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.

The extracellular polysaccharide determine the physico-chemical surface properties of Microcystis

Microcystis possesses the capacity to form colonies and blooms in lakes and reservoirs worldwide, causing significant ecological challenges in aquatic ecosystems. However, little is known about the determining factors of physico-chemical surface properties that govern the competitive advantage of Microcystis. Here, The physico-chemical surface properties of Microcystis wesenbergii and Microcystis aeruginosa, including specific surface area (SSA), hydrophobicity, zeta potential, and functional groups were investigated. Additionally, the extracellular polysaccharide (EPS) were analyzed. Laboratory-cultured Microcystis exhibited hydrophilic, a negative zeta potential and negatively charged. Furthermore, no significant relationship was shown between these properties and the cultivation stage. Microcystis wesenbergii exhibited low free energy of cohesion, high surface free energy, high growth rate, and high EPS content during the logarithmic phase. On the other hand, M. aeruginosa displayed lower free energy of cohesion, high surface free energy, high EPS content, and high growth rate during the stationary phase. These characteristics contribute to their respective competitive advantage. Furthermore, the relationship between EPS and surface properties was investigated. The polysaccharide component of EPS primarily influenced the SSA and total surface energy of Microcystis. Likewise, the protein component of EPS influenced hydrophobicity and surface tension. The polysaccharide composition, including glucuronic acid, xylose, and fructose, mainly influenced surface properties. Additionally, hydrophilic groups such as O-H and P-O-P played a crucial role in determining hydrophobicity in Microcystis. This study elucidates that EPS influenced the SSA, hydrophobicity, and surface free energy of Microcystis cells, which in turn impact the formation of Microcystis blooms and the collection.

Development of a joint derivatization protocol for the unequivocal identification of the monosaccharide composition in four dendrobium polysaccharides and free monosaccharide by GC-MS

The determination of monosaccharides is crucial for studying the structure of polysaccharides and the composition of free monosaccharides in living organisms. Based on previous derivatization gas chromatography-mass spectrometry (GC-MS) methods, we aimed to develop a novel analytical protocol for better quantifying monosaccharides. In this study, sugar alcohol acetylation, saccharonitrile acetylation, silylation and a combination of sugar alcohols acetylation and saccharonitrile acetylation were compared. The optimal method was verified with the monosaccharide determination of four polysaccharides and four free monosaccharides from Dendrobium. The results showed that the novel combined derivatization method was superior to the other three methods in terms of content analysis of monosaccharides. Furthermore, it possessed good linearity (all calibration curves showed relative coefficients ≥ 0.999), sensitivity, precision (relative standard deviation < 2%), and accuracy (recovery, 95.7-105%). Finally, the novel method established in this study was successfully employed in determining the monosaccharide composition of four polysaccharides and four free monosaccharide samples from Dendrobium.

The Antioxidant and Anti-Complementary Activities of Crude Polysaccharides from Trifoliate Orange (Poncirus trifoliate) Seeds

In this study, I extracted the crude polysaccharides from trifoliate orange (Poncirus trifoliate) seeds, known as TSCP, using water extraction and ethanol precipitation. The monosaccharide composition of TSCP was in the following order: arabinose (28.28 mol%)> galactose (16.76 mol%)> galacturonic acid+glucuronic acid (13.6 mol%)> glucose (12.45 mol%)> rhamnose (4.18 mol%)> mannose (0.57 mol%)> fucose (0.32 mol%). Its total polyphenol contents were 28.66 and 70.96 μg/mL at 1 and 10 mg/mL, respectively (P<0.01). Further, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity of 10 mg/mL TSCP (31.67%) was higher than that of 1 mg/mL TSCP (8.07%; P<0.01) and also higher than its 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (11.97%) at the same concentration (10 mg/mL; P<0.01). The anti-complementary property of TSCP increased in a concentration-dependent manner (P<0.001), and at 1,000 μg/mL, it was comparable (61.36%) to the positive control (60%) consisting of polysaccharide-K. In conclusion, TSCP might be a potential immune modulator.

Impact of Six Extraction Methods on Molecular Composition and Antioxidant Activity of Polysaccharides from Young Hulless Barley Leaves

Young hulless barley leaves are gaining recognition for potential health benefits, and the method of extracting polysaccharides from them is critical for potential food industry applications. This study delves into a comparative analysis of six distinct fiber extraction techniques: hot water extraction; high-pressure steam extraction; alkaline extraction; xylanase extraction; cellulase extraction; and combined xylanase and cellulase extraction. This analysis included a thorough comparison of polysaccharide-monosaccharide composition, structural properties, antioxidant activities (DPPH, ABTS, and FRAP), and rheological properties among fibers extracted using these methods. The results underscore that the combined enzymatic extraction method yielded the highest extraction yield (22.63%), while the rest of the methods yielded reasonable yields (~20%), except for hot water extraction (4.11%). Monosaccharide composition exhibited divergence across methods; alkaline extraction yielded a high abundance of xylose residues, whereas the three enzymatic methods demonstrated elevated galactose components. The extracted crude polysaccharides exhibited relatively low molecular weights, ranging from 5.919 × 104 Da to 3.773 × 105 Da across different extraction methods. Regarding antioxidant activities, alkaline extraction yielded the highest value in the ABTS assay, whereas enzymatically extracted polysaccharides, despite higher yield, demonstrated lower antioxidant capacity. In addition, enzymatically extracted polysaccharides exerted stronger shear thinning behavior and higher initial viscosity.

