Purification, characterization and antioxidant activity of polysaccharides from Porphyra haitanensis

Extraction, purification, structural characteristics and biological properties of the polysaccharides from Rubus L: A review

Rubus L. is widely distributed throughout the world as a medicinal and food plant with rich values. There is increasing evidence that Rubus L. polysaccharides are important and representative active macromolecules with abundant in vitro and in vivo bioactivities, such as: antioxidant, immunomodulatory, hypoglycemic, anti-inflammatory, anti-tumor, anti-fatigue and so on. Despite significant advancements in research, a comprehensive and systematic review of Rubus L. polysaccharides has been absent. In this paper, we innovatively provide an in-depth overview of the extraction and purification methods, structural characterization, biological activities, possible molecular mechanisms, toxicity and applications of Rubus L. polysaccharides for the first time. In addition, the existing literature was quantitatively analyzed by bibliometrics. The paper also focuses on the challenges and future perspectives of the existing studies with a view to providing new insights and directions for the future development of Rubus L. polysaccharides.

In vitro assessment of the effect of Porphyra haitanensis polysaccharides on the intestinal flora of allergic mice

This study systematically investigated the modulatory effects of Porphyra haitanensis polysaccharides (PHP) and its two P. haitanensis polysaccharide components (PHP40 and PHP80) on gut microbiota in ovalbumin (OVA)-sensitized mice via in vitro fermentation. PHP40 and PHP80 exhibited sulfate contents of 5.94 ± 0.05 % and 11.72 ± 0.03 %, respectively, with galactose and glucose as dominant monosaccharides. The different polysaccharide components had different effects on the aforementioned changes in the species composition and structure of the gut microbiota in allergic mice, with distinct dominant microbial profiles across groups. PHP could promote Bacillus and Enterococcus proliferation while inhibiting Staphylococcus. PHP40 and PHP80 could promote Enterococcus and Enterobacter growth but suppressed Staphylococcus and Bacillus. Functional prediction indicated PHP significantly improved galactose metabolism and primary/secondary bile acid biosynthesis, potentially alleviating allergic responses.

Differences in extraction methods influence the physicochemical properties, antiradical, and anti-inflammatory effects of porphyran from Pyropia dentata

The anti-inflammatory and anti-radical activities of Pyropia dentata porphyran (PDP) prepared by different extraction techniques were investigated. Water shaking extraction (WE), ultrasound extraction (UE), acid extraction (Aci.E), and alkaline extraction (Alk.E) yielded four pure constituents of PDP. Various PDPs were characterized for their chemical composition and structure. Alk.E-PDP exhibited the most potent anti-radical activity among the four PDP extracts. Alk.E-PDP demonstrated 81 % DPPH radical scavenging activity at 15 mg/mL, approximately two-fold higher than the other extracts. All four PDP extracts were also investigated for their anti-inflammatory and immunoregulatory functions using lipopolysaccharide (LPS)-stimulated THP-1 macrophages. WE-PDP stimulated the secretion of IL-6 (1250 pg/mL) and IL-10 (400 pg/mL) at 1 mg/mL in THP-1 macrophages. Under LPS-stimulated conditions, Alk.E-PDP reduced IL-6 levels from 200 to 100 pg/mL and TNF-α levels from 550 to 230 pg/mL. These results indicated that the obtained extracts can significantly inhibit LPS-induced inflammation and promote cytokine production in THP-1 cells. WE-PDP and Alk.E-PDP exhibited the most potent activities among the four extracts. Collectively, PDP's potential as a natural, non-toxic anti-inflammatory agent was demonstrated. PDP may be utilized in various biomedical applications, including vaccine adjuvants.

Physicochemical characterization and evaluation of the antioxidant potential of water-soluble polysaccharides from red microalgae, Rhodomonas salina

Rhodomonas salina is a red microalgal species belonging to the class cryptophyceae, which holds huge commercial value due to its rich biochemical composition, including proteins, fatty acids and pigments. However, detailed characterization on the chemical and physical properties of carbohydrates from R. salina are limited. The main objective of this study is to isolate water-soluble polysaccharides from Rhodomonas salina and investigate their physicochemical properties and in-vitro antioxidant activity. Investigation using chromatographic and spectroscopic techniques revealed that the major polysaccharide in R. salina is a α-glucan having (1 → 4) linked-d-Glucopyranose linkages. It is a semi-crystalline polysaccharide having thermal stability up to 245 °C and exhibits Newtonian fluid behaviour in an aqueous solution. The polysaccharide also exhibits moderate scavenging activities against DPPH free radicals and hydroxyl radicals. The findings provide a strong foundation for understanding the functional potential and scope of applications of this novel polysaccharide. Being a α-glucan, R. salina polysaccharide holds potential to be explored as a feedstock of bioethanol production in biotechnology and biorefinery industries.

Hypoglycemic and Gut Microbiota-Modulating Effects of Pectin from Citrus aurantium "Changshanhuyou" Residue in Type 2 Diabetes Mellitus Mice

To fully utilize the Citrus aurantium "Changshanhuyou" resource, the hypoglycemic effect and mechanisms of action of pectin from Changshanhuyou residue (HYP) were studied. HYP considerably inhibited α-glucosidase, suggesting its potent in vitro hypoglycemic activity. In streptozotocin-induced type 2 diabetes mellitus (T2DM) mice, HYP significantly increased the body weight, survival rate, hexokinase activity, and glycogen content and decreased fasting blood glucose, oral glucose tolerance, liver weight, and glycated serum protein levels. Furthermore, HYP remarkably improved glycolipid metabolism-related indices in both serum and liver, IL-6 and TNF-α levels in serum, and antioxidant enzyme activities in liver. HYP also modulated mRNA expression of the key factors (e.g., Akt, PI3K, IRS2, InsR, GLUT4, G6 Pase, PEPCK, AMPK, GS, and GSK-3β) and increased short chain fatty acid production and abundance of beneficial bacteria. Thus, the underlying hypoglycemic mechanism of HYP may involve the activation of PI3K/Akt, AMPK, and GS/GSK-3β signaling pathways and modulation of gut microbiota composition.

Marine algal polysaccharides: Multifunctional bioactive ingredients for cosmetic formulations

Marine algal polysaccharides (MAP) are increasingly recognized as versatile bioactive ingredients in cosmetics due to their wide-ranging therapeutic benefits and eco-friendly sourcing. Sourced from red, brown, and green algae, these polysaccharides deliver numerous advantages for skin health, including antioxidant, anti-inflammatory, anti-aging, hydrating, and regenerative properties. As demand for natural and sustainable products grows, MAP offer a renewable and environmentally responsible alternative to synthetic chemicals. This review examines the chemical structures, extraction methods, biological activities, and cosmetic applications of key MAP, such as carrageenans, alginates, fucoidans, laminaran, ulvan, and sulfated rhamnan. It also discusses emerging research trends, innovative extraction techniques, and the formulation of multifunctional products that combine these polysaccharides with other bioactive compounds. As consumer preferences increasingly lean toward ethical and sustainable choices, MAP are well-positioned to contribute to the development of high-performance cosmetic products that meet both industry standards and consumer expectations.

