Natural sources,refined extraction,biosynthesis,metabolism,and bioactivities of dietary polymethoxyflavones(PMFs)

Polymethoxyflavones(PMFs)are a type of uncommon dietary flavonoids,characterized by more than one methoxy group,which exist in limited plant species,like Citrus species and Kaempferia parviflora.In addition,different PMFs,such as nobiletin,sinensetin,tangeretin,and casticin,have been isolated from these natural sources.PMFs have received increasing attention due to their multiple bioactivities,such as antioxidant,anti-inflammatory,anti-cancer,metabolic regulatory,immunoregulatory,neuroprotective,and skin protective effects.These bioactivities of PMFs should be associated with the regulation of critical molecular targets and the interaction with gut microbiota.In order to provide a comprehensive and updated review of PMFs,their natural sources,refined extraction,biosynthesis,metabolism,and bioactivities are summarised and discussed,with the emphasis on the molecular mechanisms of PMFs on regulating different chronic diseases.Overall,PMFs may be promising flavonoids to the forefront of nutraceuticals for the prevention and/or treatment of certain human chronic diseases.

Structural identification and antioxidative activity evaluation of flaxseed lignan macromolecules: structure-activity correlation

Flaxseed lignan macromolecules(FLM)are a class of important secondary metabolites in fl axseed,which have been widely concerned due to their biological and pharmacological properties,especially for their antioxidative activity.For the composition and structure of FLM,our results confirmed that ferulic acid glycoside(FerAG)was directly ester-linked with herbacetin diglucoside(HDG)or pinoresinol diglucoside(PDG),which might determine the beginning of FLM biosynthesis.Additionally,p-coumaric acid glycoside(CouAG)might determine the end of chain extension during FLM synthesis in fl axseed.FLM exhibited higher antioxidative activity in polar systems,as shown by its superior 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging capacity compared to the 2,2’-azinobis(3-ehtylbenzothiazolin-6-sulfnic acid)(ABTS)cation free radical scavenging capacity in non-polar systems.Moreover,the antioxidative activity of FLM was found to be highly dependent on its composition and structure.In particular,it was positively correlated with the number of phenolic hydroxyl groups(longer FLM chains)and inversely related to the steric hindrance at the ends(lower levels of FerAG and CouAG).These fi ndings verifi ed the potential application of FLM in nonpolar systems,particularly in functional food emulsions。

Evaluation of the binding affinity and antioxidant activity of phlorizin to pepsin and trypsin

Phlorizin(PHL)is a natural compound with strong antioxidant properties mainly found in apples.In this paper,the interaction mechanism of PHL with pepsin and trypsin was comparatively evaluated by computer simulation,fluorescence spectra,circular dichroism(CD),and Fourier transform infrared(FT-IR)spectra at a molecular level.Fluorescence spectra showed that PHL quenches the pepsin/trypsin by static quenching.Thermodynamic parameters indicated that PHL binds to pepsin mainly through hydrogen bonds and van der Waals forces,and that of trypsin was electrostatic forces.The ground state complexes PHL and protease have a moderate affinity of 105 L/mol PHL binds more strongly to trypsin than to pepsin.CD and FT-IR spectra results showed that pepsin/trypsin decreased theβ-sheet content and slightly changed its secondary structure upon PHL.These experimental results are mutually verified with the predicted computer-aid simulation results.Upon PHL and trypsin binding,the antioxidant capacity of PHL was elevated.Nevertheless,the antioxidant capacity of PHL was decreased after binding to pepsin.This work elucidates the binding of PHL binding mechanisms to pepsin/trypsin and provides useful information for the digestion of PHL to improve the application of PHL in food processing.

Effects of potassium lactate on sensory attributes,bacterial community succession and biogenic amines formation in Rugao ham

To deepen the understanding in the effect of potassium lactate on the sensory quality and safety of Rugao ham,sensory attributes,physicochemical parameters,total volatile basic nitrogen(TVBN),microorganism community and biogenic amines of Rugao ham manufactured with different potassium lactate levels(0%,0.5%,1%,2%)were investigated;the relationship between microbial community and the formation of TVBN and biogenic amines was further evaluated.With the increase of potassium lactate from 0%to 2%,the increased sensory scores and the decreased total aerobic bacterial count and TVBN were observed;the abundance of Staphylococcus increased,while the content of Halomonas decreased.LDA effect size(LEf Se)and correlations analysis showed that Staphylococcus equorum and Lactobacillus fermentum could be the key species to improve sensory scores and decrease biogenic amines and TVBN.Metabolic pathway analysis further showed that amino acids metabolism and nitrogen metabolism were mainly involved in decreasing TVBN and biogenic amines in the treatment of 2%potassium lactate.