Shaping the phycosphere: Analysis of the EPS in diatom-bacterial co-cultures

The phycosphere is a unique niche that fosters complex interactions between microalgae and associated bacteria. The formation of this extracellular environment, and the associated bacterial biodiversity, is heavily influenced by the secretion of extracellular polymers, primarily driven by phototrophic organisms. The exopolysaccharides (EPS) represent the largest fraction of the microalgae-derived exudates, which can be specifically used by heterotrophic bacteria as substrates for metabolic processes. Furthermore, it has been proposed that bacteria and their extracellular factors play a role in both the release and composition of the EPS. In this study, two model microorganisms, the diatom Phaeodactylum tricornutum CCAP 1055/15 and the bacterium Pseudoalteromonas haloplanktis TAC125, were co-cultured in a dual system to assess how their interactions modify the phycosphere chemical composition by analyzing the EPS monosaccharide profile released in the culture media by the two partners. We demonstrate that microalgal-bacterial interactions in this simplified model significantly influenced the architecture of their extracellular environment. We observed that the composition of the exo-environment, as described by the EPS monosaccharide profiles, varied under different culture conditions and times of incubation. This study reports an initial characterization of the molecular modifications occurring in the extracellular environment surrounding two relevant representatives of marine systems.

Composition analysis and prebiotics properties of polysaccharides extracted from Lepista sordida submerged cultivation mycelium

In this paper, Lepista sordida polysaccharides (LSP) were separated from Lepista sordida (L. sordida) mainly using the Ultrasonic-Micro Wave Synergy Extraction (UMSE) method and purified by graded alcohol precipitation. Three polysaccharide components: 40%-LSP-UMSE, 60%-LSP-UMSE, and 80%-LSP-UMSE were obtained and further analyzed the physicochemical properties, structural characteristics, and antioxidant activity. And the effects on the proliferation of Lactobacillus casei of three polysaccharide components were studied. The characteristic absorption peaks and the β-glycosidic bond of three polysaccharide components were the direct expression at UV 200 nm using UV and FT-IR spectroscopy. The three polysaccharide components were mainly composed of glucose, mannose, galactose, and ribose using high-performance liquid chromatography (HPLC) analysis. The antioxidant activity study revealed that the polysaccharides obtained by the UMSE method had better antioxidant activity compared to the traditional "Hot Water Extraction (HWE)" method. In addition, the polysaccharide components promoted the proliferation of L. casei to some extent. 40%-LSP-UMSE, 80%-LSP-UMSE as the carbon source had better acid production than the control inulin. Three LSP-UMSE used as a carbon source compared with glucose for culturing L. casei could significantly improve its tolerance to bile salts. Results are helpful to develop the bioactive polysaccharides from Lepista sordida and beneficial to develop a unique health and functional product in the future.

Monosaccharide Composition and In Vitro Activity to HCT-116 Cells of Purslane Polysaccharides after a Covalent Chemical Selenylation

The anti-cancer effects of selenylated plant polysaccharides are a focus of research. As a natural plant with extensive biological effects, there have been few studies related to edible purslane (Portulaca oleracea L.). Thus, in this study, soluble P. oleracea polysaccharides (PPS) were extracted from the dried P. oleracea and then selenylated chemically using the HNO₃-Na₂SeO₃ method to obtain two selenylated products, namely, SePPS1 and SePPS2. Compared with the extracted PPS, SePPS1 and SePPS2 had much higher Se contents (840.3 and 1770.5 versus 66.0 mg/kg) while also showing lower contents in three saccharides-arabinose, fucose, and ribose-and higher contents in seven saccharides including galactose, glucose, fructose, mannose, rhamnose, galacturonic acid, and glucuronic acid, but a stable xylose content demonstrated that the performed chemical selenylation of PPS led to changes in monosaccharide composition. Moreover, SePPS1 and SePPS2 shared similar features with respect to monosaccharide composition and possessed higher bioactivity than PPS in human colon cancer HCT-116 cells. Generally, SePPS1 and SePPS2 were more active than PPS with respect to cell growth inhibition, the alteration of cell morphology, disruption of mitochondrial membrane potential, intracellular reactive oxygen species (ROS) generation, the induction of cell apoptosis, and upregulation or downregulation of five apoptosis-related genes and proteins such as Bax, Bcl-2, caspases-3/-9, and cytochrome C, that cause cell apoptosis and growth suppression via the ROS-mediated mitochondrial pathway. SePPS2 consistently showed the highest capacity to exert these observed effects on the targeted cells, suggesting that the performed chemical selenylation of PPS (in particular when higher degrees of selenylation are reached) resulted in an increase in activity in the cells. It can thus be concluded that the performed selenylation of PPS was able to incorporate inorganic Se into the final PPS products, changing their monosaccharide composition and endowing them with enhanced nutraceutical and anti-cancer effects in the colon.

Comparison of the Antioxidant Activities and Polysaccharide Characterization of Fresh and Dry Dendrobium officinale Kimura et Migo

It is generally believed that fresh Dendrobium officinale (FDO) has more significant pharmacological activity than dried Dendrobium officinale (DDO); however, the difference has not been clearly shown. Our study compared their antioxidant properties both in vitro and in vivo, and the molecular weight arrangement and monosaccharide composition of the fresh Dendrobium officinale polysaccharides (FDOPs) and the dried Dendrobium officinale polysaccharides (DDOPs) were analyzed by HPLC-GPC and GC-MS. The results showed that the FDO and its polysaccharides had more significant effects on scavenging DPPH, ABTS, and hydroxyl radicals than the DDO. In addition, both the FDO and DDO significantly reduced lipid peroxidation levels and increased the SOD, T-AOC, CAT, and GSH levels in mice with acute liver damage caused by CCl₄, while the FDO and its polysaccharides were more effective. Histopathological analysis further verified the protective effect of the Dendrobium polysaccharides on CCl₄-induced liver injury. The determination of the polysaccharides revealed that the polysaccharide and mannose contents of the FDO were significantly higher than their dried counterparts, and the homogeneous arrangement of the polysaccharides in the FDO was degraded into three polysaccharide fragments of different molecular weights in the DDO. Overall, our data identified differences in the antioxidant activities of the FDO and DDO, as well as the reasons for these differences.

