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 a...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.展开更多
Organic-inorganic MoO_(3)/PI(MoPI)composites were prepared using a simple one-pot thermal copolymerization method.The resulting composites exhibited enhanced photocatalytic activity for the selective oxidation of benz...Organic-inorganic MoO_(3)/PI(MoPI)composites were prepared using a simple one-pot thermal copolymerization method.The resulting composites exhibited enhanced photocatalytic activity for the selective oxidation of benzylamine to N-benzylidene benzylamine(N-BDBA)in ambient air under simulated solar light irradiation compared to pristine MoO_(3) or polyimide(PI).In particular,the MoPI composite with a 0.3:1 molar ratio of Mo to melamine,referred to as MoPI-0.3,demonstrated the best performance in the photo-oxidation of benzylamine,achieving a benzylamine conversion of 95%with a N-BDBA selectivity exceeding 99%after 3 h irradiation.The enhanced photocatalytic activity of the MoPI-0.3 catalyst was attributed to the formation of a direct Z-scheme heterojunction between MoO_(3) and PI,facilitating more efficient separation of the photoinduced electrons and holes.Additionally,the MoPI-0.3 composite maintained considerably high activity over four consecutive cycles,highlighting its good stability and recyclability.Furthermore,the MoPI-0.3 composite could photo-oxidize benzylamine derivatives and heterocyclic amines to their corresponding imines,demonstrating the universal applicability of this composite catalyst.展开更多
Trace amines(TAs)are metabolically related to catecholamine and associated with cancer and neurological disorders.Comprehensive measurement of TAs is essential for understanding pathological processes and providing pr...Trace amines(TAs)are metabolically related to catecholamine and associated with cancer and neurological disorders.Comprehensive measurement of TAs is essential for understanding pathological processes and providing proper drug intervention.However,the trace amounts and chemical instability of TAs challenge quantification.Here,diisopropyl phosphite coupled with chip two-dimensional(2D)liquid chromatography tandem triple-quadrupole mass spectrometry(LC-QQQ/MS)was developed to simultaneously determine TAs and associated metabolites.The results showed that the sensitivities of TAs increased up to 5520 times compared with those using nonderivatized LC-QQQ/MS.This sensitive method was utilized to investigate their alterations in hepatoma cells after treatment with sorafenib.The significantly altered TAs and associated metabolites suggested that phenylalanine and tyrosine metabolic pathways were related to sorafenib treatment in Hep3B cells.This sensitive method has great potential to elucidate the mechanism and diagnose diseases considering that an increasing number of physiological functions of TAs have been discovered in recent decades.展开更多
Numerous small-molecule amines(SMAs)play critical roles in maintaining bone homeostasis and promoting bone regeneration regardless of whether they are applied as drugs or biomaterials.On the one hand,SMAs promote bone...Numerous small-molecule amines(SMAs)play critical roles in maintaining bone homeostasis and promoting bone regeneration regardless of whether they are applied as drugs or biomaterials.On the one hand,SMAs promote bone formation or inhibit bone resorption through the regulation of key molecular signaling pathways in osteoblasts/osteoclasts;on the other hand,owing to their alkaline properties as well as their antioxidant and anti-inflammatory features,most SMAs create a favorable microenvironment for bone homeostasis.However,due to a lack of information on their structure/bioactivity and underlying mechanisms of action,certain SMAs cannot be developed into drugs or biomaterials for bone disease treatment.In this review,we thoroughly summarize the current understanding of SMA effects on bone homeostasis,including descriptions of their classifications,biochemical features,recent research advances in bone biology and related regulatory mechanisms in bone regeneration.In addition,we discuss the challenges and prospects of SMA translational research.展开更多
Meat products are an important part in our daily diet,providing valuable nutrients for the human body.However,heating processes cause the meat to become more appetizing with changes in texture,appearance,flavor,and ch...Meat products are an important part in our daily diet,providing valuable nutrients for the human body.However,heating processes cause the meat to become more appetizing with changes in texture,appearance,flavor,and chemical properties by the altering of protein structure and other ingredients.As one kind of cooking-induced contaminants,heterocyclic aromatic amines(HAAs)are widely present in protein aceous food products with strong carcinogenic and mutagenic properties.In order to promote the safety of traditional meat products,this review focused on the formation,metabolism,biological monitoring and inhibitory mechanism of HAA.An overview of the formation pathways,hazards,and control methods of HAAs during food processing in recent years was studied,aiming to provide some valuable information for exploring effective methods to inhibit the production of associated hazards during food processing.Systematic selection of different types of flavonoids to explore their effects on the formation of HAAs in an actual barbecue system can provide theoretical reference for effectively controlling the formation of HAAs and reducing their harm to human health.展开更多
