A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic ...A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.展开更多
Acetylcholinesterase inhibitors are the most frequently prescribed anti-Alzheimer＇s drugs. A series of 5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester derivatives as the novel acetylcholinesterase inhibito...Acetylcholinesterase inhibitors are the most frequently prescribed anti-Alzheimer＇s drugs. A series of 5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester derivatives as the novel acetylcholinesterase inhibitors was designed based on virtual screening methods. The target compounds were synthesized with Biginelli reaction and Hantzsch-type condensation of dihydropyrimidines with substituted phenacyl chlorides, and were characterized with elemental analysis, IR, MS, ^1H NMR, and ^13C NMR. The biological evaluation against human acetylcholinesterase in vitro indicated all the target compounds show more than 50% inhibition at 10μmol/L by means of the Ellman method. The results provide a starting point for the development of novel drugs to treat Alzheimer＇s disease and lay the foundation of searching for improved acetylcholinesterase inhibitors with the novel scaffolds.展开更多
2,2’-Bithiophene-5-carboxylic acid (BTA) thin-films on platinum (Pt) electrodes were electrochemically prepared in acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate (TBAP) and 0.05 M BTA. These fi...2,2’-Bithiophene-5-carboxylic acid (BTA) thin-films on platinum (Pt) electrodes were electrochemically prepared in acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate (TBAP) and 0.05 M BTA. These films were complexes with several metal ions such as Cu2+, Ag+ and Co2+. Their structural characteristics were compared with those of powder complexes chemically prepared from BTA and the corresponding metal ion. IR and XPS techniques reveal that the film complexes with metal ions have the same structures as the corresponding powder complexes. The electrocatalytic activity of BTA film-metal ions has been investigated toward ascorbic acid (AA) oxidation and compared to that obtained on a free BTA film. BTA film-metal ions exhibit good catalytic proprieties and better detection of AA than a free BTA film. This new propriety allows these films to be used as electrochemical sensors. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.展开更多
A practical synthesis of stereoisomers of 3-aminocyclohexanecarboxylic acid and cis-3-aminocyclohexene-5- carboxylic acid was achieved from cyclohexene-4-carboxylic acid via a key resolving approach with chiral 1-phen...A practical synthesis of stereoisomers of 3-aminocyclohexanecarboxylic acid and cis-3-aminocyclohexene-5- carboxylic acid was achieved from cyclohexene-4-carboxylic acid via a key resolving approach with chiral 1-phenylethylamine.展开更多
Reference genes, stably expressing in different tissues and cells, are commonly used as the references in expression analysis. Selecting the optimum reference gene is crucial to the success of experiments. In this stu...Reference genes, stably expressing in different tissues and cells, are commonly used as the references in expression analysis. Selecting the optimum reference gene is crucial to the success of experiments. In this study, the expression stabilities of nine common reference genes, including ACT2, 18 S r RNA, APRT, EF-1α, RNA POL II, TUBα, TUBβ, GAPDH and TLF of Agropyron mongolicum, were studied under drought condition. Among them, 18 S r RNA was found to be the most optimum reference gene under drought stress by the analyzing of ge Norm and Norm Finder software. Quantitative expression levels of P5 CS using 18 S r RNA as the reference gene, and proline contents under drought stress in A. mongolicum were further operated, and we found the expression level of P5 CS gene and proline content had a significantly positive relationship（R^2=0.7763, P〈0.05）. This study established and validated 18 S r RNA as the reference genes in A. mongolicum under drought stress, providing a powerful tool for the quantitative expression analysis of drought genes in A. mongolicum.展开更多
Four new complexes, [Zn（btca）（2,2＇-bpy）] （1）, [Mn（btca）（2,2＇-bpy）] （2）, [Co（btca）（phen）] （3）, and [Cu（btca）- （phen）] （4）, （Hzbtca=benzotriazole-5-carboxylic acid, 2,2＇-bpy=2,2＇-bipyridine,...Four new complexes, [Zn（btca）（2,2＇-bpy）] （1）, [Mn（btca）（2,2＇-bpy）] （2）, [Co（btca）（phen）] （3）, and [Cu（btca）- （phen）] （4）, （Hzbtca=benzotriazole-5-carboxylic acid, 2,2＇-bpy=2,2＇-bipyridine, phen= 1,10-phenanthroline）, were successfully synthesized and characterized by elemental analysis, single crystal X-ray diffraction, and IR spectros- copy. Complexes 1-4 crystallize in the orthorhombic system with space group of Pbca and show similar 2D layers, which are interlinked to supramolecular networks by π-π stacking interactions. Furthermore, TGA curves show that complexes 1-4 have good thermal stability. Solid-state fluorescent property of complex 1 was also investigated at room temperature.展开更多
