Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant ...Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant plasmids pET28a(+)EccslH28,pET28a(+)EccslH41,pET28a(+)EccslH122 and pET28a(+)EccslH184 were prepared and transformed into E.coli to express the recombinant enzymes.Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70℃,while their optimum pH value and pH stability were not affected,which proved that the introduction of disulfide bond improved the thermal stability ofβ-1,4 glucanase.展开更多
Sodium alkyl thiosulfates(Bunte salts) can be readily reduced to the corresponding disulfides with TiCl4/Sm system in good to excellent yields under mild conditions
A colorimetric method for the direct determination of hydrogen peroxide in aqueous solution is described. H2O2 stoichiometrically converts 4-nitrophenyl boronic acid or 4-nitrophenyl boronic acid pinacol ester into 4-...A colorimetric method for the direct determination of hydrogen peroxide in aqueous solution is described. H2O2 stoichiometrically converts 4-nitrophenyl boronic acid or 4-nitrophenyl boronic acid pinacol ester into 4-nitrophenol, which can be quantified by measuring the absorption at 400 nm in neutral or basic media. The reactions proceed fast under basic conditions and complete in 2 minutes to at pH 11 and 80?C. The linear range for the colorimetric method extends beyond 1.0 to 40 μM H2O2, and the limit of detection is ~1.0 μM H2O2. This method offers a convenient and practical process for rapid determination of hydrogen peroxide in aqueous media. Compared to many other techniques in H2O2 detection, this process is a direct measurement of H2O2, and is relatively unaffected by the presence of various salts, metal ions and the chelator EDTA.展开更多
The title compound 2-（2-chloro-4-nitrophenyl）-4-（4-chlorophenyl）-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 （C29H30Cl2N3O7P, Mr = 633.44） was synthesized and its structure was cha...The title compound 2-（2-chloro-4-nitrophenyl）-4-（4-chlorophenyl）-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 （C29H30Cl2N3O7P, Mr = 633.44） was synthesized and its structure was characterized by IR, MS, ^1H NMR, ^13C NMR, ^31p NMR, elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1^-, a = 9.1549（3）, b = 10.7168（4）, c = 17.6272（6）A, α = 102.9363（12）, β = 90.2713（9）, γ = 117.4265（10）°, V= 1484.41（9）A^3, Z= 2,μ（MoKa） = 0.323, F（000） = 658, Z= 2, De= 1.417 g/cm^3, the final R = 0.0687 and wR = 0.2066 for 4943 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the diazaphospholine ring is almost planar and the two ethoxy groups bonded on the 3a- and 4-positions are in trans configurations. Its antiproliferative activity was also tested in vitro against four human tumor cell lines.展开更多
By using 1-methyl-2-formyl-5 -Y-substituted pyrrole (4-nitrophenyl)hydrazones as a model for nitrogen-containing heterocyclic aromatic compounds, the emission wavelength [lambda(max(em))] values df their fluorescence ...By using 1-methyl-2-formyl-5 -Y-substituted pyrrole (4-nitrophenyl)hydrazones as a model for nitrogen-containing heterocyclic aromatic compounds, the emission wavelength [lambda(max(em))] values df their fluorescence spectra have been measured. Correlation results show that the Delta E-em values are mainly affected by polar effects, but spin-delocalizatin effects also exist.展开更多
The new title compound 4-chloro-N-（2-（2-nitrophenyl）acetoxy）-N-（m-tolyl）benza- mide （C：2HI7C1N2Os, Mr = 424.82） has been synthesized via the reaction of 4-chloro-N-hydroxy-N- （m-tolyl）benzamide with 2-（2-n...The new title compound 4-chloro-N-（2-（2-nitrophenyl）acetoxy）-N-（m-tolyl）benza- mide （C：2HI7C1N2Os, Mr = 424.82） has been synthesized via the reaction of 4-chloro-N-hydroxy-N- （m-tolyl）benzamide with 2-（2-nitrophenyl）acetyl chloride. The structure of the product was confirmed by 1H NMR, 13C NMR, IR, HRMS （ESI） and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/c with a = 13.0269（10）, b =6.7251（6）, c = 23.9313（16） A, β = 99.931（6）°, V = 2065.1（3） A3, Z = 4, Dc = 1.366 g/cm3, F（000） = 880,μ = 0.221 mm-1, the final R = 0.0600 and wR = 0.1754 for 1981 observed reflections （I〉 20（/））. X-ray analysis indicates that the chloro-phenyl ring （C（10）℃（15）） and the methyl-substituted benzene ring （C（16）℃（21）） are not coplanar with the nitro-substituted benzene ring （C（1）--C（6））, with the dihedral angle to be 70.78° and 63.72°, respectively. Hydrogen bonds C（2）-H（2）...O（2） and C（7）-H（7B）...O（5） are observed.展开更多
Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic a...Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic and elemental analysis and single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1 with unit cell dime sions a = 8.7137(10), b = 10.2010(14), c = 10.6593(13), α = 62.671(9), β = 82.701(10), γ = 79.762(10), V = 827.21(8) ?3, Z = 2.展开更多
A new triazene reagent 1-(6-ethoxyl-2-benzothiazolyl)-3-(4-nitrophenyl)-triazene (EtOBThTPT) has been synthesized. The colour reaction of EtOBTNPT with Hg(II) has been studied. At pH = 10.1-10.7, in the presence of Tr...A new triazene reagent 1-(6-ethoxyl-2-benzothiazolyl)-3-(4-nitrophenyl)-triazene (EtOBThTPT) has been synthesized. The colour reaction of EtOBTNPT with Hg(II) has been studied. At pH = 10.1-10.7, in the presence of Triton X-100, the reagent with Hg(II) forms an orange-yellow complex with high sensitivity. The molar absorptivity is 2.38 X 10(5) L.mol(-1).cm(-1). Beer's law is obeyed for Hg(II) in the range of 0-7 mu g/25 ml.展开更多
This paper introduces the synthesis of a new color reagent 1-(6-nitro-2-benzothiazolyl)3-(4-nitrophenyl)-triazene (NBTNPT) and the color reaction of NBTNPT with Cd (II) has been studied. In the presence of Triton X-10...This paper introduces the synthesis of a new color reagent 1-(6-nitro-2-benzothiazolyl)3-(4-nitrophenyl)-triazene (NBTNPT) and the color reaction of NBTNPT with Cd (II) has been studied. In the presence of Triton X-100, the reagent with Cd (II) forms an orange-yellow complex (1:1) at pH=11.5-12.3, the molar absorptivity is 2.81x10(5)L . mol(-1)m(-1) by dual-wavelength spectrophotometry, Beers law is obeyed in the range of 0-280 mu g/L for Cd (II).展开更多
基金Supported by the National Key Research and Development Plan of China(2019YFC1905902,2019YFC1905900)Key Research and Development Plan in Shandong Province(2020CXGC010603,2021ZDSYS10,2022CXGC020206)+2 种基金"Open Competition Mechanism"Project of Qilu University of Technology(Shandong Academy of Sciences)(2022JBZ01-06)Taishan Industry Leading Talent Program(tscy20180103)National Natural Science Foundation of China(31801527)。
文摘Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant plasmids pET28a(+)EccslH28,pET28a(+)EccslH41,pET28a(+)EccslH122 and pET28a(+)EccslH184 were prepared and transformed into E.coli to express the recombinant enzymes.Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70℃,while their optimum pH value and pH stability were not affected,which proved that the introduction of disulfide bond improved the thermal stability ofβ-1,4 glucanase.
文摘Sodium alkyl thiosulfates(Bunte salts) can be readily reduced to the corresponding disulfides with TiCl4/Sm system in good to excellent yields under mild conditions
文摘A colorimetric method for the direct determination of hydrogen peroxide in aqueous solution is described. H2O2 stoichiometrically converts 4-nitrophenyl boronic acid or 4-nitrophenyl boronic acid pinacol ester into 4-nitrophenol, which can be quantified by measuring the absorption at 400 nm in neutral or basic media. The reactions proceed fast under basic conditions and complete in 2 minutes to at pH 11 and 80?C. The linear range for the colorimetric method extends beyond 1.0 to 40 μM H2O2, and the limit of detection is ~1.0 μM H2O2. This method offers a convenient and practical process for rapid determination of hydrogen peroxide in aqueous media. Compared to many other techniques in H2O2 detection, this process is a direct measurement of H2O2, and is relatively unaffected by the presence of various salts, metal ions and the chelator EDTA.
