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Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper explored the in vitro inhibitory mechanism of polyphenol-rich rose extracts (REs) from an edible rose flower against α-glucosidase using multispectral and molecular docking techniques. Results showed that REs had an inhibitory effect on α-Glu activity (IC50 of 1.96 μg/mL); specifically, the samples pretreated by tri-frequency ultrasound (20/40/60 kHz) exhibited a significantly (p < 0.05) stronger inhibitory effect on α-Glu activity with an IC50 of 1.33 μg/mL. The Lineweaver–Burk assay indicated that REs were mixed-type inhibitors and could statically quench the endogenous fluorescence of α-Glu. REs increased the chance of polypeptide chain misfolding by altering the microenvironment around tryptophan and tyrosine residues and disrupting the natural conformation of the enzyme. Molecular docking results showed that polyhydroxy phenolics had a high fit to the active site of α-Glu, so REs with high polymerization and numerous phenolic hydroxyl groups had a stronger inhibitory effect. Therefore, this study provides new insights into polyphenol-rich REs as potential α-glucosidase inhibitors. [ABSTRACT FROM AUTHOR]

The mechanism of α-glucosidase inhibition by theaflavin-3,3’-digallate (TFDG) was analyzed using enzyme inhibition kinetics, multi-spectroscopies and molecular docking. The results indicated that the inhibition was reversible and displayed a mixed type of competitive and non-competitive inhibition. TFDG quenched the intrinsic fluorescence of α-glucosidase by forming a complex with it. Thermodynamic parameters suggested that the binding was a spontaneous, endothermic and entropy-increasing process, mainly driven by hydrophobic interactions. The binding enhanced the hydrophobicity near Tyr residue and the polarity around Trp residue, reducing the contents of α-helix, β-sheet and β-turn. Molecular docking revealed that TFDG bound in close proximity to the enzyme’s active site, engaging in two hydrophobic interactions with Phe450 and Trp406 residues, respectively, as well as forming three hydrogen bonds with amino acid residues Asp203, Phe450 and Gln603, respectively. This study provides evidence for the potential of TFDG as a feasible candidate functional factor for the treatment of diabetes.

This study was performed to investigate the inhibitory mechanisms of 3 plant polyphenols, grape seed extract (GSE), lotus seed proanthocyanidins (LSPC) and lotus root polyphenol extract (LRPE), against Shewanella putrefaciens. Their antibacterial effects were determined in terms of minimum inhibitory concentration (MIC) and the growth curve of S. putrefaciens. By scanning electron microscopy (SEM), relative conductivity, propyridine iodide (PI) staining, alkaline phosphatase (AKP) activity, extracellular protein content, nucleic acid leakage, Na+ K+ -ATPase activity and membrane protein fluorescence analysis, the antibacterial mechanism was explored. The results showed that the MICs of GSE, LRPE and LSPC were 31.25, 62.25 and 125.00 μg/mL, respectively. After S. putrefaciens was treated with the polyphenols, the position of membrane proteins was changed, the fluorescence intensity was reduced, the morphology was altered, the surface became wrinkled and sunken, and the growth was significantly inhibited. In addition, the activity of extracellular AKP, the contents of nucleic acid and extracellular protein in the bacterial suspension, relative conductivity and PI intake were significantly increased, and Na+ K+-ATPase was inactivated to a certain extent, thereby leading to cell death.