Synthesis of Nano-Selenium from Bombyx batryticatus Polypeptide and Exploring Its Antioxidant and Skin Whitening Ability

To increase the stability of selenium in nano state and further improve its antioxidant and skin whitening ability, Bombyx batryticatus polypeptide (BBPP) was prepared. The optimum synthesis conditions of Bombyx batryticatus polypeptide nano-selenium (BBPP-SeNPs) were determined by a double-peak method. BBPP-SeNPs were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), and particle size analysis (PSS). The 1,1-Diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide anion free radical scavenging rate, and total antioxidant capacity of BBPP, vitamin C (VC), and BBPP-SeNPs were measured for comparison. The inhibitory ability of BBPP and BBPP-SeNPs on tyrosinase was measured. Using mouse modeling, the skin whitening ability of VC and BBPP-SeNPs was measured. The results showed that the optimal conditions were obtained when the concentration of BBPP was 0.16 mg/mL, sodium selenite was 0.01 mol/L, ultrasound was carried out for 30 min, ascorbic acid was added in 0.04 mol/L, and stirring temperature was 20 °C for 4 h. The antioxidant capacity of BBPP-SeNPs has significantly improved. It can be observed that BBPP-SeNPs has obvious scavenging ability on skin-reactive oxygen species through a Reactive Oxygen Species (ROS) staining section. Through Hematoxylin-Eosin (H&E) staining, it can be proven that BBPP-SeNPs has a high security threshold.

Rheological Behavior, Textural Properties, and Antioxidant Activity of Porphyra yezoensis Polysaccharide

Porphyra yezoensis has attracted much attention due to its gelling properties and bioactivity. In this study, the chemical structure of Porphyra yezoensis polysaccharides (PYPSs) was characterized, and the effects of concentration, temperature, pH, and calcium ion (Ca2+) addition on the rheological properties of PYPS were systematically investigated. Chemical composition analysis indicated that PYPS primarily contained galactose (89.76%) and sulfate (15.57%). Rheological tests demonstrated that PYPS exhibited typical pseudoplastic properties, with apparent viscosity increasing with an increasing concentration. Temperature elevation from 30 °C to 90 °C weakened the intermolecular forces and reduced the apparent viscosity, whereas neutral pH (7.0) provided an optimal electrostatic equilibrium to maintain the highest viscosity. Ca2+ could modulate the interactions between PYPS molecules and affect the formation of the gel network structure. When the Ca2+ concentration reached the optimal value of 6 mM, the calcium bridges formed between Ca2+ and PYPS molecules not only enhanced the rheological behavior and textural properties but also formed a smooth and well-ordered network structure, achieving the highest value of fractal dimension (Df = 2.9600), though excessive Ca2+ disrupted this well-ordered structure. Furthermore, PYPS possessed significant scavenging ability against DPPH, ABTS, and HO• radicals, demonstrating its potential application as a natural antioxidant in functional foods.

Purification and structural characterization of a neutral polysaccharide from Boletus auripes using self-made quaternary chitosan cryogel

The purification of polysaccharides is an essential preliminary step in determining their chemical structure, although it presents significant challenges. In this research, a macro-porous monolith of quaternary chitosan cryogel was synthesized for the purification of a neutral polysaccharide from Boletus auripes. A homogeneous neutral polysaccharide (BAP-1a1) with a weight-average molecular weight of 4.13 × 105 Da and a polydispersity index of 1.28 was successfully isolated. The structure of BAP-1a1 was elucidated through a comprehensive characterization utilizing size exclusion chromatography (SEC) combined with laser light scattering (LLS), infrared spectroscopy, monosaccharide composition analysis, methylation analysis, and nuclear magnetic resonance (NMR) spectroscopy. The results revealed that the BAP-1a1 was characterized as a glucan with a backbone structure consisting of 1,4-α-D-Glcp and 1,3-β-D-Glcp glycosidic linkages in a molar ratio of 2:1. Additionally, a minority of branched chains of 1-α-D-Glcp are attached to 1,3-β-D-Glcp residues at the C6 position. In vitro antioxidant activity assays demonstrated that BAP-1a1 exhibits a dose-dependent scavenging effect on ABTS and DPPH radicals with EC50 values of 0.58 and 1.04 mg/mL, respectively. These findings indicated that Boletus auripes possesses the potential to be utilized as a natural agent in antioxidant functional foods.

Evaluation of the antioxidant and antityrosinase activities of Prosopis juliflora fruit extract as a novel multifunctional bioactive ingredient and its potential applicability in pro-ageing and skin colour harmonization cosmetic products

OBJECTIVE

Prosopis juliflora, commonly known as algaroba or mesquite, was introduced and has since proliferated throughout the semi-arid region of the Caatinga biome. Various studies have documented its properties, including antimicrobial, antioxidant, and antitumor activities, attributed to the presence of diverse secondary metabolites such as alkaloids, terpenoids, tannins, and flavonoids. The objective of this study was to evaluate the antioxidant and antityrosinase activities of P. juliflora fruit extract as a multifunctional active ingredient, and to develop cosmetic formulations containing this vegetal extract for potential applications in skincare products targeting pro-ageing and skin colour homogenization properties.

METHODS

The extraction process followed established protocols. Chemical characterization of the extract involved quantification of total flavonoids and phenolic compounds, along with Liquid Chromatography-Mass Spectrometry (LC-MS) analysis. In vitro antioxidant activity was assessed using different methods. Antityrosinase activity was determined by employing enzymatic assays. Cosmetic formulations containing Disodium EDTA, Phenoxyethanol (and) Ethylhexyl Glycerin, Distilled Water, Sodium Acrylates Copolymer Lecithin, Polyacrylamide (and) C13-14 Isoparaffin (and) Laureth-7, and 3.0% of the investigated plant extract were subjected to preliminary and accelerated stability tests.

RESULTS

The extract demonstrated a concentration of total flavonoids (1.71 ± 0.26 μg EQ/mg) and exhibited concentrations of phenolic compounds at 0.21 ± 0.01 mg EAG/g. Metabolites such as flavonoids and saponins were annotated, as well as some of their respective glycosidic derivatives. The extract showed antioxidant potential and the ability to inhibit the oxidation cascade in both the initiation and propagation phases. Moreover, the extract exhibited noteworthy inhibition of antityrosinase activity, presenting 62.48 ± 2.09 at a concentration of 30.00 mg/mL. The formulations were stable in accelerated stability tests over a 60-day period.

CONCLUSION

This research not only demonstrates scientifically by demonstrating the potential of a plant from the Caatinga biome with antioxidant and antityrosinase properties in the development of cosmetic products aimed at pro-ageing effects and skin colour harmonization, but also adds value to the P. juliflora production chain. This valorization encompasses various aspects which include environmental, social, and biodiversity responsibilities.

Structure-Antioxidant Activity Relationship of Polysaccharides Isolated by Microwave/Ultrasonic-Assisted Extraction from Pleurotus ferulae

To investigate the structure-antioxidant activity relationship, Pleurotus ferulae polysaccharides were extracted using ultrasonic (U-PFPS) and microwave/ultrasonic-assisted methods (MU-PFPS). Compared to U-PFPS with a molecular weight of 1.566 × 103 kDa, MU-PFPS exhibited a lower molecular weight of 89.26 kDa. In addition, unlike U-PFPS, which is primarily composed of glucose (Glu:Man:Gal = 91.1:3.5:5.4), MU-PFPS has a more balanced composition of Glu:Man:Gal in the ratio of 39.4:27.8:32.8 and contains more branched chains. Furthermore, antioxidant analysis revealed that high concentration (at concentrations above 600 μg/mL) MU-PFPS demonstrated stronger protective effects against oxidative damage in RAW264.7 cells than U-PFPS did. Collectively, these data suggest that lower molecular weight and higher branching degree of polysaccharides at appropriate concentrations may correlate with enhanced antioxidant enzyme activities. Our work provides a method for isolating polysaccharides with higher antioxidant activity and offers insights into the structure-activity relationship of polysaccharides, laying the foundation for future applications in polysaccharide modification and structural characterization.

