Structural characterization and anti-proliferative activities of partially degraded polysaccharides from peach gum

A novel polysaccharide from Citrus aurantium L.: Structural properties and antitumor activities in vitro and invivo

A novel cold-water-soluble polysaccharide (CALP-1-1) was isolated and purified from Citrus aurantium L. Besides determining its in vitro and in vivo anti-tumor activities, its structure was characterised. The results reveal that CALP-1-1 mainly consists of Rha, Ara, Gal, GalA, and GlcA (molar ratio, 1:14.56:19.27:2.27:1.29) with three main linkages. Its average molecular weight was 2.04 × 103 kDa. Moreover, the triple helix structure of CALP-1-1 was proved by Congo-red and circular dichroism (CD). The in vitro experimental results demonstrate that CALP-1-1 significantly inhibited the proliferation of HepG2 cells with typical apoptotic features by inducing cell cycle arrest in the S phase. Furthermore, in vivo anti-tumor experiments suggest that CALP-1-1 could induce H22 solid tumor cells apoptosis and exhibit anti-tumor effects by protecting immune organs and intensifying the secretion of immune cells (macrophages, lymphocytes and NK cells). In conclusion, CALP-1-1 might be a promising component for cancer treatment.

Structural characteristics of peach gum arabinogalactan and its mechanism of inhibitory effect on leukemia cells

The polysaccharide PGP with a molecular weight of 5.48 × 106 Da was isolated from Peach gum using alkaline electrolyte water as a solvent. HPLC, FT-IR, UV-vis, GC-MS, and NMR results indicated that PGP consisted of arabinose, xylose, mannose, glucuronic acid, and galactose with a molar ratio of 1.00:0.23:0.08:0.04:0.83, and was an AG-II arabinogalactan with β-D-(1 → 6)-Galp backbone and O-3 and O-4 branched chains. The advanced structure showed that PGP was an irregular lamellar structure of polysaccharide molecules with a specialized structure formed by the combination of crystalline and amorphous forms. Cell experiments showed that PGP treatment significantly induced apoptosis in leukemia cells, resulting in a decrease in mitochondrial membrane potential and an increase in ROS production. Western blotting assay showed that PGP could inhibit the proliferation of K562 and HL60 cells through the combination of Fas/FasL-mediated exogenous death receptor pathway and endogenous mitochondrial pathway, blocking the cell cycle at G1 phase and causing apoptosis. This study provided new ideas for the conformational relationship of Peach gum polysaccharides and confirmed the potential application of PGP in the development of anti-leukemia drugs.

Zein/peach gum composite antibacterial absorbent pads loaded with thirteen-spices essential oil: Preparation, characterization and its application in pork preservation

Thirteen-spices essential oil (TSEO) is an extract derived from a blend of thirteen traditional Chinese spices "Shisan Xiang". It has garnered significant interest for its application in meat preservation, owing to its distinctive flavor profile and potent antibacterial properties. In this study, we developed monolayer and multilayer biocomposite films composed of zein (ZN) and peach gum (PG), integrated with TSEO, utilizing a continuous casting method, to address plastic pollution and food safety by developing innovative, biodegradable packaging from food byproducts. These films were designed to function as antibacterial absorbent pads (TSEO-ZN/PG) aimed at extending the shelf life of chilled pork. The self-assembly behavior of TSEO-doped ZN within a continuous PG matrix is influenced by the casting layers. The TSEO-ZN/PG film exhibited a heterogeneous cross-sectional structure characterized by cavities that entrapped TSEO droplets and ZN microspheres. This morphology influenced swelling (2609.43 %), water vapor permeability (1.63 ± 0.23), and TSEO retention-release behavior. By adjusting the ZN/PG ratio in the intermediate layer, the films demonstrated enhanced resistance to breakage (8.969 ± 0.744 %) and thermal stability (285.00 °C). Furthermore, these films significantly impeded the proliferation of Staphylococcus aureus (53.13 %) and Escherichia coli (72.64 %). An extended shelf life of 2 days was observed in the preservation test of chilled pork characterized by significantly lower TVC, pH, and color changes compared to the control. The TSEO-ZN/PG absorbent pads developed in this study exhibited antimicrobial and adsorption properties that potentially enhance the storage quality of chilled pork.

Simulated Gastrointestinal Digestion and In Vitro Fecal Fermentation of Purified Pyracantha fortuneana (Maxim.) Li Fruit Pectin

Pyracantha fortuneana, an underutilized wild plant, has been found to have a high nutritional value. This study used simulated digestion and fecal fermentation models to investigate the digestive properties of the purified acidic pectin polysaccharide of Pyracantha fortuneana and its impact on the gut microbiota and metabolites. Pyracantha fortuneana polysaccharide (PFP) is mainly composed of rhamnose (Rha), galacturonic acid (GalA), glucose (Glc), galactose (Gal), and arabinose (Ara), with a molecular weight (Mw) of 851.25 kDa. Following simulated digestion, the Mw of PFP remained consistent. The reduced sugar content showed minimal change, suggesting that PFP exhibits resistance to gastrointestinal digestion and can effectively reach the colon. Following fecal fermentation, the molecular weight, monosaccharide, and carbohydrate contents of PFP decreased, while the short-chain fatty acid content increased. This suggests that PFP is susceptible to degradation by microorganisms and can be metabolized into acetic acid and n-butyric acid, contributing to the regulation of intestinal health. Meanwhile, PFP promotes the reproduction of beneficial bacteria such as Bacteroides, Dialister, and Dysgonomonas, inhibits the growth of harmful bacteria like Proteus, and generates metabolites such as thiamine, leonuriside A, oxoadipic acid, S-hydroxymethylglutathione, and isonicotinic acid, which exert beneficial effects on human health. These results indicate that PFP has great potential in regulating the gut microbiota and generating beneficial metabolites to promote intestinal functional health and can be used as a prebiotic to prevent diseases by improving intestinal health.

Structure characterization and protective effect against UVB irradiation of polysaccharides isolated from the peach gums

Peach gum polysaccharides (PGPs) have attracted increasing attention for their potential biological properties and application in the food and cosmetic industries. This study aimed to investigate the structural characteristics and anti-photoaging activity of PGPs. The purification of PGPs resulted in two polysaccharides (PGP-1 and PGP-2). Results showed that PGP-1 and PGP-2 had a molecular weight of 4515.31 kDa and 15.02 kDa, respectively. Their structures were elucidated via GC-MS and NMR spectrum and proved to be an arabinogalactan. In addition, PGP-1 and PGP-2 do not have mucous-membrane irritation on chicken embryo CAM. Mainly, PGP-1 (1.5 mg/mL) significantly inhibits the expressions of MMPs (MMP-1, MMP-3, and MMP-12) in the UVB-induced human immortalized epidermal cells (HaCaT), indicating that PGP-1 could reduce collagen loss caused by UVB irradiation. PGP-1 also can inhibit cell senescence and apoptosis by reducing p16, p21, and p53 protein expressions. Based on these findings, our data suggested that PGPs may be used to develop effective natural anti-photoaging ingredients to promote skin health.