基于超低温诱导的风味咖啡滋味及抗氧化活性分析

以卡蒂姆咖啡鲜果为研究对象,分析超低温(-40℃)、低温(-20℃)、软冻温度(-7℃)、冰温(-2℃)、冷藏温度(4℃)、常温(25℃)处理咖啡鲜果后咖啡熟豆的生物碱、有机酸含量及抗氧化活性,利用系统聚类对结果进行分类分析,最后通过感官评定进行验证。结果显示:不同温度处理咖啡后酸味相关化合物苹果酸含量由低到高为-40℃<25℃<-20℃<4℃<-7℃<-2℃,苦涩味相关化合物奎宁酸含量由低到高为-40℃<25℃<4℃<-20℃<-7℃<-2℃,葫芦巴碱含量由低到高为-40℃<25℃<4℃<-20℃<-2℃<-7℃。-40℃处理咖啡鲜果,其苹果酸、奎宁酸、葫芦巴碱含量均为最低,分别为3.83、531.91、9.31 mg/g。-40℃处理感官评分最高,能得到诸如热带水果、牛奶巧克力、黑莓等风味。不同温度处理咖啡鲜果后咖啡熟豆中多酚、黄酮含量差异显著,1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl radical,DPPH)、2,2’-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐[2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS]阳离子自由基清除能力差异显著。系统聚类(平方欧式距离为15)获得的分类结果与滋味呈味物质含量、抗氧化性结果一致。综上可得,超低温(-40℃)诱导处理咖啡鲜果可获得风味独特的咖啡。

Physical and emulsifying properties of pea protein:influence of combined physical modification by flaxseed gum and ultrasonic treatment

This study characterized and compared the physical and emulsifying properties of pea protein(PP)and its modified proteins(ultrasound treated-PP(PPU),flaxseed gum(FG)treated PP(PPFG)and ultrasound treated-PPFG(PPFGU)).The results showed FG triggered the formation of loosely attached complex with PP via physical modification under gentle magnetic stirring at pH 7.0,while ultrasound played an important role in reducing protein size,increasing surface hydrophobicity and molecular fluidity onto oil-water interface.So ultrasound further enhanced the interaction of PP with FG,and produced the PPFGU complex with smaller droplet size,higherζ-potential and lower turbidity.Further,combination of FG and ultrasound improved the physical properties of PP with higher viscosity,stiffer gels(defined as higher elastic modulus),stronger hydrophobic properties,better thermal stability,and fast protein absorption rate.Therefore,the PPFGU coarse emulsion performed highest emulsifying activity index(EAI)and emulsion stability index(ESI)that the stabilized nanoemulsion obtained smallest droplet size,higherζ-potential,and longest storage stability.The combination of FG and ultrasonic treatment will be an effective approach to improving the emulsifying property and thermal stability of PP,which can be considered as a potential plant-based emulsifier applied in the food industry.

Study on β-TCP Coated Porous Mg as a Bone Tissue Engineering Scaffold Material

Three-dimensional honeycomb-structured magnesium （Mg） scaffolds with interconnected pores of accurately controlled pore size and porosity were fabricated by laser perforation technique. Biodegradable and bioactiveβ- tricalcium phosphate （β-TCP） coatings were prepared on and the biodegradation mechanism was simply evaluated the porous Mg to further improve its biocompatibility, in vitro. It was found that the mechanical properties of this type of porous Mg significantly depended on its porosity. Elastic modulus and compressive strength similar to human bones could be obtained for the porous Mg with porosity of 42.6%-51%. It was observed that the human osteosarcoma cells （UMR106） were well adhered and proliferated on the surface of the β- TCP coated porous Mg, which indicates that theβ-TCP coated porous Mg is promising to be a bone tissue engineering scaffold material.

Bacteroides utilization for dietary polysaccharides and their beneficial effects on gut health

Polysaccharide was a class of macromolecular substance with various bioactive functions.Gut symbiotic microorganisms could utilize the polysaccharides from various sources,thus have important impact on human health.Bacteroides represented one of the dominant colonizers in the human gut.The utilization of polysaccharide by Bacteroides was important for supporting the function and stability of gut microbiota.After the degradation of polysaccharides by Bacteroides,gut microbes could ferment the monosaccharides and oligosaccharides degraded from polysaccharides into some metabolites,such as short-chain fatty acids(SCFAs),amino acids,etc.Among the metabolites,the SCFAs could have beneficial effects on gut health.This review summarized the niches of Bacteroides among gut microbiota,and also described the gene clusters and membrane proteins involved in the utilization processes of polysaccharide by gut Bacteroides.SCFAs could act as energy substrates for intestinal epithelial cells,inhibit histone deacetylases and activate G protein-coupled receptors.In addition,the future perspectives in investigating new degradation pathways for polysaccharide,and using polysaccharides or their metabolites as therapeutic approaches for diseases mediated by the gut dysbiosis were also provided.