A salt/salt aqueous two-phase system based on pH-switchable deep eutectic solvent for the extraction and separation of mulberry polysaccharides

With the aim of expanding the potential application scope of mulberries, eleven pH-switchable deep eutectic solvents were screened for the ultrasonic-assisted extraction of mulberry polysaccharides, and a salt/salt aqueous two-phase system was constructed for the efficient separation of mulberry polysaccharides by regulating the system pH. DES-9 (tetraethylammonium chloride: octanoic acid molar ratio = 1: 2) with a critical response pH value of approximately 6.1 was concluded to be the best extraction solvent for extracting mulberry polysaccharides. A maximum polysaccharide extraction yield of 270.71 mg/g was obtained under the optimal conditions. The maximum polysaccharide extraction efficiency was 78.09 % for the pH-driven tetraethylammonium chloride/K2HPO4 aqueous two-phase system. An acidic β-pyran mulberry polysaccharide with a low-molecular weight of 9.26 kDa and a confirmed monosaccharide composition were obtained. This efficient and environmentally friendly polysaccharide separation method offers a new approach for the efficient extraction and utilization of other plant polysaccharides.

Ultra-high pressure assisted extraction of polysaccharide from Bangia fusco-purpurea: Structure and in vitro hypolipidemic activity

The structure and in vitro hypolipidemic activity of Bangia fusco-purpurea polysaccharide (BFP) assisted extracted with ultra-high pressure (UHP) at 100-600 MPa were studied. Compared to native BFP, UHP assisted extracted BFP had a more loose network structure with higher total sugar and uronic acid contents while less molecular weight (p < 0.05). Moreover, UHP assisted extraction significantly improved the in vitro hypolipidemic and antioxidant activity of BFP. Especially at 400 MPa UHP, the cholesterol adsorption and antioxidant capacities of BFP were increased by approximately 38.02 % and 11.69 %-32.29 %, respectively. BFP with UHP assisted extraction could alleviate oleic acid-induced lipid accumulation and lipid oxidation in HepG2 cells more effectively by activating the AMPK signaling pathway as well as inhibiting PPARγ expression, which was much related with its reduced molecular weight and loose network structure. The findings indicated that UHP assisted extracted BFP has better potential to develop natural hypolipidemic agent.

Recent advance of physicochemical, structural properties, potential health benefits and application of bioactive macromolecules from Porphyra haitanensis: A review

Porphyra haitanensis (P. haitanensis) belongs to the class Rhodophyta and the family Bangiaceae, which is a unique artificially cultivated seaweed in China, especially in the coastal areas of Fujian and Zhejiang province. P. haitanensis is rich in amino acids, mineral elements, proteins, polysaccharides, and trace elements, with proteins and polysaccharides being the main components. P. haitanensis proteins and polysaccharides have variety of biological activities, including antioxidant, anticancer, immunomodulatory, anti-allergic and anti-aging activities, among others. This review introduced and summarized the preparation, isolation and purification, phytochemistry and structural properties, and biological activities of P. haitanensis proteins and polysaccharide, as well as their biomedical and food applications. Furthermore, a thorough analysis of the current trends and perspectives on P. haitanensis bioactive macromolecules were highlighted and prospected. Hopefully, this review can provide a useful reference value for the development and application of P. haitanensis bioactive macromolecules in the field of biomedical and food in the future.

Optimization of the Deproteinization Process via Response Surface Methodology, Preliminary Characterization, and the Determination of the Antioxidant Activities of Polysaccharides from Vitis vinifera L. SuoSuo

In this study, the response surface method (RSM) was used to optimize the deproteinization process of polysaccharides from Vitis vinifera L. SuoSuo (VTP). The antioxidant capacities of polysaccharides before and after deproteinization were evaluated. The structure of deproteinized VTP (DVTP), which has relatively strong antioxidant activity, was characterized, and the protective effect of DVTP on H2O2-induced HT22 cell damage was evaluated. The results of the RSM experiment revealed that the ideal parameters for deproteinization included a chloroform/n-butanol ratio (v/v) of 4.6:1, a polysaccharide/Sevage reagent (v/v) ratio of 2:1, a shaking time of 25 min, and five rounds of deproteinization. Preliminary characterization revealed that the DVTP was an acidic heteropolysaccharide composed of seven monosaccharides, among which the molar ratio of galacturonic acid was 40.65. FT-IR and the determination of uronic acid content revealed that DVTP contained abundant uronic acid and that the content was greater than that of VTP. In vitro, the antioxidant activity assay revealed that the hydroxyl radical scavenging capacity and total antioxidant capacity of DVTP were greater than those of VTP. In the range of 0.6~0.8 mg/mL, the DPPH scavenging capacities of VTP and DVTP were greater than that of vitamin C. In addition, cell viability was measured via a CCK-8 assay, which revealed that DVTP had a strong defense effect on H2O2-induced damage to HT22 cells. These findings suggest that DVTP has high antioxidant activity and could be used as a natural antioxidant in functional foods and medicines.

Optimization of Ultrasonic-Assisted Extraction, Characterization and Antioxidant and Immunoregulatory Activities of Arthrospira platensis Polysaccharides

This study aimed to enhance the ultrasonic-assisted extraction (UAE) yield of seawater Arthrospira platensis polysaccharides (APPs) and investigate its structural characteristics and bioactivities. The optimization of UAE achieved a maximum crude polysaccharides yield of 14.78%. The optimal extraction conditions were a liquid-solid ratio of 30.00 mL/g, extraction temperature of 81 °C, ultrasonic power at 92 W and extraction time at 30 min. After purification through cellulose DEAE-52 and Sephadex G-100 columns, two polysaccharide elutions (APP-1 and APP-2) were obtained. APP-2 had stronger antioxidant and immunoregulatory activities than APP-1, thus the characterization of APP-2 was conducted. APP-2 was an acidic polysaccharide consisting of rhamnose, glucose, mannose and glucuronic acid at a ratio of 1.00:24.21:7.63:1.53. It possessed a molecular weight of 72.48 kDa. Additionally, APP-2 had linear and irregular spherical particles and amorphous structures, which contained pyranoid polysaccharides with alpha/beta glycosidic bonds. These findings offered the foundation for APP-2 as an antioxidant and immunomodulator applied in the food, pharmaceutical and cosmetic industries.

Isolation, Characterization, Moisturization and Anti-HepG2 Cell Activities of a Novel Polysaccharide from Cyanobacterium aponinum

Polysaccharides from cyanobacteria are extensively reported for their complex structures, good biocompatibility, and diverse bioactivities, but only a few cyanobacterial species have been exploited for the biotechnological production of polysaccharides. According to our previous study, the newly isolated marine cyanobacterium Cyanobacterium aponinum SCSIO-45682 was a good candidate for polysaccharide production. This work provided a systematic study of the extraction optimization, isolation, structural characterization, and bioactivity evaluation of polysaccharides from C. aponinum SCSIO-45682. Results showed that the crude polysaccharide yield of C. aponinum reached 17.02% by hot water extraction. The crude polysaccharides showed a porous and fibrous structure, as well as good moisture absorption and retention capacities comparable to that of sodium alginate. A homogeneous polysaccharide (Cyanobacterium aponinum polysaccharide, CAP) was obtained after cellulose DEAE-52 column and Sephadex G-100 column purification. CAP possessed a high molecular weight of 4596.64 kDa. It was mainly composed of fucose, galactose, and galacturonic acid, with a molar ratio of 15.27:11.39:8.64. The uronic acid content and sulfate content of CAP was 12.96% and 18.06%, respectively. Furthermore, CAP showed an in vitro growth inhibition effect on human hepatocellular carcinoma (HepG2) cells. The above results indicated the potential of polysaccharides from the marine cyanobacterium C. aponinum SCSIO-45682 as a moisturizer and anticancer addictive applied in cosmetical and pharmaceutical industries.