Application of a Polysaccharide Purification Instrument-The Preparation and Characterization of Soybean Soluble Polysaccharide

Polysaccharides in plants and microorganisms have important application value, and their purification and preparation is a prerequisite for in-depth research. However, there is currently a lack of dedicated separation and purification instruments for polysaccharide substances. In our previous work, a polysaccharide purification instrument (PSPI) was designed using post-column split-flow and post-column derivatization schemes and developed. In this study, the PSPI was applied to separation and preparation of the soybean soluble polysaccharides (SSPSs) and obtained the purified SSPS (SSPS-P). The total carbohydrate content in SSPS-P reached 97.2%, compared to 81.7% in SSPS, and the carbohydrate recovery rate was 86.5%. The composition and structure of SSPS-P have been assessed by HPLC, FT-IR, and NMR. SSPS-P was a polysaccharide with a molecular weight (Mw) of 354 KDa, composed of D-glc, D-gal and L-ara with the molar ratio of 0.02:2.08:1.01. The structure of SSPS-P was mainly →4)-β-galp-(1→unit. The α-L-araf residues were also detected in the form of T-α-L-araf-(1→2)-α-L-araf-(1→, →3)-α-L-araf-(1→ and →3,5)-α-araf-(1→. PSPI could be applied for rapid and precise separation and preparation of polysaccharides.

Purification, structural characterization and immunomodulatory activity of a polysaccharide isolated from Scutellaria baicalensis stem-leaf

In our research, a novel polysaccharide (named SSP-3a) with uniform molecular weight was extracted from Scutellaria baicalensis stem-leaf. The structural analysis revealed that SSP-3a was an acidic polysaccharide with a heavy average molecular weight of 1.83 × 105 Da. By HPLC, the primary constituents of SSP-3a were mannose (11.60 %), glucuronic acid (42.99 %), glucose (23.43 %), and xylose (22.04 %). According to FT-IR and 1H NMR analysis, it was confirmed to be a β-configuration pyranose with a CO stretching vibrational peak. The immunomodulation results also showed that SSP-3a not only significantly promoted RAW264.7 cell proliferation and phagocytosis, but also stimulated the release of NO and cytokines. Furthermore, mechanistic studies suggested that SSP-3a had the ability to trigger MAPKs and NF-κB immunological signaling pathways via TLR4 receptors. The findings suggested that SSP-3a might be a beneficial active component for the food and pharmaceutical industries.

Comparison of structural characteristics and anti-tumor activity of two alkali extracted peach gum arabinogalactan

Two polysaccharides, PGP-90 and PGP-100 (molecular weights of 7.59 × 102 kDa and 10.48 × 102 kDa, respectively), were isolated from Peach gum using alkaline electrolyte water as an extraction solution. Structural characterization showed that PGP-90 and PGP-100 are AG-II arabinogalactans with β-D-(1 → 6)-Galp as the main chain and 1 → 3 Araf and 1 → 5 Araf branched chains at O-3 and O-4 positions. Animal experiments showed that PGP-90 and PGP-100 significantly improved immune function, enhance the proliferative capacity of lymphocytes and phagocytosis of peritoneal macrophages, and regulated the ratio of lymphocyte subpopulations in S180 tumor-bearing mice. Meanwhile, PGP-90 and PGP-100 promoted the secretion of cytokines (TNF-α, IFN-γ, and IL-2) by activated macrophages and blocked apoptosis at the G1 phase, resulting in tumor suppression rates of 40.80 % and 46.30 % (100 mg/kg), respectively, with PGP-100 demonstrating stronger in vivo anti-tumor activity. The above experimental results indicate that Peach gum polysaccharides have the potential to be functional anti-tumor agents.

Hierarchical porous structure design and water activation in hydrogels containing hyperbranched peach gum polysaccharide for efficient solar water evaporation

Solar-powered interfacial evaporation is a developing and sustainable technique increasingly utilized in desalination and wastewater purification. This technology involves the creation of cellulose nanofiber (CNF)/polylactic acid (PLA) composite aerogels through the Pickering emulsion approach. Self-floating aero-hydrogel (E-VGP) with a hierarchical porous structure was formed on a viscous mixture containing polyvinyl alcohol (PVA), peach gum polysaccharide (PGP), and polypyrrole (PPy) via an in-situ polymerization process. Furthermore, by modifying the hydrolysis time of PGP with a hyperbranched polyhydroxy structure, VGP hybrid hydrogels of varying microscopic molecular sizes were produced. Additionally, solar vapor generators (SVG) with diverse macroscopic structures were fabricated using molds. The V8G4-12hP0.2 hybrid hydrogel, synthesized using PGP hydrolyzed for 12 h, exhibited an evaporation enthalpy of water at 1204 J g-1. This capacity effectively activates water and enables low enthalpy evaporation. Conversely, the macrostructural design allows the cylindrical rod raised sundial-shaped structure of SVG3 to possess an expanded evaporation area, minimize energy loss, and even harness additional energy from its nonradiative side. Consequently, this micro-macrostructural design enables SVG3 to attain an exceptionally high evaporation rate of 3.13 kg m-2 h-1 under 1 Sun exposure. Moreover, SVG3 demonstrates robust water purification abilities, suggesting significant potential for application in both desalination and industrial wastewater treatment.

Understanding the two-stage degradation process of peach gum polysaccharide within ultrasonic field

This study investigated the dynamic degradation process of peach gum polysaccharide (PGPS) within ultrasonic field. The results show that the molecular weight, intrinsic viscosity, and polydispersity of PGPS were rapidly reduced within the initial 30 min and then gradually decreased. The solubility of PGPS was drastically improved from 3.0% to 40.0-42.0% (w/w) after 120 min. The conformation of PGPS changed from an extended chain to a flexible random coil within initial time of ultrasound, and gradually tended to be compact spheres. The apparent viscosity of PGPS significantly decreased after 30 min, and PGPS solution exhibited a near-Newtonian fluid behavior. It is possible that these above changes are a result of random cleavage of the decrosslinking and the backbone of PGPS, resulting in the preservation of its primary structure. The results will provide a fundamental basis for orientation design and process control of ultrasonic degradation of PGPS.

