Polysaccharide Research Articles

Zn2Mo3O8/ZnMo8O10/Mo8O23 nanocomposites; structural properties, synthesis and its emerging application in electrochemical hydrogen storage

Electrode materials based on zinc molybdenum oxides were designed by the saccharide-assisted sol-gel procedure for electrochemical hydrogen storage (EHS). By using different characterization methods to observe the formation of nanostructures, it was possible to determine that carbon texture was present on the nanostructured surfaces of zinc molybdenum oxides. The effects of employing various saccharides (mono, di, and poly saccharides) as carbon sources and fuel on the microstructure, electrochemical behaviors, and purity of synthesized samples were compared. The growth of nanocomposites including Zn2Mo3O8, ZnMo8O10, and Mo8O23 phases was facilitated by the saccharide. A charge-discharge method was used to build three-electrode cells and expose them to galvanostatic cycling. To ascertain the stability of electrode architectures, cycling performance at various rates was carried out. The samples' hydrogen storage capabilities were examined, and the sample generated with glucose showed an optimum capacity about 1017 mAhg−1 after 15th cycle.

Inhibition of denitrification and enhancement of microbial interactions in the AGS system by high concentrations of quinoline

Quinoline represents a highly toxic and structurally stable nitrogen-containing heterocyclic compound in coking wastewater, posing a potential threat to human beings and the ecological environment. In this study, we investigated the impact of gradually elevating quinoline concentration on pollutant removal efficiency, sludge characteristics, microbial community and their interactions in the aerobic granular sludge (AGS) system. The results demonstrated that AGS was capable of effectively degrading quinoline, with a final removal rate of 90 mg/L quinoline reaching 98.54 ± 0.28%. Notably, the denitrification process was significantly impeded in the presence of 90 mg/L quinoline, with the Phase D effluent displaying a notably high NO3--N concentration of 37.09 ± 21.81 mg/L, primarily attributed to the reduced abundance of norank_f_A4b bacteria. As the quinoline concentration increased, the sludge particle size diminished from 3.46 to 2.60 mm, while the settling performance deteriorated significantly, escalating from 31.29 ± 1.63 mL/g to 62.32 ± 2.87 mL/g. Meanwhile, the protein (PN) content in EPS gradually increased (from 19.87 ± 0.88 mg/g MLVSS to 51.22 ± 3.21 mg/g MLVSS), while the polysaccharide (PS) content fluctuated. Quinoline profoundly modified microbial community composition and structure, with deterministic processes dominating community assembly. Network analysis indicated intensified and complex microbial interactions at 90 mg/L quinoline, characterized by significantly higher positive correlations. In addition, rare taxa (RT) dominated the network nodes, with 74 of 93 key species belonging to RT, highlighting their pivotal roles in sustaining system functions and strengthening microbial connections. This study provides new insights into the effects of quinoline on microbial community structure and interactions in AGS system.

Integration of MALDI glycotyping and NMR analysis to uncover an O-antigen substructure from pathogenic Escherichia coli O111

Escherichia coli O111 serotype is a critical pathogenic E. coli strain that causes severe, potentially fatal complications. Despite its reported variation, only one structure of the O-antigen polysaccharide from E. coli O111 has been reported. Here, a substructure of the O-antigen from E. coli O111 was characterized using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and NMR analysis. MALDI glycotyping revealed differing O-antigen repeating unit masses of Δm/z 787 and 828 in the E. coli strains and lipopolysaccharides from the O111 serogroup. This variation was caused by the replacement of the hexose residue with hexosamine in the repeating units, which was further confirmed by LIFT-TOF/TOF analysis. Structural elucidation of the O111 substructure by NMR analysis further demonstrated replacement of the hydroxyl group with an N-acetyl group on the terminal glucose residue of the O-antigen pentasaccharide repeating unit. To our knowledge, this study is the first to provide a detailed structural analysis of a new O-antigen substructure from the E. coli O111 serogroup.

