and thermally stable sheet-like acidity heteropolysaccharides. The results of in vitro antioxidant models(DPPH, ABTS, hydroxyl free radicals) showed that the polysaccharides of A. villosum had good in vitro antioxidant capacity. This research aims to provide a theoretical basis for the application andproduct development of polysaccharides from A. villosum.

Effects of Different Molecular Weight Polysaccharides From Dendrobium officinale Kimura & Migo on Human Colorectal Cancer and Transcriptome Analysis of Differentially Expressed Genes.

We investigated the antitumor effects of four fractions of Dendrobium officinale Kimura & Migo (D. officinale) polysaccharides with different molecular weights (Mw), Astragalus membranaceus polysaccharides (APS) and Lentinus edodes polysaccharides (LNT) on colorectal cancer (CRC) using a zebrafish xenograft model. Transcriptome sequencing was performed to further explore the possible antitumor mechanisms of D. officinale polysaccharides. Fractions of D. officinale polysaccharides, LNT, and APS could significantly inhibit the growth of HT-29 cells in a zebrafish xenograft model. One fraction of D. officinale polysaccharides called DOPW-1 (Mw of 389.98 kDa) exhibited the strongest tumor inhibition. Compared with the control group, RNA-seq revealed that the DOPW-1–treated experimental group had 119 differentially expressed genes (DEGs), of which 45 had upregulated expression and 74 had downregulated expression. Analyses using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes suggested that the pathway “apoptosis-multiple species” was the most significantly enriched. Our data indicated that 1) fractions of D. officinale polysaccharides of Mw 389.98 kDa were most suitable against CRC; 2) DOPW-1 could be developed into a clinical agent against CRC; and 3) an apoptosis pathway is important for DOPW-1 to inhibit the proliferation of HT-29 cells.

Hyaluronan-coated nanoparticles for active tumor targeting: Influence of polysaccharide molecular weight on cell uptake

Here we aimed to correlate different molecular weights of hyaluronic acid (HA), 200, 800 and 1437 kDa, used to decorate poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs), to their cell uptakes. NP internalization kinetics in CD44-overexpressing breast carcinoma cells were quantified, using healthy fibroblast cells as reference. Actually, NP uptake and selectivity by tumor cells were maximized for NPs HA 800 kDa, while being minimum for NPs HA1400 kDa. This unexpected result could be explained considering that the interaction between NPs and tumor cells is dictated by rearrangement and conformation of that segment of HA chain that actually protrudes from the NPs. Overall, results obtained in this work point at how HA molecular weight, is pivotal project parameter in NP formulation to promote active targeting in the CD44 overexpressing cancer cells.

Characteristics and antifatigue activity of graded polysaccharides from Ganoderma lucidum separated by cascade membrane technology

In this paper, cascade membrane technology was utilized to classify polysaccharides from Ganoderma lucidum (GLPs). The properties and antifatigue activity of graded polysaccharides were identified and compared. GLPs were separated using cascade ultrafiltration membranes of 100 kDa, 10 kDa and 1 kDa in sequence. The molecular weights of polysaccharides in these GLP fractions were approximately 322.0 kDa, 18.8 kDa and 6.4 kDa, and all polysaccharides were in active β-configurations. This showed that all graded GLPs could elongate swimming time, improve endurance and promote fatigue recovery, especially polysaccharides with molecular weights above 10 kDa. This demonstrated that GLPs could decrease the activities of SUN and CK and the levels of MDA and BLA. They also increased the level of Gly, accelerated fat transformation, and improved the activities of GPx, SOD and LDH in all treated mice. Accordingly, GLPs above 10 kDa might be potential agents with antifatigue activity.

Novel rich-in-soluble dietary fiber apple ingredient obtained from the synergistic effect of high hydrostatic pressure aided by Celluclast®

The apple by-product is the remaining solid obtained after fruit processing, mainly constituted by insoluble dietary fiber. However, soluble dietary fiber would be more desirable due to its positive health effects. The simultaneous application of high hydrostatic pressure (HHP), namely at 200, 400, and 600 MPa, for 15 and 30 min holding time, and the commercial enzyme Celluclast® (92 EGU) allowed a high molecular weight carbohydrates solubilisation achieving therefore, a safe soluble dietary fiber-rich product. HHP facilitated the cell wall accessibility, as it was observed by scanning electron microscopy which revealed a considerable cell wall disruption; whereas, the food-grade enzyme activity led to a decrease of the soluble polysaccharides molecular weight (MW), mainly in the major MW polysaccharide, i.e. HHP-sample: 6.13*104 kDa; HHP + enzyme-sample: 4.26*104 kDa. The solubilisation is at the cost of the augmentation (p < 0.05) of mainly, glucose, uronic acids and arabinose. The soluble dietary fiber-rich product present greater water retention capacity, oil holding capacity, and emulsion activity, which increased more than eight times as compared to the control. These results support an enhancement of apple by-product technological and nutritional qualities, hence it could be utilised as a safe and effective functional ingredient.