The prevention of enzymatic browning through the application of tyrosinase inhibitors has become a research focus in food industry. In this article, multi-spectroscopic and computational simulation was used to study the binding behavior and inhibition mechanism of aloin to tyrosinase. It found that aloin was an effective inhibitor of tyrosinase activity with a mixed type inhibition. Aloin bound to tyrosinase through hydrophobic forces, causing a conformational change in the enzyme and resulting in its inherent fluorescence being quenched. There was a binding site for aloin with tyrosinase and the binding constant was approximately 104 L mol−1. Molecular simulations showed that hydrophobic and hydrogen-bonding forces were the main factors in the binding of aloin to tyrosinase. Aloin introduced into the active site of tyrosinase interacted with amino acid residues Gly281, His244, Val283, Ala286 and His263, occupying the catalytic center of the tyrosinase and blocking substrate entry, resulting in tyrosinase inhibition. Molecular dynamics simulation further indicated that the binding of aloin changed the secondary structure of tyrosinase with little effect on the microenvironment of tyrosinase amino acid residues. This study offers new understanding of the mechanisms of activity of aloin as a tyrosinase inhibitor. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] Hypothesis: Graphene quantum dots (GQDs) with various functional groups are hypothesized to inhibit the α-synuclein (αS) dimerization, a crucial step in Parkinson's disease pathogenesis. The potential of differently functionalized GQDs is systematically explored. Experiments: All-atom replica-exchange molecular dynamics simulations (accumulating to 75.6 μs) in explicit water were performed to study the dimerization of the αS non-amyloid component region and the influence of GQDs modified with various functional groups. Conformation ensemble, binding behavior, and free energy analysis were conducted. Findings: All studied GQDs inhibit β-sheet and backbone hydrogen bond formation in αS dimers, leading to looser oligomeric conformations. Charged GQDs severely impede the growth of extended β-sheets by providing extra contact surface. GQD binding primarily disrupts αS inter-peptide interactions through π-π stacking, CH-π interactions, and for charged GQDs, additionally through salt-bridge and hydrogen bonding interactions. GQD-COO– showed the most optimal inhibitory effect, binding mode, and intensity, which holds promise for the development of nanomedicines targeting amyloid aggregation in neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Copyright of China Condiment is the property of China Condiment and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abnormal melanogenesis can lead to hyperpigmentation. Tyrosinase (TYR), a key rate-limiting enzyme in melanin production, is an important therapeutic target for these disorders. We investigated the TYR inhibitory activity of hydrolysates extracted from the muscle tissue of Takifugu flavidus (TFMH). We used computer-aided virtual screening to identify a novel peptide that potently inhibited melanin synthesis, simulated its binding mode to TYR, and evaluated functional efficacy in vitro and in vivo. TFMH inhibited the diphenolase activities of mTYR, reducing TYR substrate binding activity and effectively inhibiting melanin synthesis. TFMH indirectly reduced cAMP response element-binding protein phosphorylation in vitro by downregulating melanocortin 1 receptor expression, thereby inhibiting expression of the microphthalmia-associated transcription factor, further decreasing TYR, tyrosinase related protein 1, and dopachrome tautomerase expression and ultimately impeding melanin synthesis. In zebrafish, TFMH significantly reduced black spot formation. TFMH (200 μg/mL) decreased zebrafish TYR activity by 43% and melanin content by 52%. Molecular dynamics simulations over 100 ns revealed that the FGFRSP (T-6) peptide stably binds mushroom TYR via hydrogen bonds and ionic interactions. T-6 (400 μmol/L) reduced melanin content in B16F10 melanoma cells by 71% and TYR activity by 79%. In zebrafish, T-6 (200 μmol/L) inhibited melanin production by 64%. TFMH and T-6 exhibit good potential for the development of natural skin-whitening cosmetic products. [ABSTRACT FROM AUTHOR]

In order to investigate the interaction between aloe emodin and α-glucosidase, enzyme kinetics, ultraviolet (UV) spectroscopy, infrared (IR) spectroscopy and fluorescence spectroscopy were employed to investigate the inhibitory mechanism of aloe emodin on α-glucosidase and the synergistic effect of aloe emodin in combination with acarbose was also investigated in this study. The results showed that aloe emodin had better inhibitory effect on α-glucosidase as both a non-competitive and anti-competitive inhibitor when compared with acarbose. The results of UV spectroscopy indicated that a new complex was formed through the interaction between aloe emodin and α-glucosidase. The characteristic vibrations of amide groups in the IR spectra indicated that the structural conformation of α-glucosidase changed with the addition of aloe emodin. The results of fluorescence quenching experiments showed that the endogenous fluorescence of α-glucosidase was statically quenched by aloe emodin. In addition, it was also found that aloe emodin combined with acarbose had a synergistic inhibitory effect on α-glucosidase activity. This study provides an experimental basis for the future application of aloe emodin in health foods for regulating blood glucose.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is a pivotal immune checkpoint receptor, playing a crucial role in modulating T-cell activation. In this study, we delved into the underlying mechanism by which a common mutation, G199R, in the cytoplasmic domain of CTLA-4 impacts its inhibitory function. Utilizing nuclear magnetic resonance (NMR) spectroscopy and biochemical techniques, we mapped the conformational changes induced by this mutation and investigated its role in CTLA-4 activity. Our findings reveal that this mutation leads to a distinct conformational alteration, enhancing protein–membrane interactions. Moreover, functional assays demonstrated an improved capacity of the G199R mutant to downregulate T-cell activation, underscoring its potential role in immune-related disorders. These results not only enhance our understanding of CTLA-4 regulatory mechanisms but also provide insights for targeted therapeutic strategies addressing immune dysregulation linked to CTLA-4 mutations. [ABSTRACT FROM AUTHOR]