Systematic Characteristics of Fucoidan: Intriguing Features for New Pharmacological Interventions

Fucoidan, a sulfated polysaccharide found primarily in brown algae, is known for exhibiting various biological activities, many of which have been attributed to its sulfate content. However, recent advancements in techniques for analyzing polysaccharide structures have highlighted that not only the sulfate groups but also the composition, molecular weight, and structures of the polysaccharides and their monomers play a crucial role in modulating biological effects. This review comprehensively provides the monosaccharide composition, degree of sulfation, molecular weight distribution, and linkage of glycosidic bonds of fucoidan, focusing on the diversity of its biological activities based on various characteristics. The implications of these findings for future applications and potential therapeutic uses of fucoidan are also discussed.

The effects of different extraction methods on the structure and antioxidant properties of Bletilla striata polysaccharide

Bletilla striata polysaccharide (BSP) is one of the main active ingredients of the traditional Chinese medicine Bletilla striata (Thunb) Richb.f and the extraction method of BSP has a significant impact on its properties. This study investigated the effects of four extraction methods, namely hot water extraction, ultrasonic extraction, enzyme extraction, and microwave extraction, on the structure and antioxidant properties of BSP. Characterization results from FTIR and NMR showed that all four BSP consisted mainly of glucose and mannose, forming α-glycosidic and β-glycosidic linkages to form glucomannan. Hot water extraction had the lowest extraction rate of BSP at 21.78% ± 0.73%. The polysaccharide BSP-H obtained from hot water extraction had the smallest absolute Zeta potential and Grain size, but the largest molecular weight at 204 kDa. It exhibited the best thermal stability and superior antioxidant activity compared to polysaccharides extracted using the other three methods, as evaluated by three different antioxidant assays. Although the antioxidant activity of BSP-V was slightly weaker, it showed a significant improvement compared to the remaining two polysaccharides. These results suggest that hot water extraction is the most suitable method for large-scale application of BSP, preserving its activity effectively, thus facilitating practical production and product development.

Exploring the potential mechanisms of polysaccharides against gastric ulcer: Network pharmacology analysis and molecular docking validation

AbstractGastric ulcer is a common peptic ulcer that affects human health and life quality seriously. As anti‐gastric ulcer drugs usually cause side‐effects, polysaccharides may be the potential alternatives because of better effectiveness and less toxicity. Although the anti‐gastric ulcer activities of polysaccharides have been widely reported, the mechanisms have not yet been well‐disclosed. In this study, network pharmacology analysis was performed to explore the potential mechanisms of polysaccharides against gastric ulcer, and the results were validated by molecular docking. Results indicated that β‐glucan, arabinogalactan, xylan, and arabinan were the key structures, and ABL1, AKT1, androgen receptor, epidermal growth factor receptor, v‐Ha‐ras Harvey rat sarcoma viral oncogene homolog, HSP90AA1, mitogen‐activated protein kinase 8 (MAPK8), MAPK14, NOS2, PIK3R1, RAC1, ras homolog gene family member A, and proto‐oncogene tyrosine‐protein kinase Src were the core targets for polysaccharides in treating gastric ulcer. Polysaccharides have influences on 1958 GO items and 199 KEGG pathways, and their anti‐gastric ulcer activities are related to MAPK, Ras, PI3K‐Akt, vascular endothelial growth factor, prolactin, FoxO and Rap1 signaling pathways, etc. Molecular docking validation showed that the results of network pharmacology analysis were credible, and interactions between polysaccharide structures and core targets were observed. This study contributes to understanding the mechanisms of polysaccharides in treating gastric ulcer and provides references for future activity screening and mechanism research in anti‐gastric ulcer.

Daily glycome and transcriptome profiling reveals polysaccharide structures and correlated glycosyltransferases critical for cotton fiber growth.

