Polysaccharides from banana (Musa spp.) blossoms: Isolation, identification and anti-glycation effects

Structural characterization of two novel heteropolysaccharides from Catharanthus roseus and the evaluation of their immunological activities

Catharanthus roseus, a plant with significant therapeutic value in Chinese folk medicine, contain numerous secondary metabolites. However, the primary metabolites, specifically polysaccharides which might play an important role in immunotherapy, have received limited attention. In the present study, two novel polysaccharides, designated as CRPS-1 and CRPS-2, were isolated from C. roseus. The structures of CRPS-1 and CRPS-2 were characterized using a combination of HPSEC, HPLC, IR, GC-MS, 1D NMR and 2D NMR. Both CRPS-1 and CRPS-2 were identified as homogeneous heteropolysaccharides. Additionally, the weight-average molecular weight of CRPS-2 was lower than that of CRPS-1. The backbone of CRPS-1 was composed of 1,3-α-L-Araf, 1,5-α-L-Araf, 1,3,5-α-L-Araf, 1,3,4-α-L-Rhap, 1,3-α-D-Galp, 1,3,4-α-D-Galp, 1,4-β-D-Manp, and side chains comprised of T-α-L-Araf, T-β-D-Manp, and β-D-Glcp-(1 → 3)-α-D-Galp-(1 → 3) -α-L-Rhap-(1→. CRPS-2 mainly consisted of 1,3-α-D-Galp, 1,3,4-α-D-Galp, 1,6-β-D-Manp, 1,5-α-L-Araf, 1,3,5-α-L-Araf, 1,3-α-L-Rhap and 1,3,4-α-L-Fucp with complex branching structures. Furthermore, CRPS-2 could significantly enhance proliferation and phagocytosis, as well as the secretion of cytokines in RAW264.7 cells. It demonstrated potent immunoregulatory activity by activating the MAPK/Akt/NF-κB signaling pathways. In summary, the utilization of galactose-enriched and low-molecular-weight polysaccharides exhibits great potential in the advancement of innovative functional foods that may provide health benefits.

Preparation, characterization and in vitro antioxidant activities of a homogeneous polysaccharide from Prunella vulgaris

Prunella vulgaris is a medicinal and edible homologous plant, commonly used as a folk medicine to treat diseases. The Prunella vulgaris polysaccharides (PVPs) are reported with the antioxidant activity. This work was designed to isolate, characterize, and test the antioxidant activity of purified PVPs from P. vulgaris. A new homogeneous polysaccharide (PVP-1) was prepared by the DEAE column from PVPs, and diverse chromatography/spectroscopy and chemical methods were simultaneously employed to characterize the fine structure of PVP-1. The result showed PVP-1 had a triple helix structure, and the repeating structural unit of PVP-1 was composed of →6)-β-D-Galp-(1→6)-β-D-Galp-(3,1→6)-β-D-Galp-(1→6)-β-D-Galp-(1→ as the main chain, together with →6)-β-D-Galp-(1,3→1)-α-D-Araf-(5→1)-β-D-Galp-(4→1)-α-D-Galp-(2→ and →6)-β-D-Galp-(1,3→1)-α-D-GlcAp-(4→1)-α-D-Glcp-(4→1)-α-D-Galp as the branch chains. The main monosaccharides of PVP-1 were galactose (Gal, 41.25 %), galactose-OMe (Gal-OMe, 27.73 %), arabinose (Ara, 10.63 %), mannose (Man, 9.86 %), glucose (Glc, 3.88 %), glucuronic acid (GlcA, 2.86 %), ribose (Rib, 1.79 %), and xylose (Xyl, 1.76 %). In addition, the scanning electron microscopy (SEM) displayed that the surface of PVP-1 was rough and porous. PVP-1 gave the scavenging rates of the DPPH, ABTS, and hydroxyl radical lower than vitamin C at the same concentration, with the highest scavenging rate of DPPH radical at 82.71 % ± 4.19 % (5 mg/mL).