Polyimide(PI) is an organic polymer material with good stability and diverse sources that has attracted widespread attention in the field of photocatalysis. In this study, a series of PI photocatalysts were synthesize...Polyimide(PI) is an organic polymer material with good stability and diverse sources that has attracted widespread attention in the field of photocatalysis. In this study, a series of PI photocatalysts were synthesized by a thermal polymerization approach using pyromellitic dianhydride(PMDA) and various diamine monomers(melamine(MA), 4,4′-oxydianiline, and melem) as the precursors as well as different heating rates. The effects of the diamine precursor and heating rate on the structure, composition, morphology, and optical properties of the as-prepared PI materials were systematically investigated by various characterization techniques. The selective photo-oxidation of benzylamine was used as a model reaction to evaluate the photocatalytic activities of the resulting PI samples for the oxidation of amines to imines. The results revealed that the PI sample prepared using MA and PMDA as the precursors and a heating rate of 7 ℃/min(MA-PI-7) exhibited the best catalytic performance, with 98% benzylamine conversion and 98% selectivity for N-benzylidene benzylamine after 4 h of irradiation. Several benzylamine derivatives and heterocyclic amines also underwent the photo-oxidation reaction over the MA-PI-7 catalyst to afford the corresponding imines with good activity. In addition, MA-PI-7 exhibited good stability over four successive photocatalytic cycles.展开更多
Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via r...Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.展开更多
Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years,we developed two sustainable routes(i.e.,the impregnation method and the one-pot synthesis)to prepa...Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years,we developed two sustainable routes(i.e.,the impregnation method and the one-pot synthesis)to prepare the hydrochar-supported catalysts and tested its catalytic performance on the reductive amination.Several techniques,such as TEM,XRD and XPS,were adopted to characterize the structural and catalytic features of samples.Results indicated that the impregnation method favors the formation of outer-sphere surface complexes with porous structure as well as well-distributed metallic nanoparticles,while the one-pot synthesis tends to form the inner-sphere surface complexes with relatively smooth appearance and amorphous metals.This difference explains the better activity of catalysts prepared by the impregnation method which can selectively convert benzaldehyde to benzylamine with an excellent yield of 93.7%under the optimal reaction conditions;in contrast,the catalyst prepared by the one-pot synthesis only exhibits a low selectivity near to zero.Furthermore,the gram-scale test catalyzed by the same catalysts exhibits a similar yield of benzylamine in comparison to its smaller scale,which is comparable to the previously reported heterogeneous noble-based catalysts.More surprisingly,the prepared catalysts can be expediently recycled by a magnetic bar and remain the satisfying catalytic activity after reusing up to five times.In conclusion,these developed catalysts enable the synthesis of functional amines with excellent selectivity and carbon balance,proving cost-effective and sustainable access to the wide application of reductive amination.展开更多
In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4...In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid (IL) phase was injected directly into the high performance liquid chromatography (HPLC) system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection (LOD, S/N = 3) for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations (R.S.D., n = 6) were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.展开更多
In current paper, a quantitative structure-activity relationship (QSAR) study was performed for the prediction of acute toxicity of aromatic amines. A set of 56 compounds was randomly divided into a training set of ...In current paper, a quantitative structure-activity relationship (QSAR) study was performed for the prediction of acute toxicity of aromatic amines. A set of 56 compounds was randomly divided into a training set of 46 compounds and a test set of 10 compounds. The electronic and topological descriptors computed by the Scigress package and Dragon software were used as predictor variables. Multiple linear regression (MLR) and support vector machine (SVM) were utilized to build the linear and nonlinear QSAR models, respectively. The obtained models with five descriptors show strong predictive ability. The linear model fits the training set with R2 = 0.71, with higher SVM values of R2 = 0.77. The validation results obtained from the test set indicate that the SVM model is comparable or superior to that obtained by MLR, both in terms of prediction ability and robustness.展开更多