Comparative transcriptome analysis for the biosynthesis of antioxidant exopolysaccharide in Streptococcus thermophilus CS6

BACKGROUND

Food grade Streptococcus thermophilus produces biological exopolysaccharides (EPSs) with great potential with respect to catering for higher health-promoting demands; however, how S. thermophilus regulates the biosynthesis of EPS is not completely understood, decelerating the application of these polymers. In our previous study, maltose, soy peptone and initial pH were three key factors of enhancing EPS yield in S. thermophilus CS6. Therefore, we aimed to investigate the regulating mechanisms of EPS biosynthesis in S. thermophilus CS6 via the method of comparative transcriptome and differential carbohydrate metabolism.

RESULTS

Soy peptone addition (58.6 g L^-1 ) and a moderate pH (6.5) contributed to a high bacterial biomass and a high EPS yield (407 mg L^-1 ). Maltose, soy peptone and initial pH greatly influenced lactose utilization in CS6. Soy peptone addition induced a high accumulation of mannose and arabinose in intracellular CS6, differential monosaccharide composition (mannose, glucose and arabinose) in EPS and high radical [2,2-diphenyl-1-picrylhydrazyl, superoxide and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] scavenging activities. Carbohydrate transportation, sugar activation and eps cluster-associated genes were differentially expressed to regulate EPS biosynthesis. Correlation analysis indicated high production of EPSs depended on high expression of lacS, galPMKUTE, pgm, gt2-5&4-1 and epsLM.

CONCLUSION

The production of antioxidant EPS in S. thermophilus CS6 depended on the regulation of galactose metabolism cluster and eps cluster. The present study recommends a new approach for enhancing EPS production by transcriptomic regulation for further food and health application of EPS. © 2022 Society of Chemical Industry.

Added Value of Ascophyllum nodosum Side Stream Utilization during Seaweed Meal Processing

Ascophyllum nodosum contains many valuable compounds, including polyphenols, peptides, and carotenoids that have been shown to exhibit biological activities. These compounds are not a priority ingredient in seaweed meal products for the current users. Hence, the aim of the study was to investigate the chemical and bioactive characteristics of A. nodosum as affected by seasonal variation and evaluate the potential benefits of alternative processing and the utilization of side streams for product development. The analysis of raw materials, press liquid, and press cake from alternative processing and the commercial seaweed meal at different harvesting periods indicated that the chemical composition is linked to the reproductive state of the algae. Phenolic content and ORAC activity increased following the seaweed's fertile period, making alternative processing more promising in July and October compared to June. Several valuable ingredients were obtained in the press liquid, including polyphenols, which can be used in the development of new high-value bioactive products. The suggested alternative processing does not have a negative effect on the composition and quality of the current seaweed meal products. Hence, the extraction of valuable ingredients from the fresh biomass during the processing of seaweed meal could be a feasible option to increase the value and sustainability of seaweed processing.

Isolation, Chemical Characterization and Antioxidant Activity of Pectic Polysaccharides of Fireweed (Epilobium angustifolium L.)

The aim of this study was to isolate pectins with antioxidant activity from the leaves of Epilobium angustifolium L. Two pectins, EA-4.0 and EA-0.8, with galacturonic acid contents of 88 and 91% were isolated from the leaves of E. angustifolium L. by the treatment of plant raw materials with aqueous hydrochloric acid at pH 4.0 and 0.8, respectively. EA-4.0 and EA-0.8 were found to scavenge the DPPH radical in a concentration-dependent manner at 17–133 μg/mL, whereas commercial apple pectin scavenged at 0.5–2 mg/mL. The antioxidant activity of EA-4.0 was the highest and exceeded the activity of EA-0.8 and a commercial apple pectin by 2 and 39 times (IC₅₀—0.050, 0.109 and 1.961 mg/mL), respectively. Pectins EA-4.0 and EA-0.8 were found to possess superoxide radical scavenging activity, with IC₅₀s equal to 0.27 and 0.97 mg/mL, respectively. Correlation analysis of the composition and activity of 32 polysaccharide fractions obtained by enzyme hydrolysis and anionic exchange chromatography revealed that the antioxidant capacity of fireweed pectins is mainly due to phenolics and is partially associated with xylogalacturonan chains. The data obtained demonstrate that pectic polysaccharides appeared to be bioactive components of fireweed leaves with high antioxidant activity, which depend on pH at their extraction.

Determination of monosaccharides in Lycium barbarum fruit polysaccharide by an efficient UHPLC-QTRAP-MS/MS method

INTRODUCTION

Pre-column derivatisation using 1-phenyl-3-methyl-5-pyrazolone (PMP) is a common method for monosaccharide determination. Herein, a specific ultra-high-performance liquid chromatography quadrupole trap tandem mass spectrometry (UHPLC-QTRAP-MS/MS) method was developed and used for the determination of monosaccharide composition of Lycium barbarum polysaccharide (LBP).

OBJECTIVE

Exploration of a new efficient method for monosaccharide determination.