Effects of Chemical Modification on the Structure and Biological Activities of Polysaccharides Extracted from Inonotus Obliquus by Microwave

A novel polysaccharide, Inonotus obliquus polysaccharide (IOP), was extracted using a microwave extraction method and subsequently subjected to modifications through sulfation, carboxymethylation, phosphorylation, and acetylation. Its physical and chemical properties were analyzed using various chemical techniques, including high-pressure liquid chromatography, ultraviolet light, Fourier-transform infrared spectroscopy, X-ray diffraction, Congo red test, and scanning electron microscopy. The antioxidant capacity was assessed using DPPH, ABTS, and hydroxyl radical assays, as well as by measuring the reducing power. Additionally, hypoglycemic activity was evaluated through α-glucosidase and α-amylase assays. The results indicated that the chemical modifications effectively altered the physical and chemical properties, as well as the biological activities of IOP. Compared to the unmodified IOP, the derivatives exhibited reduced sugar content, uronic acid content, and molecular weight, while demonstrating varying levels of antioxidant and hypoglycemic capabilities. Notably, the carboxymethylated IOP (IOP-C) displayed lower molecular weight, higher ABTS free radical scavenging rate, greater reducing ability, and increased α-amylase inhibition rate. Therefore, IOP-C shows promise as a potential edible antioxidant and hypoglycemic agent.

Production and biological activity of β-1,3-xylo-oligosaccharides using xylanase from Caulerpa lentillifera

In this study, β-1,3-xylanase (Xyl3088) was designed and prepared by constructing the expression vector plasmid and expressing and purifying the fusion protein. β-1,3-xylo-oligosaccharides were obtained through the specific enzymatic degradation of β-1, 3-xylan from Caulerpa lentillifera. The enzymolysis conditions were established and optimized as follows: Tris-HCl solution 0.05 mol/L, temperature of 37 °C, enzyme amount of 250 μL, and enzymolysis time of 24 h. The oligosaccharides' compositions and structural characterization were identified by thin-layer chromatography (TLC), ion chromatography (IC) and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS). The IC50 values for scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-3-ethyl-benzothiazoline-p-sulfonic acid (ABTS+), and superoxide anion radical (•O2-) were 13.108, 1.258, and 65.926 mg/mL for β-1,3-xylo-oligosaccharides, respectively, and 27.588, 373.048, and 269.12 mg/mL for β-1,4-xylo-oligosaccharides, respectively. Compared with β-1,4-xylo-oligosaccharides, β-1,3-xylo-oligosaccharides had substantial antioxidant activity and their antioxidant effects were concentration dependent. β-1,3-xylo-oligosaccharides also possessed a stronger anti-inflammatory effect on RAW 264.7 cells stimulated by lipopolysaccharide (LPS) than β-1,4-xylo-oligosaccharides. At a working concentration of 100 μg/mL, β-1,3-xylo-oligosaccharides inhibited the release of NO and affected the expression of IL-1β, TNF-α, and other proteins secreted by cells, effectively promoting the release of pro-inflammatory mediators by immune cells in response to external stimuli and achieving anti-inflammatory effects. Therefore, β-1,3-xylo-oligosaccharides are valuable products in food and pharmaceutical industries.

Recent progress in Porphyra haitanensis polysaccharides: Extraction, purification, structural insights, and their impact on gastrointestinal health and oxidative stress management

Porphyra haitanensis, a red seaweed species, represents a bountiful and sustainable marine resource. P. haitanensis polysaccharide (PHP), has garnered considerable attention for its numerous health benefits. However, the comprehensive utilization of PHP on an industrial scale has been limited by the lack of comprehensive information. In this review, we endeavor to discuss and summarize recent advancements in PHP extraction, purification, and characterization. We emphasize the multifaceted mechanisms through which PHP promotes gastrointestinal health. Furthermore, we present a summary of compelling evidence supporting PHP's protective role against oxidative stress. This includes its demonstrated potent antioxidant properties, its ability to neutralize free radicals, and its capacity to enhance the activity of antioxidant enzymes. The information presented here also lays the theoretical groundwork for future research into the structural and functional aspects of PHP, as well as its potential applications in functional foods.

Polysaccharides from Porphyra haitanensis: A Review of Their Extraction, Modification, Structures, and Bioactivities

Porphyra haitanensis (P. haitanensis), an important food source for coastal residents in China, has a long history of medicinal and edible value. P. haitanensis polysaccharides are some of the main active ingredients in P. haitanensis. It is worth noting that P. haitanensis polysaccharides have a surprising and satisfactory biological activity, which explains the various benefits of P. haitanensis to human health, such as anti-oxidation, immune regulation, anti-allergy, and anticancer properties. Hence, a systematic review aimed at comprehensively summarizing the recent research advances in P. haitanensis polysaccharides is necessary for promoting their better understanding. In this review, we systematically and comprehensively summarize the research progress on the extraction, purification, structural characterization, modification, and biological activity of P. haitanensis polysaccharides and address the shortcomings of the published research and suggest area of focus for future research, providing a new reference for the exploitation of polysaccharides from P. haitanensis in the fields of medicine and functional foods.

Metabolomic differences between non-hydrothermal treated water-soluble (WSPs) and hydrothermally treated water-insoluble (WIPs) Maitake polysaccharides fermented by Lactobacillus acidophilus and L. plantarum

Bacterial Metabolite through a fermentation process is a growing trend and a promising alternative for use as functional components. Non-hydrothermal water-soluble (WSPs) and hydrothermally treated water-insoluble (WIPs) Maitake polysaccharides were fermented with Lactobacillus acidophilus (LA) and Lactobacillus plantarum (LP). Chemical composition analysis indicated that Maitake polysaccharides contained 58.22 ± 1.35 % total sugar and 31.46 % β-glucan, essential for metabolites production. 6-glucanase was used to degrade the WIPs, and hydrothermally treated WIP fibers exhibited smooth microstructure. Hence, the LA and LP bacteria investigated the potential fermented metabolic activities and differences between WSPs(Sp1)and WIP(Sp3) Maitake polysaccharides using LC-MS, and 887 metabolites were identified. Using Venn, Partial least squares discriminant analysis (PLS-DA), VIP Metabolites, and other multivariate statistical analysis methods, metabolites were expressed differently in all samples. Due to hydrothermal processing, WIP induced the highest growth of LA and LP, with an abundance of isocitrate metabolites. Furthermore, 50 metabolite correlations were identified, leading to the classification of 6 distinct metabolic groups. Thus, the study offers the initial comprehensive analysis of metabolites in Lactobacillus-fermented Maitake polysaccharides, aiding in understanding its metabolic interactions and facilitating progress in food engineering research.

Insights into the molecular mechanisms, structure-activity relationships and application prospects of polysaccharides by regulating Nrf2-mediated antioxidant response

The occurrence and development of many diseases are closely related to oxidative stress. In this context, accumulating evidence suggests that Nrf2, as the master switch of cellular antioxidant signaling, plays a central role in controlling the expression of antioxidant genes. The core molecular mechanism of polysaccharides treatment of oxidative stress-induced diseases is to activate Keap1/Nrf2/ARE signaling pathway, promote nuclear translocation of Nrf2, and up-regulate the expression of antioxidant enzymes. However, recent studies have shown that other signaling pathways in which polysaccharides exert antioxidant effects, such as PI3K/Akt/GSK3β, JNK/Nrf2 and NF-κB, have complex crosstalk with Keap1/Nrf2/ARE, may have direct effects on the nuclear translocation of Nrf2. This suggests a new strategy for designing polysaccharides as modulators of Nrf2-dependent pathways to target the antioxidant response. Therefore, in this work, we investigate the crosstalk between Keap1/Nrf2/ARE and other antioxidant signaling pathways of polysaccharides by regulating Nrf2-mediated antioxidant response. For the first time, the structural-activity relationship of polysaccharides, including molecular weight, monosaccharide composition, and glycosidic linkage, is systematically elucidated using principal component analysis and cluster analysis. This review also summarizes the application of antioxidant polysaccharides in food, animal production, cosmetics and biomaterials. The paper has significant reference value for screening antioxidant polysaccharides targeting Nrf2.

