Influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of acidic, neutral and basic polysaccharides

An optimize adaptable method for determining the monosaccharide composition of pectic polysaccharides

Pectic polysaccharides are considered the highly complex natural plant polysaccharides which plays a vital role in plant tissue structure and human health. Detailed characterization of the monosaccharide composition can provide insights into the pectic polysaccharide structure. Nevertheless, when analyzing the monosaccharides of pectic polysaccharide, it is crucial to address the issue of incomplete hydrolysis that can occur due to the formation of acid-induced precipitates. Based on above, the main purpose of this article is to provide an optimized method for monosaccharide analysis of pectic polysaccharides through acid hydrolysis optimization using high-performance anion exchange chromatography (HPAEC) The results indicate that reducing the sample concentration to 0.5 mg/mL effectively reduces the acid gelling phenomenon and promotes the complete hydrolysis of pectin polysaccharides. The optimized parameters for acid hydrolysis involve 110 °C for 6 h in 2 M TFA. Furthermore, the consistency of this method is assessed, along with its ability to analyze pectin polysaccharides from various fruits. This hydrolysis approach holds promise for enabling accurate quantification of monosaccharide composition in pectic polysaccharides.

Preparation of high-performance antibacterial/antifungal citric acid-starch adhesives based on physical entanglement and chemical crosslinking

Starch-based wood adhesives are widely used as environmentally friendly and formaldehyde-free alternatives in the manufacturing of wood products. However, their poor water resistance and inability to inhibit bacterial/fungal growth limit their practicality. To address this issue, a physicochemical double-crosslinked network structure between citric acid, starch, and wood was prepared in this study by physically entangling the wood structure and chemically crosslinking the starch molecules, with citric acid preventing the activity of various enzymes and denatured proteins within microbial cells, thereby inhibiting bacterial and fungal growth. In water resistance cycling tests, the resulting esterified starch plywood demonstrated a 47.6 % and 13.2 % increase in water resistance compared with starch plywood and commercially available phenolic resin plywood, respectively. In addition, the tighter intermolecular bonding in the crosslinked structure results in a 31 % increase in heat resistance. The physical "nailing" and chemical crosslinking between the adhesive and the wood improved considerably the bonding strength to 98.36 %. The dual role of the physicochemical crosslinking of starch adhesives provides a straightforward strategy for the preparation of inexpensive, water-resistant, and fungal/bacterial-resistant starch adhesives, thus contributing to the promotion of starch adhesives.

The Pre- and Post-Column Derivatization on Monosaccharide Composition Analysis, a Review

Polysaccharides, as common metabolic products in organisms, play a crucial role in the growth and development of living organisms. For humans, polysaccharides represent a class of compounds with diverse applications, particularly in the medical field. Therefore, the exploration of the monosaccharide composition and structural characteristics of polysaccharides holds significant importance in understanding their biological functions. This review provides a comprehensive overview of extraction methods and hydrolysis strategies for polysaccharides. It systematically analyzes strategies and technologies for determining polysaccharide composition and discusses common derivatization reagents employed in further polysaccharide studies. Derivatization is considered a fundamental strategy for determining monosaccharides, as it not only enhances the detectability of analytes but also increases detection sensitivity, especially in liquid chromatography (LC), capillary electrophoresis (CE), and gas chromatography (GC) techniques. The review meticulously examines pre-column and post-column derivatization techniques for monosaccharide analysis, categorizing them based on diverse detection methodologies. It delves into the principles and distinctive features of various derivatization reagents, offering a comparative analysis of their strengths and limitations. Ultimately, the aim is to provide guidance for selecting the most suitable derivatization approach, taking into account the structural nuances, biological functions, and reaction dynamics of polysaccharides.

Research progress in the treatment of inflammatory bowel disease with natural polysaccharides and related structure-activity relationships

Inflammatory bowel disease (IBD) comprises a group of highly prevalent and chronic inflammatory intestinal tract diseases caused by multiple factors. Despite extensive research into the causes of the disease, IBD's pathogenic mechanisms remain unclear. Moreover, side effects of current IBD therapies restrict their long-term clinical use. In contrast, natural polysaccharides exert beneficial anti-IBD effects and offer advantages over current anti-IBD drugs, including enhanced safety and straightforward isolation from abundant and reliable sources, and thus may serve as components of functional foods and health products for use in IBD prevention and treatment. However, few reviews have explored natural polysaccharides with anti-IBD activities or the relationship between polysaccharide conformation and anti-IBD biological activity. Therefore, this review aims to summarize anti-IBD activities and potential clinical applications of polysaccharides isolated from plant, animal, microorganismal, and algal sources, while also exploring the relationship between polysaccharide conformation and anti-IBD bioactivity for the first time. Furthermore, potential mechanisms underlying polysaccharide anti-IBD effects are summarized, including intestinal microbiota modulation, intestinal inflammation alleviation, and intestinal barrier protection from IBD-induced damage. Ultimately, this review provides a theoretical foundation and valuable insights to guide the development of natural polysaccharide-containing functional foods and nutraceuticals for use as dietary IBD therapies.

