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

Polysaccharides in fruits: Biological activities, structures, and structure-activity relationships and influencing factors-A review

Fruits are a rich source of polysaccharides, and an increasing number of studies have shown that polysaccharides from fruits have a wide range of biological functions. Here, we thoroughly review recent advances in the study of the bioactivities, structures, and structure-activity relationships of fruit polysaccharides, especially highlighting the structure-activity influencing factors such as extraction methods and chemical modifications. Different extraction methods cause differences in the primary structures of polysaccharides, which in turn lead to different polysaccharide biological activities. Differences in the degree of modification, molecular weight, substitution position, and chain conformation caused by chemical modification can all affect the biological activities of fruit polysaccharides. Furthermore, we summarize the applications of fruit polysaccharides in the fields of pharmacy and medicine, foods, cosmetics, and materials. The challenges and perspectives for fruit polysaccharide research are also discussed.

The relationship between polysaccharide structure and its antioxidant activity needs to be systematically elucidated

Polysaccharides have a wide range of applications due to their excellent antioxidant activity. However, the low purity and unclear structure of polysaccharides have led some researchers to be skeptical about the antioxidant activity of polysaccharides. The current reports on the structure-activity relationship of polysaccharides are sporadic, so there is an urgent need to systematically summarize the antioxidant effects of polysaccharides with clear structures and the relationships between the structures to provide a scientific basis for the development and application of polysaccharides. This paper will systematically elucidate the structure-activity relationship of antioxidant polysaccharides, including the molecular weight, monosaccharide composition, glycosidic linkage, degree of branching, advanced conformation and chemical modification. For the first time, the antioxidant activity of polysaccharides is related to their chemical structure through histogram and radar map, and further studies using principal component analysis and cluster analysis. We critically discussed how the source, chemical structure and chemically modified groups of polysaccharides significantly contribute to their antioxidant activity and summarized the current research status and shortcomings of the structure-activity relationship of antioxidant polysaccharides. This review provides a theoretical basis and new perspective for further research on the structure-activity relationship of antioxidant polysaccharides and the development of natural antioxidants.

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.

Bamboo polysaccharides elicit hypocrellin A biosynthesis of a bambusicolous fungus Shiraia sp. S9

Hypocrellin A (HA), a fungal perylenequinone from bambusicolous Shiraia species, is a newly developed photosensitizer for photodynamic therapy in cancer and other infectious diseases. The lower yield of HA is an important bottleneck for its biomedical application. This study is the first report of the enhancement of HA production in mycelium culture of Shiraia sp. S9 by the polysaccharides from its host bamboo which serve as a strong elicitor. A purified bamboo polysaccharide (BPSE) with an average molecular weight of 34.2 kDa was found to be the most effective elicitor to enhance fungal HA production and characterized as a polysaccharide fraction mainly composed of arabinose and galactose (53.7: 36.9). When BPSE was added to the culture at 10 mg/L on day 3, the highest HA production of 422.8 mg/L was achieved on day 8, which was about 4.0-fold of the control. BPSE changed the gene expressions mainly responsible for central carbon metabolism and the cellular oxidative stress. The induced generation of H2O2 and nitric oxide was found to be involved in both the permeabilization of cell membrane and HA biosynthesis, leading to enhancements in both intra- and extracellular HA production. Our results indicated the roles of plant polysaccharides in host-fungal interactions and provided a new elicitation technique to improve fungal perylenequinone production in mycelium cultures.

Extraction, Isolation, Screening, and Preliminary Characterization of Polysaccharides with Anti-Oxidant Activities from Oudemansiella raphanipies