The control of Aspergillus niger (A. niger) is of great significance for the agricultural economy and food safety. In this study, the antifungal effect and mechanism of iturin A from Bacillus amyloliquefaciens (CGMCC No. 8473) against A. niger (ATCC 16404) were investigated using biochemical analyses and proteomics. Changes in a mycelium treated with iturin A were observed using scanning electron microscopy and transmission electron microscopy, including mycelial twisting and collapse, organelle disintegration, and intracellular vacuolization. The cytomembrane integrity of A. niger was affected by iturin A, as detected by propidium iodide staining. In addition, the generation of excess reactive oxygen species, the hyperpolarization of the mitochondrial membrane potential and malondialdehyde accumulation also indicated that iturin A induced apoptosis in A. niger through the oxidative stress pathway. Proteomics results showed that 310 proteins were differentially expressed in the A. niger mycelium exposed to iturin A, including 159 upregulated proteins and 151 downregulated proteins, which were mainly associated with energy metabolism of A. niger. We propose that iturin A might inhibit the growth of A. niger by disrupting cytomembrane integrity, via oxidative stress, and by interfering with glycolysis/gluconeogenesis and the tricarboxylic acid cycle. Overall, iturin A is a promising antifungal agent that provides a rationale for controlling A. niger contamination in food. [ABSTRACT FROM AUTHOR]

6,7-Bis-(2-methoxyethoxy)-4(3 H)-quinazolinone (BMEQ) was selected from quinazolinones for its strong tyrosinase inhibitory activity (IC 50 = 160 ± 6 μM). It suppressed tyrosinase activity in a competitive way and quenched the fluorescence of the enzyme through a static mechanism. The binding of BMEQ to tyrosinase increased the hydrophobicity of the latter and facilitated non-radiative energy transfer between them. The formation of BMEQ–tyrosinase complex was driven by hydrogen bonds and hydrophobic interactions, and it loosened the basic framework structure of tyrosinase, affecting the conformation of the enzyme, and leading to a decrease in tyrosinase activity. In addition, the BMEQ postponed the oxidation of phenolics and flavonoids by inhibiting polyphenol oxidase (PPO) and peroxidase (POD), which resulted in the inhibition of the browning of fresh-cut apples. This study identified a novel tyrosinase inhibitor BMEQ and verified its potential application for improving the preservation of postharvest fruits. [Display omitted] [ABSTRACT FROM AUTHOR]

Seedless chestnut rose (Rosa sterilis S. D. Shi, RS) is a fresh type of R. roxburghii Tratt with copious functional components in its fruit. Polysaccharides are recognized as one of the vital bioactive compounds in RS fruits, but their antioxidant and hypoglycemic properties have not been extensively explored. Hence, in this study, accelerated solvent extraction (RSP-W), citric acid (RSP-C), 5% sodium hydroxide/0.05% sodium borohydride (RSP-A), and 0.9% sodium chloride (RSP-S) solution extraction were individually utilized to obtain RS fruit polysaccharides. The physicochemical properties, structural characteristics, and biological activities were then compared. Results indicated that extraction methods had significant influences on the extraction yield, uronic acid content, monosaccharide composition, molecular weight, particle size, thermal stability, triple-helical structure, and surface morphology of RSPs apart from the major linkage bands and crystalline characteristics. The bioactivity tests showed that the RSP-S, which had the greatest amount of uronic acid and a comparatively lower molecular weight, exhibited more potent antioxidant and α-glucosidase inhibitory property. Furthermore, all RSPs inhibited α-glucosidase through a mixed-type manner and quenched their fluorescence predominantly via a static quenching mechanism, with RSP-S showing the highest binding efficiency. Our findings provide a theoretical basis for utilizing RSPs as functional ingredients in food industries. [ABSTRACT FROM AUTHOR]

Aimed at the deprived research on physicochemical synergistic inhibition and the micromechanism of inhibition. The inhibitory effect and mechanism of MgCl2, TPPI and the combination of them were studied in this research. Low-temperature oxidation gas production experiment and synchronous thermal analyzer were used to analyze the inhibition and thermal behavior effects of different inhibitors, respectively. Fourier transform infrared spectrometer experiment was used to analyze the changes of the surface functional groups on coal samples before and after inhibition. Density functional theory was used to reveal the inhibitory mechanism of TPPI. In the low-temperature oxidation experiment, the CO release of Composite Inhibitor 5 (TPPI:MgCl2 = 1:1) treatment coal samples was the least. From the characteristic temperature points and heat release, it can be seen that the composite inhibitor reflects the physicochemical synergistic effect. The addition of MgCl2 will enhance the inhibitory effect at low-temperature stage (< 400°C) and weaken the inhibitory effect at high-temperature stage (> 400°C). Composite Inhibitor 3 (TPPI:MgCl2 = 3:7) showed strong inhibitory effect in both low and high-temperature phases, the comprehensive comparison showed the best inhibitory effect. The contents of aliphatic functional groups, hydroxyl groups and carboxyl groups decreased in the coal samples treated by TPPI and composite inhibitor, while the relative contents of stable ether bond and aromatic functional groups increased. The inhibitory mechanism of TPPI is to remove the free radical as R–COO·, R–CO· and R–C· by using itself and its hydrolytic products, to interrupt the chain reaction and finally to inhibit coal spontaneous combustion. The conclusions of this article provide theoretical support for the preparation of physicochemical synergistic inhibitors and the revelation of microscopic mechanism of TPPI inhibition on coal spontaneous combustion. [ABSTRACT FROM AUTHOR]