文摘The title compound 2-（2-chloro-4-nitrophenyl）-4-（4-chlorophenyl）-3a,4- diethoxy- 2,3,3a, 4-tetrahydrochromeno[3,4-d][1,2,3]diazaphosphole 2 （C29H30Cl2N3O7P, Mr = 633.44） was synthesized and its structure was characterized by IR, MS, ^1H NMR, ^13C NMR, ^31p NMR, elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1^-, a = 9.1549（3）, b = 10.7168（4）, c = 17.6272（6）A, α = 102.9363（12）, β = 90.2713（9）, γ = 117.4265（10）°, V= 1484.41（9）A^3, Z= 2,μ（MoKa） = 0.323, F（000） = 658, Z= 2, De= 1.417 g/cm^3, the final R = 0.0687 and wR = 0.2066 for 4943 observed reflections （I 〉 2σ（I））. X-ray analysis reveals that the diazaphospholine ring is almost planar and the two ethoxy groups bonded on the 3a- and 4-positions are in trans configurations. Its antiproliferative activity was also tested in vitro against four human tumor cell lines.
文摘By using 1-methyl-2-formyl-5 -Y-substituted pyrrole (4-nitrophenyl)hydrazones as a model for nitrogen-containing heterocyclic aromatic compounds, the emission wavelength [lambda(max(em))] values df their fluorescence spectra have been measured. Correlation results show that the Delta E-em values are mainly affected by polar effects, but spin-delocalizatin effects also exist.
基金Supported by the Fundamental Research Funds for the Central Universities(lzujbky-2010-137)Lanzhou Science and Technology Bureau Program Funds(2012-2-90)
文摘The new title compound 4-chloro-N-（2-（2-nitrophenyl）acetoxy）-N-（m-tolyl）benza- mide （C：2HI7C1N2Os, Mr = 424.82） has been synthesized via the reaction of 4-chloro-N-hydroxy-N- （m-tolyl）benzamide with 2-（2-nitrophenyl）acetyl chloride. The structure of the product was confirmed by 1H NMR, 13C NMR, IR, HRMS （ESI） and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P21/c with a = 13.0269（10）, b =6.7251（6）, c = 23.9313（16） A, β = 99.931（6）°, V = 2065.1（3） A3, Z = 4, Dc = 1.366 g/cm3, F（000） = 880,μ = 0.221 mm-1, the final R = 0.0600 and wR = 0.1754 for 1981 observed reflections （I〉 20（/））. X-ray analysis indicates that the chloro-phenyl ring （C（10）℃（15）） and the methyl-substituted benzene ring （C（16）℃（21）） are not coplanar with the nitro-substituted benzene ring （C（1）--C（6））, with the dihedral angle to be 70.78° and 63.72°, respectively. Hydrogen bonds C（2）-H（2）...O（2） and C（7）-H（7B）...O（5） are observed.
文摘Synthesis of the title compound was carried out by base-catalyzed cyclization of 1-pivaloyl-3-(2-chloro-4-nitrophenyl) thiourea with α-bromoacetone produced in situ. The structure was confirmed by the spectroscopic and elemental analysis and single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1 with unit cell dime sions a = 8.7137(10), b = 10.2010(14), c = 10.6593(13), α = 62.671(9), β = 82.701(10), γ = 79.762(10), V = 827.21(8) ?3, Z = 2.
文摘A new triazene reagent 1-(6-ethoxyl-2-benzothiazolyl)-3-(4-nitrophenyl)-triazene (EtOBThTPT) has been synthesized. The colour reaction of EtOBTNPT with Hg(II) has been studied. At pH = 10.1-10.7, in the presence of Triton X-100, the reagent with Hg(II) forms an orange-yellow complex with high sensitivity. The molar absorptivity is 2.38 X 10(5) L.mol(-1).cm(-1). Beer's law is obeyed for Hg(II) in the range of 0-7 mu g/25 ml.
文摘This paper introduces the synthesis of a new color reagent 1-(6-nitro-2-benzothiazolyl)3-(4-nitrophenyl)-triazene (NBTNPT) and the color reaction of NBTNPT with Cd (II) has been studied. In the presence of Triton X-100, the reagent with Cd (II) forms an orange-yellow complex (1:1) at pH=11.5-12.3, the molar absorptivity is 2.81x10(5)L . mol(-1)m(-1) by dual-wavelength spectrophotometry, Beers law is obeyed in the range of 0-280 mu g/L for Cd (II).