Kinetic studies of the singlet oxygenation of the title compounds were performed accord- ing to Monroe's method. The reaction rate increases with temperature decreasing, leading to a ne- gative activation enthalpy...Kinetic studies of the singlet oxygenation of the title compounds were performed accord- ing to Monroe's method. The reaction rate increases with temperature decreasing, leading to a ne- gative activation enthalpy and a large negative activation entropy. These data are interpreted as the evidence for the intermediacy of an exciplex. The solvent effect on the reaction rate suggests that the “dioxetane” path involves a transition state or an intermediate with significant zwitterionic character. The electronic effect of the substituent is obvious, with electron-withdrawing substituent retarding the reaction and electron-donating substituent increasing the reaction rate. However, steric bulkiness at the 6-position does not play an important role in the reaction rate.展开更多
A mixed-ligand metal-organic complex [Cd（C7H3N3O2）（C12H8N2）]n was synthesized by cadmium（Ⅱ） nitrate, 1,10-phenanthroline（phen） and benzotriazole-5-carboxylate acid（H2btca）. Single crystal X-ray analysis ind...A mixed-ligand metal-organic complex [Cd（C7H3N3O2）（C12H8N2）]n was synthesized by cadmium（Ⅱ） nitrate, 1,10-phenanthroline（phen） and benzotriazole-5-carboxylate acid（H2btca）. Single crystal X-ray analysis indicates that complex 1 has a two-dimensional layer structure and crystallizes in an orthorhombic space group（Pbca）, with cell parameters, a=1.7422（6） nm, b=0.9264（3） nm, c=2.0729（7） nm, α=90°, β=90°,γ=90°, V=3.346（2） nm^3, Z=8. Each central Cd（Ⅱ） is six-coordinated by four N atoms, two of which are from 1,10-phenanthroline, and the other two from two different triazole nitrogen atoms and two O atoms from benzotriazole-5-carboxylate, forming a distorted octahedral geometry. Adjacent Cd（Ⅱ） centers are bridged by benzotriazole-5-carboxylate molecules to form a one-dimensional chain, which is further connected by the nitrogen atoms of btca^2- to form an extended two-dimensional wave-like layer, with OFF（offset face-to-face） stacking interactions between phen ligands in adjacent layers, which are helpful to forming the three-dimensional supramolecular structure.展开更多
A new coordination polymer with the formula of [Co（2-mpac）2（py）·4H2O）]n （1, 2-mpac = 5-methyl-2-pyrazinecarboxylic acid, py = pyrazine） has been synthesized through hydrothermal synthesis and structurally ...A new coordination polymer with the formula of [Co（2-mpac）2（py）·4H2O）]n （1, 2-mpac = 5-methyl-2-pyrazinecarboxylic acid, py = pyrazine） has been synthesized through hydrothermal synthesis and structurally characterized by X-ray single-crystal diffraction method. 1 exhibits a 3D supramolecular network. Crystal data： monoclinic, space group C2/m, a = 15.907（9）, b = 7.104（3）, c = 9.793（5）, β = 95.232（8）o, V = 1102.0（10）3, Z = 2, S = 0.995, the final R = 0.0509, wR = 0.1626 for 1002 observed reflections with （I 〉 2σ（I）） and R = 0.0530, wR = 0.1667 for all data. In addition, elemental analysis, IR and thermalgravimetric analysis are presented.展开更多
So far,the synthesis of chiral framework with achiral organic ligand still faces great challenge.Herein,three new coordinated complexes[Zn(btca)Cl]·DMA·N(CH_(3))_(2)(1),[Zn(btca)(Ac^(-))]·N(CH_(3))_(2)(...So far,the synthesis of chiral framework with achiral organic ligand still faces great challenge.Herein,three new coordinated complexes[Zn(btca)Cl]·DMA·N(CH_(3))_(2)(1),[Zn(btca)(Ac^(-))]·N(CH_(3))_(2)(2)and[Zn(btca)]·H_(2)O(3)(DMA=N,N-dimethylacetamide,btca=benzotriazole-5-carboxylate acid)were synthesized via different methods.Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 were isostructural and showed achiral layer network with fes topology,and 3 presented a chiral three-dimensional framework with eta topology.The result of this work has demonstrated that urothermal synthesis will be promising means of constructing chiral framework with achiral building block.Compound 3 also displayed an excellent property of iodine uptake.展开更多
基金Supported by the Scientific Research Foundation of Higher Education Institutions of Ningxia(No.NGY2017004)the National Natural Science Foundation of China(Nos.21763022 and 50564043)the Major Innovation Projects for Building First-class Universities in China’s Western Region(No.ZKZD2017003)
文摘A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.
