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Dendrobium nobile is a medicinal herb in traditional China and Southeast Asian countries. Employing a rat model of ethanol-induced gastric ulcer, we examined the protective effect of polysaccharide (JCP) extracted from Dendrobium nobile and explored the related mechanisms. Oral administration with 100 mg/kg and 300 mg/kg body weight JCP for days can significant prevent the formation of gastric ulcer. Moreover, JCP pretreatment could alleviate ethanol-induced histological damage, antioxidant activities, the level of epidermal growth factor, gastric concentration of prostaglandin E, and regulate the signaling pathways of mitogen-activated protein kinases and matrix metalloproteinases. This study investigated the ethanol-induced gastric ulcer protective effect of JCP for the first time, and elucidated that the protective mechanisms. [ABSTRACT FROM AUTHOR]

Polyethylene glycol (PEG) as a green solvent was employed to extract polysaccharide. The optimal conditions for PEG-based ultrasonic extraction of Dendrobium nobile Lindl. polysaccharide (JCP) were determined by response surface methodology. Under the optimal conditions: extraction temperature of 58.5 °C; ultrasound power of 193 W, and the concentration of polyethylene glycol-200 (PEG-200) solution of 45%, the highest JCP yield was obtained as 15.23 ± 0.57%, which was close to the predicted yield, 15.57%. UV and FT-IR analysis revealed the general characteristic absorption peaks of both JCP with water extraction (JCP w ) and PEG-200 solvent extraction (JCP p ). Thermal analysis of both JCPs was performed with Thermal Gravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC). Antioxidant activities of two polysaccharides were also compared and no significant difference in vitro was obtained. [ABSTRACT FROM AUTHOR]

In the work, a novel filamentou sodium alginate (SA) /ε-polylysine (PL) fiber with excellent mechanical properties and controllable sizes is prepared in an efficient and environmentally friendly manner via continuous pulling of an electrostatically assembled SA/PL composites at the contact interface of aqueous solutions of cationic polyelectrolyte ε-PL and anionic natural polysaccharide SA. The SA/PL fiber exhibits good antibacterial activity, low cytotoxicity, anti-hemolysis, bioadhesion, and environmental friendliness due to its natural raw materials and green preparation process. In vivo experiments have shown that the SA/PL fiber can promote the healing and repair of skin wounds on the backs of mice via resistance to pathogen infection, reduction of inflammation, and anti-allogeneic allergy of the wound. In summary, these results demonstrate that the SA/PL fiber is a green and biosafe multifunctional natural polymer material, with potential applications in suturing wound. [Display omitted] • A size controllable SA/PL fiber is prepared efficiently via electrostatic self-assembly. • SA/PL fiber has excellent biocompatibility, antibacterial and bioadhesion fuctions. • SA/PL fiber can promote wound healing as an antiallergic surgical suture in vivo. [ABSTRACT FROM AUTHOR]

Carboxymethyl chitosan (CMCS)-based complex coacervate has attracted much attention in drug oral delivery due to its pH-responsive property. As a unique ampholyte polymer, the self-coacervation of CMCS has great research potential. In this work, CMCS self-coacervates were prepared by adjusting the pH of the CMCS aqueous solution close to its isoelectric point. The Fourier-transformed infrared spectroscopy (FTIR) results revealed that electrostatic interactions, hydrogen bonding, and hydrophobic interactions were involved in the self-coacervation of CMCS. The obtained self-coacervates presented a dense surface structure, and were stable at a wide pH range of 3.0–6.0, and gradually dissolved under basic conditions. Although self-coacervation decreased the crystallinity and thermal stability of CMCS, the obtained coacervates showed excellent pH-responsive properties and ionic strength stability. We also investigated its potential in lactoferrin (LF) encapsulation and oral delivery. The CMCS self-coacervates exhibited a high encapsulation efficiency (EE) of 94.79 ± 0.49% and loading capacity (LC) of 26.29 ± 0.52% when the addition amount of LF was 2 mg. The simulated gastric digestion results demonstrated that CMCS self-coacervates could protect more than 80% of LF from hydrolysis and maintain the bioactivities of LF. Accordingly, the self-coacervation of CMCS could be used as a pH-responsive encapsulation and delivery strategy. [ABSTRACT FROM AUTHOR]