Presented in several types of food, bioactive amines are described as organic bases of low molecular weight. They have vasoactive, psychoactive and toxicological characteristics and constitute a potential health risk....Presented in several types of food, bioactive amines are described as organic bases of low molecular weight. They have vasoactive, psychoactive and toxicological characteristics and constitute a potential health risk. The concentration of amines formed in foods depends on the type of microorganisms present, the action of decarboxylase enzymes produced by microorganisms on specific amino acids and favorable conditions for enzymatic activity. The presence of these chemical metabolites has been suggested as a quality indicator in routine analyzes for food production and marketing monitoring. The detection of bioactive amines can be performed by chromatographic methods, fluorometric and enzymatic kits. Bioactive amine formation can be prevented mainly through the adoption of good manufacturing practices, but the industry can also use other methods such as temperature control in the production chain, modified atmosphere packaging and food irradiation. This review aims to address the formation of bioactive amines in foods, emphasizing the formation and classification of these metabolites, aspects related to health, acceptable limits, detection methods and control methods used in the industry to ensure food safety and quality. The success of this approach is linked to the importance of bioactive amines as quality indicators, as well as the discussion on the development of methodologies for determining these substances and discussion of acceptable parameters in food.展开更多
The regulation of three biogenic amines over the reproductive neuroendoerine activity of the male Scylla serrata was investigated by in vivo injection and in vitro incubation. The testicular index, the ratio of the ma...The regulation of three biogenic amines over the reproductive neuroendoerine activity of the male Scylla serrata was investigated by in vivo injection and in vitro incubation. The testicular index, the ratio of the mature sections in testes, and the ratio of Type B cells in androgenic gland were taken as the quantitative indexes. The in vivo injections indicated that: 5-HT can significantly promote the testicular development and the secretion of the androgenic gland in S. serrata; DA can inhibit the testicular development, but no influence on the secretion of the androgenic gland was found; no significant difference was observed between the OA-injected group and the concurrent control group. In vitro incubations showed that: 5-HT can stimulate the secretion of the brain and the thoracic ganglia, thus accelerating that of the androgenic gland; however, neither OA nor DA showed any significant influence on the secretion of the brain and the thoracic ganglionic mass. As to the optic ganglia, the three biogenic amines hardly have any effect on its secretion. It is the first time to report the regulation of biogenic amines over the reproductive neuroendocrine of male crustaceans through vitro experiments. Results corroborate that 5-HT activates the brain and the thoracic ganglia to secret GSH first, then promote the testicular development through the activity of the androgenic gland.展开更多
The hydrolysis process of the anticancer agents novel non-classical transplatinum( Ⅱ ) with aliphatic amines and the influence of solvent models therein have been studied by using hybrid density functional theory ...The hydrolysis process of the anticancer agents novel non-classical transplatinum( Ⅱ ) with aliphatic amines and the influence of solvent models therein have been studied by using hybrid density functional theory (B3LYP). In this study, the stepwise hydrolysis, trans[PtCl2(Am)(isopropylamine)] + 2H2O → trans-[Pt(Am)(isopropylamine)(OH2)2]^2++ 2Cl^-, was explored. Implicit solvent effects were incorporated through polarized continuum models. The stationary points on the potential energy surfaces for the first and second hydrolysis steps,proceeding via a general SN2 pathway, were fully optimized and characterized. It was found that the first hydrolysis reaction is easier than the second one and the hydrolysis of trans- [PtCl2-(isopropylamine)2] is the easiest in our studying systems. The result can assist in under- tanding the hydrolysis mechanism of trans-[PtCl2(Am)(isopropylamine)] and designing novel Pt-based anticancer drugs.展开更多