Biochemical Characterization of a Novel Thermostable Ulvan Lyase from Tamlana fucoidanivorans CW2-9

Ulvan is a complex sulfated polysaccharide extracted from Ulva, and ulvan lyases can degrade ulvan through a β-elimination mechanism to obtain oligosaccharides. In this study, a new ulvan lyase, EPL15085, which belongs to the polysaccharide lyase (PL) 28 family from Tamlana fucoidanivorans CW2-9, was characterized in detail. The optimal pH and salinity are 9.0 and 0.4 M NaCl, respectively. The Km and Vmax of recombinant EPL15085 toward ulvan are 0.80 mg·mL-1 and 11.22 μmol·min -1 mg-1·mL-1, respectively. Unexpectedly, it is very resistant to high temperatures. After treatment at 100 °C, EPL15085 maintained its ability to degrade ulvan. Molecular dynamics simulation analysis and site-directed mutagenesis analysis indicated that the strong rigidity of the disulfide bond between Cys74-Cys102 in the N-terminus is related to its thermostability. In addition, oligosaccharides with disaccharides and tetrasaccharides were the end products of EPL15085. Based on molecular docking and site-directed mutagenesis analysis, Tyr177 and Leu134 are considered to be the crucial residues for enzyme activity. In conclusion, our study identified a new PL28 family of ulvan lyases, EPL15085, with excellent heat resistance that can expand the database of ulvan lyases and provide the possibility to make full use of ulvan.

Corrosion inhibition activity of a natural polysaccharide from Dysosma versipellis using tailor-made deep eutectic solvents

In this work, a total of 18 types of choline chloride, betaine, and L-proline-based deep eutectic solvents (DESs) were synthesized to determine the extraction yield of a natural polysaccharide (PSA) from Dysosma versipellis using an ultrasound-assisted extraction method. Results indicate that the choline-oxalic acid-based DES has the best extraction yield for PSA due to the proper physical-chemical properties between PSA and DES. To evaluate the optimal extraction conditions, a response surface methodology was carried out. Under the optimal conditions, the extraction yield of PSA reaches 10.37 % (± 0.03 %), higher than the conventional extraction methods. Findings from FT-IR and NMR suggest that the extracted PSA belongs to a neutral polysaccharide with (1 → 6)-linked α-d-glucopyranose in the main chain. Interestingly, results from various electrochemical measurements show the extracted PSA exhibits excellent corrosion inhibition performance for mild steel (MS) in a 0.5 M HCl solution, with 90.8 % of maximum corrosion inhibition efficiency at 210 mg L-1. SEM and XPS measurements reveal the formation of a protective layer on the MS surface. The adsorption behaviour of extracted PSA well obeys the Langmuir adsorption isotherm containing the chemisorption and physisorption. Additionally, theoretical calculations validate the experimental findings.

Exploration and Improvement of Acid Hydrolysis Conditions for Inulin-Type Fructans Monosaccharide Composition Analysis: Monosaccharide Recovery and By-Product Identification

Acid hydrolysis serves as the primary method for determining the monosaccharide composition of polysaccharides. However, inappropriate acid hydrolysis conditions may catalyze the breakdown of monosaccharides such as fructans (Fru), generating non-sugar by-products that affect the accuracy of monosaccharide composition analysis. In this study, we determined the monosaccharide recovery rate and non-sugar by-product formation of inulin-type fructan (ITF) and Fru under varied acid hydrolysis conditions using HPAEC-PAD and UPLC-Triple-TOF/MS, respectively. The results revealed significant variations in the recovery rate of Fru within ITF under different hydrolysis conditions, while glucose remained relatively stable. Optimal hydrolysis conditions for achieving a relatively high monosaccharide recovery rate for ITF entailed 80 °C, 2 h, and 1 M sulfuric acid. Furthermore, we validated the stability of Fru during acid hydrolysis. The results indicated that Fru experienced significant degradation with an increasing temperature and acid concentration, with a pronounced decrease observed when the temperature exceeds 100 °C or the H2SO4 concentration surpasses 2 M. Finally, three common by-products associated with Fru degradation, namely 5-hydroxymethyl-2-furaldehyde, 5-methyl-2-furaldehyde, and furfural, were identified in both Fru and ITF hydrolysis processes. These findings revealed that the degradation of Fru under acidic conditions was a vital factor leading to inaccuracies in determining the Fru content during ITF monosaccharide analysis.

Structural characterization and immunomodulatory activity of a polysaccharide from Dioscotea opposita

The purified polysaccharides fraction, DOP-2, was prepared from Dioscorea opposita Thunb (D. opposita). This study combined in vitro and in vivo experiments to comprehensively investigate the index changes in RAW264.7 cells and immunocompromised mice under DOP-2 intervention, aiming to elucidate the potential mechanisms of immunomodulatory effects of DOP-2. DOP-2 (10 ∼ 500 μg/mL) significantly elevated the levels of NO, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) factors secreted by RAW264.7 cells, and restored the body weight of immunosuppressed mice and improve the degree of injury to the immune organ index, resulting in significant immunomodulatory effects. Notably, DOP-2 promoted the production of short-chain fatty acids (SCFAs) in immunosuppressed mice and modulated the composition of their gut microflora. These findings highlight the potential benefits of DOP-2 therapy in improving immune function and gut health, and will provide a theoretical basis for the application of D. opposita polysaccharides as an immunomodulatory adjuvant.