The impact of ultrasonic-assisted extraction on the in vitro hypoglycemic activity of peach gum polysaccharide in relation to its conformational conversion

BACKGROUND

Peach gum (PG) is an exudate of the peach tree (Prunus persica of the Rosaceae family), which consists primarily of polysaccharides with a large molecular weight and branching structure. Consequently, PG can only swell in water and does not dissolve easily, which severely limits its application. Current conventional extraction methods for PG polysaccharide (PGPS) are time consuming and inefficient. This study investigated the impact of ultrasonic-assisted extraction (UAE) on PGPS structure and conformation, and their relationship to hypoglycemic activity in vitro.

RESULTS

In comparison with conventional aqueous extraction, UAE enhanced PGPS yielded from 28.07-32.83% to 80.37-84.90% (w/w) in 2 h. It drastically decreased the molecular size and conformational parameters of PGPS, including weight-average molecular weight (Mw), number-average molecular weight (Mn), z-average radius of gyration (Rg), hydrodynamic radius (Rh) and instrinsic viscosity ([η]) values. Peach gum polysaccharide conformation converted extended molecules to flexible random coil chains or compact spheres with no obvious primary structure alteration. Furthermore, UAE altered the flow behavior of PGPS solution from that of a non-Newtonian fluid to that of a Newtonian fluid. As a result, PGPS treated with UAE displayed weaker inhibitory activity than untreated PGPS, mostly because UAE weakens the binding strength of PGPS to α-glucosidase. However, this negative effect of UAE on PGPS activity was compensated by the increased solubility of polysaccharide. This enabled PGPS to achieve a wider range of doses.

CONCLUSION

Ultrasonic-assisted extraction is capable of degrading PGPS efficiently while preserving its primary structure, resulting in a Newtonian fluid solution. The degraded PGPS conformations displayed a consistent correlation with their inhibitory effect on α-glucosidase activity. © 2024 Society of Chemical Industry.

Extensive Analysis of Mulberry (Morus rubra L.) Polysaccharides with Different Maturities by Using Two-Step Extraction and LC/QqQ-MS

A primary challenge of polysaccharide analysis is the need for comprehensive extraction and characterization methods. In this study, mulberry polysaccharides at different maturities were fully extracted through a two-step process involving ethylenediaminetetraacetic acid (EDTA) and sodium hydroxide (NaOH), and their structures were determined by a combination analysis of monosaccharides and glycosidic linkages based on liquid chromatography triple quadrupole mass spectrometry (LC/QqQ-MS). The results indicate mulberry polysaccharides mainly contain highly branched pectic polysaccharides, (1,3,6)-linked glucan, xylan, and xyloglucan, but the content of different portions varies at different maturity stages. HG decreases from 19.12 and 19.14% (green mulberry) to 9.80 and 6.08% (red mulberry) but increases to 17.83 and 11.83% as mulberry transitioned from red to black. In contrast, the contents of glucan showed opposite trends. When mulberry turns red to black, the RG-I arabinan chains decrease from 47.75 and 28.86% to 13.16 and 12.72%, while the galactan side chains increase from 1.18 and 1.91 to 8.3 and 6.49%, xylan and xyloglucan show an increase in content. Overall, the two-step extraction combined with LC/QqQ-MS provides a new strategy for extensive analysis of complex plant polysaccharides.

Structural characterization of an inulin neoseries-type fructan from Ophiopogonis Radix and the therapeutic effect on liver fibrosis in vivo

Ophiopogonis Radix is a well-known Traditional Chinese Medicine and functional food that is rich in polysaccharides and has fructan as a characteristic component. In this study, an inulin neoseries-type fructan designated as OJP-W2 was obtained and characterized from Ophiopogonis Radix, and its potential therapeutic effect on liver fibrosis in vivo were investigated. Structural studies revealed that OJP-W2 had a molecular weight of 5.76 kDa and was composed of glucose and fructose with a molar ratio of 1.00:30.87. Further analysis revealed OJP-W2 has a predominantly lineal (1-2)-linked β-D-fructosyl units linked to the glucose moiety of the sucrose molecule with (2-6)-linked β-D-fructosyl side chains. Pharmacological studies revealed that OJP-W2 exerted a marked hepatoprotective effect against liver fibrosis, the mechanism of action was involved in regulating collagen deposition (α-SMA, COL1A1 and liver Hyp contents) and TGF-β/Smads signaling pathway, alleviating liver inflammation (IL-1β, IL-6, CCL5 and F4/80) and MAPK signaling pathway, and inhibiting hepatic apoptosis (Bax, Bcl-2, ATF4 and Caspase 3). These data provide evidence for expanding Ophiopogonis Radix-acquired fructan types and advancing our understanding of the specific role of inulin neoseries-type fructan in liver fibrosis therapy.

Preparation and characterization of peach gum/chitosan polyelectrolyte composite films with dual cross-linking networks for antibacterial packaging

Peach gum (PG) is a valuable polymeric feedstock for developing eco-friendly, bio-safe, and functional materials. However, PG has limited use in food packaging due to its inferior mechanical and antibacterial properties. To overcome these limitations, we created a dual cross-linked network by introducing chitosan (CS) and glycerol to the PG matrix. Our research discovered that incorporating CS into the PG matrix significantly improved its Young's modulus, from 277.62 to 925.89 MPa, and its tensile strength from 5.96 to 39.94 MPa. Furthermore, the inclusion of glycerol greatly increased the elongation. These enhancements were attributed to the ionic and hydrogen-bonding interactions between the two biopolymers. Additionally, the composite films exhibited strong antibacterial effects, reducing the total number of colonies by 99.2 % and 99.9 % against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), respectively. The incorporation of CS resulted in more amorphous films, enhancing their stiffness, flexibility, and barrier properties. To assess the practical application of PG/CS composite films, we conducted a comparative analysis between non-packaged strawberries and strawberries packaged with these films. The results demonstrated that the composite polyelectrolyte film extended the shelf life of strawberries better than the non-packaged fruits.

Hepatoprotective effects of peach gum polysaccharides against alcoholic liver injury: moderation of oxidative stress and promotion of lipid metabolism

Natural polysaccharides extracted from plants have received increasing attention due to their rich bioactivity. In our study, peach gum polysaccharides (PGPs) were extracted by water extraction-alcohol precipitation method. PGPs are typical pyranose polysaccharides with a mean molecular weight of 3.68 × 106 g/mol. The antioxidant activity and hepatoprotective capacity of PGPs were studied. In vitro, assays showed that PGPs scavenged DPPH, OH, and O2- in a dose-dependent manner. PGPs exhibited antioxidative properties against alcohol-induced HL7702 cells, as evidenced by the normalization of MDA, SOD, ROS, and GSH levels. To further elucidate the hepatoprotective mechanism of PGPs, we carried out in vivo experiments in male mice. PGPs exerted hepatoprotective effects in alcohol liver disease (ALD) mice by exerting antioxidant effects, decreasing the inflammatory response and modulating lipid metabolism. In addition, metabolomic analysis indicated that PGPs mainly regulate D-glutamine and D-glutamate metabolism, alanine, aspartate and glutamate metabolism, and arginine biosynthesis to promote hepatic metabolism and maintain body functions. Overall, this study revealed that the hepatoprotective mechanism of PGPs against ALD might be associated with the regulation of oxidative stress and lipid metabolism.