The aim of the present study was to compare the ability of the myricetin and quercetin to modulate the oxidative DNA damage induced by 2-amino-3, 8- dimethylimidazo [4,5-f] quinoxaline (8-MeIQx), 2-amino- 3, 4, 8- tri...The aim of the present study was to compare the ability of the myricetin and quercetin to modulate the oxidative DNA damage induced by 2-amino-3, 8- dimethylimidazo [4,5-f] quinoxaline (8-MeIQx), 2-amino- 3, 4, 8- trimethylimidazo [4, 5-f]-quinoxaline (4,8-diMeIQx) and 2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (PhIP), in human hepatoma cells. DNA damage (strand breaks and oxidized purines/pyrimidines) was evaluated by the alkaline single-cell gel electrophoresis or comet assay. None of the myricetin and quercetin concentrations tested protected against 8-MeIQx, 4, 8-diMeIQx and PhIP-induced DNA strand breaks. The oxidized pyrimidines induced by 4, 8-diMeIQx and PhIP were reduced by myricetin but not by quercetin. Quercetin reduced the oxidized purines induced by 8-MeIQx and PhIP, while myricetin also reduced the induced by 4, 8-diMeIQx. One feasible mechanism by which myricetin and quercetin exert their protective effect towards HCAs-induced oxidative DNA could be related in part to the reduction of human CYP1A1. Another mechanism claimed to be responsible for the protective effect of myricetin and quercetin is the induction of phase II metabolizing enzymes such as UDP-glucuronyltrasferase (UGT). The ethoxyresorufin O-deethylation (CYP1A1) activity was moderately inhibited by myricetin, while little effect was observed by quercetin. On the contrary, quercetin showed the greatest increase on UDP-glucuronyltransferase activity. However, these are not the only mechanisms by which myricetin and quercetin exert their protective effect, other mechanisms such as stimulation of the repair of carcinogen-induced DNA damage and or the free radical scavenging efficiency have been also implicated. In conclusion, our results clearly indicate that myricetin was more efficient than quercetin to prevent DNA damage (oxidized purines and pyrimidines) induced by the three HCAs evaluated. This protective effect depends on the chemical structure of flavonoid and the mutagen studied.展开更多
A facile synthesis of N-methyl-N-aryl carbamates from aromatic amines and dimethyl carbonate (DMC) has been achieved with high yields in the presence of potassium carbonate (K2CO3)and tetrabutylammonium bromide (Bu4NB...A facile synthesis of N-methyl-N-aryl carbamates from aromatic amines and dimethyl carbonate (DMC) has been achieved with high yields in the presence of potassium carbonate (K2CO3)and tetrabutylammonium bromide (Bu4NBr) under solvent-free conditions.展开更多
In this paper,a method of extracting phenols from coal tar by amines aqueous solution was proposed.The effects of various amines on the extraction properties of phenols in coal tar were researched from the views of mo...In this paper,a method of extracting phenols from coal tar by amines aqueous solution was proposed.The effects of various amines on the extraction properties of phenols in coal tar were researched from the views of molecular structure.The parameters such as molar ratio,concentration,extraction time and temperature for the extraction of coal tar by the monoethanolamine and ethylenediamine aqueous solution were examined.The results show that the organic amine with more amino groups,hydroxyl structure and strong electronegativity exhibited better extraction performance.Under the optimal conditions,the extraction yields of phenols in coal tar by the monoethanolamine or ethylenediamine aqueous solution are above 80%,and the recovery yields of amines reach 99%.Furthermore,the probable geometries of complexes formed by the combination of phenols and organic amines were calculated by density function theory.In addition,several thermodynamic models were evaluated through comparing the relative deviation of simulation results by ASPEN PLUS to the experimental ones,which provide feasibility thermodynamic models for the simulation of extraction process.The present work affords a mild,efficient and green approach for the extraction of phenols from coal tar by an aqueous solution of amines in industry application.展开更多
A convenient, efficient, one-pot, novel process has been developed for the synthesis of carbamates from corresponding alkyl halides and amines using basic resin/CO2 system.
Five marinades were developed using natural antioxidants. Based on a consumer test of the appearance, three marinades were chosen for further investigation: an oregano, an acerola and a Dijon marinade, the Dijon marin...Five marinades were developed using natural antioxidants. Based on a consumer test of the appearance, three marinades were chosen for further investigation: an oregano, an acerola and a Dijon marinade, the Dijon marinade containing acerola, sumac and oregano. A barbecue and a sumac marinade were not included in the further study. In a home use test, consumers barbecued pork chops with the three marinades. Most of the consumers preferred the oregano and the Dijon marinade, while the acerola marinade was less liked. After controlled cooking using both direct and indirect heat to a core temperature of 65°C and 80°C, the content of the heterocyclic aromatic amines (HCA) PhiP, MeIQx, DiMeIQx, Harman and Norharman was analysed. All of the marinades reduced the content of MeIQx and DiMeIQx, although only with indirect heat, while PhiP was reduced using both grilling methods. Surprisingly, in particular the content of Harman—and to a lesser extent Norhaman—was very high in the Dijon-marinated chops. The results demonstrated that it was possible to develop well-liked marinades that can reduce the formation of selected HCAs.展开更多
基金supported by National Natural Science Foundation of China(32022066,32101975)Zhejiang Province Natural Science Foundation(LQ22C200017)+1 种基金China Postdoctoral Foundation(2020M681806,2021T140348)Science and Technology Programs of Ningbo(202003N4130,202002N3067)。
文摘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.