Hypoglycemic Effects of Gynura divaricata (L.) DC Polysaccharide and Action Mechanisms via Modulation of Gut Microbiota in Diabetic Mice

Aiming to provide a basis for the application of Gynura divaricata (L.) DC polysaccharide (GDP) in functional foods, the hypoglycemic effects of GDP, and action mechanisms, were investigated. Results showed that GDP effectively inhibited α-glucosidase and remarkably increased the glucose absorption, glycogen content, and pyruvate kinase and hexokinase activities of insulin-resistant HepG2 cells, indicating its potent in vitro hypoglycemic effect. In streptozotocin-induced type 2 diabetes mice, GDP significantly improved various glycolipid metabolism-related indices in serum and liver, e.g., fasting blood glucose, oral glucose tolerance, glycosylated serum protein content, serum insulin level, antioxidant enzyme activities, TG, TC, LDL-C, and HDL-C levels, and hepatic glycogen content, and recovered the structure of gut microbiota to the normal level. It was also found that GDP significantly affected the expression of related genes in the PI3K/Akt, AMPK, and GS/GSK-3β signaling pathways. Therefore, GDP regulates blood glucose possibly by directly inhibiting α-glucosidase, exerting antioxidant activity, and regulating intestinal microbiota.

Physicochemical Characterization, Antioxidant and Anticancer Activity Evaluation of an Acidic Polysaccharide from Alpinia officinarum Hance

AHP-3a, a triple-helix acidic polysaccharide isolated from Alpinia officinarum Hance, was evaluated for its anticancer and antioxidant activities. The physicochemical properties and structure of AHP-3a were investigated through gel permeation chromatography, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The weight-average molecular weight of AHP-3a was 484 kDa, with the molar percentages of GalA, Gal, Ara, Xyl, Rha, Glc, GlcA, and Fuc being 35.4%, 21.4%, 16.9%, 11.8%, 8.9%, 3.1%, 2.0%, and 0.5%, respectively. Based on the results of the monosaccharide composition analysis, methylation analysis, and NMR spectroscopy, the main chain of AHP-3a was presumed to consist of (1→4)-α-D-GalpA and (1→2)-α-L-Rhap residues, which is a pectic polysaccharide with homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) structural domains containing side chains. In addition, the results of the antioxidant activity assay revealed that the ability of AHP-3a to scavenge DPPH, ABTS, and OH free radicals increased with an increase in its concentration. Moreover, according to the results from the EdU, wound healing, and Transwell assays, AHP-3a can control the proliferation, migration, and invasion of HepG2 and Huh7 hepatocellular carcinoma cells without causing any damage to healthy cells. Thus, AHP-3a may be a natural antioxidant and anticancer component.

Extraction, structure and antioxidant activity of the polysaccharides from morels (Morchella spp.): A review

Morels (Morchella spp.), which are cultivated only in a few regions of the world, are edible mushrooms known for their various properties including antioxidation, immune regulation, antiinflammation, and antitumor effects. Polysaccharides from Morchella are principally responsible for its antioxidant activity. This paper reviews the extraction, purification, structural analysis and antioxidant activity of Morchella polysaccharides (MPs), providing updated research progress. Meanwhile, the structural-property relationships of MPs were further discussed. In addition, based on in vitro and in vivo studies, the major factors responsible for the antioxidant activity of MPs were summarized including scavenging free radicals, reduction capacity, inhibitory lipid peroxidation activity, regulating the signal transduction pathway, reducing the production of ROS and NO, etc. Finally, we hope that our research can provide a reference for further research and development of MPs.

Effects of ultra-high pressure assisted extraction on the structure, antioxidant and hypolipidemic activities of Porphyra haitanensis polysaccharides

Porphyra haitanensis polysaccharides (PHPs) have potential antioxidant and hypolipidemic activities, but still need improvement. Therefore, ultra-high pressure (UHP) assisted extraction was applied to modify the structure, antioxidant, and hypolipidemic activities of PHPs. UHP assisted extraction increased the total sugar, uronic acid, and 3,6-anhydro-ʟ-galactose contents of PHP, which increased by 15.85 %-16.12 %, 18.95 %-24.32 %, 20.54 %-23.66 % with 500-600 MPa UHP, respectively. Meanwhile, UHP modified PHP became more rough and porous than native PHP. Besides, UHP assisted extracted PHP showed better in vitro antioxidant and hypolipidemic abilities. Especially, 500-600 MPa UHP increased 72.43 %-86.42 % 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacities, 12.32 %-12.82 % pancreatic lipase inhibitory ability, and 14.93 %-15.23 % glycocholate binding abilities of PHP (p < 0.05). Moreover, UHP assisted extracted PHP greatly decreased the lipid droplet and triglyceride contents of 3T3-L1 adipocytes (p < 0.05). Our findings can provide the theoretical basis for the high value utilization of Porphyra haitanensis and its polysaccharides with UHP modification.

Effect of subcritical water temperature on the structure, antioxidant activity and immune activity of polysaccharides from Glycyrrhiza inflata Batalin

In this study, the polysaccharide from Glycyrrhiza inflata Batalin extracted by hot water (HW-GP) was further physically modified with subcritical water to obtain novel polysaccharides (SW-GP). Comparative analysis was conducted to examine the disparities in conformation and bioactivity between HW-GP and SW-GP, aiming to precisely regulate the structure of the polysaccharides and enhance their bioactivity by controlling subcritical water temperature. The results showed that, compared with HW-GP, subcritical water modification (100-160 °C) not only significantly reduced the molecular weight of polysaccharides (from 5.586 × 105 g/mol to 1.484 × 105 g/mol), but also modulated the intermolecular interaction forces, which maintain the conformation of the polysaccharides, including electrostatic and hydrophobic interactions, thereby dynamically transforming the polysaccharide chain conformation from triple helix to random coil, and the strength of the chain conformation shifted from rigid to flexible. In addition, the modification of the SW-GP structure by subcritical water also enhanced its biological activity. SW-GP (140 °C) with low molecular weight and semi-rigid triple helix conformation showed the best scavenging effect on the DPPH, ABTS, and hydroxyl radicals, and exhibited excellent antioxidant activity. SW-GP (130 °C) with medium molecular weight and semi-rigid triple helix conformation significantly promoted the proliferation and phagocytosis of RAW264.7 cells, as well as increased the release levels of NO, TNF-α, IL-6, and IL-1β, and the immunomodulatory activity was much higher than that of other polysaccharides. These findings confirmed the feasibility of using subcritical water temperature as a regulatory feature for the structure and bioactivity of glycyrrhiza polysaccharides, which may have reference significance for the modification of polysaccharides with heightened bioactivity.

Structural characterization of a polysaccharide derived from Saposhnikovia divaricatee (Turcz.) Schischk with anti-allergic and antioxidant activities

ETHNOPHARMACOLOGICAL RELEVANCE

Saposhnikoviae Radix, the dry root of Saposhnikovia divaricatee (Turcz.) Schischk, is a traditional chinese medicine used for the treatment of cold, headache, and skin pruritus.

AIM OF THE STUDY

This study aimed to identify novel active polysaccharides from Saposhnikovia divaricatee (Turcz.) Schischk and clarify their structures and bioactivities.