Recent Trends in Advanced Glycation End Products in Foods: Formation, Toxicity, and Innovative Strategies for Extraction, Detection, and Inhibition

Advanced glycation end products (AGEs) are produced in foods during their thermal treatment through routes like the Maillard reaction. They have been linked to various health issues such as diabetes, neurodegenerative disorders, and cardiovascular diseases. There are multiple pathways through which AGEs can form in foods and the body. Therefore, this review work aims to explore multiple formation pathways of AGEs to gain insights into their generation mechanisms. Furthermore, this review work has analyzed the recent trends in the detection and inhibition of AGEs in food matrices. It can be highlighted, based on the surveyed literature, that UHPLC-Orbitrap-Q-Exactive-MS and UPLC-ESI-MS/MS can produce highly sensitive results with a low limit of detection levels for AGEs in food matrices. Moreover, various works on inhibitory agents like spices, herbs, fruits, vegetables, hydrocolloids, plasma-activated water, and probiotic bacteria were assessed for their capacity to suppress the formation of AGEs in food products and simulation models. Overall, it is essential to decrease the occurrence of AGEs in food products, and future scope might include studying the interaction of macromolecular components in food products to minimize the production of AGEs without sacrificing the organoleptic qualities of processed foods.

Effects of Ultrasound-Assisted Treatment on Physicochemical Properties and Biological Activities of Polysaccharides from Sargassum

The aim of this study was to investigate the effect of ultrasonic treatment on the physicochemical properties and bioactivities of polysaccharides from Sargassum samples (SPs) extracted with different solvents. The alkali-assisted extraction of polysaccharide (SPA), acid-assisted extraction of polysaccharides from (SPB), and hot water extraction of polysaccharides (SPCs) were perofrmed on Sargassum. Ultrasonic treatment was performed with the SPA, SPB, and SPC in turn, and named USPA, USPB, and UPSC, respectively. The results showed that SPs mainly consisted of mannose, glucose, xylose, rhamnose, galactose, fucose, glucuronic acid, mannuronic acid and guluronic acid. The molecular weight of SPA (434.590 kDa) was the lowest under different solvent extractions, and the molecular weights of SPA, SPB, and SPC were reduced after sonication. SPA had a high carbohydrate content of (52.59 ± 5.16)%, and SPC possessed a high sulfate content of (3.90 ± 0.33)%. After ultrasonic treatment, the biological activities of SPs were significantly increased. The α-glucosidase inhibition assay reflected that the IC50 values of the ultrasonic treatment SPs were significantly reduced, and USPA showed the best activity, with an IC50 of (0.058 ± 0.05) mg/mL. Antioxidant assays demonstrated that USPC exhibited greater DPPH- and ABTS-scavenging capacity. In the anti-glycosylation assay, SPs after sonication demonstrated excellent inhibition of glycosylation products and protein oxidation products, with USPA showing the highest inhibition rate. In conclusion, the biological activities of SPs were enhanced after ultrasonic treatment. This study provides a theoretical reference for their use in food and medicines.

Research progress on extraction techniques, structure-activity relationship, and biological functional mechanism of berry polysaccharides: A review

In recent years, polysaccharides extracted from berries have received great attention due to their various bioactivities. However, the preparation and application of berry polysaccharides have been greatly limited due to the lack of efficient extraction techniques, unclear structure-activity relationships, and ambiguous functional mechanisms. This review discusses the technological progress in solvent extraction, assisted extraction, critical extraction, and combination extraction. The structure-activity relationship and functional mechanism (antioxidation, hypoglycemic, immunoregulation etc.) of berry polysaccharides are reviewed. After systematic exploration, we believe that industrial production is more suitable for using efficient and low-cost extraction methods, such as ultrasonic assisted extraction and microwave assisted extraction. And some of the bioactivities (antioxidant activity, hypoglycemic activity, etc.) of berry polysaccharides are closely related to their structure (molecular weight, monosaccharide composition, branching structure, etc.). Besides, berry polysaccharides exhibit bioactivities by regulating enzyme activity, cellular metabolism, gene expression, and other pathways to exert their effects on the body. These findings indicate the potential of berry polysaccharides as functional foods and drugs. This paper will contribute to the preparation, bioactivity research, and application of berry polysaccharides.