Utilization of Response Surface Methodology in Optimization of Polysaccharides Extraction from Vietnamese Red Ganoderma lucidum by Ultrasound-Assisted Enzymatic Method and Examination of Bioactivities of the Extract.

Red Ganoderma lucidum (G. lucidum) is a popular medicinal herb commonly used in Vietnamese traditional remedies due to its potential value for health. In this study, polysaccharides were extracted from G. lucidum using ultrasound-assisted enzymatic extraction method. The response surface methodology and Box–Behnken design were employed to investigate the effects of pH, extraction temperature, extraction time, and ultrasonic power on the content of polysaccharides. Based on ultraviolet-visible spectroscopy analysis, the highest content of polysaccharides in the extract was 32.08 mg/g under optimum experimental parameters including enzyme concentration of 3%, pH of 5.5, extraction temperature of 45°C, extraction time of 30 min, and ultrasonic power of 480 W. The Fourier-transform infrared spectroscopy was also used to identify the functional groups in the extracts. The molecular weights of polysaccharides were determined by gel permeation chromatography. The obtained extract was then evaluated for anticancer activities by using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, showing the anticancer activities with the half-maximal inhibitory concentration value of more than 512 μg/mL. This result suggested that UAEE could be considered as an appropriate and effective extraction method for bioactive crude polysaccharides from G. lucidum.

Fermentation of Ferulated Arabinoxylan Recovered from the Maize Bioethanol Industry

Maize by-product from the bioethanol industry (distiller’s dried grains with solubles, DDGS) is a source of ferulated arabinoxylan (AX), which is a health-promoting polysaccharide. In the present study, AX from DDGS was fermented by a representative colonic bacterial mixture (Bifidobacterium longum, Bifidobacterium adolescentis, and Bacteroides ovatus), and the effect of the fermented AX (AX-f) on the proliferation of the cell line Caco-2 was investigated. AX was efficiently metabolized by these bacteria, as evidenced by a decrease in the polysaccharide molecular weight from 209 kDa to &lt; 50 kDa in AX-f, the release of ferulic acid (FA) from polysaccharide chains (1.14 µg/mg AX-f), and the short-chain fatty acids (SCFA) production (277 µmol/50 mg AX). AX-f inhibited the proliferation of Caco-2 cells by 80–40% using concentrations from 125–1000 µg/mL. This dose-dependent inverse effect was attributed to the increased viscosity of the media due to the polysaccharide concentration. The results suggest that the AX-f dose range and the SCFA and free FA production are key determinants of antiproliferative activity. Using the same polysaccharide concentrations, non-fermented AX only inhibited the Caco-2 cells proliferation by 8%. These findings highlight the potential of AX recovered from the maize bioethanol industry as an antiproliferative agent once fermented by colonic bacteria.

Improved bioactivity and composition of Cordyceps militaris cultured with Panax ginseng

Abstract Cordyceps militaris is a commonly used edible and medicinal fungus in East Asia. Preparation of the mycelium and fermentation liquid by submerged fermentation using additives such as Panax ginseng for skin whitening applications has attracted wide attention. In the present study, we screened traditional Chinese medicines as additives to the liquid fermentation medium for C. militaris and performed systematical research on the changes of bioactivity and ginsenoside levels during the fermentation process. Total polysaccharide contents, cordycepin content, and polysaccharide molecular weight in the fermentation products were measured by UV spectrophotometry, high-performance liquid chromatography-diode array detection (HPLC/DAD), and gel permeation chromatography-multi angle laser light scattering (GPC-MALLS), respectively. In addition, the ginsenosides Rb1, Re, Rd, Rg1, and pseudoginsenoside F11 in the fermentation products were quantitatively analyzed by ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS). Panax ginseng significantly increased the cordycepin and total sugar contents, and the average molecular weight of polysaccharides in the fermentation liquid and the mycelium of C. militaris. At the same time, C. militaris enhanced the production of ginsenoside pseudoginsenoside F11, which is a unique component of Panax quinquefolium. The research provides scientific evidence for the application of C. militaris and P. ginseng as raw materials for food and medicines.