文摘Organic-inorganic MoO_(3)/PI(MoPI)composites were prepared using a simple one-pot thermal copolymerization method.The resulting composites exhibited enhanced photocatalytic activity for the selective oxidation of benzylamine to N-benzylidene benzylamine(N-BDBA)in ambient air under simulated solar light irradiation compared to pristine MoO_(3) or polyimide(PI).In particular,the MoPI composite with a 0.3:1 molar ratio of Mo to melamine,referred to as MoPI-0.3,demonstrated the best performance in the photo-oxidation of benzylamine,achieving a benzylamine conversion of 95%with a N-BDBA selectivity exceeding 99%after 3 h irradiation.The enhanced photocatalytic activity of the MoPI-0.3 catalyst was attributed to the formation of a direct Z-scheme heterojunction between MoO_(3) and PI,facilitating more efficient separation of the photoinduced electrons and holes.Additionally,the MoPI-0.3 composite maintained considerably high activity over four consecutive cycles,highlighting its good stability and recyclability.Furthermore,the MoPI-0.3 composite could photo-oxidize benzylamine derivatives and heterocyclic amines to their corresponding imines,demonstrating the universal applicability of this composite catalyst.
基金supported by the Science and Technology Development Fund,Macao,China(Grant No.:FDCT0044/2018/AFJ).
文摘Trace amines(TAs)are metabolically related to catecholamine and associated with cancer and neurological disorders.Comprehensive measurement of TAs is essential for understanding pathological processes and providing proper drug intervention.However,the trace amounts and chemical instability of TAs challenge quantification.Here,diisopropyl phosphite coupled with chip two-dimensional(2D)liquid chromatography tandem triple-quadrupole mass spectrometry(LC-QQQ/MS)was developed to simultaneously determine TAs and associated metabolites.The results showed that the sensitivities of TAs increased up to 5520 times compared with those using nonderivatized LC-QQQ/MS.This sensitive method was utilized to investigate their alterations in hepatoma cells after treatment with sorafenib.The significantly altered TAs and associated metabolites suggested that phenylalanine and tyrosine metabolic pathways were related to sorafenib treatment in Hep3B cells.This sensitive method has great potential to elucidate the mechanism and diagnose diseases considering that an increasing number of physiological functions of TAs have been discovered in recent decades.
基金the support for this work from the National Natural Science Foundation of China [Grant Nos.32122046,32000959,82030067,and 82161160342]the National Key R&D Program [Grant No.2018YFA0703100]+3 种基金the Youth Innovation Promotion Association of CAS [Grant No.2019350]the Guangdong Natural Science Foundation [Grant No.2020A1515111190]the Shenzhen Fundamental Research Foundation [Grant Nos.JCYJ20190812162809131,JCYJ20200109114006014,JCYJ20210324113001005,JCYJ20210324115814040,and JSGGKQTD20210831174330015]the Shenzhen Fund for Guangdong Provincial High-level Clinical Key Specialties [Grant No.SZGSP001]。
文摘Numerous small-molecule amines(SMAs)play critical roles in maintaining bone homeostasis and promoting bone regeneration regardless of whether they are applied as drugs or biomaterials.On the one hand,SMAs promote bone formation or inhibit bone resorption through the regulation of key molecular signaling pathways in osteoblasts/osteoclasts;on the other hand,owing to their alkaline properties as well as their antioxidant and anti-inflammatory features,most SMAs create a favorable microenvironment for bone homeostasis.However,due to a lack of information on their structure/bioactivity and underlying mechanisms of action,certain SMAs cannot be developed into drugs or biomaterials for bone disease treatment.In this review,we thoroughly summarize the current understanding of SMA effects on bone homeostasis,including descriptions of their classifications,biochemical features,recent research advances in bone biology and related regulatory mechanisms in bone regeneration.In addition,we discuss the challenges and prospects of SMA translational research.
基金supported by National Postdoctoral Program(2020M682073)the National Natural Science Foundation of China(NSFC,32061160477)+1 种基金The National Natural Science Foundation of China(32272315,32072209)the Natural Science Foundation of Guangdong Province(2022A1515010694).