Molecular weight-dependent antitumor effects of prunes-derived type I arabinogalactan on human and murine triple wild-type melanomas

The regulation of metastasis-related cellular aspects of two structurally similar AGIs from prunes tea infusion, with different molar masses, was studied in vitro against Triple Wild-Type metastatic melanoma (TWM) from murine and human origin. The higher molar mass AGI (AGI-78KDa) induced TWMs cells death and, in murine cell line, it decreased some metastasis-related cellular processes: invasiveness capacity, cell-extracellular matrix interaction, and colonies sizes. The lower molar mass AGI (AGI-12KDa) did not induce cell death but decreased TWMs proliferation rate and, in murine cell line, it decreased cell adhesion and colonies sizes. Both AGIs alter the clonogenic capacity of human cell line. In spite to understand why we saw so many differences between AGIs effects on murine and human cell lines we performed in silico analysis that demonstrated differential gene expression profiles between them. Complementary network topological predictions suggested that AGIs can modulate multiple pathways in a specie-dependent manner, which explain differential results obtained in vitro between cell lines. Our results pointed to therapeutic potential of AGIs from prunes tea against TWMs and showed that molecular weight of AGIs may influence their antitumor effects.

Exploring apple pectic polysaccharides: Extraction, characterization, and biological activities - A comprehensive review

Apple (Malus domestica) is a popular and ancient fruit of the Myrtaceae family. Apple fruit is well-known for its great nutritional and phytochemical content consisted of beneficial compounds such as polyphenols, polysaccharides, sterols, and organic acids. Polysaccharides extracted from different parts of the apple fruit, including the peel, pomace, or the whole fruit, have been extensively studied. Researchers have investigated the structural characteristics of these polysaccharides, such as molecular weight, type of monosaccharide unit, type of linkage and its position and arrangement. Besides this, functional properties and physicochemical and of apple polysaccharides have also been studied, along with the effects of extraction procedures, storage, and processing on cell wall polysaccharides. Various extraction techniques, including hot water extraction, enzymatic extraction, and solvent-assisted extraction, have been studied. From the findings, it was evident that apple polysaccharides are mainly composed of (1 → 3), (1 → 6): α-β-glycosidic linkage. Moreover, the apple polysaccharides were demonstrated to exhibit antioxidant, hepatoprotective, anti-cancer, hypoilipidemic, and enzyme inhibitory properties in vitro and in vivo. The potential applications of apple polysaccharides in the food, cosmetic, pharmaceutical, nutraceutical industries have also been explored in the present review. Overall, the research on apple polysaccharides highlights their significant potential as a source of biologically active compounds with various health benefits and practical applications.

Effect of peach gum polysaccharide on the rheological and 3D printing properties of gelatin-based functional gummy candy

Excellent 3D printing materials must exhibit good extrudability and supportability, but these two characteristics are often contradictory. In this study, peach gum polysaccharide (PGP) was added to gelatin to prepare a 3D-printed functional gummy candy encapsulating curcumin. Rheology tests indicated that adding PGP could effectively improve the apparent viscosity and thermal stability and consequently improve the 3D printability and supportability of the products. When PGP addition was 6 %, the printing accuracy was higher than 90 %. Texture and microstructure analysis further revealed that PGP addition promoting a dense gel structure formed and the water holding capacity and supportability of gel materials were enhanced. Furthermore, the in vitro gastrointestinal digestion tests showed that after 6 h of simulated gastrointestinal fluid digestion, the retention rate of curcumin was nearly 80 %. The above results indicated that the composite gel of PGP and gelatin is a good 3D printing base material for nutrient delivery.

Exploring the partial degradation of polysaccharides: Structure, mechanism, bioactivities, and perspectives

Polysaccharides are promising biomolecules with lowtoxicity and diverse bioactivities in food processing and clinical drug development. However, an essential prerequisite for their applications is the fine structure characterization. Due to the complexity of polysaccharide structure, partial degradation is a powerful tool for fine structure analysis, which can effectively provide valid information on the structure of backbone and branching glycosidic fragments of complex polysaccharides. This review aims to conclude current methods of partial degradation employed for polysaccharide structural characterization, discuss the molecular mechanisms, and describe the molecular structure and solution properties of degraded polysaccharides. In addition, the effects of polysaccharide degradation on the conformational relationships between the molecular structure and bioactivities, such as antioxidant, antitumor, and immunomodulatory activities, are also discussed. Finally, we summarize the prospects and current challenges for the partial degradation of polysaccharides. This review will be of great value for the scientific elucidation of polysaccharide fine structures and potential applications.

A polysaccharide NAP-3 from Naematelia aurantialba: Structural characterization and adjunctive hypoglycemic activity

A novel polysaccharide (NAP-3) was isolated and purified from Naematelia aurantialba after water extraction. The structure of NAP-3, which was determined by FT-IR, HPLC, GC-MS, and NMR, indicated that NAP-3 was a homogeneous polysaccharide with the molecular weight of 428 kDa, mainly consisted of β-1, 3-D-Manp, β-1, 2, 3-D-Manp, β-D-Xylp, β-1, 4-D-Glcp, β-1, 4-D-Rhap in a molar ratio of 6.49: 1.11: 2.4: 0.13: 0.83. In vitro α-glucosidase and α-amylase inhibitory assay showed that NAP-3 had a low IC₅₀ value, which exhibited similar enzyme inhibitory activity as acarbose. NAP-3 was evaluated as an adjuvant with metformin for antidiabetic therapy in HFD/STZ-induced diabetic mice and insulin resistance HepG2 cells. The combination of NAP-3 and metformin in diabetic mice exhibited significant hypoglycemic activity, reducing body weight, serum insulin levels, glucose tolerance, insulin tolerance, and increasing antioxidant levels compared to metformin alone. The combination of NAP-3 and metformin improved oxidative stress by increasing ROS clearance, thereby enhancing glucose uptake in HepG2 cells. This study provided new data for the study of Naematelia aurantialba polysaccharides and offers a new adjuvant therapy for the treatment of diabetes.