METHODS

In our study, hydrochloric acid was used to hydrolyse the polysaccharide obtained from L. barbarum fruits. Principal component analysis (PCA) and technique for order of preference by similarity to ideal solution (TOPSIS) analysis were used for comprehensive evaluation of the samples. The results showed that LBP was composed of seven monosaccharides: galactose, arabinose, mannose, rhamnose, xylose, ribose, and glucose. The linear relationship of the seven monosaccharides was optimum within a certain concentration range. Quantitative recoveries of the seven monosaccharides from the samples ranged from 94.76% to 102.11%.

RESULTS

A rapid quantitative detection method was established, in which the hydrolysis time was reduced from 12 h to 2 h. By using LBP as one of the indexes to evaluate the quality of L. barbarum, L. barbarum from Zhongning County, Ningxia Province, was identified as having the best quality among the varieties tested.

CONCLUSION

The UHPLC-QTRAP-MS/MS pre-column derivatisation method used in this study was simple, accurate, and sensitive, with good repeatability, and can be used for quality evaluation and origin distinction of L. barbarum and other medicinal plants.

Structure Differences of Water Soluble Polysaccharides in Astragalus membranaceus Induced by Origin and Their Bioactivity

Astragalus membranaceus is a functional food with multiple bioactivities. It presents differentiated health benefits due to origins. Polysaccharides (APS) are the leading bioactive macromolecules of A. membranaceus, which are highly related to its health benefits. However, the effect of origin on the structural characteristics of APSs remains unclear. In this work, polysaccharides from four origins were isolated and identified by NMR. The results showed APSs of four origins had identical monosaccharide composition and glycosidic linkage. Rhamnogalacturonan II pectins and α-(1→4)-glucan were the dominant polysaccharides. However, the level of methyl ester in pectins varied to a large extent. The molecular weight profiles of APSs were also different. Inner Mongolia APS had the largest percentage of 20-40 kDa polysaccharides. Molecular weight and methyl ester level were two important parameters determining the difference of APSs from four origins. These results were helpful to recognize the origin-related quality of A. membranaceus.

Effects of Efficient Expression of Vitreoscilla Hemoglobin on Production, Monosaccharide Composition, and Antioxidant Activity of Exopolysaccharides in Ganoderma lucidum

A Vitreoscilla hemoglobin (VHb) gene was efficiently expressed by the optimization of codons and intron addition in G. lucidum. Expression of the VHb gene was confirmed by genome PCR, quantitative real-time PCR and carbon monoxide (CO)-difference spectrum analysis in the transformant. The effects of the efficient expression of VHb gene on production, monosaccharide compostion, and antioxidant activity of G. lucidum exopolysaccharides were studied. The maximum production of exopolysaccharides in the VHb gene-bearing transformant was 1.63 g/L, which was 1.5-fold higher than expression in the wild-type strain. Efficient expression of the VHb gene did not change the monosaccharide composition or distribution of molecular weight, but it increased the mole percentage ratio of galactose and mannose in G. lucidum exopolysaccharide. Exopolysaccharides from the transformant had higher scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH) radical capacity and reducing power than those from the wild-type strain. These results may be helpful for increasing production and application of exopolysaccharides produced by G. lucidum fermentation.

Determination and analysis of monosaccharides in Polygonatum cyrtonema Hua polysaccharides from different areas by ultra-high-performance liquid chromatography quadrupole trap tandem mass spectrometry

We wanted to explore a new method for the determination of monosaccharides in Polygonatum cyrtonema Hua polysaccharide using the ultra-high-performance liquid chromatography quadrupole trap tandem mass spectrometry. In this study, hydrochloric acid was used instead of trifluoroacetic acid to hydrolyze polysaccharides, and hydrolysis time was greatly reduced from 5-9 h to 1 h. The 1-phenyl-3-methyl-5-pyrazolone was used for pre-column derivatization of monosaccharides. The parameters of linearity (R²  > 0.999), stability (1.63-2.52%), intra-day and inter-day precision (0.69-0.95%, 1.81-2.77%), repeatability (1.89-2.65%), and recovery (97.63-102.24%) of the method were verified. Satisfactory validation results showed this method could be used to determine the target components. The results indicated the polysaccharide contained glucose, mannose, rhamnose, galactose, ribose, and arabinose. Technique for order preference by similarity to an ideal solution and principal component analysis were used to build an evaluation model based on the monosaccharide composition. The evaluation results showed that the samples from the Qingyang County of Anhui Province were the best when the monosaccharides were used as the evaluation index. Therefore, a new method was established to detect the monosaccharide content of polysaccharides from Polygonatum cyrtonema Hua and comprehensively evaluate the quality of Chinese medicines with polysaccharides as the main active ingredient.

Extrusion Processing of Pure Chokeberry (Aronia melanocarpa) Pomace: Impact on Dietary Fiber Profile and Bioactive Compounds

The partial substitution of starch with dietary fiber (DF) in extruded ready-to-eat texturized (RTE) cereals has been suggested as a strategy to reduce the high glycemic index of these food products. Here, we study the impact of extrusion processing on pure chokeberry (Aronia melanocarpa) pomace powder (CPP) rich in DF and polyphenols (PP) focusing on the content and profile of the DF fractions, stability of PP, and techno-functional properties of the extrudates. Using a co-rotating twin-screw extruder, different screw speeds were applied to CPP with different water contents (cw), which resulted in specific mechanical energies (SME) in the range of 145-222 Whkg-1 and material temperatures (TM) in the range of 123-155 °C. High molecular weight soluble DF contents slightly increase with increasing thermomechanical stress up to 16.1 ± 0.8 g/100 g dm as compared to CPP (11.5 ± 1.2 g/100 g dm), but total DF (TDF) contents (58.6 ± 0.8 g/100 g dm) did not change. DF structural analysis revealed extrusion-based changes in the portions of pectic polysaccharides (type I rhamnogalacturonan) in the soluble and insoluble DF fractions. Contents of thermolabile anthocyanins decrease linearly with SME and temperature from 1.80 ± 0.09 g/100 g dm in CPP to 0.24 ± 0.06 g/100 g dm (222 Whkg-1, 155 °C), but phenolic acids and flavonoids appear to be largely unaffected. Resulting techno-functional (water absorption and water solubility) and physical properties related to the sensory characteristics (expansion, hardness, and color) of pure CPP extrudates support the expectation that granulated CPP extrudates may be a suitable food ingredient rich in DF and PP.