Cotton fiber is the most valuable naturally available material for the textile industry and the fiber length and strength are key determinants of its quality. Dynamic changes in the pectin, xyloglucan, xylan, and cellulose polysaccharide epitope content during fiber growth contribute to complex remodeling of fiber cell wall (CW) and quality. Detailed knowledge about polysaccharide compositional and structural alteration in the fiber during fiber elongation and strengthening is important to understand the molecular dynamics of fiber development and improve its quality. Here, large-scale glycome profiling coupled with fiber phenotype and transcriptome profiling was conducted on fiber collected daily covering the most critical window of fiber development. The profiling studies with high temporal resolution allowed us to identify specific polysaccharide epitopes associated with distinct fiber phenotypes that might contribute to fiber quality. This study revealed the critical role of highly branched RG-I pectin epitopes such as β-1,4-linked-galactans, β-1,6-linked-galactans, and arabinogalactans, in addition to earlier reported homogalacturonans and xyloglucans in the formation of cotton fiber middle lamella and contributing to fiber plasticity and elongation. We also propose the essential role of heteroxylans (Xyl-MeGlcA and Xyl-3Ar), as a guiding factor for secondary CW cellulose microfibril arrangement, thus contributing to fiber strength. Correlation analysis of profiles of polysaccharide epitopes from glycome data and expression profiles of glycosyltransferase-encoding genes from transcriptome data identified several key putative glycosyltransferases that are potentially involved in synthesizing the critical polysaccharide epitopes. The findings of this study provide a foundation to identify molecular factors that dictate important fiber traits.

Enhancement of livestock wastewater treatment by a novel wooden-modified biocarrier

Intensive livestock wastewater poses threat to ecosystem. A novel wooden-modified biocarrier was applied in this study to enhance the livestock wastewater treatment in anoxic-aerobic systems. Compared to the ordinary polyethylene (PE) biocarrier, the novel wooden-modified biocarrier improved the biomass owing to its rough surface and porous side wall, and had better nitrogen removal ability. The biomass of wooden-modified biocarrier was 6.3 ± 1.1 and 36.4 ± 17.0 times that of PE biocarrier in anoxic and aerobic condition, respectively. The removal rates of ammonia nitrogen and total nitrogen of this novel biocarrier on specific biofilm's aera eventually stabilized at 0.64 ± 0.10 and 0.94 ± 0.21 g N/m2/d, respectively. Notably, this wooden-modified biocarrier was conducive to increase nitrogen removal by simultaneous nitrification and denitrification to some extent. The biofilm on novel modified biocarrier had higher extracellular polymeric substances (EPS) contents than activated sludge (AS), and the proportions of polysaccharides (PS) in EPS from biocarrier were more than those from AS. Compared to PE biocarrier and AS, the wooden-modified biocarriers enhanced the enrichment of nitrifying and denitrifying bacteria, and promoted the membrane transport and aerobic nitrogen metabolism. This study confirmed the superiority of wooden-modified biocarrier and provided reference for the treatment of high concentration sewage in full-scale project.

Physicochemical properties, structure and biological activity of ginger polysaccharide: Effect of microwave infrared dual-field coupled drying

Ginger was dried by microwave infrared dual-field coupled drying (MIDFCD). The composition, structure, physicochemical properties and biological activity of ginger polysaccharides at various stages of MIDFCD were investigated. The MIDFCD significantly impacted the chemical composition, molecular weight (Mw), microstructure, and physicochemical properties of ginger polysaccharides. However, there were no notable differences in functional group composition. The Mw and chemical composition were notably influenced by microwave-infrared exposure and prolonged drying time. The degradation of polysaccharides due to high temperatures in the later stage resulted in further decreases in Mw and alterations in monosaccharide composition. These changes in chemical composition and Mw affected thermal properties, crystallization properties, particle size, rheological properties, antioxidant capacity, and hypoglycemic activity. These findings suggest that MIDFCD enhances the quality and bioactivity of natural polysaccharides. This study offers theoretical support for MIDFCD processing and the value-added utilization of ginger.