MATERIALS AND METHODS

The structure of polysaccharides was clarified by PMP-HPLC, methylation analysis, particle acid hydrolysis analysis and NMR analysis. The anti-allergic and antioxidant activities of polysaccharides were evaluated on allergic reaction model in RBL-2H3 cells and oxidative damage model of C. elegans.

RESULTS

We purified a novel homogenous polysaccharide named SP-3 from Saposhnikovia divaricatee (Turcz.) Schischk and its molecular weight was determined as 3.096 × 104 Da. Monosaccharide composition analysis revealed that SP-3 was composed of mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose (1.85: 5.22: 38.06: 2.36: 23.25: 29.26). The main linkage type of SP-3 was a repeat unit of →4,6)-β-D-Galp-(1 → 4)-α-D-GalpA-(1 → . The branches of SP-3 contained T-linked-α-L-Araf and 1,3,4-linked-α-L-Rhap. It was observed that SP-3 inhibited β-HEX release and inflammatory factors in RBL-2H3 cells subject to IgE stimulant. Meanwhile, SP-3 increased the mean lifespan of Caenorhabditis elegans under oxidative stress, reduced ROS content and increased antioxidant enzyme activities of C. elegans, potentially through activating the SOD-3.

CONCLUSIONS

A novel homogenous polysaccharide was identified from Saposhnikovia divaricatee (Turcz.) Schischk, and this polysaccharide SP-3 played key roles for the anti-allergic and antioxidant activities.

Structure-activity relationships of bioactive polysaccharides extracted from macroalgae towards biomedical application: A review

Macroalgae are valuable and structurally diverse sources of bioactive compounds among marine resources. The cell walls of macroalgae are rich in polysaccharides which exhibit a wide range of biological activities, such as anticoagulant, antioxidant, antiviral, anti-inflammatory, immunomodulatory, and antitumor activities. Macroalgae polysaccharides (MPs) have been recognized as one of the most promising candidates in the biomedical field. However, the structure-activity relationships of bioactive polysaccharides extracted from macroalgae are complex and influenced by various factors. A clear understanding of these relationships is indeed critical in developing effective biomedical applications with MPs. In line with these challenges and knowledge gaps, this paper summarized the structural characteristics of marine MPs from different sources and relevant functional and bioactive properties and particularly highlighted those essential effects of the structure-bioactivity relationships presented in biomedical applications. This review not only focused on elucidating a particular action mechanism of MPs, but also intended to identify a novel or potential application of these valued compounds in the biomedical field in terms of their structural characteristics. In the last, the challenges and prospects of MPs in structure-bioactivity elucidation were further discussed and predicted, where they were emphasized on exploring modern biotechnology approaches potentially applied to expand their promising biomedical applications.

Research progress in extraction, purification, structure of fruit and vegetable polysaccharides and their interaction with anthocyanins/starch

Fruits and vegetables contain polysaccharides, polyphenols, antioxidant enzymes, and various vitamins, etc. Fruits and vegetables polysaccharides (FVPs), as an important functional factor in health food, have various biological activities such as lowering blood sugar, blood lipids, blood pressure, inhibiting tumors, and delaying aging, etc. In addition, FVPs exhibit good physicochemical properties including low toxicity, biodegradability, biocompatibility. Increasing research has confirmed that FVPs could enhance the stability and biological activities of anthocyanins, affecting their bioavailability to improve food quality. Simultaneously, the addition of FVPs in natural starch suspension could improve the physicochemical properties of natural starch such as viscosity, gelling property, water binding capacity, and lotion stability. Hence, FVPs are widely used in the modification of natural anthocyanins/starch. A systematic review of the latest research progress and future development prospects of FVPs is very necessary to better understand them. This paper systematically reviews the latest progress in the extraction, purification, structure, and analysis techniques of FVPs. Moreover, the review also introduces the potential mechanisms, evaluation methods, and applications of the interaction between polysaccharides and anthocyanins/starch. The findings can provide important references for the further in-depth development and utilization of FVPs.

A neutral heteropolysaccharide from Halenia elliptica D. Don: Extraction, structural characterization, antioxidant and antiaging activities

Halenia elliptica D. Don (H. elliptica), which is also known as "heijicao" and "luanehuamao" in China, is recognised as a valuable Tibetan medicinal plant with polysaccharides as the main active ingredient. However, studies on the polysaccharides isolated from H. elliptica are few. A polysaccharide (HEPN-1) with a molecular weight of 10.80 kDa was mainly composed of Gal, Ara, Man, Glc, Rha and Fuc in a molar ratio of 25.56:24.52:4.58:3.37:2.62:1.00. Structural analysis showed that HEPN-1 had a backbone mainly consisting of 4-β-Galp, 3,6-β-Galp and 3,4,6-β-Galp and branched chains that contained two arabinan (R1 and R2) and two heteropolysaccharide (R3 and R4) side chains. The branching degree of HEPN-1 was 0.52. Within the range of doses (75-300 μg/mL), HEPN-1 increased the enzyme activity of SOD, CAT and GSH-Px and decreased the MDA level in H2O2-induced RAW 264.7 cells in a dose-dependent manner. After 6 weeks of intragastric administration, 300 mg/kg HEPN-1 considerably improved the learning and memory deficits in mice and the antioxidant enzyme system. Moreover, the MDA formation in D-gal-induced aging mice was inhibited, possibly partly via the activation of the PI3K/Akt and Nrf2/HO-1 signalling pathways. Therefore, HEPN-1 could serve as a potential natural antioxidant to prevent aging.

Structural characterization and antioxidant activity of processed polysaccharides PCP-F1 from Polygonatum cyrtonema Hua

Introduction

Polygonatum cyrtonema Hua. (PC) is a traditional Chinese herb with a history of use in both food and medicine. For clinical use, processed PC pieces are most commonly used, while present research has focused on crude PC polysaccharides (PCPs).

Methods

In this study, a new polysaccharide, PCP-F1, with a molecular weight of 37.46 kDa, was separated from four-time processed PCPs by column chromatography and evaluated by antioxidant activity. It was composed of glucose, mannose, galactose, rhamnose, and galacturonic acid with a molar ratio of 3.5: 2.5: 1.3: 1.8: 0.8.

Results and Discussion

The methylation analysis and two-dimensional NMR measurement revealed that the configuration of PCP-F1 contained nine residues in the primary structural unit by the chain of →3)-α-D-Glcp, →2)-α-D-Glcp (6→, →1)-ꞵ-D-Glcp (2→, →2)-α-D-GalAp (3,4→, →1) -ꞵ-D-Manp (3→, →2)-α-D-Glcp (3→, branched for →3)-α-D-Glcp, →2)-ꞵ-D-Galp (4→, →1)-ꞵ-D-Glcp (2→, →2,4)-α-D-Manp (6→, →3)-α-L-Rhap (4→. Radical scavenging assays indicated that PCP-F1 could scavenge radicals with a high scavenging rate, suggesting PCP-F1 possesses good antioxidant activity. The study confirms the importance of processed PC and offers the potential for exploiting it as a functional food.