Arabinoxylan from pearl millet bran: Optimized extraction, structural characterization, and its bioactivities

Arabinoxylan (AX) from cereals and millets have garnered attention due to the myriad of their bioactivities. Pearl millet (Pennisetum glaucum) bran, an underexplored milling by-product was used to extract AX (PMAX) by optimized alkali-assisted extraction using Response Surface Methodology and Central Composite Design, achieving a yield of 15.96 ± 0.39 % (w/w) under optimal conditions (0.57 M NaOH, 1:17 g/mL solid-to-liquid ratio, 60 °C, 4 h). Structural analysis revealed that PMAX was primarily composed of arabinose, xylose, glucose, galactose, and mannose (molar ratio 45.1:36.1:10.4:7.1:1.8), with a highly substituted (1 → 4)-linked β-D-xylopyranose backbone and a molecular weight of 794.88 kDa. PMAX displayed a significant reducing power of 0.617, metal chelating activity of 51.72 %, and DPPH, and ABTS radical scavenging activities (64.43 and 75.4 %, respectively at 5 mg/mL). It also demonstrated anti-glycation effects by inhibiting fructosamine (52.5 %), protein carbonyl (53.6 %), and total advanced glycation end products (77.0 %) formation, and reduced protein oxidation products such as dityrosine (84.7 %), kynurenine (80.2 %), and N'-formyl-kynurenine (50.0 %) at 5 mg/mL. PMAX induced the growth of Lactobacillus spp. in vitro and modulate gut microbiota in male Wistar rats by increasing Bacteroidetes and decreasing Firmicutes. These results provide a basis for further research on pearl millet arabinoxylan and its possible nutraceutical application.

Structural analysis, anti-inflammatory activity of the main water-soluble acidic polysaccharides (AGBP-A3) from Panax quinquefolius L berry

Background

Panax quinquefolius L, widely recognized for its valuable contributions to medicine, has aroused considerable attention globally. Different from the extensive research has been dedicated to the root of P. quinquefolius, its berry has received relatively scant focus. Given its promising medicinal properties, this study was focused on the structural characterizations and anti-inflammatory potential of acidic polysaccharides from the P. quinquefolius berry.

Materials and methods

P. quinquefolius berry was extracted with hot water, precipitated by alcohol, separated by DEAE-52-cellulose column to give a series of fractions. One of these fractions was further purified via Sephadex G-200 column to give three fractions. Then, the main fraction named as AGBP-A3 was characterized by methylation analysis, NMR spectroscopy, etc. Its anti-inflammatory activity was assessed by RAW 264.7 cell model, zebrafish model and molecular docking.

Results

The main chain comprised of α-L-Rhap, α-D-GalAp and β-D-Galp, while the branch consisted mainly of α-L-Araf, β-D-Glcp, α-D-GalAp, β-D-Galp. The RAW264.7 cell assay results showed that the inhibition rates against IL-6 and IL-1β secretion at the concentration of 625 ng/mL were 24.83 %, 11.84 %, while the inhibition rate against IL-10 secretion was 70.17 % at the concentration of 312 ng/mL. In the zebrafish assay, the migrating neutrophils were significantly reduced in number, and their migration to inflammatory tissues was inhibited. Molecular docking predictions correlated well with the results of the anti-inflammatory assay.

Conclusion

The present study demonstrated the structure of acidic polysaccharides of P. quinquefolius berry and their effect on inflammation, providing a reference for screening anti-inflammatory drugs.

A comparison study on polysaccharides extracted from banana flower using different methods: Physicochemical characterization, and antioxidant and antihyperglycemic activities

This work investigated and compared the physicochemical characteristics, and antioxidant and antihyperglycemic properties in vitro of polysaccharides from a single banana flower variety (BFPs) extracted by different methods. BFPs extracted using hot water (HWE), acidic (CAE), alkaline (AAE), enzymatic (EAE), ultrasonic (UAE) and hot water-alkaline (HAE) methods showed different chemical composition, monosaccharide composition, molecular weight, chain conformation and surface morphology, but similar infrared spectra characteristic, main glycosidic residues, crystalline internal and thermal stability, suggesting that six methods have diverse impacts on the degradation of BFPs without changing the main structure. Then, among six BFPs, the stronger antioxidant activity in vitro was found in BFP extracted by HAE, which was attributed to its maximum uronic acid content (21.67 %) and phenolic content (0.73 %), and moderate molecular weight (158.48 kDa). The highest arabinose and guluronic acid contents (18.59 % and 1.31 % in molar ratios, respectively) and the lowest uronic acid content (14.30 %) in BFP extracted by HWE contributed to its better α-glucosidase inhibitory activity in vitro (66.55 %). The data offered theoretical evidence for choosing suitable extraction methods to acquire BFPs with targeted biological activities for applications, in which HAE and HWE could serve as beneficial methods for preparing antioxidant BFP and antihyperglycemic BFP, respectively.