A polysaccharide with a triple helix structure from Agaricus bisporus: Characterization and anti-colon cancer activity

In this study, A polysaccharide WAAP-2 (121 kDa) with a triple-helical structure was isolated and purified from Agaricus bisporus for the first time. The physicochemical properties, structural characteristics and anti-colon cancer activity were preliminarily investigated. The primary structure indicated that WAAP-2 was composed of mannose, glucose and galactose and determined the position of the linkage between monosaccharide residues. The advanced structure revealed that WAAP-2 has a triple helix and tangled chain conformation. In the anti-colon cancer activity investigation, WAAP-2 exerted an apoptosis-inducing effect by causing HT-29 cell cycle arrest in S phase. WAAP-2 promoted HT-29 cell apoptosis by up-regulating the expression of Caspase-3 and Bax proteins while down-regulating the expression of Bcl-2 protein. Besides, WAAP-2 could inhibit the migration and invasion of colorectal cancer cells by inducing E-cadherin expression and inhibiting Vimentin expression to affect epithelial mesenchymal transition. This paper is of importance for the application of WAAP-2, a triple-helical structural polysaccharide from Agaricus bisporus, to low-toxicity anti-colon cancer drugs.

Oriental covalent immobilization of N-glycan binding protein via N-terminal selective modification

Lectin affinity chromatography is one of powerful tools for the study of protein glycosylation. Different lectin proteins can recognize different structures of monosaccharides or oligosaccharide units, allowing for the selective separation of glycopeptides or glycoproteins containing different polysaccharide structures. However, the N-glycans were only partially captured by most of common lectins, reducing the coverage rate of identifying N-glycoconjugates. Recently, it has been reported that the engineering variant of glycan binding protein Fbs1 has a high affinity for innermost Man3GlcNAc2 structure and is able to bind diverse types of N-glycans, which can be suitable for the analysis of protein N-glycosylation. However, efficient immobilization of protein to separation matrix is particularly challenging as it requires the functionality and integrity of the protein to be preserved. Herein, we describe a simple and robust strategy for oriental covalent immobilization of proteins on magnetic nanoparticles by N-terminal selective labeling techniques. We inserted the enterokinase cleavage site to produce the specific N- terminal glycine of protein. Under physiological conditions, the protein was immobilized on the surface of the MNPs by this glycine tag, and the enrichment process could be completed within 30 min. A whole enrichment and purification of glycan and glycopeptides were completed and analyzed by MALDI TOF-MS. The functional materials achieved stable enrichment of glycan structure in different enzyme digestion systems or complex samples, showing excellent anti-interference and applicability.

Atomistic simulations of polysaccharide materials for insights into their crystal structure, nanostructure, and dissolution mechanism

AbstractCrystalline polysaccharides are abundant in nature and can be transformed into highly functional materials. However, the molecular basis for the formation of higher-order structures remains unclear. Computer simulation is an advanced tool for modeling macromolecular structures, and the atomistic simulations provide valuable information on the crystalline polysaccharides. Fiber deformation, crystalline transition, and novel nanostructures of cellulose were characterized through molecular dynamics simulations and density functional theory calculations of models of molecular chain sheets extracted from the crystal structure of the cellulose polymorphs. Extended ensemble molecular dynamics simulations were applied to analyze the artificial crystal structure of non-natural amylose analog polysaccharides, revealing the hexagonal packing of double helices through the self-assembly of molecular chains dispersed in aqueous solution. Dissolution simulations of the cellulose and chitin crystalline fibers revealed that the anions of ionic liquids, with their solvation power, played a key role in the cleavage of intermolecular hydrogen bonds in the crystal structure, whereas the cations contributed to irreversible molecular chain dispersion. The good correlation between the actual solubility of polysaccharides and the predicted number of intermolecular hydrogen bonds prompted the development of a platform that combined simulations and machine learning for high-throughput screening of solvents for cellulose and chitin.