Transcriptome-based insights into the calcium transport mechanism of chick chorioallantoic membrane

Chorioallantoic membrane(CAM)is responsible for respiratory gas exchange,eggshell calcium transport,embryonic acid-base equilibrium,allantoic ion,and water reabsorption during avian embryonic development.To further understand the timing of CAM gene expression during chick embryonic development,especially the calcium absorption mechanism,transcriptome quantitative comparative analysis was conducted on chick CAM during the embryonic period(E)of 9,13,17,and 20 days.A total of 6378 differentially expressed genes(DEGs)were identified.Functional enrichment analysis of DEGs showed that CAM DEGs were mainly involved in biological processes such as"ion transport regulation","immune response"and"cell cycle".Time series analysis of the differential genes showed that the functional cells of CAM began to proliferate and differentiate at E9 and the calcium content of egg embryo increased significantly at E13.Simultaneously,the observation of the ultrastructure of the eggshell showed that the interstice of the fiber layer was enlarged at E13,and the mastoid layer was partly exposed.Therefore,it is preliminarily inferred that CAM calcium transport starts at E13,and genes such as TRPV6,S100 A10,and RANKL cooperate to regulate calcium release and transport.

Subfunctionalization of cation/proton antiporter 1 genes in grapevine in response to salt stress in different organs

Cation/proton antiporter 1(CPA1)proteins function as regulators of monovalent ions,pH homeostasis,and other developmental processes in plants.Better understanding of the expression and regulation of CPA1 in plant responses to salinity would help the development of scientific practices in crops worldwide.In this report,we characterized all seven CPA1 family genes in grapevine(Vitis vinifera)in response to short-term osmotic and NaCl stresses.We found that two of the seven genes have subfunctionalized to be differentially expressed in response to NaCl stress in the early stage in different organs,whereas the other five members seem to play little or no role in this response.Specifically,VIT_19s0090g01480 may control Na+compartmentalization in grapevine roots;and VIT_05s0020g01960 may influence Na+transfer in stems.Based on the dynamics of ion concentrations,electrolyte leakage rates,and CPA1 gene expression in root,stem,and leaf tissues under osmotic and NaCl stresses,we suggest how grapevine responds physiologically and molecularly to the osmotic and ion toxicity of NaCl stress in the short term.This work lays a foundation for future research on the CPA1 gene family regarding its evolutionary history and biological functions for modulating salt responses in grapevine.

Primary cilia mediate Klf2-dependant Notch activation in regenerating heart

Unlike adult mammalian heart,zebrafish heart has a remarkable capacity to regenerate after injury.Previous study has shown Notch signaling activation in the endocardium is essential for regeneration of the myocardium and this activation is mediated by hemodynamic alteration after injury,however,the molecular mechanism has not been fully explored.In this study we demonstrated that blood flow change could be perceived and transmitted in a primary cilia dependent manner to control the hemodynamic responsive klf2 gene expression and subsequent activation of Notch signaling in the endocardium.First we showed that both homologues of human gene KLF2 in zebrafish,klf2a and klf2b,could respond to hemodynamic alteration and both were required for Notch signaling activation and heart regeneration.Further experiments indicated that the upregulation of klf2 gene expression was mediated by endocardial primary cilia.Overall,our findings reveal a novel aspect of mechanical shear stress signal in activating Notch pathway and regulating cardiac regeneration.

May 2022 Greedy Kaczmarz Algorithm Using Optimal Intermediate Projection Technique for Coherent Linear Systems

The Kaczmarz algorithm is a common iterative method for solving linear systems.As an effective variant of Kaczmarz algorithm,the greedy Kaczmarz algorithm utilizes the greedy selection strategy.The two-subspace projection method performs an optimal intermediate projection in each iteration.In this paper,we introduce a new greedy Kaczmarz method,which give full play to the advantages of the two improved Kaczmarz algorithms,so that the generated iterative sequence can exponentially converge to the optimal solution.The theoretical analysis reveals that our algorithm has a smaller convergence factor than the greedy Kaczmarz method.Experimental results confirm that our new algorithm is more effective than the greedy Kaczmarz method for coherent systems and the two-subspace projection method for appropriate scale systems.