Phosphorylation Modification, Structural Characterization, Antioxidant and DNA Protection Capacities of Polysaccharides from Asarum Sieboldii Miq

Polysaccharide from Asarum sieboldii Miq (ASP) was extracted and five phosphorylation polysaccharides with different degree of substitution were obtained, namely ASPP1, ASPP2, ASPP3, ASPP4, and ASPP5 (ASPPs). The physical and chemical structure and biological activities were studied. The results suggested that the carbohydrate and protein content were reduced while uronic acid was increased after phosphorylation modification. The molecular weight of ASPPs was significantly lower than that of ASP. ASPPs were acidic heteropolysaccharides mainly composed of galacturonic acid, galactose, glucose, fructose, and arabinose. The UV-vis spectrum indicated that the polysaccharides did not contain nucleic acid or protein after modification. The Fourier transform infrared spectrum demonstrated that ASPPs contained characteristic absorption peaks of P=O and P-O-C near 1270 and 980 cm-1 . ASPPs presented a triple helix conformation, but it was not presented in ASP. The scanning electron microscopy analysis showed that the surface topography and particle structure of ASP were different after modification. Compared with ASP, ASPPs enhanced the activity to scavenge DPPH and ABTS free radicals and possessed more protective ability to DNA oxidation caused by OH⋅, GS⋅, and AAPH free radicals. These results suggest that chemical modification is beneficial for the exploitation and utilization of natural polysaccharides.

Preparation of low molecular weight polysaccharides from Tremella fuciformis by ultrasonic-assisted H2O2-Vc method: Structural characteristics, in vivo antioxidant activity and stress resistance

Different methods were used to degrade Tremella fuciformis polysaccharides (TFP) and prepare low molecular weight polysaccharides of Tremella fuciformis (TFLP) to improve their bioavailability. It was found that the TFLP prepared by ultrasonic-assisted H2O2-Vc method showed the highest level of antioxidant activity and stress resistance in C. elegans. The structural characteristics, in vivo antioxidant and stress resistance of TFLP-1 were evaluated after isolation and purification of TFLP, it was found that TFLP-1 was an acid polysaccharide with a molecular weight of 75770 Da, which mainly composed of mannose. Meanwhile, it could regulate the antioxidant activity and stress resistance in C. elegans by upregulating the transcription of fat-5, fat-7, acs-2, glp-1, hsf-1, hsp-1, mtl-1, nhr-49, skn-1 and sod-3 mRNA. The improvement effects were closely related to the significant regulation of galactose metabolism, alpha linolenic acid metabolism, and pantothenate and CoA biosynthesis metabolic pathways. These results provided insights into the high value application of Tremella fuciformis in the food industry and the development of antioxidant related functional foods.

Structural, rheological and functional properties of ultrasonic treated xanthan gums

Xanthan gum can improve the freeze-thaw stability of frozen foods. However, the high viscosity and long hydration time of xanthan gum limits its application. In this study, ultrasound was employed to reduce the viscosity of xanthan gum, and the effect of ultrasound on its physicochemical, structural, and rheological properties was investigated using High-performance size-exclusion chromatography (HPSEC), ion chromatograph, methylation analysis, 1H NMR, rheometer, etc.. The application of ultrasonic-treated xanthan gum was evaluated in frozen dough bread. Results showed that the molecular weight of xanthan gum was reduced significantly by ultrasonication (from 3.0 × 107 Da to 1.4 × 106 Da), and the monosaccharide compositions and linkage patterns of sugar residues were altered. Results revealed that ultrasonication treatment mainly broke the molecular backbone at a lower intensity, then mainly broke the side chains with increasing intensity, which significantly reduced the apparent viscosity and viscoelastic properties of xanthan gum. The results of specific volume and hardness showed that the bread containing low molecular weight xanthan gum was of better quality. Overall, this work offers a theoretical foundation for broadening the application of xanthan gum and improving its performance in frozen dough.