The study aimed to reveal the different mechanisms of delaying starch digestion by ECG, EGCG and Procyanidin based on the perspective of α-amylase-flavanol interaction and starch-flavanol interaction. The interaction characteristics of flavanols with α-amylase were studied from five aspects: enzyme inhibition, kinetics, fluorescence quenching, circular dichroism (CD) and computer simulation. The IC50 of flavanols (ECG, EGCG and Procyanidin) against α-amylase were 172.21 ± 0.22, 732.15 ± 0.13 and 504.45 ± 0.19 μg/mL according to the results of α-amylase inhibition experiment, respectively. ECG and Procyanidin showed mixed inhibition against α-amylase, while EGCG showed non-competition against α-amylase. However, thermodynamic parameters，computer-based docking and dynamic simulation proved that ECG and EGCG-α-amylase complexs were mainly driven by van der Waals and hydrogen bonds, while Procyanidin-α-amylase complexs was driven by hydrophobic interaction. In addition, it was indicated, by means of starch‑iodine complex spectroscopy, that flavanols inhibited the digestion of starch not only through bind with α-amylase but also through bind with starch. Thus, flavanols as a starch-based food additive have the potential to be employed as adjuvant therapy for diabetes. Unlabelled Image • Flavanols showed effective inhibition activity on α-amylase. • Flavanols combined with α-amylase and induced its conformational changes. • There were different interaction mechanisms between three flavanols and α-amylase. • Flavanols can change the digestion properties of starch by interacting with it [ABSTRACT FROM AUTHOR]

In this study, (-)-Epigallocatechin-3- O -gallate (EGCG) esterification reaction was catalyzed by Novozym 435, Lipozyme RM, Lipozyme TLIM, and lipase Amano 30SD in acetonitrile. Fourier transform infrared spectroscopy (FTIR) and molecular dynamic (MD) simulations were used to analyze the structural stability of different lipases in acetonitrile and their effect on EGCG esterification reaction. The results showed that conversion rate of EGCG catalyzed by Lipozyme RM was the highest, followed by Lipozyme TLIM. FTIR indicated that the secondary structure of Lipozyme RM was the most stable. MD simulations suggested that whole structural stability of Lipozyme RM in acetonitrile was superior to Novozym 435 and lipase Amano 30SD and similar to Lipozyme TLIM due to their similar conformation, while the active site of Lipozyme RM is more flexible than that of Lipozyme TLIM, which indicated that lipase with stable whole structure and flexible active site may be more conducive to the esterification of EGCG in acetonitrile. This study provided a direction for rapidly screening lipase to synthetize EGCG or other polyphenols esterified derivatives. [Display omitted] • Different lipases have different catalytic activity for EGCG esterification. • α-Helix content of lipases treated with acetonitrile decreased. • Different lipases have various tolerance to acetonitrile. • Lipozyme RM and Lipozyme TLIM have more stable structure than other lipases. • Lipase with stable structure and flexible active site benefits EGCG esterification. [ABSTRACT FROM AUTHOR]

In this study, (-)-Epigallocatechin-3- O -gallate (EGCG) esterification reaction was catalyzed by Novozym 435, Lipozyme RM, Lipozyme TLIM, and lipase Amano 30SD in acetonitrile. Fourier transform infrared spectroscopy (FTIR) and molecular dynamic (MD) simulations were used to analyze the structural stability of different lipases in acetonitrile and their effect on EGCG esterification reaction. The results showed that conversion rate of EGCG catalyzed by Lipozyme RM was the highest, followed by Lipozyme TLIM. FTIR indicated that the secondary structure of Lipozyme RM was the most stable. MD simulations suggested that whole structural stability of Lipozyme RM in acetonitrile was superior to Novozym 435 and lipase Amano 30SD and similar to Lipozyme TLIM due to their similar conformation, while the active site of Lipozyme RM is more flexible than that of Lipozyme TLIM, which indicated that lipase with stable whole structure and flexible active site may be more conducive to the esterification of EGCG in acetonitrile. This study provided a direction for rapidly screening lipase to synthetize EGCG or other polyphenols esterified derivatives. [Display omitted] • Different lipases have different catalytic activity for EGCG esterification. • α-Helix content of lipases treated with acetonitrile decreased. • Different lipases have various tolerance to acetonitrile. • Lipozyme RM and Lipozyme TLIM have more stable structure than other lipases. • Lipase with stable structure and flexible active site benefits EGCG esterification. [ABSTRACT FROM AUTHOR]