Preparation and Improvement of Physicochemical and Functional Properties of Dietary Fiber from Corn Cob Fermented by Aspergillus niger

Corn cobs were fermented with Aspergillus niger to produce soluble dietary fiber (SDF) of high quality and excellent food safety. In this work, the fermentation process was optimized by single-factor test and response surface methodology (RSM). The optimal fermentation conditions were determined to be a material-liquid ratio of 1:30, an inoculum concentration of 11%, a temperature of 32°C, a time of 6 days, and a shaking speed of 200 r/min. Under these conditions, the SDF yield of corn cob increased from 2.34% to 11.92%, and the ratio of soluble dietary fiber to total dietary fiber (SDF/TDF) reached 19.08%, meeting the requirements for high-quality dietary fiber (SDF/TDF of more than 10%). Scanning electron microscopy (SEM) and Fourier-transformed infrared spectroscopy (FT-IR) analysis revealed that the fermentation effectively degraded part of cellulose and hemicellulose, resulting in the formation of a loose and porous structure. After fermentation the water swelling capacity, water-holding capacity, and oil-holding capacity of the corn cob SDF were significantly improved and the adsorption capacity of glucose, cholesterol, and nitrite ions all increased by more than 20%. Moreover, the total phenolic content increased by 20.96%, which correlated with the higher antioxidant activity of SDF. Overall, the fermentation of corn cobs by A. niger increased the yield and enhanced the functional properties of dietary fiber (DF) as well.

From Nature-Sourced Polysaccharide Particles to Advanced Functional Materials

Polysaccharides constitute over 90% of the carbohydrate mass in nature, which makes them a promising feedstock for manufacturing sustainable materials. Polysaccharide particles (PSPs) are used as effective scavengers, carriers of chemical and biological cargos, and building blocks for the fabrication of macroscopic materials. The biocompatibility and degradability of PSPs are advantageous for their uses as biomaterials with more environmental friendliness. This review highlights the progresses in PSP applications as advanced functional materials, by describing PSP extraction, preparation, and surface functionalization with a variety of functional groups, polymers, nanoparticles, and biologically active species. This review also outlines the fabrication of PSP-derived macroscopic materials, as well as their applications in soft robotics, sensing, scavenging, water harvesting, drug delivery, and bioengineering. The paper is concluded with an outlook providing perspectives in the development and applications of PSP-derived materials.

Optimized acid hydrolysis conditions for better characterization the structure of inulin-type fructan from Polygonatum sibiricum

Polygonatum sibiricum is an edible plant species in China known for its abundant polysaccharides. However, correlations between its analytical methods and fine structure have not been established. This is usually due to incomplete cleavage of the glycosidic linkages and instability of hydrolysis. In this study, a new optimal acid hydrolysis method for monosaccharide composition (2 M H2SO4 for 1 h) and methylation analysis (2 mol TFA hydrolysis at 100 °C for 1 h) was developed for characterization of inulin-type fructans, resulting in significantly improved monosaccharide recovery and providing more reliable methylation data. The effectiveness of this method was demonstrated through its application to the study of polysaccharide from P. sibiricum (IPS-70S). The results showed that IPS-70S with a molecular weight of 3.6 kDa is an inulin-type fructans consisting of fructose and glucose in a molar ratio of 27:1. Methylation and NMR analysis indicated that IPS-70S contains →2)-Fruf-(6 → or →2)-Fruf-(1 → with branching →1,6)-Fruf-(2 → and terminates in Glcp-(1 → or Fruf-(2→. In conclusion, optimal acid hydrolysis applicable to the specific polysaccharides contribute to its structurally characterized. The newly optimized acid hydrolysis method for monosaccharide composition and methylation analysis offers a reliable and effective approach to the structural characterization of inulin-type fructans from P. sibiricum. Providing reliable basis for the overall work of NMR analysis and structural analysis, which have potential significance in the field of polysaccharides structural characterization.

Amylase-assisted extraction alters nutritional and physicochemical properties of polysaccharides and saponins isolated from Ganoderma spp

This study aimed to evaluate the efficacy of amylase in hydrolyzing complex carbohydrates of different parts of Ganoderma spp. The aqueous extracts of the Ganoderma samples were analyzed for their selected nutritional composition and physicochemical properties. The purified extracts were also structurally characterized. The aqueous canopy extracts of red-purple Ganoderma had a notably higher total sugar and saponin content than their stalks, but not for the black-type Ganoderma. The enzymatic extraction effectively improved the extraction yields, whereas the amounts of sugars and saponins in some extracts were increased after the enzymatic treatment. The results also showed that only those enzyme-treated cultivated black Ganoderma canopy had increased total sugar and total saponin content. The antioxidant activities of all stalk extracts were higher than the canopy extracts. Their emulsifying properties were comparable with lecithin due to their high saponin content. Therefore, these extracts are new natural emulsifiers.

Application of chromatography in purification and structural analysis of natural polysaccharides: A review

Polysaccharides are widely distributed in natural sources from monocytic microorganisms to higher animals, and are found in a variety of biological activities in recent decades. Natural polysaccharides have the characteristics of large molecular weight, diverse composition, and complex structure, so their purification and structural analysis are difficult issues in research. Chromatography as a powerful separation technique, plays an irreplaceable role in the separation and structural analysis of natural polysaccharides, especially in the purification of polysaccharides, the separation of hydrolysates, and the analysis of monosaccharide composition. The separation mechanisms and application of different chromatographic methods in the studies of polysaccharides were summarized in this review. Moreover, the advantages and drawbacks of various chromatography methods were discussed as well.