Differences in Polysaccharide Containment Obtained by Various Pulsed Light Irradiated Waste Mushroom Base of Yellow Flammulina Velutipes

The goal of this study was applied on the pulsed light of physical method, to promote the polysaccharide containment of mushroom base of Yellow Flammulina velutipes (Jinhua mushroom). Jinhua mushroom is a specific edible and medicinal mushroom in Taiwan that contains a variety of nutrients and bioactive components such as vitamin, carbohydrate, dietary fiber, protein, ergosterol, amino acid and umami constituents acknowledged to be beneficial for human health. Jinhua mushroom, whose appearance is also similar to white Flammulina velutipes but the functional ingredients are more than it. The polysaccharide of Jinhua mushroom base, which was irradiated the 0–80 pulses of pulsed light. Interestingly, the polysaccharide molecular weight was in the range of 3.56 to 4.30 x 106 Da of base with pulsed light (0–80 pulses), along with increasing pulsed light irradiated pulses, the polysaccharides’ viscosity (cPs) was increased. Meanwhile, we determined the moisture adsorption ability and thermal decomposition of the Jinhua mushroom base’s polysaccharide, which could be applied to a design during cosmetic materials and biomedicals. Overall, this study is a complete, forward-looking and innovative research project in agricultural waste recycling.

Effect of freeze-thaw cycles pretreatment on the vacuum freeze-drying process and physicochemical properties of the dried garlic slices

Freeze-thaw cycles (FTC) pretreatment was employed before the vacuum freeze-drying of garlic slices, aimed at improving the drying process and the quality of the end product. Cell viability, water status, internal structure, flavor, chemical composition and thermogravimetric of garlic samples were evaluated. The results indicated that FTC pretreatment reduced the drying time (22.22%–33.33%) and the energy consumption (14.25%–15.50%), owing to the water loss, the increase in free water, and the formation of porous structures. The FTC pretreatment improved thermal stability, flavor and chemical composition content of dried products. The antioxidant activity of polysaccharides extracted from FTC pretreated dried products was higher than that of the unpretreated dried product due to the reduction in polysaccharide molecular weight. This research could pave a route for future production of dried garlic slices having good quality by using the FTC pretreatment, with lower energy consumption and shorter drying time.

Structure and immunostimulating activity of a galactofuranose-rich polysaccharide from the bamboo parasite medicinal fungus Shiraia bambusicola

Ethnopharmacological relevanceShiraia bambusicola is a parasitic fungus on the twigs of bamboos. Its relatively large stroma has high medicinal value and can treat a variety of diseases such as rheumatoid arthritis, cold stomach pain, sciatica, injuries, chronic bronchitis, and infantile. It is widely distributed in many provinces in Southern China and also is also found in Japan. Aim of the studyMedicinal fungi were important resources for bioactive polysaccharides. To explore bioactive polysaccharides from Shiraia bambusicola, a heteropolysaccharide SB2-1 was purified and obtained from S. bambusicola and its immunostimulating activity was researched. Materials and methodsThe polysaccharide from S. bambusicola was extracted and purified using enzyme assisted extraction, ethanol precipitation, anion-exchange and size-exclusion chromatography. Molecular weight of polysaccharide was estimated by high performance gel permeation chromatography. Monosaccharide compositions were determined by high performance liquid chromatography after pre-column derivatization and UV detection. Structure information was elucidated by IR spectrum, GC-MS analysis after methylation and gradual acid hydrolysis of the polysaccharide. The RAW264.7 cells were used to study the immunostimulating activity in vitro. ResultsPhysicochemical and structural analyses showed that SB2-1 was a neutral heteropolysaccharide with molecular weight at 22.2 kDa and consisted of glucose, galactose and mannose at a ratio of 2.0:1.5:1.0. The structure of SB2-1 was a branched polysaccharides composed of a mannan core and side chains consisted of glucose and galactose. The mannan core was composed of (1→2)-Manp as the main chain. Glucose with (1→4)-D-Glcp, (1→2)-D-Glcp and (1→6)-D-Glcp at different degrees of polymerization were linked at C-6 and C-3 of the (1→2)-Manp as the side chains. The galactose with the linages of (1→6)-D-Galf, →2)-D-Galf(1→ and terminal D-Galf(1→ also existed in the side chain. The study on the immunostimulating activities of SB2-1 and its core structure P-2 were investigated on RAW264.7 macrophages. The results showed that SB2-1 could activate RAW264.7 macrophage and significantly improve its phagocytic ability by neutral red uptake experiment. Meanwhile, SB2-1 increased significantly higher inducible nitric oxide synthase (iNOS) production and the productions of IL-1, IL-6, IL-12 and TNF-α. The effect of SB2-1 was better than its core structure P-2 produced by gradual acid hydrolysis, which meant the side chains played an important role in the immunostimulating activities. ConclusionsThe investigation demonstrated that the galactofuranose-containing mannogalactoglucan was characteristic polysaccharides in S. bambusicola and could enhance the activation of macrophages.

