为挖掘离子液体与环境友好"洁净"溶剂方面的潜力,以N-甲基咪唑为原料,合成了[BMIm]Cl离子液体,并利用红外光谱仪和核磁共振谱仪对其化学结构进行表征,而且使用了Materials Studio 5.5计算工作站对其进行了分子建模,并使用Dmol...为挖掘离子液体与环境友好"洁净"溶剂方面的潜力,以N-甲基咪唑为原料,合成了[BMIm]Cl离子液体,并利用红外光谱仪和核磁共振谱仪对其化学结构进行表征,而且使用了Materials Studio 5.5计算工作站对其进行了分子建模,并使用Dmol3模块对其结构进行了量子化学计算和优化,离子液体的结构得到了验证。展开更多
Synthesis of 11-demethyl and 6, 6, 11-demethyl calanolides A (6-9) have been carried out by a four-step reaction sequence using a simple approach in order to investigate the structural requirements necessary for antiv...Synthesis of 11-demethyl and 6, 6, 11-demethyl calanolides A (6-9) have been carried out by a four-step reaction sequence using a simple approach in order to investigate the structural requirements necessary for antiviral activity.展开更多
以L-半胱氨酸盐酸盐为原料,合成了大蒜中三种主要的蒜氨酸——S-甲基-L-半胱氨酸亚砜、S-丙基-L-半胱氨酸亚砜和S-烯丙基-L-半胱氨酸亚砜,并通过HPLC、MS和1 H NMR方法对三种合成化合物的纯度进行了检测。结果表明,三种化合物的纯度为99...以L-半胱氨酸盐酸盐为原料,合成了大蒜中三种主要的蒜氨酸——S-甲基-L-半胱氨酸亚砜、S-丙基-L-半胱氨酸亚砜和S-烯丙基-L-半胱氨酸亚砜,并通过HPLC、MS和1 H NMR方法对三种合成化合物的纯度进行了检测。结果表明,三种化合物的纯度为99.99%,产率分别可达46.5%,34.6%,46.2%。展开更多
1 Introduction Cupro-zlnc superoxide dlsmutase（CuZn-SOD）1s a dimeric enzyme,inade of two identical SUbunits,each contai ning a Cu（Ⅱ）ion and a Zn（Ⅱ）ion.His<sub>44</sub>,His<sub>46</sub>,...1 Introduction Cupro-zlnc superoxide dlsmutase（CuZn-SOD）1s a dimeric enzyme,inade of two identical SUbunits,each contai ning a Cu（Ⅱ）ion and a Zn（Ⅱ）ion.His<sub>44</sub>,His<sub>46</sub>,His<sub>61</sub>,His<sub>118</sub> and one molecule of H<sub>2</sub>O are involved in the binding of Cu（Ⅱ）,while His<sub>61</sub>,His<sub>69</sub>,His<sub>78</sub> and ASP<sub>81</sub> coordinate to Zn（Ⅱ）. A great deal of evidence indicates that CuZnSOD is resistant to many chemical reagents or phySical treatment,whereas itis quite susceptible to reactiVe OXygen species SUCh as H<sub>2</sub>O<sub>2</sub> or ascorbate-Fe（Ⅲ）system,demonstrating inactivation and physicochernical properties alterations.It is of biological significance to study the inactiVation mechanism of CuZn-SOD by reactive Oxygen species,because the enzyme plays an important role in disproportioning superoxide radical(O<sub>2</sub><sup>?</sup>),thus preventing the damaging effect of O<sub>2</sub><sup>?</sup> or its derivatives on biomacromolecules.A seties of studies has focused on展开更多
The Structural nature of Tctracctron sinense MWL is characterized by means of Chemical analysis.GC,IR,’H NMR and <sup>C</sup>（13） NMR spectra.The researches indicated that the MWL is of guaiacyl—syring...The Structural nature of Tctracctron sinense MWL is characterized by means of Chemical analysis.GC,IR,’H NMR and <sup>C</sup>（13） NMR spectra.The researches indicated that the MWL is of guaiacyl—syringyl type.The main connective form between structural units is β—O—4aryl ether bonds.The quantity of β—O—4 and 5—5 substructures is 0.53/C<sub>9</sub> and 0.06/C<sub>9</sub>,respectively.The alipatic and phenolic hydroxy contents are respectively.The OCH<sub>3</sub> content is estimated by <sup>C</sup>（13）NMR is spectrum （1.14/C<sub>9</sub>）,which is con-sistent with chemical method（1.11/C<sub>9</sub>） The degree of condensetion of the MWL is 0.51/C<sub>9</sub>（from ’HNMR）,which is consistent with the result from <sup>C</sup>（13）NMR.展开更多