This study aimed to reveal the interaction and inhibitory mechanisms of tangeretin (TAN), nobiletin (NBT), and their acidic hydroxylated forms, 5-demethyltangeretin (5-DT) and 5-demethylnobiletin (5-DN) on porcine pancreatic lipase (PPL) using spectroscopic techniques and molecular dynamics (MD) simulation. PPL inhibition assay showed that the inhibitory activity of NBT (IC 50 value of 3.60 ± 0.19 μM) was superior to those of three polymethoxylated flavones (PMFs), indicating it may be related to the methoxy groups at the 3′-position in its molecular structure. Inhibition kinetic analyses demonstrated that the inhibition types of the 4 PMFs were consistent with the mixed inhibition model, which agreed well with the results from the ultraviolet-visible (UV–Vis) spectroscopy, Circular dichroism (CD), fluorescence spectroscopy, molecular docking, and MD simulation that PMFs could bind to the PPL catalytic site and non-catalytic site, affecting the normal spatial conformation of PPL and weakening its ability to decompose the substrate. All these findings suggest that PMFs are a kind of natural lipase inhibitors, and NBT has the potential as a lipase inhibition precursor because of its unique flavone skeleton structure. Unlabelled Image • NBT was the strongest lipase inhibitory activity (IC 50 = 3.60 ± 0.19 μM) than other 3 PMFs. • MD was applied to study the structure-activity relationship of PMFs on PPL. • The mechanism of PPL inhibition by PMFs was analyzed in vitro and in silico. • The inhibition of PMF on PPL is related to the -OCH 3 of its 3′-position. [ABSTRACT FROM AUTHOR]

A new type of double-network hydrogel, cross-linked with microcrystalline cellulose grafted with ε-polylysine (MCC-PL) and N , N -methylene bisacrylamide/acrylic acid, was synthesised to efficiently inhibit bacterial proliferation and remove heavy metals. The physicochemical properties of the MCC-PL hydrogel (MCC-PLH) were characterised using scanning electronic microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and differential thermogravimetric analysis. The adsorption results showed that the optimal adsorption conditions were temperature of 313 K at pH of 5 and 6 of Pb2+ and Cu2+, respectively. The adsorption mechanism of MCC-PLH5 was successfully determined using Freundlich isotherm, pseudo-second kinetics, and intra-particle diffusion model, in conjunction with X-ray photoelectron spectroscopy. Adsorption thermodynamic studies indicated that the process was spontaneous and endothermic. Antibacterial experiments showed that PL-grafted MCC hydrogel exhibited more efficient and durable antibacterial activity than MCC, indicating its potential for water decontamination. Unlabelled Image • Microcrystalline cellulose grafted with ε-polylysine is synthesised successfully. • Double-network composite hydrogel is prepared to remove Pb2+/Cu2+ from aqueous solutions. • MCC-PLH exhibited well antimicrobial efficiency against both the E. coli and S. aureus bacteria. • MCC-PLH has a potential for water decontamination. [ABSTRACT FROM AUTHOR]

In this study, the crude polysaccharide from argun palm (Medemia argun) fruit was extracted with hot water and deproteinized by four different methods. Its structure characterization, thermal property and antioxidant activity were investigated by FT-IR spectroscopy, Scanning electron microscope, Congo-red, I 2 -KI, DPPH• assay, ABTS•+ assay, TGA and DSC analysis. It indicated that the NaCl method was the best method in deproteinization. The argun fruit polysaccharide linked by the β-glycosidic bonds. The molecular weight of polysaccharide deproteinized with NaCl was 4.46 × 105 Da. It showed that the polysaccharide from argun palm fruit consisted of fructose, arabinose, rhamnose, galactose, glucose, xylose, and galacturonic acid. The result of TGA and DSC assay indicated that argun fruit polysaccharide has a favorable thermal stability. It was proved that, the argun fruit polysaccharide possessed high antioxidant activity and would be a new natural antioxidant. • The argun fruit polysaccharide was obtained by the hot-water extraction method. • NaCl method was the best deproteinization method for argun fruit polysaccharide. • Argun fruit polysaccharide bonded by β-glycosidic bonds. • Argun fruit polysaccharide had a good antioxidant capacity and thermal stability. [ABSTRACT FROM AUTHOR]

