Cu^(I)/amine仿生催化胺选择性氧化生成腈的反应机理研究

胺的有氧氧化是有机合成中应用广泛的过程之一,其产物腈类化合物在医药、农药和香料等重要中间体被广泛应用。通过密度泛函理论(DFT)在分子水平上对Cu^(I)/amine仿生催化体系选择性氧化胺生成腈的详细反应机理、抗衡离子及溶剂对反应活性的控制因素进行了详细分析,发现机理分为两步进行:第一步为生成关键活性亚胺中间体(5)过程,该过程存在单核(PathⅠ)和双核(PathⅡ)反应路径,计算结果表明两条路径均为可能路径,并以单核机理(PathⅠ)路径为主导路径;第二步为生成腈过程,该过程存在两条可能路径(Path A和Path B),能量跨度模型分析表明Path B为优势路径,δE=16.6 kcal/mol,TOF=4.14 s^(-1)。此外,还发现抗衡离子I^(–)的存在明显降低了反应路径的能垒,而溶剂则对反应能垒没有明显影响。

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.

One-pot Synthesis of MoO_(3)/PI Composite with Enhanced Photocatalytic Performance for Oxidative Coupling of Amines to Imines

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.

Mono Ethanol Amine (MEA) Pulping of Wheat Straw: An Environmentally Friendly Suggestion for the Fluff Pulp Production

This research aimed to investigate the effect of pulping conditions and refining intensities of wheat straw to be recommended for fluff pulp production.For this purpose,mono ethanol amine(MEA)was selected as a de-lignification agent at three levels of 50:50,25:75,and 15:85(MEA/water,W/V%),and soda-AQ 14 W/V%was used as a reference pulping.To investigate the optimal refining intensity,the obtained pulp was passed through a single disk laboratory refiner from 0 to 6 times and in two different consistencies(1.5 and 2.5 W/V%).Total yield,kappa number,ash content,and the Schopper-Riegler(SR°)freeness of the prepared pulps were investigated.Finally,hand sheets with a targeted basic weight of 70 g/m^(2) were made according to the related standards.The hand sheets were characterized using Fourier transform infrared(FTIR)spectroscopy and a field emission scanning electron microscope(FE-SEM).Sheet density,brightness,and mechanical properties such as burst,tensile,and tear indices were also investigated.The FE-SEM photographs showed that the texture of the hand sheet became denser as the refining intensity increased.External fibrillation on the surface of the fibers was also observed,especially on those refined with 2.5%consistency.The results of the chemical composition of wheat straw indicated that wheat straw containing a high percentage of holocellulose is an excellent candidate for the production of fluff pulp.The total yield and kappa number of MEA pulps increased with the decrease in MEA concentration.FTIR results indicated the presence of a peak related to amino groups in the pulp related to MEA pulp.The results also indicated that the mechanical properties of the papers,except for the tear index,were enhanced as the intensity of refining and the pulp consistency during refining increased.

Evolution of free amino acids, biogenic amines and volatile compounds in fermented sausages inoculated with Lactiplantibacillus plantarum and Staphylococcus simulans

Lactic acid bacteria and coagulase-negative staphylococci play an important role in the production of fermented sausages,such as inhibiting the growth of undesirable bacteria and antioxidant.In this study,the effects of inoculation with different starter cultures(Lactiplantibacillus plantarum HN108 and Staphylococcus simulans NJ209)on the free amino acids(FAAs),biogenic amines(BAs)and volatile compounds of fermented sausages were investigated using an amino acid analyzer,ultra performance liquid chromatography and gas chromatography-ion mobility spectrometry,respectively.The pH and carbonyl content of the inoculated group was significantly lower than those in the control group(P<0.05).L.plantarum HN108 significantly reduced the content of FAAs and BAs in fermented sausage production(P<0.05),while S.simulans NJ209 promoted the formation of FAAs(especially bitter amino acids)and exhibited slight BAs-reducing activity.In addition,L.plantarum HN108 promoted the formation of volatile compounds such as ketones,alcohols and alkenes in sausages.In conclusion,L.plantarum HN108 could contribute to reducing the content of putrescine and tyramine and forming the desirable flavor compounds in fermented sausages.Thus,L.plantarum HN108 is expected to be a starter culture that can improve the safety and flavor of fermented sausages.