Sulfated polysaccharide extracted from the alga Gracilaria domingensis modified with propionic anhydride negatively modulates acute inflammation and experimental hypernociception

Sulfated polysaccharides (PLSs) from marine algae represent a broad class of compounds with pharmacological interest, due to their therapeutic properties. PLSs have hydrophilic chains containing various chemical groups of several compositions that differ structurally and in their physicochemical and biological effects. However, this hydrophilic nature of PLSs is also responsible for some limitations in the use of these compounds. To overcome these disadvantages, PLSs can be chemically modified by grafting groups that can give the compound a more hydrophobic nature. In the present study, the PLS from Gracilaria domingensis was modified with propionic anhydride (PLS-AP) and underwent complementary characterizations by scanning electron microscopy, X-ray diffraction, infrared spectral analysis and elemental analysis. The reaction with propionic anhydride increased crystallinity and produced a chemically modified polysaccharide with new carbon, hydrogen and sulfur groups. The new characteristic of the compound may have added interesting properties to PLS, such as increased stability, amphiphilic nature and increased sulfate content, which in red marine algae SPSs produce biological activity. Regarding biological properties, PLS-AP (2.5 mg/kg) significantly reduced paw edema induced by carrageenan, histamine, serotonin, bradykinin and prostaglandin E2, as well as improved microscopic tissue damage criteria. The modified compound was also able to significantly decrease neutrophil migration, myeloperoxidase, and malondialdehyde concentrations and preserved glutathione levels in peritoneal fluid during induced peritonitis. Additionally, in antinociceptive tests, PLS-AP reduced the number of contortions induced by acetic acid and the response time to formalin-induced paw licking. Thus, PLS-AP may be a promising substance to treat inflammatory conditions.

Investigation of the polysaccharides synthesis enhancement mechanism from Agaricus bitoquis (Quél.) Sacc Chaidam and its fermentation regulation technology system based on multi-omics technologies

The polysaccharides (PS) of Agaricus bitoquis (Quél.) Sacc. Chaidam (ABSC) had attracted the attention of researchers due to their strong anti hypoxia, antioxidant, and anti fatigue activities. Therefore, this article focuses on studying the regulatory channels of exogenous additives-Lycium ruthenicum Murr. Anthocyanin (LRA) to delay fungus cell aging and promote the incremental synthesis of PS from ABSC, and optimizing the regulation system for pilot fermentation experiments. The joint analysis of Ultra High Performance Liquid Chromatography-Quadrupole-Time of Flight Mass Spectrometry (UHPLC-Q-TOFMS) and RNA sequencing (RNA-seq) database elucidates that at the molecular level, the crude extract of LRA inhibits the Telecommunications Association (TCA) cycle, transferring carbon metabolism to the synthesis of polysaccharide precursors (UDP-glucose, UDP-galactose, etc.), promoting the synthesis of PS, promoting the formation of key antioxidant substances (including flavonoids such as quercetin and alginate), improving cell membrane fluidity (saturated fatty acid to unsaturated conversion) and enhancing the degradation of toxic substances (oxidized glutathione), thereby promoting the anti-aging activity and PS synthesis ability of mycelial cells; LRA-adding could enhance the activity in the pilot fermentation of ABSC, which make the mycelia biomass, EPS and IPS production were significantly increased (89.04 %, 65.46 % and 37.64 % respectively) compared with the untreatment control. Based on the optimal fermentation system of PS synthesized in mycelium by adding LRA, Logistic, Gauss, and Asymptotic kinetic equations were used to describe the cell growth, product synthesis and regulatory substrate consumption from ABSC. The correlation coefficients of three models were all above 0.95, indicating a good fit between the experimental values and predicted value, this indicated ABSC fermentation kinetics model could better simulate the actual production process and provide theoretical data for the industrial production of polysaccharides. The results demonstrated that the present proposed LRA intensification approach could be useful to boost up the fermentation of ABSC, which possibly applied to yield increase and fermentation product acquisition of macrofungi.