A method for gel grade determination and application evaluation of two citrus pectins

Citrus paradisi Macf. cv. Changshanhuyou and Citrus paradisi Macf. cv. Star Ruby are two emerging processed citrus fruits. The processing produces lots of peel wastes rich in pectin. While more attentions were paid on pectin's functional properties, the quality about commercial application like gel grade was little investigated. In this study, we established a method for gel grade determination based on texture analyzer, the new method is economical and can be used on a large scale in the laboratory. The commercial application related qualities of two citrus pectins were also studied in detail. The results showed that the yields of Changshanhuyou and Star Ruby pectins (CHP and SRP) were 20.23 % and 18.33 %, respectively. The indexes of CHP and SRP mostly were in line with the commodity standards, except the dry weight loss. The gel grades of CHP and SRP determined by the new method were 109.9 and 96.8, respectively. The CHP aqueous solution exhibited higher apparent viscosity and better performance in stabilizing acidified milk drink (AMD) compared with commercial pectin. From the view of commercial application related qualities and functional properties, CHP could be a good potential commercial pectin.

The incorporation of peach gum polysaccharide into soy protein based microparticles improves probiotic bacterial survival during simulated gastrointestinal digestion and storage

The objective of this research was to investigate the in vitro gastrointestinal digestion and storage properties of Lactobacillus plantarum 550 encapsulated in soy protein isolate (SPI) and peach gum polysaccharide (PG) through spray drying. High survival rates (>8.1 Log CFU/g) were obtained for all encapsulation formulas containing PG. Combination of SPI and PG showed positive effects on both gastric resistance and storage stability of cells. Among the formulas tested, sample of SPI:PG = 3:1 showed the highest survival (7.88 ± 0.12 Log CFU/g), corresponding to the strongest electrostatic interaction between SPI and PG. With PG content increasing, the storage stability of probiotic was also enhanced, as PG could reduce the moisture content within microcapsules as well as scavenge free radicals generated during storage. In conclusion, the current study demonstrates that SPI combined with PG may provide effective protection to cells not only during spray drying, but also during storage and gastrointestinal digestion.

Molecular Characterization and Bioactivities of a Novel Polysaccharide from Phyllostachys pracecox Bamboo Shoot Residues

Dietary carbohydrates are unexploited in the by-products of economically valuable Phyllostachys pracecox bamboo shoots. A residue-derived polysaccharide (PBSR1) was aqueously extracted from the processing waste of this bamboo shoot species. Its primary structure and advanced conformation were elucidated by a combined analysis of spectroscopy, chromatography, 2D nuclear magnetic resonance, laser light scattering and atomic microscopy. The results indicated PBSR1 was a triple-helix galactan consisting of →6)-β-D-Galp and →3)-β-D-Galp in linear with an 863 KD molecular weight (M_w). The relationship between the radius of gyration (Rg) and intrinsic viscosity ([η]) on M_w were established as R_g = 1.95 × 10^-2M_w^0.52±0.03 (nm) and [η] = 9.04 × 10^-1M_w^0.56±0.02 (mL/g) for PBSR1 in saline solution at 25 °C, which indicated it adopted a triple-helix chain shape with a height of 1.60 ± 0.12 nm supported by a red shift of λ_max in Congo red analysis. The thermodynamic test (TG) displayed that it had excellent thermal stability for the food industry. Further, those unique structure features furnish PBSR1 on antioxidation with EC₅₀ of 0.65 mg/mL on DPPH· and an ORAC value of 329.46 ± 12.1 μmol TE/g. It also possessed pronounced immunostimulation by up-regulating pro-inflammatory signals including NO, IL-6, TNF-α and IL-1β in murine cells. Our studies provided substantial data for the high-valued application of residues and a better understanding of the structure-function relationship of polysaccharide.

Lemon gum: Non-toxic arabinogalactan isolated from Citrus × latifolia with antiproliferative property against human prostate adenocarcinoma cells

Lemon gum (LG) obtained from Citrus × latifolia in Brazil was isolated and characterized. In addition, gum biocompatibility was evaluated in vitro and in vivo by Galleria mellonella and mice model. The cytotoxicity against tumor cells was also evaluated. The ratio of arabinose:galactose: rhamnose:4-OMe-glucuronic acid was 1:0.65:0.06:0.15. Small traces of protein were detected, emphasizing the isolate purity. Molar mass was 8.08 × 10⁵ g/mol, with three different degradation events. LG showed antiproliferative activity against human prostate adenocarcinoma cancer cells, with percentage superior to 50 %. In vivo toxicity models demonstrated that LG is biocompatible polymer, with little difference in the parameters compared to control group. These results demonstrate advance in the study of LG composition and toxicity, indicating a potential for several biomedical and biotechnological future applications.

Extraction, purification, structural characterization, and hepatoprotective effect of the polysaccharide from purple sweet potato

BACKGROUND

Purple sweet potato Ipomoea batatas (L.) has long been used as a medicine and a food. It contains various bioactive substances such as polysaccharides, anthocyanins, and flavonoids. Purple sweet potato polysaccharides are known to have anti-oxidant, anti-tumor, and immunomodulatory functions. Nevertheless, studies on the structural characterization of purple sweet potato polysaccharides and their ability to prevent non-alcoholic fatty liver disease (NAFLD) have rarely been reported.

RESULTS

A novel polysaccharide (PSPP-A) was extracted and isolated from purple sweet potato, and its structural characteristics and preventive effects on NAFLD were investigated. The results indicated that PSPP-A was composed of l-rhamnose, d-arabinose, d-galactose, d-glucose, and d-glucuronic acid with molar ratios of 1.89:8.45:1.95:1.13:1. Its molecular weight was 2.63 × 10³  kDa. Methylation and nuclear magnetic resonance (NMR) analysis indicated that the glycosidic linkages were →3)-α-L-Araf-(1→, α-L-Araf-(1→, →2,4)-α-L-Rhap-(1→, 4-O-Me-β-D-GlcAp-(1→, →4)-α-D-Glcp-(1→, →4)-β-D-Galp-(1→, and →6)-β-D-Galp-(1→. Scanning electron microscopy (SEM) indicated that the structure of PSPP-A was irregular. Subsequently, the protective effect of PSPP-A on NAFLD was investigated. The results indicated that bodyweight, liver index, and triglyceride (TG), total cholesterol (TC), aspartate transaminase (AST), and alanine transaminase (ALT) content were significantly reduced by intervention of purple sweet potato polysaccharide-A (PSPP-A) compared with the - high-fat diet group. Liver histopathological analysis indicated that PSPP-A attenuated irregular hepatocyte patterns and excessive lipid vacuoles.

CONCLUSIONS

The novel polysaccharide, PSPP-A, mainly contains arabinose, which has certain preventive effects on NAFLD. This study provides a theoretical basis for further elucidating the hepatoprotective effect of purple sweet potatoes as a functional food. © 2022 Society of Chemical Industry.