Analysis of monosaccharide composition of water-soluble polysaccharides from Codium fragile by ultra-performance liquid chromatography-tandem mass spectrometry

Codium fragile is a green alga belonging to Codiales family. The sulfated polysaccharides of this alga have anti-coagulation, antiviral, anti-angiogenesis, antioxidant, and immunoregulatory properties. In this study, we developed a reliable and rapid method for the analysis of 10 monosaccharides using ultra-performance liquid chromatography-tandem mass spectrometry in the negative electrospray ionization and multiple reaction monitoring mode. Monosaccharides, including two pentoses (xylose, arabinose); two deoxyhexoses (rhamnose, fucose); three hexoses (mannose, glucose, galactose); two hexuronic acids (glucuronic acid, galacturonic acid), and an N-acetyl-hexosamine (glucosamine), were derivatized using 1-phenyl-3-methyl-5-pyrazolone and simultaneously analyzed within 9 min. Optimization of the derivatization process, especially by using various 1-phenyl-3-methyl-5-pyrazolone concentrations, was studied. The calibration curves showed good linearity with a squared correlation coefficient > 0.995. The spiked recovery was determined to be 91.1-105.7% with the relative intra-day and inter-day standard deviations ranging from 2.58-6.71% and 3.15-7.67%, respectively. The limit of detection and limit of quantification for all 10 monosaccharides ranged from 0.02 to 0.10 μg/mL and 0.05 to 0.25 μg/mL, respectively. Using this method, the monosaccharides comprising the polysaccharides of Codium fragile were determined to be arabinose, galactose, and glucose.

[High-efficiency separation and analysis of monosaccharides in Pueraria polysaccharides by pressurized capillary electrochromatography]

Pueraria polysaccharides have been proven to possess biological activities such as bacteriostasis, anti-oxidative, anti-tumor, and immunity boosting activities. The variation in the structure, composition, and amount of monosaccharides in these polysaccharides may lead to different spatial structures and biological activities. Therefore, extraction of Pueraria polysaccharides and determination of the monosaccharide composition are of great significance for activity analysis and quality control. Direct detection of saccharides is difficult because they are strongly polar and do not show absorption in the ultraviolet region. At present, the commonly used methods for saccharide detection are liquid chromatography-ultraviolet detection, gas chromatography-ultraviolet detection, and mass spectrometry. Pressurized capillary electrochromatography is a high-efficiency microseparation technology. In this study, two kinds of Pueraria polysaccharides were extracted by an ultrasonic-assisted method, and response surface methodology was performed to explore the conditions for ultrasonic-assisted extraction of polysaccharides from Pueraria. The interaction effects of four factors, the liquid-solid ratio, ultrasonic extraction time, ultrasonic extraction temperature, and ultrasonic power, on the extraction rate of the polysaccharides were analyzed. By combining the optimal conditions predicted by the software and the actual equipment conditions, the optimal extraction conditions for Pueraria polysaccharides were chosen as follows:ultrasonic extraction temperature, 90℃; liquid-solid ratio of Pueraria thomsonii Benth, 20 mL/g; liquid-solid ratio of Pueraria lobata Ohwi, 40 mL/g; ultrasonic extraction time, 30 min; ultrasonic power, 180 W. Through data fitting, the multiple quadratic regression equation of the four factors on the extraction rate of Pueraria polysaccharides was established. A novel method based on pressurized capillary electrochromatography for the separation and analysis of eight neutral monosaccharides has been established. The monosaccharides were derivatized by the 1-phenyl-3-methyl-5-pyrazolone pre-column derivatization method. The separation conditions for these monosaccharides were explored, and the buffer concentration, buffer pH, applied voltage, type of chromatographic column, and mobile phase ratio were optimized. Finally, the established pressurized capillary electrochromatography-ultraviolet detection method was applied to the detection and identification of two kinds of actual Pueraria polysaccharide samples. The results of response surface analysis showed that among the four experimental factors, ultrasonic extraction temperature had the greatest influence on the extraction rate of polysaccharides from the two kinds of Pueraria, followed by the liquid-solid ratio; the influence of the ultrasonic extraction time and ultrasonic power was relatively weak. The experimental conditions were determined as follows:the separation of eight neutral monosaccharide derivatives could be realized within 24 min on a Halo-2.7 μm core-shell C18 capillary column with acetonitrile-50 mmol/L ammonium acetate aqueous solution (18:82, v/v, pH 4.1) as the mobile phase, by detection at 250 nm under an applied voltage of-20 kV. The separation and detection speeds and the column efficiency achieved with this method were much better than those obtained with the traditional liquid chromatography method. The results show that the proposed method has a good linear relationship and good repeatability. The separation and identification results for the actual samples showed that the polysaccharides of Pueraria thomsonii Benth were mainly composed of glucose, mannose, rhamnose, and fucose in the molar ratio 1.00:0.16:0.14:0.07. The polysaccharides of Pueraria lobata Ohwi were mainly composed of glucose and mannose in the molar ratio 1.00:0.70. This study provides a novel method for the rapid and efficient separation and detection of neutral monosaccharides, and serves as a reference for analyzing the monosaccharide composition of Pueraria polysaccharides.

