国际上依据咪唑甘油磷酸酯脱水酶(IGPD)底物结构筛选,成功获得了一系列含氮杂环磷酸酯类化合物作为IGPD抑制剂,然而IGPD与含氮杂环磷酸酯类抑制剂间的作用模式尚不清楚.本研究利用Gaussian 03程序,基于密度泛函理论B3LYP方法,选择6-31G*...国际上依据咪唑甘油磷酸酯脱水酶(IGPD)底物结构筛选,成功获得了一系列含氮杂环磷酸酯类化合物作为IGPD抑制剂,然而IGPD与含氮杂环磷酸酯类抑制剂间的作用模式尚不清楚.本研究利用Gaussian 03程序,基于密度泛函理论B3LYP方法,选择6-31G**基组优化含氮杂环磷酸酯类化合物,在确定其稳定构象的基础上利用分子对接、力学优化构建IGPD与其含氮杂环磷酸酯类抑制剂相互作用的复合物结构,基于化合物的电子结构(前线轨道能级及组成、原子电荷、自然键轨道等)、复合物的空间结构(抑制剂识别IGPD的功能域、分子间氢键、van der Waals相互作用等)探讨了IGPD与含氮杂环磷酸酯类抑制剂作用方式,确定了含氮杂环电荷分布、磷酸根离子电荷分布、前线轨道LUMO能级是影响抑制剂活性的内在因素,为进一步筛选、优化高效的新型除草剂提供了重要信息.展开更多
为了研究增鲜肽的增鲜机制,通过分子模拟技术结合感官评价分析3条鸡肉源肽LPLQD、DGGRYY和DEAGPSIVH的增鲜作用、增鲜肽-谷氨酸-味觉受体互作分子机制及其动态结合过程。增鲜肽的特性分析结果表明,3条增鲜肽水溶性较好且无毒性。感官分...为了研究增鲜肽的增鲜机制,通过分子模拟技术结合感官评价分析3条鸡肉源肽LPLQD、DGGRYY和DEAGPSIVH的增鲜作用、增鲜肽-谷氨酸-味觉受体互作分子机制及其动态结合过程。增鲜肽的特性分析结果表明,3条增鲜肽水溶性较好且无毒性。感官分析结果显示,3条增鲜肽均对质量分数0.35%谷氨酸钠溶液具有鲜味感知加成作用。分子对接结果表明,增鲜肽的存在显著增加了配体体系与味觉受体亚型1(taste receptor type 1,T1R1)间的相互作用,包括静电相互作用、疏水相互作用和氢键相互作用,从而增强了配体体系与T1R1之间的结合稳定性。在分子动力学模拟过程中,鲜味受体T1R1胞外捕蝇草结构域相对稳定,而富半胱氨酸结构域存在较大的空间波动。氢键数量统计结果显示,增鲜肽加入配体体系能够增加配体与受体间氢键相互作用,从而增强配体与受体的结合强度。通过前沿分子轨道计算确定了Ser、Tyr、Gln、Arg和His等氨基酸残基为增鲜肽与T1R1结合的主要活性位点。以上研究结果可为理解增鲜肽的增鲜机制以及新型增鲜剂的开发提供理论支持。展开更多
The molecular geometries, frontier molecular orbital properties, and absorption and emission properties of three 4-phenoxy-1,8-naphthalimide derivatives, namely 4-phenoxy-N-（2-hydroxyethyl）-1,8-naphthalimide（1）,4-...The molecular geometries, frontier molecular orbital properties, and absorption and emission properties of three 4-phenoxy-1,8-naphthalimide derivatives, namely 4-phenoxy-N-（2-hydroxyethyl）-1,8-naphthalimide（1）,4-（2-tert-butylphenoxy）-N-（2-hydroxyethyl）-1,8-naphthalimide（2）, and 4-[2,4-di（tert-butyl）]phenoxy-N-（2-hydroxyethyl）-1,8-naphthalimide（3）, are investigated by density functional theory（DFT） and time-dependent density functional theory（TD-DFT） calculations in conjunction with polarizable continuum models（PCMs）. Four functionals and ten basis sets are employed for 1 to calculate the electron transition energies, which were compared with the experimental observations. Our results reveal that the B3LYP/6-311＋G（d,p） method is the best choice to reproduce the experimental spectra. Moreover, the effects of substituents on the molecular geometries, electronic structures, absorption and emission spectra are also studied at the B3LYP/6-311＋G（d,p） level. We find that the gap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO） decreases with increasing the number of tert-butyl substituents onto the phenoxy groups, suggesting red-shift of the absorption and emission bands. This is related to the increase of conjugation from 1 to 2 and 3. Our calculations are in good agreement with the experimental results.展开更多