Response surface methodology (RSM) was used to find the optimal extraction process of Oudemansiella raphanipies polysaccharides (ORPs). The results showed that the optimal extraction parameters were an alkali concentration of 0.02 mol/L, a ratio of material to liquid of 1:112.7 g/mL, an extraction temperature of 66.0 °C, and an extraction time of 4.0 h. Under the optimal conditions, the yield of ORPs was raised to 16.2 ± 0.1%. The antioxidant activities of ORPs-I~V were determined and compared, and ORPs-V was further purified by chromatography, with an average molecular weight (Mw) of 18.86 kDa. The structure of ORPs-V was determined by Fourier transform-infrared spectroscopy (FT-IR), monosaccharide analysis, and nuclear magnetic resonance (NMR) spectroscopy. The ORPs-V comprised fucose, rhamnose, arabinose, glucose, galactose, mannose, xylose, fructose, galacturonic acid, and glucuronic acid at a ratio of 1.73:1.20:1.13:2.87:8.71:2.89:1.42:0.81. Compared to other ORPs, ORPs-V showed the strongest antioxidant activities (ABTS radical cation, hydroxyl radical and DPPH scavenging activities, and reducing power), and were able to significantly increase the activities of superoxide dismutase, catalase, lactate dehydrogenase, and glutathione peroxidase. However, they reduced the malondialdehyde content in mice fed a high-fat diet. These results indicate that ORPs-V may be good anti-oxidant agents to be applied in functional foods.

Systematic Comparison of Structural Characterization of Polysaccharides from Ziziphus Jujuba cv. Muzao

To investigate the structural information differences of Ziziphus Jujuba cv. Muzao polysaccharides, ten samples were successfully extracted from aqueous and alkaline solutions, prepared via DEAE-Sepharose Fast Flow through different eluents and Sephacryl S-300 columns, and systematically analyzed. Their characteristics were studied and then compared using chemical testing, high-performance gel permeation chromatography (HPGPC), gas chromatography (GC), methylation analysis, and NMR spectroscopy. The data achieved demonstrated that different jujube polysaccharide fractions possessed different structural characteristics, and most of them belonged to pectic polysaccharides. Overall, the structural information difference of jujube polysaccharides was preliminarily illuminated, which could not only promote the potential application of Z. Jujuba cv. Muzao polysaccharides but also provide an effective way to analyze the structures of polysaccharides from other genera jujube fruit.

Structural characterization of a new high molecular weight polysaccharide from jujube fruit

From Ziziphus Jujuba cv. Muzao fruit, a new polysaccharide (PZMP3-1) with high molecular weight was isolated. Constructional characterization revealed that PZMP3-1 comprized 2.56 rhamnose, 7.70 arabinoses, 3.73 galactose, and 6.73 galactose, and it has a 241 kDa average molecular weight. The principal structural components of PZMP3-1 were 1,2,4 and 1,4-linked GalpA, 1,4-linked Galp, 1,3 and 1,5-linked Araf, and 1-linked Rhap based on methylation and nuclear magnetic resonance spectroscopy (NMR) analyses. X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), atomic force microscopy (AFM), and scanning electron microscopy (SEM) structural analysis of PZMP3-1 revealed a tangled and branching pattern. Overall, these structural results suggested that PZMP3-1 could have unique bioactivities and be widely used in nutritional supplements.

Extraction and characterization of a pectin from sea buckthorn peel

Sea buckthorn peel is the by-product of the sea buckthorn processing, which contains many bioactive compounds. In this paper, sea buckthorn high methoxyl pectin (SBHMP) was obtained, with a yield of 8% and a light-colored. The SBHMP was a high methoxyl with a degree of esterification of 57.75% and uronic acid content of 65.35%. The structural and morphological characterization of SBHMP were analyzed by high-performance liquid chromatography, Fourier-transform infrared spectroscopy, and scanning electron microscopy. Results showed that SBHMP presented a sheet and layered stacked morphological, and was mainly composed of galacturonic acid, arabinose, galactose, rhamnose, and mannose, which indicated that SBHMP mainly consisted of homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) type pectin polysaccharides. In addition, SBHMP also presented significant gel, thickening, and emulsifying properties. The results exhibited that SBHMP could form jelly-like gels under acid and high sucrose conditions, presenting a shear-thinning behavior and increasing apparent viscosity with the enhancement of pectin and sucrose contents. Besides, SBHMP could form oil-in-water emulsions with pectin concentrations of 1.0–3.0%. When the SBHMP concentrations were 2.0 and 3.0%, the emulsions were stable during 7 days of storage. Findings in this paper demonstrated the potential of SBHMP to be a food thickener and emulsifier and support the in-depth utilization of sea buckthorn by-products.