Sulfated modification, characterization and monosaccharide composition analysis of Undaria pinnatifida polysaccharides and anti-tumor activity

Undaria pinnatifida (U. pinnatifida) polysaccharides (UPPS) are considered to be the major bioactive components of U. pinnatifida. The aim of the present study was to investigate the separation, sulfated modification, characterization and monosaccharide composition of UPPS. The optimal processing conditions were as follows: Distilled water-to-solid ratio, 50 ml/g; extraction time, 300 min; and extraction temperature, 90˚C. The major polysaccharide fraction of U. pinnatifida (UPPS-B1) was purified via DEAE-52 and Sephadex G-200 column chromatography. The chlorosulfonic acid-pyridine method was applied for sulfation modification. UPPS-B1 and sulfated (S)-UPPS-B1 were characterized via chemical analysis, ultraviolet-visible and Fourier-transformed infrared spectroscopy, gas chromatography and high-performance liquid chromatography. The total sugar content of UPPS-B1 and S-UPPS-B1 was 79.78 and 77.28%, respectively. The sulfate radical content of UPPS-B1 and S-UPPS-B1 was 8.53 and 29.12%, whilst the content of uronic acid was 9.29 and 7.98%, respectively. The average molecular weight of UPPS-B1 and S-UPPS-B1 was determined to be 37 and 110 kD, respectively. UPPS-B1 was considered to be a heteropolysaccharide composed of xylose, mannose, glucose and galactose at a ratio of 7.9:8.7:12.0:9.8. In addition, S-UPPS-B1 was a heteropolysaccharide composed of xylose, mannose, glucose and galactose at a ratio of 1.0:9.7:6.4:1.6. The results of the tumor growth inhibition experiment demonstrated that UPPS-B1 exhibited anti-tumor activity in vivo, which was improved following sulfation to yield S-UPPS-B1.

Preparation, Characterization, and Immuno-Enhancing Activity of Polysaccharides from Glycyrrhiza uralensis

Glycyrrhiza uralensis is a Chinese herbal medicine with various bioactivities. Three fractions (GUPS-I, GUPS-II and GUPS-III) of G. uralensis polysaccharides (GUPS) were obtained with molecular weights of 1.06, 29.1, and 14.9 kDa, respectively. The monosaccharide compositions of GUPS-II and GUPS-III were similar, while that of GUPS-I was distinctively different. The results of scanning electron microscopy, FT-IR, and NMR suggested that GUPS-II and GUPS-III were flaky with a smooth surface and contained α- and β-glycosidic linkages, while GUPS-I was granulated and contained only α-glycosidic linkages. Moreover, GUPS-II and GUPS-III exhibited better bioactivities on the maturation and cytokine production of dendritic cells (DCs) in vitro than that of GUPS-I. An in vivo experiment showed that only GUPS-II significantly enhanced the maturation of DCs. These results indicate that GUPS-II has the potential to be used in combination with cancer immunotherapy to enhance the therapeutic effect.

Simultaneous Use of Stimulatory Agents to Enhance the Production and Hypoglycaemic Activity of Polysaccharides from Inonotus obliquus by Submerged Fermentation

This study aimed to determine the effect of applying stimulatory agents to liquid cultured Inonotus obliquus on the simultaneous accumulation of exo-polysaccharides (EPS) and their monosaccharide composition. Different stimulatory agents (VB₆, VB₁, betulin and birch extract) were investigated for their effects on active exo-polysaccharides by submerged fermentation of I. obliquus. The mycelial biomass, reducing sugar content, EPS yield and α-glucosidase inhibition rate were determined, and the EPS obtained was analyzed for monosaccharide composition. The results showed that the addition of all the four stimulatory agents could significantly increase the inhibitory activity against α-glucosidase of EPS than the control, whereas EPS from 4 μg/mL VB₁-containing medium had the best effect with an estimated IC₅₀ value 24.34 μg/mL. Among the four stimulatory agents, VB₆ gave maximum production of mycelial biomass and EPS at the concentration of 4 μg/mL with a increase of 50.79% and 114.46%, respectively. In addition, betulin had a significant effect on increasing the EPS yield and activity, and birch extract had a significantly stimulatory effect on the mycelial growth and the polysaccharides activity, only slightly worse than VB₆ and VB₁. Moreover, the addition of different stimulatory agents changed the monosaccharide composition of polysaccharides, which had a correlation with polysaccharide activity.

[Study on quantification method of non-starch polysaccharides in Dendrobium catenatum]

The non-starch polysaccharides,mainly composed of glucomannans,are the major bioactive compounds in Dendrobium catenatum. In order to evaluate the quality of the medicinal materials and guide the production and processing,a quantification method of non-starch polysaccharides was established by stems of D. catenatum C15 strain collected from the pear epiphytic cultivation. The non-starch polysaccharides were obtained by " water extraction,α-amylase pretreatment,and alcohol precipitation once" method. The contents of starches,non-starch polysaccharides and monosaccharides were analyzed. In addition,the system suitability was tested. Compared with method of the Chinese Pharmacopoeia( 2015 edition),the contents of total polysaccharides,glucose,and mannose were decreased by 20. 9%,58. 8% and 1. 6% respectively. The method effectively digested starch and retained non-starch polysaccharides,and the analysis result was accurate and repeatable. Therefore,it is suitable for the content measurement of non-starch polysaccharides of D. catenatum. Furthermore,it could be an alternative method for quality control of D. catenatum and a reference in the determination of non-starch polysaccharides in other starch-containing medicinal materials.