Physicochemical characterization and antioxidant activity of sulphated polysaccharides derived from Porphyra haitanensis

This study was designed to fully characterize Porphyra haitanensis polysaccharides, and to evaluate their antioxidant activity. The polysaccharides primarily contained galactose and 3,6-anhydrogalactose in a molar ratio of 1.2:1.0, respectively and sulfate content about 3.8%. The molecular weight of polysaccharides is 2.5 × 105 Da. Scanning electron microscopy and atomic force microscopy of the polysaccharides pointed towards an irregular network with more or less hexagonal and a few rectangular pores. The chemical structure was confirmed through Fourier transform infrared spectroscopy, and 1D and 2D nuclear magnetic resonance structural characterization wherein → 4–3,6-anhydro-α-L-galactopyranose-(1 → 3)-β-D-galactopyranose segments. The extracted polysaccharides revealed relatively high 2, 2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity (53.16% at 2 mg/mL), moderate 2,2-diphenyl-1-picrylhydrazyl radical scavenging efficacy (34.63% at 2 mg/mL), and low hydroxyl radical scavenging potential (23.80% at 2 mg/mL). Further purification of these polysaccharides, hence, is advised for their potential role as antioxidants in the food, pharmaceutical and cosmeceutical industry.

Characterization of Neem (Azadirachita indica) Gum Exudates Using Analytical Tools and Pharmaceutical Approaches

Background: Polysaccharide has been used as excipient in pharmaceutical and biomedical sciences. Objective: Objective of present research was to characterize crude Neem Gum Polysaccharide (NGP) for their possible applications in food, cosmetics and pharmaceutical industry. Methods: Purified NGP was characterized in terms of phytochemical screening, organoleptic properties, solubility, micromeritic properties, TLC analysis, ash value, microbial load, molecular confirmation, molecular weight, swelling behaviour, foaming ability, surface morphology, IR spectral analysis, 1H NMR and mass spectra analysis. Suspending properties of NGP was also evaluated using paracetamol as model drug. Results: TLC analysis of NGP shows the presence of polar components in native polysaccharide. Results showed that NGP exhibit pseudoplastic flow with 19.22 x103 kJ kg-1 activation energy and 0.013 Reynold’s number. Thermodynamic parameters i.e. change in enthalpy ΔHv and change in entropy ΔSv was found to be 301.97 KJ/mol and 53.64 JK-1mol-1 respectively. Viscosity average molecular weight of NGP polysaccharide was found to be 94750 D. Foam capacity and foam stability of 1 %w/v solution of NGP was found to be 41 % and 64 % respectively. Mathematical approach also determined coiled conformation of NGP solution. Mass spectra of NGP shows characteristics fragmentation pattern with initial cleavage of glycosidic bond. 1H NMR spectra reveal the presence of 1 alpha – O-C- Methyl Hydrogen (CH3) and tetrahydropyran hydrogen. Conclusion: From the findings of the research it can be concluded that NGP can be used as excipient in cosmaceuticals and pharmaceuticals and attract rheologist for its characteristics rheological behavior.