Recent advances in qualitative and quantitative analysis of polysaccharides in natural medicines: A critical review

Polysaccharides from natural medicines, being safe and effective natural mixtures, show great potential to be developed into botanical drugs. However, there is yet one polysaccharide-based case that has fulfilled the Botanical Guidance definition of a botanical drug product. One of the reasons is the analytical methods commonly used for qualitative and quantitative analysis of polysaccharides fall far behind the quality control criteria of botanical drugs. Here we systemically reviewed the recent advances in analytical methods. A critical evaluation of the strength and weaknesses of these methods was provided, together with possible solutions to the difficulties. Mass spectrometry with or without robust chromatographic separation was increasingly employed. And scientists have made significant progress in simplifying polysaccharide quantification by depolymerizing it into oligosaccharides. This oligosaccharides-based strategy is promising for qualitative and quantitative analysis of polysaccharides. And continuous efforts are still needed to develop a standardized quality control method that is specific, accurate, repeatable, and applicable for analyzing individual components in natural medicine formulas.

A Systematic Review on Polysaccharides from Dendrobium Genus: Recent Advances in the Preparation, Structural Characterization, Bioactive Molecular Mechanisms, and Applications

Dendrobium polysaccharides (DPSs) have aroused people's increasing attention in recent years as a result of their outstanding edible and medicinal values and non-toxic property. This review systematically summarized recent progress in the different preparation techniques, structural characteristics, modification, various pharmacological activities and molecular mechanisms, structure-activity relationships, and current industrial applications in the medicinal, food, and cosmetics fields of DPSs. Additionally, some recommendations for future investigations were provided. A variety of methods were applied for the extraction and purification of DPSs. They possessed primary structures (e.g., glucomannan, rhamnogalacturonan I type pectin, heteroxylan, and galactoglucan) and conformational structures (e.g., random coil, rod, globular, and a slight triple-helical). And different molecular weights, monosaccharide compositions, linkage types, and modifications could largely affect DPSs' bioactivities (e.g., immunomodulatory, anti-diabetic, hepatoprotective, gastrointestinal protective, antitumor, anti-inflammatory, and anti-oxidant activities). It was worth mentioning that DPSs were significant pharmaceutical remedies and therapeutic supplements especially due to their strong immunity enhancement abilities. We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.

Glycosaminoglycan Quality Control by Monosaccharide Analysis

Glycosaminoglycans (GAGs) are heterogeneous biomacromolecules made by all animal cells with overlapping molecular weight and high negative charge densities, which make thorough separation of different types of GAGs and elimination of all GAG-binding proteins difficult. Even with the constant challenge of quality control, chondroitin sulfate, dermatan sulfate, heparan sulfate, and heparin glycosaminoglycans (GAGs) have been used as nutraceuticals and modern drugs for many years worldwide. Testing galactosamine in heparin has been added to the USP monograph after contaminated heparin event, but the general monosaccharide composition analysis has not been developed for GAG quality control purposes. Using a PCR-facilitated hydrolysis assay, the hydrolyzed GAG saccharides were labeled with 1-phenyl-3-methyl-5-pyrazolone (PMP) and quantified by high performance liquid chromatography (HPLC) coupled with mass spectrometry (MS). Glucosamine was found in both chondroitin sulfate and dermatan sulfate whereas galactosamine was observed in both heparan sulfate and heparin, indicating the cross contamination among different types of GAGs. Moreover, fucose was detected in chondroitin sulfate, dermatan sulfate, and heparan sulfate, and both fucose and mannose were detected in chondroitin sulfate, suggesting the co-presence of other types of glycans or novel fucosylated GAG structures. Furthermore, both the amount and structure of acid-resistant disaccharides provide distinguishable features for each type of GAGs at the same hydrolysis condition. Thus, monosaccharide analysis provides a practical and quantitative way for GAG quality control.

Ultrasonic extraction, structural characterization, and antioxidant activity of oligosaccharides from red yeast rice

Red yeast rice is consumed as a medicinal food to lower blood lipids. Besides, it is used to color food, make wine, etc. In this study, water-soluble oligosaccharides in red yeast rice were extracted by ultrasonic-assisted extraction method. The parameters to extract oligosaccharides from red yeast rice were optimized by the Box-Behnken design under the following optimal extraction conditions: extraction temperature, 60°C; extraction time, 97 min; and liquid/material ratio, 25 ml/g. The structure and the antioxidant activity of the new oligosaccharide were preliminarily investigated. Total carbohydrates extracted from red yeast rice with 80% ethanol-water solution (v/v) were first removed from pigments using D101 macroporous adsorption resin. The total sugar contents were then purified by DE52 resins and Sephadex G-25 resins to obtain red yeast rice oligosaccharides, coded as RYRO1. Structural characterization experiments indicated that RYRO1 is an oligosaccharide with a weight average molecular weight of 874 Da and a theoretical degree of polymerization of 4.86. RYRO1 is composed of mannose, glucosamine, glucose, and galactose with a molar ratio of 0.248:0.019:1:0.026. The ABTS, DPPH, and hydroxyl free radical scavenging assays showed antioxidant nature of RYRO1.