Achieving a superior Na storage performance of Fe-based Prussian blue cathode by coating perylene tetracarboxylic dianhydride amine

Fe-based Prussian blue(Fe-PB)cathode material shows great application potential in sodium(Na)-ion batteries due to its high theoretical capacity,long cycle life,low cost,and simple preparation process.However,the crystalline water and vacancies of Fe-PB lattice,the low electrical conductivity,and the dissolution of metal ions lead to limited capacity and poor cycling stability.In this work,a perylene tetracarboxylic dianhydride amine(PTCDA)coating layer is successfully fabricated on the surface of Fe-PB by a liquid-phase method.The aminated PTCDA(PTCA)coating not only increases the specific surface area and electronic conductivity but also effectively reduces the crystalline water and vacancies,which avoids the erosion of Fe-PB by electrolyte.Consequently,the PTCA layer reduces the charge transfer resistance,enhances the Na-ion diffusion coefficient,and improves the structure stability.The PTCA-coated Fe-PB exhibits superior Na storage performance with a first discharge capacity of 145.2 mAh g^(−1) at 100 mA g^(−1).Long cycling tests exhibit minimal capacity decay of 0.027%per cycle over 1000 cycles at 1 A g^(−1).Therefore,this PTCA coating strategy has shown promising competence in enhancing the electrochemical performance of Fe-PB,which can potentially serve as a universal electrode coating strategy for Na-ion batteries.

Effect of the presence of trace sulfur dioxide on piperazine-based amine absorbents for carbon dioxide capture

The effect of the presence of trace SO_(2)in industrial flue gas on the amine-scrubbing-based absorption process for CO_(2)capture has been a matter of concern.This study aimed to investigate the effect of trace SO_(2)on the CO_(2)capture process using piperazine-based amine absorbents,focusing on SO_(2)-resistance capability,SO_(2)/CO_(2)absorption selectivity,and cyclic stability.The presence of trace SO_(2)not only restrains CO_(2)absorption,but also promotes the formation of carbamate within the piperazine-based amine absorbents.Remarkably,the incorporation of aminoethyl group in piperazine-based amine absorbents can enhance the SO_(2)-resistance capability by promoting the formation of carbamate,while piperazine-based amine absorbents with hydroxyethyl group can promote the formation of bicarbonate to reduce the SO_(2)-resistance capability.The work offers valuable insights into the efficient application of novel amine absorbents for CO_(2)capture from practical industrial flue gas.

Activation mechanism of conventional electrolytes with amine solvents:Species evolution and hydride-containing interphase formation

Rechargeable magnesium(Mg)-metal batteries have brought great expect to overcome the safety and energy density concerns of typical lithium-ion batteries.However,interracial passivation of the Mgmetal anode impairs the reversible Mg plating/stripping chemistries,resulting in low Coulombic efficiency and large overpotential.In this work,a facile isobutylamine(IBA)-assisted activation strategy has been proposed and the fundamental mechanism has been unveiled in a specific way of evolving active species and forming MgH_(2)-based solid-electrolyte interphase.After introducing IBA into a typical electrolyte of magnesium bis(trifluoromethanesulfo nyl) imide(Mg(TFSI)_(2)) in diglyme(G2) solvents,electrolyte species of [Mg^(2+)(IBA)5]^(2+) and protonated amine-based cations of [(IBA)H]^(+) have been detected by nuclear magnetic resonance and mass spectra.This not only indicates direct solvation of IBA toward Mg^(2+)but also suggests its ionization,which is central to mitigating the decomposition of G2 and TFSI anions by forming neutrally charged [(IBAH^(+))(TFSI^(-))]~0 and other complex ions.A series of experiments,including cryogenic-electron microscopy,D_(2)O titration-mass spectra,and time of flight secondary ion mass spectrometry results,reveal a thin,non-passivated,and MgH_(2)-containing interphase on the Mg-metal anode.Besides,uniform and dendrite-free Mg electrodeposits have been revealed in composite electrolytes.Benefiting from the activation effects of IBA,the composite electrolyte displays superior electrochemical performance(overpotential is approximately 0.16 V versus 2.00 V for conventional electrolyte;Coulombic efficiency is above 90% versus <10% for conventional electrolyte).This work offers a fresh direction to advanced electrolyte design for next-generation rechargeable batteries.