This study was designed to explore the inhibitory effect and mechanism of sea-buckthorn flavonoids on the formation of acrylamide. In order to study the inhibitory effect of sea-buckthorn flavonoids on the formation of acrylamide, the dose-effect relationship of sea-buckthorn flavonoids inhibiting the formation of acrylamide was investigated in the Asn-Glu simulation system. Then the formation/elimination kinetic model and mechanism kinetic model were used to evaluate the products of Maillard reaction by UV absorption spectrum, liquid chromatography-tandem mass spectrometry, and high performance liquid chromatography to explore the inhibitory mechanism of sea-buckthorn flavonoids on the formation of acrylamide. The results confirmed that sea-buckthorn flavonoids could effectively reduce the formation of acrylamide and achieve a maximum reduction rate 62.1%. The formation/elimination kinetic model demonstrated that sea-buckthorn flavonoids significantly reduced the formation rate constants a, tcg of acrylamide (P0.05), indicating that sea-buckthorn flavonoids mainly inhibited the formation stage of acrylamide, and had no effect on the elimination process. The mechanism kinetic model suggested that sea-buckthorn flavonoids actively reduced the production rate of acrylamide k2 and the production rate of melanin k3 (P

This paper explored the in vitro inhibitory mechanism of polyphenol-rich rose extracts (REs) from an edible rose flower against α-glucosidase using multispectral and molecular docking techniques. Results showed that REs had an inhibitory effect on α-Glu activity (IC50 of 1.96 μg/mL); specifically, the samples pretreated by tri-frequency ultrasound (20/40/60 kHz) exhibited a significantly (p < 0.05) stronger inhibitory effect on α-Glu activity with an IC50 of 1.33 μg/mL. The Lineweaver–Burk assay indicated that REs were mixed-type inhibitors and could statically quench the endogenous fluorescence of α-Glu. REs increased the chance of polypeptide chain misfolding by altering the microenvironment around tryptophan and tyrosine residues and disrupting the natural conformation of the enzyme. Molecular docking results showed that polyhydroxy phenolics had a high fit to the active site of α-Glu, so REs with high polymerization and numerous phenolic hydroxyl groups had a stronger inhibitory effect. Therefore, this study provides new insights into polyphenol-rich REs as potential α-glucosidase inhibitors.

The inhibitory effect of fumigation with 1-octen-3-ol against the growth and deoxynivalenol (DON) biosynthesis of Fusarium graminearum PH-1 was determined, and the possible mechanism involved was investigated by evaluating cell membrane integrity, oxidative stress level and the expression of key genes related to DON biosynthesis. The results showed that 1-octen-3-ol significantly inhibited the mycelial growth, spore germination and mycotoxin production of F. graminearum in a concentration-dependent manner (P < 0.05). After 7 days of fumigation with 100 μL/L 1-octen-3-ol, the inhibition rates of mycelial growth, spore germination and deoxynivalenol production were 60.70%, 100.00% and 97.50%, respectively. Further studies showed that 1-octen-3-ol treatment effectively damaged the cell membrane integrity and increased the membrane permeability of F. graminearum, leading to a significant reduction of ergosterol levels and serious leakage of cell contents. Moreover, 1-octen-3-ol interfered with the oxidative stress balance of F. graminearum and downregulated the expression of DON biosynthesis-related genes such as TRI4, TRI5, TRI8, TRI10, TRI12, and TRI101. In conclusion, 1-octen-3-ol can effectively inhibit the growth and DON biosynthesis of F. graminearum by damaging cell membrane integrity, interfering with oxidative stress balance and regulating key gene expression.