In vitro Prebiotic Properties of Garlic Polysaccharides and Its Oligosaccharide Mixtures Obtained by Acid Hydrolysis

Fructans and oligofructose are usually used as prebiotics without any limitation in functional food or food ingredients. The degree of polymerization (DP) of polysaccharides affects the utilization of probiotics. Garlic is rich in fructans. The objective of this study was to extract and purify polysaccharides from garlic, analyze its composition, hydrolyze them using HCl, and then evaluate the prebiotic potential of the garlic neutral polysaccharides (GPs) before and after hydrolysis. GPs were 6.57 × 10³ Da with a composition of fructose and glucose at a ratio of 4:1. After acid hydrolysis, low molecular weight fraction in garlic oligofructose (GOs) may be eliminated through ultrafiltration. The content of oligosaccharides with an average DP < 10 increased from 15 to 75%. GPs and GOS had a stronger resistance to acid conditions in human stomach than fructooligosaccharide, and GOs showed better prebiotic properties on the growth of lactobacilli than GPs. This study evaluates the prebiotic potential of the garlic frutctans and oligosaccharides mixtures obtained by acid hydrolysis, which may be used as an ingredient in functional food and nutraceutical products.

Optimizing acid hydrolysis for monosaccharide compositional analysis of Nostoc cf. linckia acidic exopolysaccharide

The exact estimation of monosaccharide composition is important in the primary structure elucidation of polysaccharides. An acid hydrolysis is usually performed for glycosidic bonds cleavage and releasing of monosaccharides. In this study, optimal conditions of total acid hydrolysis using trifluoroacetic acid (TFA) of acidic lactylated Nostoc cf. linckia exopolysaccharide (EPS) were investigated by NMR spectroscopy. Results of a series of experiments with modified acid concentration, temperature and time of hydrolysis, have shown 2 M TFA, 110 °C, 3 h as the most optimal. The stability of EPS monosaccharide components was also explored. Low stability was found at all tested conditions already during the first hour of hydrolysis; all neutral monosaccharides were degraded from 25% to 40% and glucuronic acid to 75%. NMR, contrary to standard techniques used in monosaccharide compositional analysis (HPLC, HPAEC), allowed simultaneous quantification of all GlcA forms; the free one, that one linked in oligosaccharides, as well as GlcA degradation product γ-lactone. NMR as detection method improves information about uronic acid content in EPS.

Potential Valorization of Hazelnut Shells through Extraction, Purification and Structural Characterization of Prebiotic Compounds: A Critical Review

Hazelnuts are one of the most widely consumed nuts, but their production creates large quantities of by-products, especially shells, that could be upcycled into much more valuable products. Recent studies have shown that hazelnut shell hemicellulose is particularly rich in compounds that are potential precursors of xylooligosaccharides and arabino-xylooligosaccharides ((A)XOS), previously defined as emerging prebiotics very beneficial for human health. The production of these compounds on an industrial scale-up could have big consequences on the functional foods market. However, to produce (A)XOS from a lignocellulosic biomass, such as hazelnut shell, is not easy. Many methods for the extraction and the purification of these prebiotics have been developed, but they all have different efficiencies and consequences, including on the chemical structure of the obtained (A)XOS. The latter, in turn, is strongly correlated to the nutritional effects they have on health, which is why the optimization of the structural characterization process is also necessary. Therefore, this review aims to summarize the progress made by research in this field, so as to contribute to the exploitation of hazelnut waste streams through a circular economy approach, increasing the value of this biomass through the production of new functional ingredients.

Characterizations of glucose-rich polysaccharides from Amomum longiligulare T.L. Wu fruits and their effects on immunogenicities of infectious bursal disease virus VP2 protein

The aim of this study is to explore the characterization of Amomum longiligulare T.L. Wu fruits polysaccharide (ALP) and their immune enhancement effects. Two homogeneous polysaccharides (ALP1 and ALP2) were isolated from the fruits. The structural characterization results showed that ALP1 (26.10 kDa) and ALP2 (64.10 kDa) were both mainly composed of glucose. Furthermore, ALP1 was consisted of (1,2)-α-D-Glcp, (1,2,3)-α-D-Glcp and T-α-D-Glcp, while ALP2 was consisted of T-α-D-Glcp, (1,3)-α-D-Glcp and (1,3,6)-α-D-Glcp. Afterwards, the immune enhancement effects of two polysaccharides were evaluated by determining their effects on immunogenicities of infectious bursal disease virus (IBDV) VP2 protein. Chickens were immunized with IBDV VP2 protein accompanied with ALP1/ALP2. And the results indicated both ALP1 and ALP2 promoted the weights and bursa of fabricius indexes of chickens. In addition, both two polysaccharides increased specific IBDV antibody levels, while ALP1 possessed higher immune enhancement ability and was expected to be an adjuvant for IBDV VP2 protein.

Xyloglucan Oligosaccharides Hydrolysis by Exo-Acting Glycoside Hydrolases from Hyperthermophilic Microorganism Saccharolobus solfataricus

In the field of biocatalysis and the development of a bio-based economy, hemicellulases have attracted great interest for various applications in industrial processes. However, the study of the catalytic activity of the lignocellulose-degrading enzymes needs to be improved to achieve the efficient hydrolysis of plant biomasses. In this framework, hemicellulases from hyperthermophilic archaea show interesting features as biocatalysts and provide many advantages in industrial applications thanks to their stability in the harsh conditions encountered during the pretreatment process. However, the hemicellulases from archaea are less studied compared to their bacterial counterpart, and the activity of most of them has been barely tested on natural substrates. Here, we investigated the hydrolysis of xyloglucan oligosaccharides from two different plants by using, both synergistically and individually, three glycoside hydrolases from Saccharolobus solfataricus: a GH1 β-gluco-/β-galactosidase, a α-fucosidase belonging to GH29, and a α-xylosidase from GH31. The results showed that the three enzymes were able to release monosaccharides from xyloglucan oligosaccharides after incubation at 65 °C. The concerted actions of β-gluco-/β-galactosidase and the α-xylosidase on both xyloglucan oligosaccharides have been observed, while the α-fucosidase was capable of releasing all α-linked fucose units from xyloglucan from apple pomace, representing the first GH29 enzyme belonging to subfamily A that is active on xyloglucan.