New 4-imino-4H-Chromeno[2,3-d]Pyrimidin-3(5H)-Amine: Synthesis, Cytotoxic Effects on Tumoral Cell Lines and in Silico ADMET Properties

The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was established according to their spectroscopic analysis, such as FT-IR, NMR and mass spectroscopy. These new compounds were tested for their antiproliferative activities on seven representative human tumoral cell lines (Huh7 D12, Caco2, MDA-MB231, MDA-MB468, HCT116, PC3 and MCF7) and also on fibroblasts. Among them, only the compounds 6c showed micromolar cytotoxic activity on tumor cell lines (1.8 50 50 > 25 μM). Finally, in silico ADMET studies ware performed to investigate the possibility of using of the identified compound 6c as potential anti-tumor compound.

规则型数据采掘工具集AMINER

介绍了一个规则型数据采掘工具集AMINER ,其目标是增强知识表达的能力 ,并形成一个实用的数据采掘工具 ,使其能适用于多种不同的应用领域。工具集以一定程度上通用的CRD方法为基本采掘算法 ,分为数据预处理、数据采掘和数据评价三大主要模块。系统原型是一个在关系或演绎数据库中采掘规则型知识 ,并对领域知识和采掘结果进行管理的系统 ,其主要功能包括数据采掘、领域知识的管理和采掘结果的管理。最后 ,对未来的工作提出了展望。

Dynamics simulation of tertiary amines adsorbing on kaolinite(001) plane

The collecting power of tertiary amines（DRN,DEN and DPN） on kaolinite follows the order of DENDPNDRN.After reacting with DRN,DEN and DPN,the surface potentials of kaolinite increase remarkably,and the recruitments caused by collectors also follow the order of DENDPNDRN.The results of dynamics simulation show that the geometries of substituent groups bonding to N are deflected and twisted,and some of bond angles are changed when tertiary amines cations adsorb on kaolinite（001） surface.Based on the results of dynamics simulations and quantum chemistry calculations,the electrostatic forces between three tertiary amines cations and 4×4×3（001） plane of kaolinite are 1.38×10？7 N（DRN12H＋）,1.44×10-6 N（DEN12H＋）,1.383×10-6 N（DPN12H＋）,respectively.

Semicarbazide-Sensitive Amine Oxidase对血糖调节作用研究

Semicarbazide-Sensitive Amine Oxidase(SSAO)是一类在人体内广泛分布但生理功能尚不清楚的酶。本研究中我们首次在动物模型上发现了SSAO活性对大鼠血糖的影响。通过使用SSAO的高选择性抑制剂MDL-72974A以及它的内源性底物甲胺等对动物进行处理,研究血糖与SSAO活性的关系。SSAO活性用同位素标记法以14C-苯甲胺为底物进行测定,血糖则采用己糖激酶法测定。此外我们还测定了尿甲醛排泄以考察SSAO催化脱氨反应是否发生。实验结果显示,抑制SSAO活性可以导致动物血糖升高,并且SSAO底物甲胺可以降低糖尿病鼠血糖。这些结果表明SSAO可能在血糖调节方面有某种作用,进一步研究将对发展糖尿病治疗策略有重要意义。

Optimization of reaction for synthesis of polyisobutylene amine between amination agent and epoxy polyisobutylene