A series of dye molecules was designed theoretically.Particularly,azoles and their derivatives were chosen as the modifying groups linking to ancillary ligands of [Ru（dcbpyH2）2（NCS）2]（N3,dcbpy=4,4＇-dicarboxy2,2...A series of dye molecules was designed theoretically.Particularly,azoles and their derivatives were chosen as the modifying groups linking to ancillary ligands of [Ru（dcbpyH2）2（NCS）2]（N3,dcbpy=4,4＇-dicarboxy2,2＇-bipyridine;NCS=thiocyanato）.Density functional theory（DFT） based approaches were applied to exploring the electronic structures and properties of all these systems.The dye molecule with 1,2,4-triazole groups which exhibits a very high intensity of absorption in visible region,was obtained.Time-dependent DFT（TD-DFT） results indicate that the ancillary ligand dominates the molecular orbital（MO） energy levels and masters the absorption transition nature to a certain extent.The deprotonation of anchoring ligand not only affects the frontier MO energy levels but also controls the energy gaps of the highest occupied MO（HOMO） to the lowest unoccupied MO（LUMO） and LUMO to LUMO＋1 orbital.If the gap between LUMO-LUMO＋1 is small enough,the higher efficiency of dye-sensitized solar cell（DSSC） should be expected.展开更多
The title compound, 1-（naphthalene-2-yl）-2-（1H-pyrazol-1-yl）ethanone O-butyl oxime, I, was synthesized. The crystal and molecular structures of I were determined by IR, 1H-NMR, mass spectrum, elemental analysis an...The title compound, 1-（naphthalene-2-yl）-2-（1H-pyrazol-1-yl）ethanone O-butyl oxime, I, was synthesized. The crystal and molecular structures of I were determined by IR, 1H-NMR, mass spectrum, elemental analysis and X-ray single crystal diffraction. Molecular geometry from X-ray experiment of I in the ground state was compared using the Density Functional Theory （DFT） with B3LYP/6-311G（d,p） basis set. In addition, DFT calculation, molecular electrostatic potentials （MEP） and frontier molecular orbitals of I were performed at the B3LYP/6-311G（d,p） level of the theory.展开更多
文摘国际上依据咪唑甘油磷酸酯脱水酶(IGPD)底物结构筛选,成功获得了一系列含氮杂环磷酸酯类化合物作为IGPD抑制剂,然而IGPD与含氮杂环磷酸酯类抑制剂间的作用模式尚不清楚.本研究利用Gaussian 03程序,基于密度泛函理论B3LYP方法,选择6-31G**基组优化含氮杂环磷酸酯类化合物,在确定其稳定构象的基础上利用分子对接、力学优化构建IGPD与其含氮杂环磷酸酯类抑制剂相互作用的复合物结构,基于化合物的电子结构(前线轨道能级及组成、原子电荷、自然键轨道等)、复合物的空间结构(抑制剂识别IGPD的功能域、分子间氢键、van der Waals相互作用等)探讨了IGPD与含氮杂环磷酸酯类抑制剂作用方式,确定了含氮杂环电荷分布、磷酸根离子电荷分布、前线轨道LUMO能级是影响抑制剂活性的内在因素,为进一步筛选、优化高效的新型除草剂提供了重要信息.