Extraction, purification, physicochemical properties and antioxidant activity of a new polysaccharide from Ocimum album L. seed

In this study, a novel polysaccharide fraction from Ocimum album seed was extracted and then purified by Cellulose DEAE-52 and Sephadex G-200 anion exchange chromatography. The structural, physicochemical and antioxidant properties of the main polysaccharide fraction (OAP-1A) were evaluated. The purified polysaccharide contained 94.3% carbohydrate, 3.56% moisture and 2.14% ash and result of gel permeation chromatography (GPC) showed average molecular weight of 593 kDa. The results of high-performance liquid chromatography (HPLC) showed that OAP-1A was a neutral hetero-polysaccharide composed of mannose (35.7%), glucose (33.32%), galactose (19.6%) and rhamnose (11.38%). In addition, GC-MS data, nuclear magnetic resonance (NMR) spectrum and Fourier transform infrared (FT-IR) analysis revealed that the backbone of OAP-1A consists of →3)-β-D-Manp-(1→, →3,4)-β-D-Manp-(1→, →3,6)-β-D-Manp-(1→, →3)-α-D-Glcp-(1→, →6)-β-D-Galp-(1→, →4)-α-L-Rhap-(1→ and α-D-Glcp-(1→. X-ray diffraction (XRD) analysis showed semi-crystalline structure in OAP-1A. Differential scanning colorimeter (DSC) and thermo-gravimetry analysis (TGA) indicated that OAP-1A had relatively high thermal stability. Moreover, OAP-1A showed strong scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals.

Oligosaccharides from Polygonatum Cyrtonema Hua: Structural characterization and treatment of LPS-induced peritonitis in mice

Fructooligosaccharide was isolated from Polygonatum Cyrtonema Hua (PFOS) for the first time. Structure characterized using FT-IR, MALDI-TOF-MS, NMR, AFM, and TEM, indicated that PFOS was graminan-type fructan with a degree of polymerization ranging from 5 to 10. A murine model of lipopolysaccharide (LPS)-induced peritonitis was used to evaluate the in vivo anti-inflammatory and lung protective efficacy of PFOS. The result shown that pretreatment with PFOS (1.0 mg/mL) in peritonitis-induced mice could significantly inhibit the level of pro-inflammatory cytokines (TNF-α, IL-1β) in serum (P < 0.001), increase mice survival rate from 12.5 % to 54 % (P < 0.05), and alleviated lung injury through ameliorating the damage of the pulmonary cellular architecture and reducing inflammatory monocyte accumulation in lung tissue. This effect of oligosaccharides could explain the traditional usage of P. cyrtonema as a tonic medicine for respiratory problems and it could be used as a potential natural ingredient with anti-inflammatory activity.

Recombinant Lentinula edodes xylanase improved the hydrolysis and in vitro ruminal fermentation of soybean straw by changing its fiber structure

Soybean straw cannot be efficiently degraded and utilized by ruminants due to the complex cross-linked structure among cellulose, hemicellulose, and lignin in its cell wall. Xylanase can degrade the xylan component of hemicellulose, destroy the xylan-lignin matrix and, consequently, would theoretically improve the hydrolysis effectiveness of cellulose. Therefore, this study was performed to investigate the effects of recombinant Lentinula edodes xylanase (rLeXyn11A) on fiber structure, hydrolysis, and in vitro ruminal fermentation of soybean straw. Treatment with rLeXyn11A enhanced the hydrolysis of soybean straw with an evident increase in productions of ribose, rhamnose, and xylose. Soybean straw treated by rLeXyn11A had lower hemicellulose content and greater cellulose and lignin contents. The rLeXyn11A could remove xylan, loosen unordered fibrous networks, enhance substrate porosity, and rearrange lignin, consequently increasing the exposure of cellulose and improving the cellulase hydrolysis of soybean straw. Supplemental rLeXyn11A stimulated the dry matter digestion, volatile fatty acids production, and microbial protein synthesis during in vitro ruminal incubation. This paper demonstrated that rLeXyn11A could strengthen the cellulase hydrolysis and in vitro ruminal fermentation of soybean straw by degrading xylan and changing fiber structure, showing its potential for improving the utilization of soybean straw in ruminants.

Ulvan lyase assisted structural characterization of ulvan from Ulva pertusa and its antiviral activity against vesicular stomatitis virus

Marine green algae are valuable sources of diverse health-promoting bioactive components. Ulvan is suitable for biological applications due to its unique structure and numerous bioactivities. Here, the complex structure of ulvan from Ulva pertusa was analyzed using specific ulvan lyase degradation, MS, and NMR detection. Its structure mainly consists of →4)-β-d-GlcA-(1 → 4)-α-l-Rha3S-(1 → and →4)-β-d-Xyl-(1 → 4)-α-l-Rha3S-(1 → repeating units. Small amounts of →4)-α-l-IdoA-(1 → 4)-α-l-Rha3S-(1 → unit also exist. In addition, a minor number of branches, a single GlcA, and a long branch containing GlcA-Glc were linked to Rha3S. The antiviral activity of the ulvan and its degraded fragments were further investigated. Ulvan (1068.2 kDa) and ulvan-F1 (38.5 kDa) with relatively high molecular weight showed potency of inhibiting the infection and replication of vesicular stomatitis virus (VSV) at 100 μg/mL, the inhibition rate of VSV replication was 40.75% and 40.13%, respectively. These results indicated that ulvan has potential as a functional agent.