Structural characterization of peach gum polysaccharide and its effects on the regulation of DSS-induced acute colitis

The structure and the effect of polysaccharide from peach gum (DPG2) on ameliorating DSS-induced acute colitis in mice were investigated in the present study. The results showed that DPG2 was identified as an AG II arabinogalactan with the backbone of β-D-(1 → 6)-galactan, which consisted of mannose, glucuronic acid, galactose, xylose and arabinose with a molar ratio of 4.64:1.02:2.61:39.82:3.89:48.02. Moreover, DPG2 behaved as a flexible chain conformation with a coil-like structure with a molecular weight (M_w) of 5.21 × 10⁵ g/mol. Furthermore, the worm-like chain model parameters for DPG2 were estimated as follows: M_L = 379 nm^-1, q = 0.74 nm and d = 0.82 nm. The results of the animal assay showed that the intake of DPG2 not only effectively improved the phenotypes of DSS-induced colitis in mice, but also significantly improved the oxidative stress status of mice, such as regulating NO content and T-SOD and MPO levels and repairing oxidative damage to the colonic mucosa. Moreover, DPG2 improved the inflammation of DSS-induced colitis in mice by inhibiting the secretion of the proinflammatory cytokines TNF-α, IFN-γ, IL-1β, IL-6 and IL-17. Therefore, these results suggested that peach gum polysaccharide showed protective effects against colitis, and has great potential for the application of functional components in the food industry.

The Antiproliferative Activity of a Mixture of Peptide and Oligosaccharide Extracts Obtained from Defatted Rapeseed Meal on Breast Cancer Cells and Human Fibroblasts

Oligosaccharide and peptide extracts obtained separately from defatted rapeseed meal (DRM) have shown antiproliferative activities on the MCF-7 breast cancer cell line. However, oligosaccharide extracts were not tested on human fibroblasts and have low yields. The objective of the present study was to combine two antiproliferative extracts, the peptides and oligosaccharides, that were obtained independently with commercial enzymes from DRM, allowing improvement of the mass yield and antiproliferative activity. The DRM was solubilized in an alkaline medium to obtain an insoluble meal residue (IMR) and an alkaline extract (RAE). To produce the oligosaccharide extract from IMR, three enzymes and different enzyme/substrate ratios were used. The oligosaccharide extract (molecular weight <30 kDa) recovered with the commercial enzyme. Endogalacturonase showed an 80% inhibition on MCF-7 cells at 20 mg/mL. The combination of this oligosaccharide extract with the peptide extract (obtained with Alkalase 2.4 L from a RAE at 10 mg/mL) inhibited 84.3% of MCF-7 cells proliferation at a concentration of 20 mg/mL, exhibiting no cytotoxic effects on fibroblasts. The mass yield of the extract pool was 27.07% (based on initial DRM). It can be concluded that a mixture of antiproliferative extracts was produced from DRM which was selective against MCF-7 cells.

Effect of Yeast Fermentation on the Physicochemical Properties and Bioactivities of Polysaccharides of Dendrobium officinale

Fermentation is an effective method for enhancing the biological activity of polysaccharides, but research on its effect on Dendrobium officinal polysaccharides is rare. In this study, the effects of mono-fermentation (Saccharomyces cerevisiae FBKL2.8022, Sc; Wickerhamomyces anomalous FBKL2.8023, Wa) and co-fermentation (Sc+Wa) on the physicochemical properties and bioactivity of Dendrobium officinal polysaccharides were investigated. Meanwhile, the polysaccharide (DOP) obtained from Dendrobium officinale was used as a control. Four homogeneous polysaccharides were obtained by isolation and purification and named DOSCP, DOWAP, DOSWP, and DOP. The results showed that DOSCP, DOWAP, DOSWP, and DOP consisted of mannose and glucose with ratios of 3.31:1, 5.56:1, 2.40:1, and 3.29:1, respectively. The molecular weights (Mws) of the four polysaccharides were 25.73 kDa, 15.01 kDa, 17.67 kDa, and 1268.21 kDa. The antioxidant activity of DOSCP, DOWAP, and DOSWP was better than that of DOP. Additionally, all four polysaccharides were able to reduce the inflammatory response of LPS-induced RAW 264.7 macrophages in the mice without a significant difference. Yeast fermentation significantly reduced the molecular weight and improved the antioxidant activity of Dendrobium officinale polysaccharides, indicating a potential way to improve its antioxidant activity.

In Vitro Digestion and Fecal Fermentation of Peach Gum Polysaccharides with Different Molecular Weights and Their Impacts on Gut Microbiota

In the present study, we investigated the in vitro digestion and fermentation characteristics of three peach gum polysaccharides (PGPs) of different molecular weights; i.e., AEPG2 (1.64 × 107 g/mol), DPG2 (5.21 × 105 g/mol), and LP100R (8.50 × 104 g/mol). We observed that PGPs were indigestible during the oral, gastrointestinal, and intestinal stages. However, they were utilized by the gut microbiota with utilization rates in the order of DPG2 > AEPG2 > LP100R. Furthermore, arabinose in PGPs was preferentially utilized by the gut microbiota followed by galactose and xylose. Fermentation of peach gum polysaccharides could significantly increase the production of short-chain fatty acids (SCFAs), especially n-butyric acid. In addition, PGPs with different molecular weights values were predominantly fermented by different bacterial species. AEPG2 and DPG2 were fermented by the Bacteroidetes bacteria Bacteroides, while the dominant n-butyrate-producing bacteria was Faecalibacterium. While the LP100R was fermented by Bacteroides, Parabacteroides, Phascolarctobacterium, Dialister, Lachnospiraceae, and Blautia, the dominant n-butyrate-producing bacteria was Megamonas. These results indicated that PGPs are potential prebiotics for the food industry.

Ultrasonic Extraction Process of Polysaccharides from Dendrobium nobile Lindl.: Optimization, Physicochemical Properties and Anti-Inflammatory Activity

To optimize the ultrasonic extraction process of polysaccharides from Dendrobium nobile Lindl. (DNP), the extraction method was conducted through a single-factor test and the response-surface methodology (RSM). With the optimal extraction process (liquid–solid ratio of 40 mL/g, ultrasonic time of 30 min, and ultrasonic power of 400 W), the maximum extraction yield was 5.16 ± 0.41%. DNP1 and DNP2 were then fractionated via DEAE-QFF and Sephacryl S-300 HR chromatography. The molecular weight (Mw) of DNP1 was identified as 67.72 kDa, composed of Man (75.86 ± 0.05%) and Glc (24.14 ± 0.05%), and the Mw of DNP2 was 37.45 kDa, composed of Man (72.32 ± 0.03%) and Glc (27.68 ± 0.03%). Anti-inflammatory assays results showed that as DNPs were 200 μg/mL, and the contents of NO, TNF-α, IL-1β, IL-6 and IL-10 in LPS-induced RAW 264.7 cells were about 13.39% and 13.39%, 43.88% and 43.51%, 17.80% and 15.37%, 13.84% and 20.66%, and 938.85% and 907.77% of those in control group, respectively. It was indicated that DNP1 and DNP2 inhibited the inflammatory response of RAW 264.7 cells induced by LPS via suppressing the level of NO and pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) and promoting the secretion of anti-inflammatory cytokine (IL-10). Therefore, DNP1 and DNP2 have potential applications in the treatment of inflammatory injury.