Structural characterization of red yeast rice-derived polysaccharide and its promotion of lipid metabolism and gut function in high-fat diet-induced mice

This study explored the structure and biological activities of a novel polysaccharide, PRY1–1, isolated from red yeast rice (RYR) through solid-state fermentation and biotransformation by Monascus purpureus. The structure of PRY1–1 was characterized by Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and other analytical techniques, revealing distinct differences from previously identified mycelial and extracellular polysaccharides. Functional assessments were performed on high-fat diet (HFD)-induced mice to evaluate the impact of PRY1–1 on lipid metabolism and gut function. The results demonstrated that PRY1–1 effectively ameliorated HFD-induced lipid metabolism disorders in the liver and epididymal white adipose tissue (eWAT) by regulating the levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), leptin, adiponectin. Additionally, PRY1–1 protected gut function by enhancing gut barrier integrity, modulating gut microbiota composition, and regulating gut metabolite levels. This study offers new insights into the mechanisms by which RYR polysaccharides influence lipid metabolism, highlighting the potential of PRY1–1 as a functional component with significant health benefits.

Comparative analysis of polysaccharide and cell wall structure in Aspergillus nidulans and Aspergillus fumigatus by solid-state NMR

Invasive aspergillosis poses a significant threat to immunocompromised patients, leading to high mortality rates associated with these infections. Targeting the biosynthesis of cell wall carbohydrates is a promising strategy for antifungal drug development and will be advanced by a molecular-level understanding of the native structures of polysaccharides within their cellular context. Solid-state NMR spectroscopy has recently provided detailed insights into the cell wall organization of Aspergillus fumigatus, but genetic and biochemical evidence highlights species-specific differences among Aspergillus species. In this study, we employed a combination of 13C, 15N, and 1H-detection solid-state NMR, supplemented by Dynamic Nuclear Polarization (DNP), to compare the structural organization of cell wall polymers and their assembly in the cell walls of A. fumigatus and A. nidulans, both of which are key model organisms and human pathogens. The two species exhibited a similar rigid core architecture, consisting of chitin, α-glucan, and β-glucan, which contributed to comparable cell wall properties, including polymer dynamics, water retention, and supramolecular organization. However, differences were observed in the chitin, galactosaminogalactan, protein, and lipid content, as well as in the dynamics of galactomannan and the structure of the glucan matrix.

Extraction technology determines the properties of bamboo shoots dietary fiber concentrate and its application in chicken mince gels: Systematic analysis

This study investigated how physical, chemical, and enzymatic extraction technologies affected the physicochemical properties of bamboo shoot insoluble dietary fiber (IDF). Additionally, the effects of IDF extracted by these techniques on the gel properties, water retention, microstructure, and digestibility of chicken mince gels were evaluated. Results showed that IDFs extracted by physical (P-IDF), chemical (C-IDF), and enzymatic (E-IDF) exhibited a typical cellulose polysaccharide structure and strong water and oil retention capabilities, with the highest values reaching 14.18 g/g and 6.74 g/g, respectively. Compared to P-IDF, C-IDF and E-IDF displayed a rougher porous structure and stronger adsorption capacities for glucose (409.91 mg/g and 604.95 mg/g), cholesterol (54.46 mg/g and 64.06 mg/g), sodium cholate, and nitrite. The addition of IDF improved the water retention, water stability, texture, and rheological properties of chicken mince gels, and had no negative effect on the digestion of chicken mince proteins. On the one hand, the hydrophilic groups exposed in IDF absorb water and fill the gel networks, reducing the formation of water channels in the gel and improving water stability. Furthermore, the hydrophilic groups on the glucose unit that makes up the IDF interacts with the proteins through the hydrogen bond and the transformation of protein β-structure to α-structure, promoting the formation of gel network structure and improving gel texture and rheological properties. E-IDF and C-IDF showed better overall gel performances, but E-IDF had better dry matter digestibility, protein digestibility, and gastrointestinal digestive effects. Therefore, IDF prepared by enzymatic hydrolysis is more suitable for chicken mince processing.