Tyrosinase is vital in fruit and vegetable browning and melanin synthesis, crucial for food preservation and pharmaceuticals. We investigated 6′-O-caffeoylarbutin's inhibition, safety, and preservation on tyrosinase. Using HPLC, we analyzed its effect on mushroom tyrosinase and confirmed reversible competitive inhibition. UV_vis and fluorescence spectroscopy revealed a stable complex formation with specific binding, causing enzyme conformational changes. Molecular docking and simulations highlighted strong binding, enabled by hydrogen bonds and hydrophobic interactions. Cellular tests showed growth reduction of A375 cells with mild HaCaT cell toxicity, indicating favorable safety. Animal experiments demonstrated slight toxicity within safe doses. Preservation trials on apple juice showcased 6′-O-caffeoylarbutin's potential in reducing browning. In essence, this study reveals intricate mechanisms and applications of 6′-O-caffeoylarbutin as an effective tyrosinase inhibitor, emphasizing its importance in food preservation and pharmaceuticals. Our research enhances understanding in this field, laying a solid foundation for future exploration. [ABSTRACT FROM AUTHOR]

α -Glucosidase inhibitors can effectively control postprandial hyperglycemia and play a crucial role in treating type II diabetes. Geranylated compounds have been demonstrated to have strong α -glucosidase inhibitory activity, while their interaction mechanism was still unclear. In this study, we investigated the inhibition mechanisms of three structurally different geranylated compounds with significant α -glucosidase inhibition (puerarol, 8-geranyl-7, 3′-dihydroxy-4′-methoxyisoflavone, and xanthoangelol) separated from Pueraria lobata. The IC 50 values of these compounds were 6.14 ± 0.20, 2.35 ± 0.02, and 1.98 ± 0.07 μ M, respectively. It was found that puerarol acted as a non-competitive inhibitor, while 8-geranyl-7, 3′-dihydroxy-4′-methoxyisoflavone and xanthoangelol acted as un-competitive inhibitors. Fluorescence and circular dichroism data indicated that all three geranylated compounds statically quenched the fluorescence of α -glucosidase, and bound to α -glucosidase through a single binding site, inducing rearrangement of α -glucosidase and leading to conformational changes. Thermodynamic analysis and molecular docking revealed that puerarol interacted with α -glucosidase through hydrogen bonds and van der Waals forces, while the other two compounds primarily interacted through hydrophobic forces. This study elucidated the binding mechanism between three different structural geranylated compounds and α -glucosidase for the first time, which could contribute to the development of functional additives for the prevention and treatment of type II diabetes. [Display omitted] • Geranylated compounds demonstrated potent inhibitory activity against α-glucosidase. • Binding site of geranylated compounds in α-glucosidase differed from the active site. • Geranylated compounds bound to α-glucosidase by various complex forces. • Inhibition mechanism of α -glucosidase was further validated by molecular docking. [ABSTRACT FROM AUTHOR]

Cetylpyridine chloride (CPC), a quaternary ammonium compound renowned for its antimicrobial properties, has emerged as a promising tyrosinase inhibitor. However, the precise mechanism of its inhibitory effects remains elusive. Therefore, this study endeavors to elucidate CPC's inhibitory effects and molecular mechanisms through spectroscopic analyses and computational molecular docking. Our findings unveil CPC as a reversible, competitive inhibitor of tyrosinase, achieved through hydrophobic interactions that effectively obstruct the enzymatic active site. These insights prompted the evaluation of 25 CPC analogs, assessing their monophenolase and diphenolase activities. Notably, this investigation unveiled a previously unreported class of tyrosinase inhibitors, making a substantial contribution to the existing literature. Furthermore, a preliminary structure-activity relationship analysis was conducted on a series of CPC analogs, indicating the necessity of a long alkyl chain with a minimum length of 14 carbons and a hydrophilic functional group. Our results demonstrate the potential for designing novel tyrosinase inhibitors with enhanced inhibitory capabilities, while also shedding light on surfactant-protein binding mechanisms. [Display omitted] • Cetylpyridine chloride inhibits tyrosinase via hydrophobic interactions. • Evaluation of 25 analogs discovers novel tyrosinase inhibitors. • Insights: Analog chains need ≥ 14 carbons and a hydrophilic group. • Potential for enhanced tyrosinase inhibitors and surfactant-protein binding insights. [ABSTRACT FROM AUTHOR]

Inhibition of the Embryonic Ectoderm Development (EED) subunit in Polycomb Repressive Complex 2 (PRC2) can inhibit tumor growth. In this paper, we selected six experimentally designed EED competitive Inhibitors of the triazolopyrimidine derivatives class. We investigated the difference in the binding mode of the natural substrate to the Inhibitors and the effects of differences in the parent nuclei, heads, and tails of the Inhibitors on the inhibitory capacity. The results showed that the binding free energy of this class of Inhibitors was close to or lower compared to the natural substrate, providing an energetic basis for competitive inhibition. For the Inhibitors, the presence of a strong negatively charged group at the 6-position of the parent nucleus or the 8′-position of the head would make the hydrogen atom on the head imino group prone to flip, resulting in the vertical movement of the parent nucleus, which significantly decreased the inhibitory ability. When the 6-position of the parent nucleus was a nonpolar group, the parent nucleus would move horizontally, slightly decreasing the inhibitory ability. When the 8′-position of the head was methylene, it formed an intramolecular hydrophobic interaction with the benzene ring on the tail, resulting in a significant increase in inhibition ability. [ABSTRACT FROM AUTHOR]