[Study on polysaccharide content and monosaccharide composition of Polyporus umbellatus from different production areas]

In order to provide scientific basics for exploitation and sufficient application of Polyporus umbellatus resources and study the monosaccharide composition of P. umbellatus polysaccharides,the anthrone-sulfuric acid method was applied to compare polysaccharide content of P. umbellatus from 17 producing areas. The monosaccharides were derived by 1-phenyl-3-methyl-5-pyrazolone( PMP) and the derivatives were identified by UPLC-MS/MS and the content of each monosaccharide component was determined simultaneously. The results demonstrated that there was a certain difference in total polysaccharide content of P. umbellatus from different regions,and the content of total P. umbellatus polysaccharide from Shaanxi province and Sichuan province( 1. 15% and 1. 90%) was relatively higher than that of others areas. Polysaccharides from P. umbellatus was mainly composed of eight monosaccharides,including glucose,glucuronic acid,galactose,ribose,xylose,arabinose,mannose and fucose. The contents of glucose( 17. 65 mg·g-1) was higher than others. The ribose was the lowest( 0. 13 mg·g-1). In addition,fructose,rhamnose and galacturonic acid were also detected in some samples. Furthermore,the results of cluster analysis( CA) and principal component analysis( PCA) indicated that totally 17 batches of P. umbellatus polysaccharide could be classified into three clusters,samples collected from Wuchang in Heilongjiang province were clustered into one group separately. The study can provide a basis for rational utilization of P. umbellatus resources,and also implies the sequence of monosaccharide linking and pharmacological activity of P. umbellatus polysaccharides.

[Composition analysis and antioxidant activity of polysaccharide from Hibiscus syriacus]

The flower of Hibiscus syriacus has good ornamental and edible-medicinal values.In this study,four samples of two varieties,namely white multiple petals flower and pink multiple petals flower,were selected as test materials.And the optimum extraction conditions,relative molecular weight,monosaccharide composition and antioxidant activity of polysaccharides in flower were investigated.Through single factor experiment and response surface,the optimal extract conditions of polysaccharide were designed as follows:extraction temperature at 96.8℃,ratio of material to liquid of 43.5∶1 m L·g~(-1),extraction time of 3.1 h.Polysaccharides of H.syriacus flowers were analyzed by high performance gel chromatography.The average molecular masses of the 4 polysaccharide samples were1.49×10~5,1.25×10~5,1.01×10~5,1.37×10~5,respectively.Polysaccharides of H.syriacus flowers were mainly composed of glucose,mannose,galactose,rhamnose and arabinose by pre-column derivatization HPLC.The ratio of galactose was the highest in five monosaccharide,and the ratio of galactose to glucose was 1.656-4.496.In addition,crude polysaccharides of H.syriacus flowers showed potential antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)assay,total reducing capacity assay and ABTS assay in vitro,and its antioxidant effect showed a good dose-effect relationship with the concentration of crude polysaccharides.Among the tested varieties,polysaccharides of pink multiple petals flower and white multiple petals flower had the same molecular masses and monosaccharides composition,but the antioxidant activity of the polysaccharides of pink multiple petals flower was higher than that of the white flowers.The results of this study can provide a theoretical basis for the application of H.syriacus flower in the field of functional foods.

Bioactive Mushroom Polysaccharides: A Review on Monosaccharide Composition, Biosynthesis and Regulation

Mushrooms are widely distributed around the world and are heavily consumed because of their nutritional value and medicinal properties. Polysaccharides (PSs) are an important component of mushrooms, a major factor in their bioactive properties, and have been intensively studied during the past two decades. Monosaccharide composition/combinations are important determinants of PS bioactivities. This review summarizes: (i) monosaccharide composition/combinations in various mushroom PSs, and their relationships with PS bioactivities; (ii) possible biosynthetic pathways of mushroom PSs and effects of key enzymes on monosaccharide composition; (iii) regulation strategies in PS biosynthesis, and prospects for controllable biosynthesis of PSs with enhanced bioactivities.

Sugar Composition Analysis of Fuzi Polysaccharides by HPLC-MSn and Their Protective Effects on Schwann Cells Exposed to High Glucose

Fuzi has been used to treat diabetic complications for many years in china. In a previous study, we have shown that Fuzi aqueous extract can attenuate Diabetic peripheral neuropathy (DPN) in rats and protect Schwann cells from injury. Thus, the protective effect of Fuzi polysaccharides (FPS) on high glucose-induced SCs and the preliminary mechanism were investigated. Firstly, the FPS were obtained and their monose composition was analyzed by the combination of pre-column derivatization and high performance liquid chromatography coupled with electrospray ionization multi-tandem mass spectrometry (HPLC/ESI-MSⁿ). The results witnessed the efficiency of this method and seven monosaccharides were tentatively identified, among which fucose was first reported. Simultaneously, m/z 215 can be considered as diagnostic ions to confirm the number of monosaccharides. Next, high glucose-induced SC model was applied and divided into model group, treated group of FPS, normal and osmotic control group. After treatment for 48 h, the data showed FPS could significantly decrease the intracellular ROS and apoptosis, which were determined by the corresponding fluorescent probes. Then, the expression of oxidative stress-related proteins in SCs were measured by Western blot. Furthermore, the protein tests found that FPS markedly up-regulated superoxide dismutase (SOD), catalase (CAT) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) protein level, but down-regulated NADPH oxidase-1 (Nox1) protein level. Moreover, FPS could also increase AMP-activated protein kinase (AMPK) activation significantly. Hence, we preliminary deduced that AMPK-PGC-1α pathway may play an important role in the protective effect of FPS against high glucose-induced cell damage.