文摘Acetylcholinesterase inhibitors are the most frequently prescribed anti-Alzheimer＇s drugs. A series of 5H-thiazolo[3,2-a]pyrimidine-6-carboxylic acid ethyl ester derivatives as the novel acetylcholinesterase inhibitors was designed based on virtual screening methods. The target compounds were synthesized with Biginelli reaction and Hantzsch-type condensation of dihydropyrimidines with substituted phenacyl chlorides, and were characterized with elemental analysis, IR, MS, ^1H NMR, and ^13C NMR. The biological evaluation against human acetylcholinesterase in vitro indicated all the target compounds show more than 50% inhibition at 10μmol/L by means of the Ellman method. The results provide a starting point for the development of novel drugs to treat Alzheimer＇s disease and lay the foundation of searching for improved acetylcholinesterase inhibitors with the novel scaffolds.
文摘2,2’-Bithiophene-5-carboxylic acid (BTA) thin-films on platinum (Pt) electrodes were electrochemically prepared in acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate (TBAP) and 0.05 M BTA. These films were complexes with several metal ions such as Cu2+, Ag+ and Co2+. Their structural characteristics were compared with those of powder complexes chemically prepared from BTA and the corresponding metal ion. IR and XPS techniques reveal that the film complexes with metal ions have the same structures as the corresponding powder complexes. The electrocatalytic activity of BTA film-metal ions has been investigated toward ascorbic acid (AA) oxidation and compared to that obtained on a free BTA film. BTA film-metal ions exhibit good catalytic proprieties and better detection of AA than a free BTA film. This new propriety allows these films to be used as electrochemical sensors. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.
基金Project supported by the National Natural Science Foundation of China （Nos. 20172050, 20025205）.
文摘A practical synthesis of stereoisomers of 3-aminocyclohexanecarboxylic acid and cis-3-aminocyclohexene-5- carboxylic acid was achieved from cyclohexene-4-carboxylic acid via a key resolving approach with chiral 1-phenylethylamine.
基金supported by the Western Light Project of Chinese Academy of Sciencesthe National Natural Science Foundation of China(31060057)the National Natural Science Foundation of Inner Mongolia,China(2015MS0305)
文摘Reference genes, stably expressing in different tissues and cells, are commonly used as the references in expression analysis. Selecting the optimum reference gene is crucial to the success of experiments. In this study, the expression stabilities of nine common reference genes, including ACT2, 18 S r RNA, APRT, EF-1α, RNA POL II, TUBα, TUBβ, GAPDH and TLF of Agropyron mongolicum, were studied under drought condition. Among them, 18 S r RNA was found to be the most optimum reference gene under drought stress by the analyzing of ge Norm and Norm Finder software. Quantitative expression levels of P5 CS using 18 S r RNA as the reference gene, and proline contents under drought stress in A. mongolicum were further operated, and we found the expression level of P5 CS gene and proline content had a significantly positive relationship（R^2=0.7763, P〈0.05）. This study established and validated 18 S r RNA as the reference genes in A. mongolicum under drought stress, providing a powerful tool for the quantitative expression analysis of drought genes in A. mongolicum.
文摘Four new complexes, [Zn（btca）（2,2＇-bpy）] （1）, [Mn（btca）（2,2＇-bpy）] （2）, [Co（btca）（phen）] （3）, and [Cu（btca）- （phen）] （4）, （Hzbtca=benzotriazole-5-carboxylic acid, 2,2＇-bpy=2,2＇-bipyridine, phen= 1,10-phenanthroline）, were successfully synthesized and characterized by elemental analysis, single crystal X-ray diffraction, and IR spectros- copy. Complexes 1-4 crystallize in the orthorhombic system with space group of Pbca and show similar 2D layers, which are interlinked to supramolecular networks by π-π stacking interactions. Furthermore, TGA curves show that complexes 1-4 have good thermal stability. Solid-state fluorescent property of complex 1 was also investigated at room temperature.