The targeted identification of a-glucosidase inhibitors from the crude ethyl acetate of Lycopodiella cernua (L.) Pic. Serm (L.cernua) was guided by high-resolution inhibition profiling. The a-glucosidase inhibition profiling and HPLC-QTOF-MS showed tannins and serratenes were the corresponding antidiabetic constituents. Two new serratenes named 3β, 21β-dihydroxyserra-14-en-24-oic acid-3β-(4'-methoxy-5'-hydroxybenzoate) (4), 3β, 21α-dihydroxyserra-14-en-24-oic acid-3β-(4'-methoxy-5'-hydroxybenzoate) (7), together with two known compounds (5 and 6) were isolated. Their structures were elucidated by HR-ESI-MS and NMR. Compounds 5-7 inhibited the a-glucosidase activity in a non-competitive manner with Ki values ranging from 1.29 to 12.9 μM. The molecular docking result unveiled that 4-7 bound to the residues at the channel site, which enabled to block the substrate access. In addition, the molecular dynamics (MD) simulation of the most active compound 7 and a-glucosidase indicated the 40-methoxy-50-hydroxybenzoate group formed the stable hydrogen bonds and pi-pi T-shaped interactions with Arg312, Gln350 and Phe300 residues, while the rings D and E were stabilized by hydrophobic interaction. [ABSTRACT FROM AUTHOR]

The suppression effect of adding different proportions of NaCl and NaHCO3 powder on flour explosion was studied by using Hartmann experimental device and 20 L spherical explosive device. The results showed that with the increase of NaCl and NaHCO3 concentrations, the flame speed and propagation distance decreased gradually. The maximum explosion pressure Pmax and the maximum pressure rise rate (dP/dt)max decreased significantly. When 80% NaCl and NaHCO3 were added, the average flame propagation velocity reduced to 2.73 m/s and 0.56 m/s, respectively, and the maximum explosion pressure less than 0.15MPa, the flour explosion could be inhibited by NaCl and NaHCO3. NaHCO3 was more effective than NaCl in inhibiting flame propagation and explosion overpressure. Finally, combined with the pyrolysis characteristics of NaCl and NaHCO3, the mechanism of inhibitors inhibiting the explosion of flour was further studied. The endothermic decomposition of NaHCO3 produced inert gas, diluted oxygen concentration, captured active free radicals, and terminated the combustion chain reaction. NaCl inhibits the explosion of flour by absorbing heat and coating it. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main proteases (Mpro) are highly conserved cysteine‐rich proteins that can be covalently modified by numerous natural and synthetic compounds. Herein, we constructed an integrative approach to efficiently discover covalent inhibitors of Mpro from complex herbal matrices. This work begins with biological screening of 60 clinically used antiviral herbal medicines, among which Lonicera japonica Flos (LJF) demonstrated the strongest anti‐Mpro effect (IC50 = 37.82 μg/mL). Mass spectrometry (MS)‐based chemical analysis and chemoproteomic profiling revealed that LJF extract contains at least 50 constituents, of which 22 exhibited the capability to covalently modify Mpro. We subsequently verified the anti‐Mpro effects of these covalent binders. Gallic acid and quercetin were found to potently inhibit severe acute respiratory syndrome coronavirus 2 Mpro in dose‐ and time‐ dependent manners, with the IC50 values below 10 µM. The inactivation kinetics, binding affinity and binding mode of gallic acid and quercetin were further characterized by fluorescence resonance energy transfer, surface plasmon resonance, and covalent docking simulations. Overall, this study established a practical approach for efficiently discovering the covalent inhibitors of Mpro from herbal medicines by integrating target‐based high‐throughput screening and MS‐based assays, which would greatly facilitate the discovery of key antiviral constituents from medicinal plants. [ABSTRACT FROM AUTHOR]