Effects of inoculation with Bacillus arenosi on physical and biochemical properties of soil, and surface runoff and erosion in degraded forestlands of Northern Iran

A viable practice to improve key properties of soil, and reduce runoff generation and erosion may be inoculation with selected bacteria. However, no previous studies have evaluated whether the direct inoculation of Bacillus arenosi K64 (hereafter simply indicated as B. arenosi) to soil impacts the main physical and biochemical properties of soil as well as the runoff and erosion rates. This study has measured the infiltration rate (IR), tensile strength (TS), mean weight diameter (MWD), polysaccharides (PS) and important enzymes of soil (β-glucosidase, N-acetyl glucosaminidase, phosphatase and arylsulphatase) in degraded forest soils (Northern Iran) inoculated with B. arenosi in comparison to untreated soils (control). Moreover, the runoff coefficient and soil loss have been measured in plots with soil sampled in those sites under natural rainfalls. IR, TS and MWD increased by 65 % to 160 % in treated soils compared to the control. PS and enzymes were significantly higher (by 20 % to 200 %) after soil inoculation. A noticeable decrease in both surface runoff and soil loss (both by 45 %) in the inoculated soils resulted from those changes. High correlations between the hydrological response of soil on one side, and the measured physical and biochemical variables on the other side were observed. A derivative variable calculated by the Principal Component Analysis can be considered as a meaningful parameter to estimate the changes in soil properties and response due to inoculation with bacteria. Agglomerative Hierarchical Cluster Analysis clearly discriminated the treated from the untreated soils. This study has demonstrated that soil inoculation with B. arenosi plays a significant role in reducing runoff generation and soil erosion under the experimental conditions, thanks to the general improvement in physical and biochemical properties of soil.

A Review of Applications, Forms, Extraction, and Dissolution of Chitin

Background: Polymeric organic particles made by organisms or natural biopolymers, are considered as greener materials, more environmentally friendly and durable. Because of its exceptional structural properties, wide abundant, lack of toxicity, biocompatibility, simplicity of alteration and promised potentials, chitin is a sustainable material. It is composed of β(1,4)-linked N-acetyl-glucosamine units and represents the most abundant structural polysaccharide of invertebrates, including such marine phyla as sponges, corals, annelid worms, mollusks, and arthropods. This biopolymer is mostly found in the skeletal structures of invertebrates, and plays a crucial role in their rigidity, stiffness, and other mechanical properties. Chitin is recognized as one of the universal templates in biomineralization, with respect to both biocalcification and biosilicification. Conclusion: This review is concerned with chitin. For a set of uses, chitin with its derivatives are receiving more and more attention. The popularity of this plentiful biopolymer has skyrocketed in recent years. Studies on the use of chitin show that these biopolymers have a lot of potential for managing wounds, getting rid of toxic metals, farming, bone regenerative engineering, etc.

1H-NMR, HPSEC-RID, and HPAEC-PAD Characterization of Polysaccharides Extracted by Hydrodynamic Cavitation from Apple and Pomegranate By-Products for Their Valorization: A Focus on Pectin

Several chemical analytical methods were applied to characterize the chemical structure of polysaccharides extracted from discarded apples and pomegranate peels using hydrodynamic cavitation methods in a circular economy perspective. In particular, the purity of the polysaccharides and the degrees of acetylation and methylation were evaluated by proton Nuclear Magnetic Resonance (1H-NMR) analysis; simple sugars and galacturonic acid were analyzed simultaneously by High-Performance Anion Exchange Chromatography—Pulsed Amperometric Detector (HPAEC-PAD); the molecular weight of the extracted polysaccharides was determined by High-Performance Size Exclusion Chromatography-Refractive Index Detector (HPSEC-RID). The results showed a negligible presence of co-precipitated proteins/tannins, easily removed by dialysis, as well as other co-precipitated molecules such as monosaccharides and organic acids. Polysaccharides from apples consisted mainly of pectic material with a prevalence of homogalacturonans. Polysaccharides from pomegranate peels showed greater compositional variability with significant amounts of arabinose and galactose, a lower content of pectin, and the presence of rhamnogalacturonans I. Both polysaccharides were highly methylated and differed in the degree of acetylation, which could lead to different properties. Polysaccharides from apples presented two main molecular weights (>805 kDa and 348–805 kDa, respectively), while those from pomegranate peel showed a major fraction at 348 kDa and minor fractions < 23 kDa. In conclusion, the research tools proposed by this study have allowed defining the macrostructure of polysaccharides in a quick and efficient way to valorize these food by-products.