文摘Meat products are an important part in our daily diet,providing valuable nutrients for the human body.However,heating processes cause the meat to become more appetizing with changes in texture,appearance,flavor,and chemical properties by the altering of protein structure and other ingredients.As one kind of cooking-induced contaminants,heterocyclic aromatic amines(HAAs)are widely present in protein aceous food products with strong carcinogenic and mutagenic properties.In order to promote the safety of traditional meat products,this review focused on the formation,metabolism,biological monitoring and inhibitory mechanism of HAA.An overview of the formation pathways,hazards,and control methods of HAAs during food processing in recent years was studied,aiming to provide some valuable information for exploring effective methods to inhibit the production of associated hazards during food processing.Systematic selection of different types of flavonoids to explore their effects on the formation of HAAs in an actual barbecue system can provide theoretical reference for effectively controlling the formation of HAAs and reducing their harm to human health.
基金the Opening Project of Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan(Grant number:LZJ2101)the Fundamental Research Funds of China West Normal University(Grant number:19D038).
文摘Polyimide(PI) is an organic polymer material with good stability and diverse sources that has attracted widespread attention in the field of photocatalysis. In this study, a series of PI photocatalysts were synthesized by a thermal polymerization approach using pyromellitic dianhydride(PMDA) and various diamine monomers(melamine(MA), 4,4′-oxydianiline, and melem) as the precursors as well as different heating rates. The effects of the diamine precursor and heating rate on the structure, composition, morphology, and optical properties of the as-prepared PI materials were systematically investigated by various characterization techniques. The selective photo-oxidation of benzylamine was used as a model reaction to evaluate the photocatalytic activities of the resulting PI samples for the oxidation of amines to imines. The results revealed that the PI sample prepared using MA and PMDA as the precursors and a heating rate of 7 ℃/min(MA-PI-7) exhibited the best catalytic performance, with 98% benzylamine conversion and 98% selectivity for N-benzylidene benzylamine after 4 h of irradiation. Several benzylamine derivatives and heterocyclic amines also underwent the photo-oxidation reaction over the MA-PI-7 catalyst to afford the corresponding imines with good activity. In addition, MA-PI-7 exhibited good stability over four successive photocatalytic cycles.
基金supported by Chinese Academy of Sciences,China(Grant No.QYZDY-SSW-SLH013-2)Henan Normal University,China。
文摘Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.
基金This work was supported financially by the National Key R&D Program of China(2018YFB1501500)National Natural Science Foundation of China(51976225).
文摘Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years,we developed two sustainable routes(i.e.,the impregnation method and the one-pot synthesis)to prepare the hydrochar-supported catalysts and tested its catalytic performance on the reductive amination.Several techniques,such as TEM,XRD and XPS,were adopted to characterize the structural and catalytic features of samples.Results indicated that the impregnation method favors the formation of outer-sphere surface complexes with porous structure as well as well-distributed metallic nanoparticles,while the one-pot synthesis tends to form the inner-sphere surface complexes with relatively smooth appearance and amorphous metals.This difference explains the better activity of catalysts prepared by the impregnation method which can selectively convert benzaldehyde to benzylamine with an excellent yield of 93.7%under the optimal reaction conditions;in contrast,the catalyst prepared by the one-pot synthesis only exhibits a low selectivity near to zero.Furthermore,the gram-scale test catalyzed by the same catalysts exhibits a similar yield of benzylamine in comparison to its smaller scale,which is comparable to the previously reported heterogeneous noble-based catalysts.More surprisingly,the prepared catalysts can be expediently recycled by a magnetic bar and remain the satisfying catalytic activity after reusing up to five times.In conclusion,these developed catalysts enable the synthesis of functional amines with excellent selectivity and carbon balance,proving cost-effective and sustainable access to the wide application of reductive amination.
基金the National Natural Science Foundation of China(Nos.20375035,20527005,20775070)by Zhejiang Provincial Natural Science Foundation of China(Nos.Z404105,Y507252).
文摘In this work, a new microextraction method termed ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME) was demonstrated for the extraction of 2-methylaniline, 4-chloroaniline, 1-naphthylamine and 4-aminobiphenyl in aqueous matrices. After extraction the ionic liquid (IL) phase was injected directly into the high performance liquid chromatography (HPLC) system for determination. Some parameters that might affect the extraction efficiency were optimized. Under the optimum conditions, good linear relationship, sensitivity and reproducibility were obtained. The limits of detection (LOD, S/N = 3) for the four analytes were in the range of 0.45-2.6 μg L^-1. The relative standard deviations (R.S.D., n = 6) were in the range of 6.2-9.8%. This method was applied for the analysis of the real water samples. The recoveries ranged from 93.4 to 106.4%. The main advantages of the method are high speed, high recovery, good repeatability and volatile organic solvent-free.