Non-wood forest diseases affect and restrict the development of non--wood forest industry in China. Biological control has attracted more attentions for its friendliness to environment and human health. At present, biological control agents have been widely used, which can control diseases through the competition for nutrients, hyperparasitism and production of antibiotics against phytopathogens, and the stimulation of plant growth and induction of host defense mechanisms. Plant essential oils could inhibit pathogens by affecting the synthesis and function of cell wall and cell membrane of pathogens, interfering with respiration and energy metabolism of pathogens, synthesis of genetic material and related function regulation, function of biofilm and quorum sensing system. The antagonistic mechanism of biocontrol agents against pathogens and the inhibitory mechanism of plant essential oil were reviewed to provide reference for biological control of non-wood forest diseases. The potential of low cost and high efficiency plant essential oil in biological control of non-wood forest diseases was also prospected. [ABSTRACT FROM AUTHOR]

Heterocyclic amines (HAs) are a class of toxic compounds with strong teratogenic and carcinogenic activities which are produced during thermal processing of meat products. Three types of HAs, including 2-amino-3-methyl-imidazo[4,5-f]-quinoline (IQ) and 2-amino-3,4-dimethyl-imidazo[4,5-f]-quinoline (MeIQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), and 1-methyl-9H-pyrido[3,4-b]indole (harmane) and 9H-pyrido[3,4-b]indole (norharman), are common and widely distributed in heat-processed meat products. This article briefly analyzes the formation pathways and mechanisms of these HAs, elucidates the inhibitory mechanism of exogenous plant polyphenols on their formation, and clarifies the structure-activity relationship of polyphenol compounds for the inhibition of their formation. This review will provide theoretical guidance for the effective application of plant polyphenols to control the formation of HAs in heat-processed meat products.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cognitive remediation therapy interventions could improve cognitive functioning in subjects with autism. To investigate the benefit of a short cognitive training rehabilitation in children with autism spectrum disorder (ASD) on pursuit and fixation performances. We recruited two groups (G1 and G2) of 30 children with ASD, sex‐, IQ‐ and age‐matched (mean 11.6 ± 0.5 years), and pursuit and fixation eye movements were recorded twice at T1 and T2. Between T1 and T2, a 10‐min cognitive training was performed by the G1 group only, whereas the G2 group had a 10‐min of rest. For all children with ASD enrolled in the study, there was a positive correlation between restricted and repetitive behaviour scores of both Autism Diagnostic Interview‐Revised (ADI‐R) and the Autism Diagnostic Observation Schedule (ADOS) and the number of saccades recorded during the fixation task at T1. At T1, oculomotor performances were similar for both groups of ASD children (G1 and G2). At T2, we observed a significant reduction in the number of saccades made during both pursuit and fixation tasks. Our findings underlined the importance to promote cognitive training rehabilitation for children with ASD, leading to a better performance in inhibitory and attention functioning responsible for pursuit and fixation eye movement's performance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Essential oils (EOs), derived from aromatic plants, exhibit properties beneficial to health, such as anti-inflammatory, anti-oxidative, antidiabetic, and antiaging effects. However, the effect of EOs and their interaction in binary combinations against tyrosinase is not yet known. Objective: To evaluate the underlying mechanisms of EOs and their interaction in binary combinations against tyrosinas. Design: We explored to investigate the inhibitory effect of 65 EOs and the interaction among cinnamon, bay, and magnolia officinalis in their binary combinations against tyrosinase. In addition, the main constituents of cinnamon, bay, and magnolia officinalis were analyzed by gas chromatography–mass spectrometry (GC–MS). Results: The results showed that the most potent EOs against tyrosinase were cinnamon, bay, and magnolia officinalis with IC50 values of 25.7, 30.8, and 61.9 μg/mL, respectively. Moreover, the inhibitory mechanism and kinetics studies revealed that cinnamon and bay were reversible and competitive-type inhibitors, and magnolia officinalis was a reversible and mixed-type inhibitor. In addition, these results, assessed in mixtures of three binary combinations, indicated that the combination of cinnamon with bay at different dose and at dose ratio had a strong antagonistic effect against tyrosinase. Magnolia officinalis combined with cinnamon or bay experienced both antagonistic and synergistic effect in anti-tyrosinase activity. Conclusion: It is revealed that natural EOs would be promising to be effective anti-tyrosinase agents, and binary combinations of cinnamon, bay, and magnolia officinalis might not have synergistic effects on tyrosinase under certain condition.