基金This report was partially supported by the National Natural Science Foundation of China
文摘Kinetic studies of the singlet oxygenation of the title compounds were performed accord- ing to Monroe's method. The reaction rate increases with temperature decreasing, leading to a ne- gative activation enthalpy and a large negative activation entropy. These data are interpreted as the evidence for the intermediacy of an exciplex. The solvent effect on the reaction rate suggests that the “dioxetane” path involves a transition state or an intermediate with significant zwitterionic character. The electronic effect of the substituent is obvious, with electron-withdrawing substituent retarding the reaction and electron-donating substituent increasing the reaction rate. However, steric bulkiness at the 6-position does not play an important role in the reaction rate.
基金Supported by the Natural Science Foundation of Zhejiang Province, China（No.LY12B01005）, the Project of Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, China（No.2012MCIF02）, the Disciplines Program of Ningbo University, China（No.KXL11057） and the Doctor Fund of Ningbo University, China（No.XYL10009）.
文摘A mixed-ligand metal-organic complex [Cd（C7H3N3O2）（C12H8N2）]n was synthesized by cadmium（Ⅱ） nitrate, 1,10-phenanthroline（phen） and benzotriazole-5-carboxylate acid（H2btca）. Single crystal X-ray analysis indicates that complex 1 has a two-dimensional layer structure and crystallizes in an orthorhombic space group（Pbca）, with cell parameters, a=1.7422（6） nm, b=0.9264（3） nm, c=2.0729（7） nm, α=90°, β=90°,γ=90°, V=3.346（2） nm^3, Z=8. Each central Cd（Ⅱ） is six-coordinated by four N atoms, two of which are from 1,10-phenanthroline, and the other two from two different triazole nitrogen atoms and two O atoms from benzotriazole-5-carboxylate, forming a distorted octahedral geometry. Adjacent Cd（Ⅱ） centers are bridged by benzotriazole-5-carboxylate molecules to form a one-dimensional chain, which is further connected by the nitrogen atoms of btca^2- to form an extended two-dimensional wave-like layer, with OFF（offset face-to-face） stacking interactions between phen ligands in adjacent layers, which are helpful to forming the three-dimensional supramolecular structure.
基金Natural Science Foundation of Shaanxi Province (2009JQ2015,2010JM2009)Special Research Fund of Education Department of Shaanxi Province (09JK798, 2010JK902)
文摘A new coordination polymer with the formula of [Co（2-mpac）2（py）·4H2O）]n （1, 2-mpac = 5-methyl-2-pyrazinecarboxylic acid, py = pyrazine） has been synthesized through hydrothermal synthesis and structurally characterized by X-ray single-crystal diffraction method. 1 exhibits a 3D supramolecular network. Crystal data： monoclinic, space group C2/m, a = 15.907（9）, b = 7.104（3）, c = 9.793（5）, β = 95.232（8）o, V = 1102.0（10）3, Z = 2, S = 0.995, the final R = 0.0509, wR = 0.1626 for 1002 observed reflections with （I 〉 2σ（I）） and R = 0.0530, wR = 0.1667 for all data. In addition, elemental analysis, IR and thermalgravimetric analysis are presented.
基金supported by the Science and Technology Planning Project in Sichuan Province(2019YJ0686)the Science and Technology Planning Project in Panzhihua City(2019ZD-G-11)。
文摘So far,the synthesis of chiral framework with achiral organic ligand still faces great challenge.Herein,three new coordinated complexes[Zn(btca)Cl]·DMA·N(CH_(3))_(2)(1),[Zn(btca)(Ac^(-))]·N(CH_(3))_(2)(2)and[Zn(btca)]·H_(2)O(3)(DMA=N,N-dimethylacetamide,btca=benzotriazole-5-carboxylate acid)were synthesized via different methods.Single-crystal X-ray diffraction analysis revealed that compounds 1 and 2 were isostructural and showed achiral layer network with fes topology,and 3 presented a chiral three-dimensional framework with eta topology.The result of this work has demonstrated that urothermal synthesis will be promising means of constructing chiral framework with achiral building block.Compound 3 also displayed an excellent property of iodine uptake.