基金Supported by the Ministry of Environmental Protection of China(No.2011467037)
文摘In current paper, a quantitative structure-activity relationship (QSAR) study was performed for the prediction of acute toxicity of aromatic amines. A set of 56 compounds was randomly divided into a training set of 46 compounds and a test set of 10 compounds. The electronic and topological descriptors computed by the Scigress package and Dragon software were used as predictor variables. Multiple linear regression (MLR) and support vector machine (SVM) were utilized to build the linear and nonlinear QSAR models, respectively. The obtained models with five descriptors show strong predictive ability. The linear model fits the training set with R2 = 0.71, with higher SVM values of R2 = 0.77. The validation results obtained from the test set indicate that the SVM model is comparable or superior to that obtained by MLR, both in terms of prediction ability and robustness.
文摘Presented in several types of food, bioactive amines are described as organic bases of low molecular weight. They have vasoactive, psychoactive and toxicological characteristics and constitute a potential health risk. The concentration of amines formed in foods depends on the type of microorganisms present, the action of decarboxylase enzymes produced by microorganisms on specific amino acids and favorable conditions for enzymatic activity. The presence of these chemical metabolites has been suggested as a quality indicator in routine analyzes for food production and marketing monitoring. The detection of bioactive amines can be performed by chromatographic methods, fluorometric and enzymatic kits. Bioactive amine formation can be prevented mainly through the adoption of good manufacturing practices, but the industry can also use other methods such as temperature control in the production chain, modified atmosphere packaging and food irradiation. This review aims to address the formation of bioactive amines in foods, emphasizing the formation and classification of these metabolites, aspects related to health, acceptable limits, detection methods and control methods used in the industry to ensure food safety and quality. The success of this approach is linked to the importance of bioactive amines as quality indicators, as well as the discussion on the development of methodologies for determining these substances and discussion of acceptable parameters in food.
基金supported by the National Natural Science Foundation of China under contract No.30300269the National High Technology Research and Development Program("863"program)of China under contract No.2002AA603013.
文摘The regulation of three biogenic amines over the reproductive neuroendoerine activity of the male Scylla serrata was investigated by in vivo injection and in vitro incubation. The testicular index, the ratio of the mature sections in testes, and the ratio of Type B cells in androgenic gland were taken as the quantitative indexes. The in vivo injections indicated that: 5-HT can significantly promote the testicular development and the secretion of the androgenic gland in S. serrata; DA can inhibit the testicular development, but no influence on the secretion of the androgenic gland was found; no significant difference was observed between the OA-injected group and the concurrent control group. In vitro incubations showed that: 5-HT can stimulate the secretion of the brain and the thoracic ganglia, thus accelerating that of the androgenic gland; however, neither OA nor DA showed any significant influence on the secretion of the brain and the thoracic ganglionic mass. As to the optic ganglia, the three biogenic amines hardly have any effect on its secretion. It is the first time to report the regulation of biogenic amines over the reproductive neuroendocrine of male crustaceans through vitro experiments. Results corroborate that 5-HT activates the brain and the thoracic ganglia to secret GSH first, then promote the testicular development through the activity of the androgenic gland.
基金This work was supported by the Science Foundation of Jinan University (639)
文摘The hydrolysis process of the anticancer agents novel non-classical transplatinum( Ⅱ ) with aliphatic amines and the influence of solvent models therein have been studied by using hybrid density functional theory (B3LYP). In this study, the stepwise hydrolysis, trans[PtCl2(Am)(isopropylamine)] + 2H2O → trans-[Pt(Am)(isopropylamine)(OH2)2]^2++ 2Cl^-, was explored. Implicit solvent effects were incorporated through polarized continuum models. The stationary points on the potential energy surfaces for the first and second hydrolysis steps,proceeding via a general SN2 pathway, were fully optimized and characterized. It was found that the first hydrolysis reaction is easier than the second one and the hydrolysis of trans- [PtCl2-(isopropylamine)2] is the easiest in our studying systems. The result can assist in under- tanding the hydrolysis mechanism of trans-[PtCl2(Am)(isopropylamine)] and designing novel Pt-based anticancer drugs.