An optimization study on the amination reaction of epoxy polyisobutylene for synthesis of polyisobutylene amine is presented. The experimental results indicate that n-butanol and ethylenediamine are the suitable solvent and amination agents for the reaction, respectively. The reaction yield of the amination reaction is notably increased with the enhanced molar ratio of either n-butanol against epoxy polyisobutylene or ethylenediamine against epoxy polyisobutylene. Also, the yield is enhanced with increasing temperature and time during the experimental range. Strikingly, the yield reaches as high as 91. 30% under optimal conditions; with the molar ratio of ethylenediamine, n-butanol and PIBO of 10∶ 6∶ 1, the reaction temperature of 150 ℃ and the reaction time of 6 h. In addition, the yield of the reaction is slightly decreased with the enhanced water content of the system. Accordingly, the mass concentration of water should be controlled within 1. 7% during the reaction.

Effects of N-(3',4',5'-Trimethoxycinnamoyl) ortho-Aminobenzoic Acid on Antigen-induced Contraction of Guinea-pig Ileum and the Degranulation of and Histamine Release from Mast Cells

N-(3′,4′,5′-Trimethoxycinnamoyl)ortho-aminobenzoic acid(TOA),at the concentration of 80μg/ml,significantly inhibited the antigen-induced contraction of ileum isolated from the actively sensitized guinea-pig.At the concentrations of 25 and 50μg/ml, TOA inhibited homocytotropic antibody-mediated degranulation of mast cells in the rat mesentery,and also inhibited anaphylactic histamine release from rat peritoneal mast cells.

SAPO-34 synthesized with n-butylamine as a template and its catalytic application in the methanol amination reaction

SAPO-34 was synthesized with n-butylamine（BA） as a template for the first time.Crystallization temperature and initial Si amount were important factors leading to successful syntheses.Lamellar AlPO-kanemite tends to form as the major phase or as an impurity of SAPO-34 at lower crystallization temperatures,though a higher initial Si amount may offer a positive effect on the crystallization of SAPO-34 that mitigates the low temperature.Higher temperature（240℃） can effectively suppress the generation of lamellar materials and allow the synthesis of pure SAPO-34 with a wider range of Si incorporation.The crystallization processes at 200 and 240℃ were investigated and compared.We used the aminothermal method to synthesize SAPO-34-BA at 240℃ and also found n-propylamine is a suitable template for the synthesis of SAPO-34.The SAPO-34-BA products were characterized by many techniques.SAPO-34-BA has good thermal stability,crystallinity and porosity.BA remained intact in the crystals with ~1.8 BA molecule per chabazite cage.The catalytic performance of SAPO-34 was tested in the methanol amination reaction,which showed high methanol conversion and selectivity for methylamine plus dimethylamine under the conditions investigated,suggesting that this material is a good candidate for the synthesis of methylamines.

PECH-amine的合成及其在棉织物靛蓝染色中的应用

为提高棉织物靛蓝染料的上染率,缩短染色工艺流程,对阳离子改性剂聚环氧氯丙烷胺化物(PECH-a-mine)的制备工艺进行了研究。采用FTIR、1 HNMR对PECH-amine的结构进行了表征,GPC测定其分子量分布,并对经PECH-amine改性棉织物的染色深度K/S值和色牢度进行测试。实验结果表明:合成PECH-amine的最佳反应条件为:m(聚环氧氯丙烷)∶m(二甲胺)=1∶2,温度90℃,时间8h。PECH-amine改性棉织物K/S值高达25.06,而相同染色条件下未改性棉织物的K/S值仅为16.60。染色织物的耐洗牢度、干摩擦牢度和湿摩擦牢度良好。

Adsorption of formaldehyde vapor by amine-functionalized mesoporous silica materials