The bioactivity and gastrointestinal stability of epicatechin gallate (ECG) may be affected by processing conditions. Results showed that the antioxidant ability and inhibitory activity on xanthine oxidase (XO) of ECG were higher at low pH values. Appropriate microwave and heating treatments improved the antioxidant (the scavenging rate increased from 71.75% to 92.71% and 80.88% under the microwave and heating treatments) and XO inhibitory activity (the inhibitory rate increased from 47.11% to 56.89% and 51.85% at the microwave and heating treatments) of ECG. The treated ECG led to a more compact structure of XO. Moreover, there may be synergistic antioxidant and inhibitory effects between ECG and its degradation products. The bioaccessibility of ECG after simulated digestion was untreated > microwave > heating, and the microwave−treated ECG still had good XO inhibitory activity after digestion. These findings may provide some significant information for the development of functional foods enriched in catechins. [ABSTRACT FROM AUTHOR]

Metabolomics has been widely used to identify changes in relevant differential metabolites. The metabolites of Saccharomyces cerevisiae cells supplemented with ferulic acid and p-coumaric acid were prepared and extracted. Untargeted metabolomics analysis of saccharomyces cerevisiae metabolites was performed. In addition, GNPS, Respect and MassBank databases were used to search and compare the information in the whole database. It was found that 100 and 92 different metabolites were significantly changed (P value < 0.05, VIP value > 1,) in Saccharomyces cerevisiae cells treated with ferulic acid and p-coumaric acid respectively. Including isothiocyanate, L-threonine, adenosine, glycerin phospholipid choline, niacinamide and palmitic acid. These metabolites with significant differences were enriched by KEGG pathway using MetPA database. [ABSTRACT FROM AUTHOR]

Human islet amyloid polypeptide (hIAPP) is the major component of the amyloid deposited in the pancreas of patients with type 2 diabetes mellitus. Its aggregation and consequent production of intermediates are believed to be responsible for its cytotoxicity and pathological processes. Recently, graphene quantum dots (GQDs) are proved to effectively inhibit a range of amyloid deposits. This work focuses on the influence of the charged GQDs on hIAPP inhibition. Microsecond all-atom molecular dynamics simulations in explicit water were performed to study the influence of charged GQDs on the structural stability of hIAPP fibril. GQDs were found to be able to destabilize the hIAPP fibril and reduce the β-sheet content. The stability of the hydrophobic core was greatly disturbed, and the hydrogen bond formation at protofibril interfaces was also hindered. The negatively and positively charged GQDs have different binding sites, dynamics, and interactions at hIAPP fibril, which is dominated by electrostatic interaction and assisted by π–π stacking, salt bridge, and hydrogen bonding interactions. The π–π stacking between GQDs and hIAPP may be influenced by the electrostatic interaction in a facilitative or competitive manner. In addition, the negatively charged GQD is suggested to be a better candidate of amyloid inhibition than the positively charged one in disruptive effect, binding modes, and binding intensity. These findings may provide useful perspectives for the design of nanomedicine for amyloid inhibition and are helpful to the development of diagnosis and screening nanotechnology for neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Torreya grandis meal has a high protein content and an appropriate amino acid ratio, making it an excellent protein source for producing ACE inhibitory peptides. To promote its application in food, medicine, and other fields, an alkaline protease hydrolysate of Torreya grandis was used in this study to isolate and identify a novel angiotensin-converting enzyme inhibitory peptide, VNDYLNW (VW-7), using ultrafiltration, gel chromatography purification, LC-MS/MS, and in silico prediction. The results show that the IC50 value of VW-7 was 205.98 µM. The Lineweaver–Burk plot showed that VW-7 had a mixed-type inhibitory effect on ACE. Meanwhile, according to the results of molecular docking, VW-7 demonstrated a strong affinity for ACE (binding energy −10 kcal/mol). VW-7 was bound to ACE through multiple binding sites. In addition, VW-7 could remain active during gastrointestinal digestion in vitro. Nitric oxide (NO) generation in human endothelial cells could rise after receiving a pretreatment with VW-7. These results indicated that Torreya grandis meal protein can be developed into products with antihypertensive function, and VW-7 has broad application prospects in the field of antihypertensive. [ABSTRACT FROM AUTHOR]

Autoimmune coagulation factor XIII (FXIII) deficiency (AiF13D) is a bleeding disorder caused by anti‐FXIII autoantibodies. Recently, we generated human monoclonal antibodies (mAbs) from the peripheral blood of an AiF13D patient and classified them into three groups: FXIII‐dissociation inhibitor, FXIII‐assembly inhibitor, and non‐neutralizing/inhibitory mAbs. However, the epitope region and molecular inhibitory mechanism of each mAb remain unknown. Here, we localized the epitope regions of the representative inhibitory mAbs A69K (dissociation inhibitor) and A78L (assembly inhibitor) to the β‐barrel‐2 domain and boundary of β‐barrel‐1&2 domains, respectively, of the FXIII‐A subunit, by combining a binding assay using its synthesized peptides and a protease‐protection assay. Our findings suggest that A69K inhibits the activation‐related conformational changes and dissociation of FXIII and that A78L competitively inhibits FXIII‐assembly. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)