Purified Tetrastigma hemsleyanum vines polysaccharide attenuates EC-induced toxicity in Caco-2 cells and Caenorhabditis elegans via DAF-16/FOXO pathway

Ethyl Carbamate (EC), as a carcinogen widely found in fermented foods, was verified that its cytotoxicity was associated with oxidative stress. Polysaccharides from natural sources due to their antioxidative capacity have attracted great attention in the past time. In this study, purified polysaccharide from Tetrastigma hemsleyanum vines (TVP) with 64.89 kDA was extracted and conducted multiple analysis to identify its structural information. It could be discovered that TVP was composed of mannose, rhamnose, glucuronic acid, glucose, galactose, and arabinose. In vitro, TVP could inhibit cytotoxicity and genotoxicity, attenuate oxidative damage and mitochondrial dysfunction induced by EC in Caco-2 cells. Meanwhile, TVP could suppress apoptosis by mTOR and Bcl-2 signaling pathways, ameliorate oxidative via Sirt1-FoxO1 and Nrf2-Keap1 signaling pathways. In vivo, EC as well triggered the decline of survival and athletic ability in Caenorhabditis elegans (C. elegans) and TVP could reverse the decline. In the meantime, TVP could ameliorate oxidative damage in N2 and daf-2 (-) mutant but fail in daf-16 (-) mutant, which suggested that DAF-16 (FOXO) might affect the antioxidative protection of TVP in C. elegans. In brief, our results manifested that TVP could attenuate EC-induced cytotoxicity both in vitro and in vivo.

Structural characterization of ulvan extracted from Ulva clathrata assisted by an ulvan lyase

Rhamnan-rich sulfated polysaccharides extracted from green algae (ulvan) constitute potentially useful natural materials for drug development. However, the characterization of their complex structures poses a challenge for their application. In this study, the structure of ulvan extracted from Ulva clathrata was analyzed with the assistance of an ulvan lyase belonging to the PL25 family. According to mass spectrometry and nuclear magnetic resonance analysis of the degraded oligosaccharides, the backbone of such a polysaccharide mainly consisted of →4)-β-d-GlcA-(1→4)-α-l-Rha3S-(1→ and →4)-β-d-Xyl-(1→4)-α-l-Rha3S-(1→ disaccharide repeating units, and the ratio is approximately 4:1. In addition, about 4% of the xylose moieties bear sulfate groups. Minor amounts of branches containing hexose and unsaturated glucuronic acid were found during the sequence analysis of hexa- to octasaccharides. These results indicated the presence of a long branch in the ulvan. The clarification of the detailed structure provides a foundation for ulvan modification and its structure-activity relationship studies.

Quantitative Analysis of Polysaccharide Composition in Polyporus umbellatus by HPLC-ESI-TOF-MS

Polyporus umbellatus is a well-known and important medicinal fungus in Asia. Its polysaccharides possess interesting bioactivities such as antitumor, antioxidant, hepatoprotective and immunomodulatory effects. A qualitative and quantitative method has been established for the analysis of 12 monosaccharides comprising polysaccharides of Polyporus umbellatus based on high-performance liquid chromatography coupled with electrospray ionization–ion trap–time of flight–mass spectrometry. The hydrolysis conditions of the polysaccharides were optimized by orthogonal design. The results of optimized hydrolysis were as follows: neutral sugars and uronic acids 4 mol/L trifluoroacetic acid (TFA), 6 h, 120 °C; and amino sugars 3 mol/L TFA, 3 h, 100 °C. The resulting monosaccharides derivatized with 1-phenyl-3-methyl-5-pyrazolone have been well separated and analyzed by the established method. Identification of the monosaccharides was carried out by analyzing the mass spectral behaviors and chromatography characteristics of 1-phenyl-3-methyl-5-pyrazolone labeled monosaccharides. The results showed that polysaccharides in Polyporus umbellatus were composed of mannose, glucosamine, rhamnose, ribose, lyxose, erythrose, glucuronic acid, galacturonic acid, glucose, galactose, xylose, and fucose. Quantitative recoveries of these monosaccharides in the samples were in the range of 96.10–103.70%. This method is simple, accurate, and sensitive for the identification and quantification of monosaccharides, and can be applied to the quality control of Polyporusumbellatus as a natural medicine.

Liquid Chromatography-Tandem Mass Spectrometry Approach for Determining Glycosidic Linkages

The structural analysis of carbohydrates remains challenging mainly due to the lack of rapid analytical methods able to determine and quantitate glycosidic linkages between the diverse monosaccharides found in natural oligosaccharides and polysaccharides. In this research, we present the first liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for the rapid and simultaneous relative quantitation of glycosidic linkages for oligosaccharide and polysaccharide characterization. The method developed employs ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC/QqQ-MS) analysis performed in multiple reaction monitoring (MRM) mode. A library of 22 glycosidic linkages was built using commercial oligosaccharide standards. Permethylation and hydrolysis conditions along with LC-MS/MS parameters were optimized resulting in a workflow requiring only 50 μg of substrate for the analysis. Samples were homogenized, permethylated, hydrolyzed, and then derivatized with 1-phenyl-3-methyl-5-pyrazolone (PMP) prior to analysis by UHPLC/MRM-MS. Separation by C18 reversed-phase UHPLC along with the simultaneous monitoring of derivatized terminal, linear, bisecting, and trisecting monosaccharide linkages by mass spectrometry is achieved within a 15 min run time. Reproducibility, efficacy, and robustness of the method was demonstrated with galactan ( Lupin) and polysaccharides within food such as whole carrots. The speed and specificity of the method enables its application toward the rapid glycosidic linkage analysis of oligosaccharides and polysaccharides.