Comparison of characterization and antioxidant activity of different citrus peel pectins

Pectins obtained from citrus peel of different cultivars and growth regions were compared based on physicochemical properties and antioxidant activity in vitro. The physicochemical features were elucidated using Fourier transform infrared (FT-IR), molecular weight distribution, monosaccharide composition, thermal behaviors and flow behaviors. Results showed that the different cultivars and growing areas have significant effects on the properties of citrus peel pectins (CPPs). Citrus peel pectins extracted by acetic acid were highly heterogeneous polysaccharides with broad molecular weight distributions and had high proportions of the RG-I domain. Among the 10 kinds of citrus peel pectins, Shatangju (CPP-6) and Xuecheng (CPP-7) own superior antioxidant biological activity and Dahongpao (CPP-3) and Buzhihuo (CPP-9) had excellent functional properties (thermal stability and viscosity). According to the correlation analysis, molecular weight, galacturonic acid content and degree of methyl-esterification were beneficial to increase the thermal stability and viscosity of citrus peel pectins, while the rhamnose content, rhamnogalacturonan I region and lower molecular weight can improve citrus peel pectins antioxidant activity. Our findings suggest that CPP-6 and CPP-7 may be useful as a potential natural antioxidant in pharmaceutical and cosmetic industries. Meanwhile, CPP-3 has great application potential in high temperature food and CPP-9 can be used as a thickener or stabilizer in the food industry.

Inhibitory effects of a water-soluble jujube polysaccharide against biofilm-forming oral pathogenic bacteria

Oral diseases caused by infectious pathogens raises significant concerns in public health. In the light of side effects of current antibiotics therapy and growing drug resistance of pathogenic bacteria, natural products have become attractive alternatives for antibiotics agents in dental practice. This current study investigated the effects of polysaccharides extracted from Zizyphus jujuba Mill. on three major oral biofilm-forming pathogenic bacteria including caries-inducing Streptococcus mutans, lesions-causing MRSA, and periodontitis-related Porphyromonas gingivalis, as well as general oral microbiota. Our results demonstrated that jujube polysaccharide prepared in this study was mainly composed by galacturonic acid with an average molecular weight 242 kDa, which were further characterized for structural features by FT-IR spectra and NMR spectroscopy analysis. This jujube polysaccharide was shown to exhibit remarkable inhibitory effects against all the tested oral bacterial pathogens through various mechanisms including growth inhibition, biofilm prevention and disruption, intervention of bacterial infection (adhesion and invasion), attenuation of cytotoxicity, modulation of excessive inflammatory response of LPS-stimulated and MRSA-infected macrophages as well as positive regulation of oral microbiota. The present study paves the way to explore jujube polysaccharides for the prevention and treatment of oral infectious diseases. Graphic Abstract.

Effects of Ball Milling Combined With Cellulase Treatment on Physicochemical Properties and in vitro Hypoglycemic Ability of Sea Buckthorn Seed Meal Insoluble Dietary Fiber

To improve the rough texture and hypoglycemic ability of sea buckthorn insoluble dietary fiber (IDF), a novel combined modification method was developed in this study. The IDF was treated with ball milling and cellulase treatment to obtain co-modified insoluble dietary fiber (CIDF). The physicochemical and functional properties of IDF, milled insoluble dietary fiber (MIDF), and CIDF were studied. After treatments, MIDF had smaller particle sizes and a looser structure, and CIDF exhibited a wrinkled surface and sparse porous structure according to scanning electron microscopy (SEM) and X-ray diffraction. Compared to IDF, MIDF and CIDF showed improved water-holding, oil-binding, and swelling capacities, improved by 16.13, 14.29, and 15.38%, and 38.5, 22.2, and 25.0%, for MIDF and CIDF, respectively. The cation exchange ability of modified samples showed improvement as well. Treatments also changed the fluidity of MIDF and CIDF. Due to the smaller particles and increased stacking, the bulk density (BD) and angle of repose of MIDF improved by 33.3% and 4.1° compared to IDF, whereas CIDF had a looser structure and thus decreased by 7.1% and 13.3° with increased fluidity. Moreover, the modification also enhanced the effects of CIDF on glucose adsorption, glucose diffusion inhibition, starch digestion inhibition, starch pasting interference, and α-amylase activity inhibition. In summary, IDF modified by ball milling combined with cellulose treatment could be developed as a functional ingredient for regulating glucose content.

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

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

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.