Purification, characterization and anti-aging capacity of mycelia zinc polysaccharide by Lentinus edodes SD-08

BACKGROUND

In the modern society, aging had been a major problem. People may rely on many medicines to delay it. However, lots of medicines were chemosynthetic, and they would do a bad side-effect on human body. Microbial sources could be used as a potential means of producing natural antioxidants. Lentinus edodes, commercial obtained in daily life, had recently become more attractive in physiological research. Zinc was now considered as a major element in assuring the correct functioning of an organism and essential for maintaining coordination of the major homeostatic networks. To investigate the bioconversion of zinc and the physiological effects of their complex (MZPS), the present studies were processed.

METHODS

Mycelia polysaccharides (MPS) and mycelia zinc polysaccharides (MZPS) of Lentinus edodes SD-08 were extracted by hot water leaching and purified by DEAE-52 cellulose anion-exchange column chromatography separately. The zinc content was determined by flame atomic absorption spectrometry. The evaluation of monosaccharide compositions and proportions used gas chromatogram. The analysis of molecular weight used HPGPC chromatogram. The typical structure of polysaccharide was evaluated by IR spectrum. The antioxidant activities in vitro measured through reducing power, the scavenging effects on hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The anti-aging activities in vivo measured through the total antioxidant capacity (T-AOC), GSH peroxide (GSH-Px), superoxide dismutase (SOD) and the contents of malondialdehyde (MDA).

RESULTS

MPS and MZPS of Lentinus edodes SD-08 were extracted and purified by DEAE-52 cellulose anion-exchange column chromatography separately, and four fractions (MPS-1, MPS-2, MZPS-1 and MZPS-2) were obtained. In addition, MPS composing of rhamnose, arabinose and mannose (molar proportion = 1.75:1.00:3.02) and MZPS containing rhamnose, arabinose, mannose and glucose (molar proportion = 7.19:2.26:1.00:8.39) were investigated by gas chromatography. Infrared spectrum analysis indicated that there were C-H, C=O and -CH2 bonds in MPS and MZPS. MPS also had the typical absorption of -NH3 (+), -NH2 and -COOH. Compared with MPS, MZPS showed in vitro positive rising of reducing power and certain scavenging effects on hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. MZPS were found to upregulate in vivo the anti-aging activities of total antioxidant capacity (T-AOC), GSH peroxide (GSH-Px), superoxide dismutase (SOD), and decrease the contents of malondialdehyde (MDA).

CONCLUSIONS

MZPS effectively showed potential anti-aging activities in vivo and antioxidant activities in vitro, and the molecular constituents, chemical bonds and functional groups of MZPS were superior to MPS, suggesting that the MZPS of L. edodes SD-08 could be used as a potential natural antioxidant.

A novel alkali extractable polysaccharide from Plantago asiatic L. Seeds and its radical-scavenging and bile acid-binding activities

A new acidic polysaccharide (PLP) was isolated and characterized from Plantago asiatic L. seeds by hot alkali extraction and chromatographic purification using DEAE cellulose and Sephacryl S-400 columns. PLP has a molecular weight of 1.15 × 10(6) Da, and a monosaccharide composition of xylose (Xyl), arabinose (Ara), glucuronic acid (GlcA), and galactose (Gal) in a molar ratio of 18.8:7.2:6.1:1. The results of methylation analysis, FT-IR, and 1D and 2D NMR indicated that PLP was a highly branched heteroxylan of β-1,4-linked Xylp backbone with three α-GlcAp-(1→3)-Araf attached to the O-3 position and one α-T-linked-GlcAp and one α-Araf-(1→5)-Araf attached to the O-2 position every eight monosaccharide residues. PLP exhibited scavenging abilities against hydroxyl, peroxyl anion, and DPPH radicals in vitro and showed significant binding capacities against cholic and chenodeoxycholic acids, suggesting its possible cholesterol-lowering activity. The results demonstrated the potential use of PLP in functional foods and nutraceuticals.

Quantification of (1→4)-β-d-Galactans in Compression Wood Using an Immuno-Dot Assay

Compression wood is a type of reaction wood formed on the underside of softwood stems when they are tilted from the vertical and on the underside of branches. Its quantification is still a matter of some scientific debate. We developed a new technique that has the potential to do this based on the higher proportions of (1→4)-β-d-galactans that occur in tracheid cell walls of compression wood. Wood was milled, partially delignified, and the non-cellulosic polysaccharides, including the (1→4)-β-d-galactans, extracted with 6 M sodium hydroxide. After neutralizing, the solution was serially diluted, and the (1→4)-β-d-galactans determined by an immuno-dot assay using the monoclonal antibody LM5, which specifically recognizes this polysaccharide. Spots were quantified using a dilution series of a commercially available (1→4)-β-d-galactan from lupin seeds. Using this method, compression and opposite woods from radiata pine (Pinus radiata) were easily distinguished based on the amounts of (1→4)-β-d-galactans extracted. The non-cellulosic polysaccharides in the milled wood samples were also hydrolysed using 2 M trifluoroacetic acid followed by the separation and quantification of the released neutral monosaccharides by high performance anion exchange chromatography. This confirmed that the compression woods contained higher proportions of galactose-containing polysaccharides than the opposite woods.