Physicochemical properties of polysaccharides from Dendrobium officinale by fractional precipitation and their preliminary antioxidant and anti-HepG2 cells activities in vitro

Background

Dendrobium officinale as a precious traditional Chinese herb is widely used in medicines and health supplements. Thus the extraction, purification and biological activities of polysaccharides from the stem of Dendrobium officinale have significant meaning on theory and application value.

Methods

The crude Dendrobium officinale polysaccharide (DOP) was obtained by hot water extraction- ethanol precipitation method, and four new polysaccharide fractions (DOP-40, DOP-50, DOP-60, and DOP-70) were further obtained from the crude DOP by fractional precipitation with ethanol method, then four fractions were further purified by Toyopearl-H65F gel resin. The molecular weight and monosaccharide composition of four purified fractions were determined by high performance anion exchange chromatography and high performance liquid chromatography. The antioxidant activities of them were evaluated by the reducing power assay, and the superoxide anion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and hydroxyl free radicals scavenging assays, respectively. Finally, the anticancer activities of them were investigated via the MTT assay and the western blot analysis using HepG2 cells.

Results

Among these four purified fractions were mainly composed of d-mannose and d-glucose with different molar ratios, and their average molecular weights were 999, 657, 243 and 50.3 kDa, respectively. What’s more, DOP-70 always exhibited the strongest antioxidant and anticancer activities, while DOP-40 and DOP-60 showed very close antioxidant and anticancer activities which were better than that of DOP-50. The western blotting analysis also showed that DOP-40, DOP-60, and DOP-70 induced apoptosis in HepG2 human liver cancer cells through the Bcl-2 and Bax-dependent pathway.

Conclusions

Fractional precipitation with ethanol could successfully apply to extract four new polysaccharide fractions from Dendrobium officinale stems, and the polysaccharide fractions possessed efficient antioxidant and anticancer activities, especially DOP-70.

Development and application of a HPLC-MS/MS method for quantitation of fucosylated chondroitin sulfate and fucoidan in sea cucumbers

Fucosylated chondroitin sulfate (FCS) and fucoidan (FUC) are two main bioactive polysaccharides in sea cucumbers. A novel method for quantitation of FCS and FUC was developed by detecting chondroitin disaccharide and fucose produced through acid hydrolysis using HPLC-MS/MS. The present method showed satisfactory performance for both saccharides. It was applied to assay sea cucumbers (Stichopus japonicus) reared in pond grow-out or bottom sowing, and the results were compared with those obtained by traditional HPLC method and 1,9-dimethylmethylene blue test, which could only provide the total sea cucumber polysaccharide (SCP) contents. No difference of total SCP content was observed between sea cucumbers reared through different ways, while a higher ratio of FCS to FUC of sea cucumbers of pond grow-out was revealed by the present method. Thus, this novel method is potential to quantify the two polysaccharides and could be a powerful tool for quality evaluation of sea cucumbers.

Optimizing microwave-assisted hydrolysis conditions for monosaccharide composition analyses of different polysaccharides

Releasing all monosaccharides during acid hydrolysis for composition analysis of polysaccharides has been a time consuming process. In current study, an efficient (10 μL sample + 10 μL acid), sensitive, and quick monosaccharide composition analysis of polysaccharides was accomplished by using microwave-assisted HCl hydrolysis (10 min) of the polysaccharides followed by high-performance anion-exchange chromatography (HPAEC) combined with pulsed amperometric detection (PAD) analysis. Compared to the conventional hydrolysis procedure, this method is an efficient approach for monosaccharide composition analysis of acidic, basic, and neutral polysaccharides and particularly suited to polysaccharides that are difficult to hydrolyse fully such as chitosan, heparin and chondroitin sulfates.

Scope and limitations of carbohydrate hydrolysis for de novo glycan sequencing using a hydrogen peroxide/metallopeptide-based glycosidase mimetic

Acidic hydrolysis is commonly used as a first step to break down oligo- and polysaccharides into monosaccharide units for structural analysis. While easy to set up and amenable to mass spectrometry detection, acid hydrolysis is not without its drawbacks. For example, ring-destruction side reactions and degradation products, along with difficulties in optimizing conditions from analyte to analyte, greatly limits its broad utility. Herein we report studies on a hydrogen peroxide/CuGGH metallopeptide-based glycosidase mimetic design for a more efficient and controllable carbohydrate hydrolysis. A library of methyl glycosides consisting of ten common monosaccharide substrates, along with oligosaccharide substrates, was screened with the artificial glycosidase for hydrolytic activity in a high-throughput format with a robotic liquid handling system. The artificial glycosidase was found to be active towards most screened linkages, including alpha- and beta-anomers, thus serving as a potential alternative method for traditional acidic hydrolysis approaches of oligosaccharides.