文摘The aim of the present study was to compare the ability of the myricetin and quercetin to modulate the oxidative DNA damage induced by 2-amino-3, 8- dimethylimidazo [4,5-f] quinoxaline (8-MeIQx), 2-amino- 3, 4, 8- trimethylimidazo [4, 5-f]-quinoxaline (4,8-diMeIQx) and 2-amino-1-methyl-6-phenyl-imidazo [4,5-b] pyridine (PhIP), in human hepatoma cells. DNA damage (strand breaks and oxidized purines/pyrimidines) was evaluated by the alkaline single-cell gel electrophoresis or comet assay. None of the myricetin and quercetin concentrations tested protected against 8-MeIQx, 4, 8-diMeIQx and PhIP-induced DNA strand breaks. The oxidized pyrimidines induced by 4, 8-diMeIQx and PhIP were reduced by myricetin but not by quercetin. Quercetin reduced the oxidized purines induced by 8-MeIQx and PhIP, while myricetin also reduced the induced by 4, 8-diMeIQx. One feasible mechanism by which myricetin and quercetin exert their protective effect towards HCAs-induced oxidative DNA could be related in part to the reduction of human CYP1A1. Another mechanism claimed to be responsible for the protective effect of myricetin and quercetin is the induction of phase II metabolizing enzymes such as UDP-glucuronyltrasferase (UGT). The ethoxyresorufin O-deethylation (CYP1A1) activity was moderately inhibited by myricetin, while little effect was observed by quercetin. On the contrary, quercetin showed the greatest increase on UDP-glucuronyltransferase activity. However, these are not the only mechanisms by which myricetin and quercetin exert their protective effect, other mechanisms such as stimulation of the repair of carcinogen-induced DNA damage and or the free radical scavenging efficiency have been also implicated. In conclusion, our results clearly indicate that myricetin was more efficient than quercetin to prevent DNA damage (oxidized purines and pyrimidines) induced by the three HCAs evaluated. This protective effect depends on the chemical structure of flavonoid and the mutagen studied.
文摘A facile synthesis of N-methyl-N-aryl carbamates from aromatic amines and dimethyl carbonate (DMC) has been achieved with high yields in the presence of potassium carbonate (K2CO3)and tetrabutylammonium bromide (Bu4NBr) under solvent-free conditions.
基金financial support by the National Natural Science Foundation of China(21676226,21606186)the Natural Science Foundation for Distinguished Young Scholars in Hunan Province(2018JJ1023)+1 种基金Key Research and Development Program in Hunan Province(2019GK2041)Collaborative Innovation Center of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization。
文摘In this paper,a method of extracting phenols from coal tar by amines aqueous solution was proposed.The effects of various amines on the extraction properties of phenols in coal tar were researched from the views of molecular structure.The parameters such as molar ratio,concentration,extraction time and temperature for the extraction of coal tar by the monoethanolamine and ethylenediamine aqueous solution were examined.The results show that the organic amine with more amino groups,hydroxyl structure and strong electronegativity exhibited better extraction performance.Under the optimal conditions,the extraction yields of phenols in coal tar by the monoethanolamine or ethylenediamine aqueous solution are above 80%,and the recovery yields of amines reach 99%.Furthermore,the probable geometries of complexes formed by the combination of phenols and organic amines were calculated by density function theory.In addition,several thermodynamic models were evaluated through comparing the relative deviation of simulation results by ASPEN PLUS to the experimental ones,which provide feasibility thermodynamic models for the simulation of extraction process.The present work affords a mild,efficient and green approach for the extraction of phenols from coal tar by an aqueous solution of amines in industry application.
文摘A convenient, efficient, one-pot, novel process has been developed for the synthesis of carbamates from corresponding alkyl halides and amines using basic resin/CO2 system.
文摘Five marinades were developed using natural antioxidants. Based on a consumer test of the appearance, three marinades were chosen for further investigation: an oregano, an acerola and a Dijon marinade, the Dijon marinade containing acerola, sumac and oregano. A barbecue and a sumac marinade were not included in the further study. In a home use test, consumers barbecued pork chops with the three marinades. Most of the consumers preferred the oregano and the Dijon marinade, while the acerola marinade was less liked. After controlled cooking using both direct and indirect heat to a core temperature of 65°C and 80°C, the content of the heterocyclic aromatic amines (HCA) PhiP, MeIQx, DiMeIQx, Harman and Norharman was analysed. All of the marinades reduced the content of MeIQx and DiMeIQx, although only with indirect heat, while PhiP was reduced using both grilling methods. Surprisingly, in particular the content of Harman—and to a lesser extent Norhaman—was very high in the Dijon-marinated chops. The results demonstrated that it was possible to develop well-liked marinades that can reduce the formation of selected HCAs.