文摘为了研究增鲜肽的增鲜机制,通过分子模拟技术结合感官评价分析3条鸡肉源肽LPLQD、DGGRYY和DEAGPSIVH的增鲜作用、增鲜肽-谷氨酸-味觉受体互作分子机制及其动态结合过程。增鲜肽的特性分析结果表明,3条增鲜肽水溶性较好且无毒性。感官分析结果显示,3条增鲜肽均对质量分数0.35%谷氨酸钠溶液具有鲜味感知加成作用。分子对接结果表明,增鲜肽的存在显著增加了配体体系与味觉受体亚型1(taste receptor type 1,T1R1)间的相互作用,包括静电相互作用、疏水相互作用和氢键相互作用,从而增强了配体体系与T1R1之间的结合稳定性。在分子动力学模拟过程中,鲜味受体T1R1胞外捕蝇草结构域相对稳定,而富半胱氨酸结构域存在较大的空间波动。氢键数量统计结果显示,增鲜肽加入配体体系能够增加配体与受体间氢键相互作用,从而增强配体与受体的结合强度。通过前沿分子轨道计算确定了Ser、Tyr、Gln、Arg和His等氨基酸残基为增鲜肽与T1R1结合的主要活性位点。以上研究结果可为理解增鲜肽的增鲜机制以及新型增鲜剂的开发提供理论支持。
基金supported by the Scientific Research Fund of Hubei Provincial Education Department(No.Q20122909)the Open Fund of Key Laboratory of Biologic Resources Protection and Utilization of Hubei Province(No.PKLHB1314)the First-class Discipline of Forestry in Hubei Minzu University
文摘The molecular geometries, frontier molecular orbital properties, and absorption and emission properties of three 4-phenoxy-1,8-naphthalimide derivatives, namely 4-phenoxy-N-（2-hydroxyethyl）-1,8-naphthalimide（1）,4-（2-tert-butylphenoxy）-N-（2-hydroxyethyl）-1,8-naphthalimide（2）, and 4-[2,4-di（tert-butyl）]phenoxy-N-（2-hydroxyethyl）-1,8-naphthalimide（3）, are investigated by density functional theory（DFT） and time-dependent density functional theory（TD-DFT） calculations in conjunction with polarizable continuum models（PCMs）. Four functionals and ten basis sets are employed for 1 to calculate the electron transition energies, which were compared with the experimental observations. Our results reveal that the B3LYP/6-311＋G（d,p） method is the best choice to reproduce the experimental spectra. Moreover, the effects of substituents on the molecular geometries, electronic structures, absorption and emission spectra are also studied at the B3LYP/6-311＋G（d,p） level. We find that the gap between the highest occupied molecular orbital（HOMO） and the lowest unoccupied molecular orbital（LUMO） decreases with increasing the number of tert-butyl substituents onto the phenoxy groups, suggesting red-shift of the absorption and emission bands. This is related to the increase of conjugation from 1 to 2 and 3. Our calculations are in good agreement with the experimental results.
基金Supported by the National Natural Science Foundation of China(Nos.20973076,21003057)the Specialized Research Fund for the Doctoral Program of Higher Education,China(No.20110061110018)
文摘A series of dye molecules was designed theoretically.Particularly,azoles and their derivatives were chosen as the modifying groups linking to ancillary ligands of [Ru（dcbpyH2）2（NCS）2]（N3,dcbpy=4,4＇-dicarboxy2,2＇-bipyridine;NCS=thiocyanato）.Density functional theory（DFT） based approaches were applied to exploring the electronic structures and properties of all these systems.The dye molecule with 1,2,4-triazole groups which exhibits a very high intensity of absorption in visible region,was obtained.Time-dependent DFT（TD-DFT） results indicate that the ancillary ligand dominates the molecular orbital（MO） energy levels and masters the absorption transition nature to a certain extent.The deprotonation of anchoring ligand not only affects the frontier MO energy levels but also controls the energy gaps of the highest occupied MO（HOMO） to the lowest unoccupied MO（LUMO） and LUMO to LUMO＋1 orbital.If the gap between LUMO-LUMO＋1 is small enough,the higher efficiency of dye-sensitized solar cell（DSSC） should be expected.
基金the Faculty of Arts and Sciences, Ondokuz Mayιs University, Turkey, for the use of the Stoe IPDSII diffractometer (purchased under grant No. F279 of the University Research Fund)
文摘The title compound, 1-（naphthalene-2-yl）-2-（1H-pyrazol-1-yl）ethanone O-butyl oxime, I, was synthesized. The crystal and molecular structures of I were determined by IR, 1H-NMR, mass spectrum, elemental analysis and X-ray single crystal diffraction. Molecular geometry from X-ray experiment of I in the ground state was compared using the Density Functional Theory （DFT） with B3LYP/6-311G（d,p） basis set. In addition, DFT calculation, molecular electrostatic potentials （MEP） and frontier molecular orbitals of I were performed at the B3LYP/6-311G（d,p） level of the theory.