• The fingered citron extract was encapsulated using different carrier agents. • GMS microcapsules had the highest encapsulation yield and efficiency. • The physicochemical properties of GMS microcapsules indicated good storage stability. • GMS microcapsules had a good ability to reconstitute the powders. • DSC, SEM, XRD, and FT-IR analysis confirmed the quality of the GMS microcapsules. The aim of this study was to investigate the characteristics of the Fingered citron extract (FCE) microcapsules powders with different formulations of the encapsulation carrier agents [gum arabic (GA), maltodextrin (MD), modified starch (MS), and whey protein (WP)], which are obtained through spray drying. Encapsulation yield, encapsulation efficiency, moisture content, hygroscopicity, water activity, density properties, Carr's index, cohesiveness, flowability, porosity, wettability, solubility, color, particle size, thermal behavior, relative crystallinity, and micrographs were analyzed. Moreover, chemical structure of the microcapsule powder was identified using Fourier transform infrared spectroscopy (FT-IR). Best results were achieved when Fingered citron extract was encapsulated using gum arabic/maltodextrin/modified starch (GMS) formulation as carrier agents, where it had the highest encapsulation yield (89.39%) and encapsulation efficiency (87.20%). Furthermore, it achieved the best result in density properties, flowability, porosity, wettability, and relative crystallinity. These results have shown that using gum arabic/maltodextrin/modified starch formulation was superior for production of the Fingered citron extract microcapsules powders. [ABSTRACT FROM AUTHOR]

Se-enriched green tea has been widely used as a functional food and disease prevention. In this study, two kinds of homogeneous polysaccharides namely ASe-TPS2 and NSe-TPS2 were obtained from artificial and natural Se-enriched teas with the molecular weights of 6.73 × 103 Da and 2.44 × 105 Da. The structures of ASe-TPS2 and NSe-TPS2 were characterized by monosaccharide composition analysis, partial acid hydrolysis, methylation, FT-IR spectroscopy, NMR spectroscopy, SEM and TGA analysis. It showed that ASe-TPS2 and NSe-TPS2 were acidic polysaccharides containing high amount of uronic acid. The structure of the ASe-TPS2 was mainly composed of β‑D‑(1 → 3)‑Glcp, α‑D‑(1 → 4)‑GalpA, (1 → 4)‑Glcp, α‑L‑(1 → 2)‑Rhap and α‑D‑(1 → 4)‑GalpA, and the non-reducing ends were mainly composed of Araf and Xylp. However, the NSe-TPS2 was mainly composed of β‑D-(1 → 4)‑Glcp and α‑D‑(1 → 4)-GalpA, and the branches were mainly composed of β‑L‑(1 → 2)‑Araf, α‑D‑(1 → 3)‑Galp and β‑L‑(1 → 2)‑Rhap whereas the non-reducing ends were mainly composed of Glcp and Galp residues. These results suggested that the distinction of selenylation methods could present different polysaccharide chain structures. • Natural and artificial Se-polysaccharides were acidic polysaccharides containing high amount of uronic acids. • ASe-TPS2 was mainly composed of β‑D‑(1 → 3)‑Glcp and α‑D‑(1 → 4)‑GalpA, (1 → 4)‑Glcp, α‑L‑(1 → 2)‑Rhap and α‑D‑(1 → 4)‑GalpA. • NSe‑TPS2 was mainly composed of β‑D‑(1 → 4)‑Glcp and α‑D‑(1 → 4)‑GalpA. • Different selenylation methods could lead to different polysaccharide structure. [ABSTRACT FROM AUTHOR]