Enzyme-extracted raspberry pectin exhibits a high-branched structure and enhanced anti-inflammatory properties than hot acid-extracted pectin

To characterize the structure of purified raspberry pectin and discuss the impact of different extraction methods on the pectin structure, raspberry pectin was extracted by hot-acid and enzyme method and purified by stepwise ethanol precipitation and ion-exchange chromatography isolation. Enzyme-extracted raspberry pectin (RPE50%-3) presented relatively intact structure with molecular weight of 5 × 10⁴ g/mol and the degree of methylation was 39%. The 1D/2D NMR analysis demonstrated RPE50%-3 was a high-branched pectin mainly containing 50% homogalacturonan, 16% branched α-1,5-arabinan and α-1,3-arabinan, 18% β-1,4-galactan and β-1,6-galactan. Acid-extracted raspberry pectin (RPA50%-3) contained less arabinan than RPE50%-3. Moreover, RPE50%-3 inhibited the nitric oxide (NO), TNF-α, IL-6 production of lipopolysaccharide-induced macrophages by 67%, 22% and 46% at the dosage of 200 ug/mL, while the inhibitory rate of RPA50%-3 were 33%, 9%, and 1%, respectively. These results suggested that enzyme-extracted raspberry pectin contained more arabinan sidechains and exhibited better immunomodulatory effect.

Chain conformations and steady-shear viscosity properties of pectic polysaccharides from apple and tomato

In this study, apple pectin (AP) and tomato pectin (TP) were demonstrated to be a high-ester (74.8%) polysaccharide with the weight-average molecular weight (Mw ) of ∼ 243 kDa and a low-ester (45.9%) polysaccharide with the Mw of ∼ 19 kDa, respectively. The semi-rigid chain conformations of pectic polysaccharides in NaNO3 aqueous solution were deduced according to the Smidsrød "B values" of AP (0.025) and TP (0.029), while AP and TP exhibited higher stiffness in water due to the electric repulsion of carboxyl groups, which was visually observed by AFM images. Under steady shear, the shear-thickening behaviors of AP and TP in NaNO3 aqueous solutions were observed in the shear rate range of < 1 s-1, which were attributed to the disruption of the ordered arrangement induced by semi-rigid pectin chains into randomly entangled structure by weak shear force. AP exhibited stronger shear-thickening behavior due to the formation of more entanglements resulted from the higher Mw and longer side chains highly branched at rhamngalacturonan region. This study provides the scientific basis for the construction of the relationship of steady-shear property with chain conformation and molecular weight of pectin.

A review on peach gum polysaccharide: Hydrolysis, structure, properties and applications

To achieve sustainable development, increasing attention has been paid to the utilization of renewable polysaccharides extracted from plant gum instead of synthetic materials. Peach gum polysaccharide (PGP) is a typical polysaccharide, which can be readily obtained by hydrolysis of peach gum, one of the abundant plant gums in the world. In the past decade, the research on the hydrolysis, structure, properties and applications of PGP has aroused great interest. The PGP with highly branched macromolecular structure shows remarkable merits of numerous functional groups, excellent water solubility, good biocompatibility, favorable emulsifying property, fine antioxidant and antibacterial activity, and low cost. The application of PGP has expanded from the pharmaceutical field to the fields of food, adsorbents, functional carbon materials, binders and gel materials. This review systematically introduces the research progress of PGP, as well as the opportunities and challenges faced by PGP in scientific research and practical application.

Purification, chemical analysis and inhibitory effects on galectin-3 of enzymatic pH-modified citrus pectin

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EMCP is fractionated by ion-exchange and gel permeation chromatographies.

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EMCP fractions contain glucan backbone and different saccharides as side chains.

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RG-II domain may weaken the binding strength between EMCP fractions and Gal-3.

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EMCP-3p and EMCP-2p exhibit strong cytotoxicity against MCF-7 and A549 cell lines.

Modified citrus pectin (MCP), a commercially available dietary supplement prepared from citrus pectin, contains several different polysaccharide domains, but its primary chemical structure and the binding epitopes that antagonize galectin-3 function remain unclear. In this study, five fractions were isolated from MCP after endo-polygalacturonase degradation (EMCP) and a combination of DEAE-cellulose and Sepharose CL-6B or Sephadex G-75 chromatography. Their primary structures, abilities to inhibit galectin-3-mediated hemagglutination, and antiproliferation activities on MCF-7 and A549 cell lines were studied. Results showed that EMCP-3p, one of the five fractions, was composed of Glc (89.8%), Gal (3.8%), Ara (3.1%), GalA (1.1%), Man (0.9%), and Rha (1.3%) with an average molecular weight of 88.4 KDa, which had the most substantial degree of galectin-3 inhibition with an MIC of 31.25 μg/mL, and it exhibited remarkable cytotoxicity against MCF-7 (36.7%) and A549 (57.4%) cell lines. These results provide new insight into the structure–function relationships of EMCP-derived polysaccharides.

Similar hypoglycemic effects of glucomannan and its enzyme degraded products from Amorphophallus albus on type 2 diabetes mellitus in mice and potential mechanisms

In the present study, the hypoglycemic effects of glucomannan (AGM) and its enzyme-degraded products from Amorphophallus albus were investigated. Four degraded products were prepared through ultrafiltration of β-glucanase-degraded products of AGM. The hypoglycemic activities were evaluated in HFD-STZ-induced type 2 diabetes mellitus (T2DM) mice, and the diversity of gut bacteria was analyzed by 16S rRNA gene sequencing; the fecal short chain fatty acids (SCFAs) and endogenous metabolites were determined by UPLC-QTOF-MS/MS. It was found that AGM and its enzyme-degraded products, though with different molecular weights, had similar β-glycosidic bonds and monosaccharide compositions, exerted similar strength of hypoglycemic effects, and reinstated with a similar extent the disordered gut microbiota and the contents of SCFAs and endogenous metabolites. It was speculated that the hypoglycemic activity of AGM is decided by not the molecular weight but the glycosidic bonds/monosaccharide composition of AGM, which might be structurally specific to the gut bacteria, and thus certain SCFAs and endogenous metabolites that are related to the occurrence and therapy of T2DM. This study provides a scientific basis for using AGM as potential prebiotics beneficial for prevention or therapeutic treatment of T2DM.