Molecular weight determination of heparosan- and chondroitin-like capsular polysaccharides: figuring out differences between wild -type and engineered Escherichia coli strains

Heparin and chondroitin sulfate are used as anti-thrombic and anti-osteoarthritis drugs, respectively, but their pharmacological actions depend on their structural characteristics such as their sulfation grade and their molecular weight. In the last years, new fermentation-based biotechnological approaches have tried to obtain heparin and chondroitin sulfate starting from the heparosan and chondroitin-like capsular polysaccharides produced by Escherichia coli K5 and K4. The study of the microbial capsular polysaccharide molecular weight is critical to obtain nature-like or structural tailor cut glycosaminoglycan homologues. However, so far, it has been scarcely investigated. In this paper, for the first time, a new protocol was set up to determine the molecular weights of the capsular polysaccharides of three wild-type and three engineered E. coli K5 and K4 strains. The protocol includes a small-scale downstream train to purify the intact polysaccharides, directly from the fermentation broth supernatants, by using ultrafiltration membranes and anion exchange chromatography, and it couples size exclusion chromatography analyses with triple detector array. In the purification high recovery (> 85.0%) and the removal of the main contaminant, the lipopolysaccharide, were obtained. The averaged molecular weights of the wild-type capsular polysaccharides ranged from 51.3 to 90.9kDa, while the engineered strains produced polysaccharides with higher molecular weights, ranging from 68.4 to 130.6kDa, but with similar polydispersity values between 1.1 and 1.5.

Structural elucidation and hepatoprotective activities of polysaccharides from a mutant mSM-105 of Catathelasma ventricosum with enhanced production of 1,6-β-glucan

Catathelasma ventricosum is a popular edible officinal mushroom in southwest China. The mycelial polysaccharides from Catathelasma ventricosum (mCVPS) mainly composed of β-glucan which was widely regarded as a kind of prebiotic. In order to improve its yield, a mutant strain (mSM-105) by UV mutagenesis combined with ethyl methane sulfonate (EMS) treatment was developed, which showed a higher β-glucan production than the parent strain (SM-16). Results showed that mSM-105 possessed the yield of β-glucan as high as 85.3% after 15-day cultivation, while the parent strain was about 67% under the same condition. The molecular weight of polysaccharide from SM-16 and mSM-105, determined by gel permeation chromatography and gas chromatograph, was estimated to be from 3.8 × 103 to 2.5 × 107 Da. From the infrared (IR) and methylation analysis, the polysaccharide from mSM-105 referred as mCVPS-M was found to mainly consist of β-d-glucopyranose with 1,6 linkages. And the relative proportion of 1,6-β-d-Glcp estimated on sugar linkage of mCVPS-M was 47% higher than that of mCVPS. Moreover, in mice subjected to CCl4-induced hepatotoxicity, pretreatments with mCVPS and mCVPS-M at the same dose (200 mg/kg/d) both significantly (P < 0.05) decreased the levels of alanine aminotransferase (AST), aspartate aminotransferase (ALT) and malondialdehyde (MDA) and increased antioxidant enzyme activities such as, catalase (CAT), superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GSH-Px). Hepatic histopathological observation further confirmed that mCVPS-M had stronger hepatoprotection to normalize the histopathological changes. These results suggest that mCVPS-M might possess a more significant protective effect against CCl4 induced hepatocyte damage injury than mCVPS, by mediating antioxidant activities, free radical scavenging effects and alleviation of lipid oxidation, in which a vital role may played by 1,6-β-glucan.

Effects of deproteinization methods on primary structure and antioxidant activity of Ganoderma lucidum polysaccharides

Ganoderma lucidum polysaccharides (GLP) as one of water-soluble polysaccharides has attracted much attention because of its bioactivities, especially antioxidant activity. Deproteinization is an essential step in the purification process of polysaccharides. In this study, three classic deproteinization methods, including neutral protease method, TCA precipitation and CaCl2 salting out, were evaluated for crude GLP processing. The methods had ability to remove proteins (71.50–87.36%), and meanwhile polysaccharide loss (8.35–11.39%) was observed. Structure analysis indicated that these deproteinization methods had no significant effect (p > 0.05) on molecular weight of polysaccharides, but led to varying degrees of glycoside bond losses (1.14–64.05%). Moreover, the antioxidant activities of deproteinized polysaccharides were measured in vitro by hydroxyl radical, reducing power, 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) free radical and ferric-reducing antioxidant power tests. Purified GLP by enzymolysis maintained the strongest antioxidants activities with the retention rate of over 47.40%, and its deproteinization efficiency and polysaccharide loss ratio were 74.03% and 11.39% respectively. In view of relatively high purity and antioxidant activity, enzymolysis was a suitable deproteinization method for GLP production.