Structural characterization and antioxidant activity of polysaccharides extracted from Porphyra haitanensis by different methods

This study was to investigate the structure and antioxidant activity of Porphyra haitanensis polysaccharides (PHPs) extracted by different methods, including water extraction (PHP), ultra-high pressure (UHP-PHP), ultrasonic (US-PHP) and microwave assisted water extraction (M-PHP). Compared with water extraction, the total sugar, sulfate and uronic acid contents of PHPs was enhanced by ultra-high pressure, ultrasonic and microwave assisted treatments, especially those of UHP-PHP were increased by 24.35 %, 12.84 % and 27.51 %, respectively (p < 0.05). Meanwhile, these assisted treatments affected the monosaccharide ratio of polysaccharides and significantly reduced the protein content, molecular weight as well as particle size of PHPs (p < 0.05), and resulted in a loose microstructure with more porosity and fragments. PHP, UHP-PHP, US-PHP, and M-PHP all possessed in vitro antioxidant capacity. Among them, UHP-PHP had the strongest oxygen radical absorbance capacity, DPPH and ·OH radicals scavenging capacity, which increased by 48.46 %, 116.24 %, and 14.98 % respectively. Moreover, PHPs particularly UHP-PHP effectively increased the cell viability and reduced ROS levels of H₂O₂ induced RAW264.7 cells (p < 0.05), indicating their good effects against cell oxidative damage. The findings suggested that PHPs with ultra-high pressure assisted treatments has the better potential to develop natural antioxidant.

Preparation, antioxidant and tyrosinase inhibitory activities of chitosan oligosaccharide-hydroxypyridinone conjugates

Two novel chitosan oligosaccharide (COS)-hydroxypyridone (HPO) conjugates were prepared by reacting chitosan oligosaccharide with 2-chloromethyl-5-hydroxypyridone (HPO), which was synthesized by a series of reactions starting from kojic acid. The degree of substitution of COS-HPO2 reached 1.2, with a yield of 74.9%. The structure of the two conjugates (COS-HPO1 and COS-HPO2) was identified by NMR and FT-IR analysis. The two conjugates showed significantly higher free radical (DPPH•, ABTS^+• and •OH) scavenging activity and reducing power than those of COS and HPO (p < 0.05). Both COS-HPO1 and COS-HPO2 possessed significantly stronger tyrosinase inhibitory activity than those of COS, with IC₅₀ values of 0.67 and 0.28 mg/mL for monophenolase, 0.73 and 0.30 mg/mL for diphenolase, respectively. In addition, the conjugates were found to be non-toxic to RAW264.7 macrophages and MRC-5 human lung cells. This work proposes a facile method to enhance the oxidative and tyrosinase inhibitory properties of COS.

Effect of Black Tea Powder on Antioxidant Activity and Gel Characteristics of Silver Carp Fish Balls

The effect of black tea powder on the antioxidant activity and gel characteristics of fish balls from silver carp were investigated after freezing storage for 7 days. The results show that black tea powder with different concentrations of 0.1%, 0.2% and 0.3% (w/w) could significantly increase the antioxidant activity of fish balls (p < 0.05). In particular, at the concentration of 0.3%, the antioxidant activity was the strongest among these samples, where the reducing power, DPPH, ABTS and OH free radical scavenging rate were up to 0.33, 57.93%, 89.24% and 50.64%, respectively. In addition, black tea powder at the level of 0.3% significantly increased the gel strength, hardness and chewiness while greatly reducing the whiteness of the fish balls (p < 0.05). ESEM observation found that the addition of black tea powder could promote the crosslinking of proteins and reduced the pore size of the gel network structure of the fish balls. The results suggest that black tea powder could be used as a natural antioxidant and gel texture enhancer in fish balls, which we found to be much related to the phenolic compounds of black tea powder.

Extraction, Characterization, and Antioxidant Activity of Polysaccharides from Ajwa Seed and Flesh

The date palm has been cultivated in dry and hot areas of the planet for much of human history. In the Kingdom of Saudi Arabia, dates are the main crop used as a source of food. Among several species of date fruits, the Ajwa AL-Madinah date is unique, growing only in Al-Madinah geographical region. The Ajwa date is used in traditional medicine due to its abundant active components and therapeutic properties. This study investigates the structural properties and the antioxidant effects of water-soluble polysaccharides extracted from Ajwa flesh and seed. The polysaccharides were isolated by two techniques including hot water and ultrasonic extraction. After isolation and partial purification, the physicochemical properties of four samples of polysaccharides extracted from flesh and seed were studied by several techniques including FTIR, solid-state NMR, elemental analysis, and mass spectrometry. Several radical scavenging experiments were combined to study the antioxidant activity of the polysaccharide compounds. FTIR and NMR results showed a structure typical of heterogeneous polysaccharides. Mass spectrometry revealed that the polysaccharide samples were composed mainly of mannose, glucose, galactose, xylose, arabinose, galacturonic acid, and fucose. In addition, the physicochemical properties and composition of polysaccharides extracted from flesh and seed were compared. The extracted polysaccharides showed antioxidant activity, with 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, Fe chelating ability, hydroxyl free radical scavenging ability, and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. These results highlight their potential to be a useful nutritional element or supplemental medication.

Isolation and purification of Tartary buckwheat polysaccharides and their effect on gut microbiota

Tartary buckwheat (Fagopyrum tataricum) is rich in polysaccharides that can be utilized by the gut microbiota (GM) and provide several health benefits. However, the mechanisms underlying the action of these polysaccharides remain unclear to date. In this study, Tartary buckwheat polysaccharides (TBP) were purified, and five fractions were obtained. The composition of these fractions was determined using ion chromatography. Different TBP components were investigated regarding their probiotic effect on three species of Bifidobacteria and Lactobacillus rhamnosus. In addition, the effect of TBP on GM and short-chain fatty acids (SCFAs) was evaluated. Results showed that the probiotic effect of TBP fraction was dependent on their composition. The polysaccharides present in different fractions had specific probiotic effects. TBP-1.0, mainly composed of fucose, glucose, and d-galactose, exhibited the strongest proliferation effect on L. rhamnosus, while TBP-W, rich in glucose, d-galactose, and fructose, had the best promoting effect on Bifidobacterium longum and Bifidobacterium adolescentis growth. Furthermore, TBP-0.2, composed of d-galacturonic acid, d-galactose, xylose, and arabinose, exhibited its highest impact on Bifidobacterium breve growth. The composition of GM was significantly altered by adding TBP during fecal fermentation, with an increased relative abundance of Lactococcus, Phascolarctobacterium, Bacteroidetes, and Shigella. Simultaneously, the level of SCFA was also significantly increased by TBP. Our findings indicate that Tartary buckwheat can provide specific dietary polysaccharide sources to modulate and maintain GM diversity. They provide a basis for Tartary buckwheat commercial utilization for GM modulation.

On-line pre-column FRAP-based antioxidant reaction coupled with HPLC-DAD-TOF/MS for rapid screening of natural antioxidants from different parts of Polygonum viviparum†

Polygonum viviparum L. (PV) is a widely used resource plant with high medicinal, feeding and ecological values. Our studies show that PV has strong antioxidant activity. However, up to date, the antioxidant activity and components in other parts were not fully elucidated. In the present study, a new online pre-column ferric ion reducing antioxidant power (FRAP)-based antioxidant reaction coupled with high performance liquid chromatography-diode array detector-quadrupole-time-of-flight mass spectrometry (HPLC-DAD-TOF/MS) was developed for rapid and high-throughput screening of natural antioxidants from three different parts of PV including stems and leaves, fruits and rhizomes. In this procedure, it was assumed that the peak areas of compounds with potential antioxidant activity in HPLC chromatograms would be greatly diminished or vanish after incubating with the FRAP. The online incubation conditions including mixed ratios of sample and FRAP solution and reaction times were firstly optimized with six standards. Then, the repeatability of the screening system was evaluated by analysis of the samples of stems and leaves of PV. As a result, a total of 21 compounds mainly including flavonoids and phenolic acids were screened from the three parts of PV. In conclusion, the present study provided a simple and effective strategy to rapidly screen antioxidants in natural products.

Polygonum viviparum L. (PV) is a widely used resource plant with high medicinal, feeding and ecological values.