The amine-functionalized mesoporous silica materials were prepared via the co-condensation reaction of tetraethoxysilane and three types of organoalkoxysilanes： 3-aminopropyl-trimethoxysilane, n-（2-aminoethyl）-3-aminopropyltrimethoxysilane, and 3-（2-（2- aminoehtylamino）ethylamino） propyl-trimethoxysilane. Cetyltrimethylammonium bromide was used as a template for forming pores, Specific surface area and pore volume of the amine-functionalized mesoporous silica materials were determined using surface area and pore size analyzer. Fourier transform infrared （FTIR） spectroscope was employed for identifying the functional groups on pore surface. In addition, the amine-functionalized mesoporous silica materials were applied as adsorbents for adsorbing formaldehyde vapor. FTIR spectra showed the evidence of the reaction between formaldehyde molecules and amine groups on pore surface of adsorbents. The equilibrium data of formaldehyde adsorbed on the adsorbents were analyzed using the Langmuir, Freundlich and Temkin isotherm. The sample functionalized from n-（2-aminoethyl）-3-aminopropyltrimethoxysilane showed the highest adsorption capacity owing to its amine groups and the large pore diameter.

The CO_2 absorption and desorption performance of the triethylenetetramine + N,N-diethylethanolamine + H_2O system

Post-combustion CO_2 capture(PCC) process faces significant challenge of high regeneration energy consumption.Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration energy consumption because only the CO_2-concentrated phase should be regenerated. In this work, aqueous solutions of triethylenetetramine(TETA) and N,N-diethylethanolamine(DEEA) are found to be efficient biphasic absorbents of CO_2. The effects of the solvent composition, total amine concentration, and temperature on the absorption behavior, as well as the effect of temperature on the desorption behavior of TETA–DEEA–H2 O system were investigated. An aqueous solution of 1 mol·L-1 TETA and 4 mol·L-1 DEEA spontaneously separates into two liquid phases after a certain amount of CO_2 is absorbed and it shows high CO_2 absorption/desorption performance.About 99.4% of the absorbed CO_2 is found in the lower phase, which corresponds to a CO_2 absorption capacity of 3.44 mol·kg-1. The appropriate absorption and desorption temperatures are found to be 30 °C and 90 °C,respectively. The thermal analysis indicates that the heat of absorption of the 1 mol·L-1 TETA and 4 mol·L-1 DEEA solution is-84.38 kJ·(mol CO_2)-1 which is 6.92 kJ·(mol CO_2)-1 less than that of aqueous MEA. The reaction heat, sensible heat, and the vaporization heat of the TETA–DEEA–H2 O system are lower than that of the aqueous MEA, while its CO_2 capacity is higher. Thus the TETA–DEEA–H2 O system is potentially a better absorbent for the post-combustion CO_2 capture process.

Adsorption separation of carbon dioxide, methane and nitrogen on monoethanol amine modified β-zeolite

A new type of composite adsorbents was synthesized by incorporating monoethanol amine （MEA） into β-zeolite. The parent and MEA- functionalized β-zeolites were characterized by X-ray diffraction （XRD）, N2 adsorption, and thermogravimetric analysis （TGA）. The adsorption behavior of carbon dioxide （CO2）, methane （CH4）, and nitrogen （N2） on these adsorbents was investigated at 303 K. The results show that the structure of zeolite was well preserved after MEA modification. In comparison with CH4 and N2, CO2 was preferentially adsorbed on the adsorbents investigated. The introduction of MEA significantly improved the selectivity of both CO2/CH4 and CO2/N2, the optimal selectivity of CO2/CH4 can reach 7.70 on 40 wt% of MEA-functionalized β-zeolite （MEA（40）-β） at 1 atm. It is worth noticing that a very high selectivity of CO2/N2 of 25.67 was obtained on MEA（40）-β. Steric effect and chemical adsorbate-adsorbent interaction were responsible for such high adsorption selectivity of CO2. The present MEA-functionalized β-zeolite adsorbents may be a good candidate for applications in flue gas separation, as well as natural gas and landfill gas purifications.

Amine-silica composites for CO_2 capture: A short review

Amine-silica composite materials for post-combustion COcapture have attracted considerable attention because of their high COuptake at low COconcentrations, excellent COcapture selectivity in the presence of moisture, and lower energy requirements for sorbent regeneration. This review discusses the recent advances in amine-silica composites for COcapture, including adsorbent preparation and characterization, COcapture under dry and moisture conditions at different COpartial pressures, sorbent regeneration, and stability after many cyclic sorption-desorption runs.