Synergistic gelling mechanism of RG-I rich citrus pectic polysaccharide at different esterification degree in calcium-induced gelation

RG-I rich pectic polysaccharide is common in fruit and vegetable and possesses health benefits. However, it is removed during commercial pectin production because of poor gelling properties. Synergistic gelation can improve rheological properties of RG-I pectic polysaccharide and expand its application in functional food hydrocolloids. In the study, RG-I rich pectic polysaccharides at different degree of esterification was extracted from citrus membrane by sequential mild acidic (0.4% HCl, 28 °C) and alkaline (0.6% NaOH, 32 °C) treatment. The pectic polysaccharide from acid water (PA) composes of 41% RG-I and 44% HG with DM of 45%, while the pectic polysaccharide from basic water (PB) composed of 63% RG-I and 19% HG with DM of 15%. PA/PB blend gel under CaCO₃-glucono-δ-lactone system showed improved rheological properties compared with pure gels. Ca-bridges connected pectin aggregates and promoted the three-dimensional structure of PA/PB blend gels, while neutral sugar side-chains prompted hydrogen bonds and strengthened gel network.

Prunus armeniaca gum exudates: An overview on purification, structure, physicochemical properties, and applications

Prunus armeniaca gum exudate (PAGE) is obtained from the trunk branches of apricot trees. PAGE is a high-molecular-weight polysaccharide with arabinogalactan structure. The physicochemical and rheological characteristics of this gum have been investigated in various researches. PAGE offers a good potential for use as an emulsifying, binding, and stabilizing agent in food and pharmaceutical industries. It also can be used as an organic additive in tissue culture media, synthesizing of metallic nanoparticles, binding potential in tablets, antioxidant agent, and corrosion inhibitor. For desirable emulsifying, stabilizing, shelf life-enhancing properties, and antioxidant activity of PAGE, it can be used as additive in many foods. We present here a comprehensive review on the existing literatures on characterization of this source of polysaccharide to explore its potential applications in various systems.

Structural characteristics and enhanced biological activities of partially degraded arabinogalactan from larch sawdust

Larch arabinogalactan (AG), extracted from Larix gmelinii sawdust, was depolymerized by H₂O₂ oxidation and purified by gel column to yield a novel degraded fraction (AGD2). The structural analysis indicated AGD2 had lower arabinose content and molecular weight compared with AG, in which the ratio of galactose and arabinose was changed from 7:3 to 16:1, the molecular weight was decreased from 50.2 kDa to 3.7 kDa, and the chain conformation spread from highly branched structure to flexible strand. It was one kind of β-D-(1 → 3)-galactan with fewer β-D-(1 → 6)-Galp side branches at O-6 position. Further, the results of the Gal-3 binding and immunomodulatory assay suggested that the unbinding force of AGD2 onto Gal-3 was as twice as AG to be 76 ± 11 pN at the loading rate of 0.15 μm/s. It could better promote the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) than AG in a dose-dependent manner.

Optimized preparation of eugenol microcapsules and its effect on hepatic steatosis in HepG2 cells

This study was aimed at evaluating the potential of peach gum (PG) and gelatin in the microencapsulation of eugenol and the intervention of eugenol microcapsules on hepatic steatosis in vitro. Response surface method (RSM) was used to optimize the encapsulation conditions of eugenol microcapsules. The microcapsules were characterized by scanning electron microscopy (SEM), dynamic Light Scattering (DLS), Fourier transform infrared spectroscopy (FT-IR) and release behavior in vitro was determined. The effect of eugenol microcapsules on free fatty acids (FFA) treated hepatocellular cells (HepG₂) cells was evaluated by oil red O staining and intracellular total cholesterol (TC) and triglyceride (TG) determination. The results showed that the optimal encapsulation conditions were as follows: the PG-gelatin ratio was 1.6:1.4, the core-wall ratio was 1.6:1.4, the pH was 4 and the emulsification speed was 9000 r/min. The optimized microcapsules were smooth spherical with a size of about 3.09 ± 0.58 μm and the encapsulation was confirmed by FT-IR. In vitro release behavior showed that eugenol microcapsules could be released stably in a neutral environment for 72 h. Oil red O staining showed that 50 and 100 μM eugenol microcapsules could significantly inhibit the lipid accumulation and reduce the TC and TG in steatotic HepG₂ cells induced by FFA. Therefore, PG and gelatin can be used as excellent carriers for the microencapsulation of volatile compounds in the field of biomedical industry, and eugenol microcapsules is a promising preparation for the treatment of nonalcoholic fatty liver disease (NAFLD).

Structure-activity relationship of Citrus segment membrane RG-I pectin against Galectin-3: The galactan is not the only important factor

Rhamnogalacturonan I (RG-I) pectin are regarded as strong galectin-3 (Gal-3) antagonist because of galactan sidechains. The present study focused on discussing the effects of more structural regions in pectin on the anti-Gal-3 activity. The water-soluble pectin (WSP) recovered from citrus canning processing water was categorized as RG-I pectin. The controlled enzymatic hydrolysis was employed to sequentially remove the α-1,5-arabinan, homogalaturonan and β-1,4-galactan in WSP. The Gal-3-binding affinity KD (kd/ka) of WSP and debranched pectins were calculated to be 0.32 μM, 0.48 μM, 0.56 μM and 1.93 μM. Moreover, based on the more sensitive cell line (MCF-7) model, the IC₃₀ value of WSP was lower than these of modified pectins, indicating decreased anti-Gal-3 activity. Our results suggested that the total amount of neutral sugar sidechains, the length of arabinan and cooperation between HG and RG-I played important roles in the anti-Gal-3 activity of WSP, not the Gal/Ara ratio or RG-I/HG ratio. These results provided a new insight into structure-activity relationship of citrus segment membrane RG-I as a galectin-3 antagonist and a new functional food.

Facile synthesis of amphiphilic peach gum polysaccharide as a robust host for efficient encapsulation of methylene blue and methyl orange dyes from water

Despite impressive progress of macromolecular encapsulation technique based on hyperbranched polymer (HP), the use of natural HP for guest encapsulation has rarely been reported. Herein, we present the simple synthesis of amphiphilic PGP-DC from natural peach gum polysaccharide (PGP) and demonstrate that the PGP-DC can be utilized as a robust host for encapsulation of dye molecules from water. The influences of initial dye concentration, dosage of PGP-DC, pH, ionic strength, and encapsulation mode on the encapsulation were systematically studied. The PGP-DC simultaneously exhibited fast encapsulation rate and superior encapsulation capability. Under optimal conditions, the encapsulation capacity of PGP-DC towards methylene blue (MB) (1 mM) can reach as high as 182.67 mg/g, which compares favorably to other separation techniques. Moreover, the MB-encapsulated PGP-DC could be well regenerated in acidic solution. Based on its simple synthetic process, excellent encapsulation performance and fine reusability, the PGP-DC holds great promise for using as a host for practical encapsulation applications.