Purification, physico-chemical properties and antioxidant activity of polysaccharides from Sargassum fusiforme by hydrogen peroxide/ascorbic acid-assisted extraction

The biological activities of Sargassum fusiforme polysaccharides (SFP) were affected significantly by the extraction method. In order to screen the optimum extraction technology for SFP with high yield and biological activities, six extraction methods, including hot water extraction (HWE), acid-assisted extraction (ACAE), alkali-assisted extraction (ALAE), ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and hydrogen peroxide/ascorbic acid-assisted extraction (HAE) were compared for the preparation of SFP. Based on the yield and in vitro antioxidant activity of the crude polysaccharides obtained by the six extraction methods, HAE was selected for the extraction of SFP. The SFP prepared by HAE (H-SFP) was purified by cellulose DEAE-52 ion-exchange chromatography, obtaining two purified fractions, namely H-SFP3 and H-SFP5. The analyses of their chemical composition, physico-chemical properties and the antioxidant capacity were performed. It was found that the crude SFP and the purified fractions possessed considerable ability to scavenge DPPH, hydroxyl and ABTS•+ radicals. These polysaccharide fractions were also found to effectively reduce the reactive oxygen species (ROS) level and increase the superoxide dismutase (SOD) activity in H2O2-induced oxidative stress RAW264.7 cells. The SFP prepared by the HAE has the potential as a natural non-toxic antioxidant and can be used as an ingredient in functional foods.

Isolation, Purification, and Antioxidant Activities of Polysaccharides from Choerospondias axillaris Leaves

The extraction, characterization and antioxidant activity of polysaccharides from Choerospondias axillaris leaves were investigated in the present study. Two purified polysaccharide fractions, CALP-1 and CALP-2, were isolated from crude Choerospondias axillaris leaf polysaccharides (CALP) by DEAE-52 cellulose chromatography and Sephadex G-100 column chromatography. The characteristics of CAL-1 and CALP-2 were determined by using High-performance Gel Permeation Chromatography (HPGPC), High-Performance Anion-Exchange Chromatography, HPAEC (HPAEC-PAD) and Fourier transform infrared spectroscopy (FTIR). CALP-1 with molecular weight of 11.20 KDa was comprised of Rhamnose, Arabinose, Galactose, Glucose, Xylose, Mannose and galacturonic acid in a molar ratio of 5.16:2.31:5.50:27.18:1.00:0.76:1.07. CAL-2 with molecular weight of 8.03 KDa consisted of Rhamnose, Arabinose, Galactose, Glucose, and galacturonic acid at a ratio of 1.38:3.63:18.84:8.28:1.45. FTIR revealed that CALP-1 and CALP-2 were acidic polysaccharides. The antioxidant activity of crude CALP, CALP-1 and CALP-2 was evaluated in vitro. The fraction CALP-2 was demonstrated to be of polysaccharide nature containing a large percentage of Galactose but no Xylose and Mannose. The antioxidant activity assays showed that CALP-1 and CALP-2 exhibited antioxidant and scavenging activities on hydroxyl and DPPH radicals in vitro. Compared with pure polysaccharide, crude CALP exhibited stronger anti-oxidant activities. These results will provide a better understanding of Choerospondias axillaris leaf polysaccharide and promote the potential applications of Choerospondias axillaris leaf polysaccharide in the pharmacological field and as a natural antioxidant.

Exopolysaccharide from Lactobacillus rhamnosus ZFM231 alleviates DSS-induced colitis in mice by regulating gut microbiota

BACKGROUND

The exopolysaccharides (EPS) produced by Lactobacillus and other probiotics are associated with many benefits, such as immune regulation, antioxidant properties, antitumor effect, and regulation of intestinal microbe homeostasis. In the present study, the modulatory effect of EPS produced by Lactobacillus rhamnosus ZFM231 on the intestinal flora of mice with inflammatory bowel disease induced by dextran sulfate solution was investigated.

RESULTS

Results indicated that weight loss, colonic length, the disease activity index score and colonic tissue damage in mice were significantly improved by EPS treatment. Compared with the model group, in the EPS-treated group, the diversity of and the composition of gut microbiota at both phylum and genus levels were found to recover to the levels of normal group, indicating the effective modulation on gut microbiota by EPS; short-chain fatty acids, including acetic acid, propionic acid and butyric acid produced by intestinal microbial metabolism, increased significantly; the level of anti-inflammatory factor transforning growth factor-β significantly increased and the level of pro-inflammatory factor tumor necrosis factor-α significantly decreased in the colonic cells of EPS-treated mice.

CONCLUSION

It is clear that EPS produced by L. rhamnosus ZFM231 could find application in functional foods with the property of anti-ulcerative colitis. The experimental results provide new insights into the probiotic effect of EPS. © 2022 Society of Chemical Industry.

Antioxidant properties of water-soluble polysaccharides prepared by co-culture fermentation of straw and shrimp shell

Herein, we present a method for producing water-soluble polysaccharides (WSPs) by co-culture fermentation of straw and shrimp shells. The chitin-degrading strain was isolated and genotypically identified as the non-pathogen Photobacterium sp. LYM-1 in this study. Photobacterium sp. LYM-1 and Aureobasidium pullulans 2012 could coexist without antagonism. WSPs concentrations were higher in co-culture fermentations of Photobacterium sp. LYM-1 and A. pullulans 2012 (PsL/AP-WSPs) compared to monocultures (PsL-WSPs and AP-WSPs). FTIR was used to examine the polysaccharide properties of three WSP fractions. The monosaccharide compositions of three WSPs fractions were primarily composed of mannose, ribose, glucosamine, glucose, galactose, and arabinose with varying molecular weights and molar ratios according to HPLC analysis. PsL/AP-WSPs showed better scavenging effects on DPPH, ABTS, and OH free radicals, demonstrating the application potential of PsL/AP-WSPs from straw and shrimp shells. The maximum yield obtained under optimum conditions (fermentation time of 6 days, temperature of 31°C, inoculum concentration of 10% (w/v), and inoculum composition of 2:1) was 5.88 ± 0.40 mg/mL, based on the PsL/AP-WSPs production optimization by orthogonal design. The results suggest that an environmentally friendly approach for WSPs production from agro-food wastes straw and shrimp shells was developed.

Physicochemical characteristics of Ganoderma lucidum oligosaccharide and its regulatory effect on intestinal flora in vitro fermentation

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G. lucidum oligosaccharide was obtained by ultrasonic enzymatic hydrolysis and Sephadex G25.

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GLO was a chain-like homogeneous oligosaccharide with a molecular weight of 1280 Da.

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GLO could not be easily degraded by digestion in the mouth, gastric and small intestine.

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GLO could be utilized and had good regulatory effects on intestinal flora.

This study explored the structure characteristics of an oligosaccharide from Ganoderma lucidum (GLO) and its regulatory functions on intestinal flora fermentation in vitro. GLO was extracted by ultrasonic-assisted enzymatic hydrolysis, and purified with a dextran gel column. Digestion properties and intestinal flora regulation effects of GLO were investigated by both simulation models. Results showed that GLO was a chain-like homogeneous oligosaccharide, composed of → 6)-β-d-Glcp-(1→, →4)-α-d-Glcp-(1→, β-d-Glcp-(1→, α-d-Manp-(1 →. Its structure could not be easily degraded by digestion in the mouth, gastric and small intestine. Accordingly, they can be utilized by the intestinal flora in large intestine. By evaluating the gas, short chain fatty acids, pH and flora abundance in vitro fermentation, it indicated that GLO had good regulatory effects on intestinal flora. Accordingly, GLO might be a potential prebiotic applied in functional foods.