For the first time, [PtdienNO_3]Cl was used as a stable reagent to modify ferricytochrome c and the reaction products were separated and purified with the CM-52 cation exchange chromatography. Five components were obt...For the first time, [PtdienNO_3]Cl was used as a stable reagent to modify ferricytochrome c and the reaction products were separated and purified with the CM-52 cation exchange chromatography. Five components were obtained, corresponding to the native cytochrome c single-labeled, dual-labeled, and triple-labeled derivatives as shown by the analysis of the molar ratio of the two metal atoms (Pt and Fe). The reduction potentials of these proteins were measured by differential pulse voltammetry. His-33 and Trp-59 were identified by^1HNMR as the binding sites of the platinum complex in the modified cytochrome c derivatives. Trp-59 was a conserved amino acid connected with the heme through hydrogen bond, which had not been modified by other transition metal complexes. The platinummodified cytochrome c derivatives might be valuable in exploring the role of the aromatic amino acids, especially Trp-59, in electron transfer.展开更多
文摘为挖掘离子液体与环境友好"洁净"溶剂方面的潜力,以N-甲基咪唑为原料,合成了[BMIm]Cl离子液体,并利用红外光谱仪和核磁共振谱仪对其化学结构进行表征,而且使用了Materials Studio 5.5计算工作站对其进行了分子建模,并使用Dmol3模块对其结构进行了量子化学计算和优化,离子液体的结构得到了验证。
文摘Synthesis of 11-demethyl and 6, 6, 11-demethyl calanolides A (6-9) have been carried out by a four-step reaction sequence using a simple approach in order to investigate the structural requirements necessary for antiviral activity.
文摘以L-半胱氨酸盐酸盐为原料,合成了大蒜中三种主要的蒜氨酸——S-甲基-L-半胱氨酸亚砜、S-丙基-L-半胱氨酸亚砜和S-烯丙基-L-半胱氨酸亚砜,并通过HPLC、MS和1 H NMR方法对三种合成化合物的纯度进行了检测。结果表明,三种化合物的纯度为99.99%,产率分别可达46.5%,34.6%,46.2%。
基金Project supported by the National Natural Science Foundation of China.
文摘1 Introduction Cupro-zlnc superoxide dlsmutase（CuZn-SOD）1s a dimeric enzyme,inade of two identical SUbunits,each contai ning a Cu（Ⅱ）ion and a Zn（Ⅱ）ion.His<sub>44</sub>,His<sub>46</sub>,His<sub>61</sub>,His<sub>118</sub> and one molecule of H<sub>2</sub>O are involved in the binding of Cu（Ⅱ）,while His<sub>61</sub>,His<sub>69</sub>,His<sub>78</sub> and ASP<sub>81</sub> coordinate to Zn（Ⅱ）. A great deal of evidence indicates that CuZnSOD is resistant to many chemical reagents or phySical treatment,whereas itis quite susceptible to reactiVe OXygen species SUCh as H<sub>2</sub>O<sub>2</sub> or ascorbate-Fe（Ⅲ）system,demonstrating inactivation and physicochernical properties alterations.It is of biological significance to study the inactiVation mechanism of CuZn-SOD by reactive Oxygen species,because the enzyme plays an important role in disproportioning superoxide radical(O<sub>2</sub><sup>?</sup>),thus preventing the damaging effect of O<sub>2</sub><sup>?</sup> or its derivatives on biomacromolecules.A seties of studies has focused on
文摘The Structural nature of Tctracctron sinense MWL is characterized by means of Chemical analysis.GC,IR,’H NMR and <sup>C</sup>（13） NMR spectra.The researches indicated that the MWL is of guaiacyl—syringyl type.The main connective form between structural units is β—O—4aryl ether bonds.The quantity of β—O—4 and 5—5 substructures is 0.53/C<sub>9</sub> and 0.06/C<sub>9</sub>,respectively.The alipatic and phenolic hydroxy contents are respectively.The OCH<sub>3</sub> content is estimated by <sup>C</sup>（13）NMR is spectrum （1.14/C<sub>9</sub>）,which is con-sistent with chemical method（1.11/C<sub>9</sub>） The degree of condensetion of the MWL is 0.51/C<sub>9</sub>（from ’HNMR）,which is consistent with the result from <sup>C</sup>（13）NMR.
基金Project supported by the National Natural Science Foundation of China and the Bio-macromolecule Laboratory, Institute of Biophysics, Academia Sinica.
文摘For the first time, [PtdienNO_3]Cl was used as a stable reagent to modify ferricytochrome c and the reaction products were separated and purified with the CM-52 cation exchange chromatography. Five components were obtained, corresponding to the native cytochrome c single-labeled, dual-labeled, and triple-labeled derivatives as shown by the analysis of the molar ratio of the two metal atoms (Pt and Fe). The reduction potentials of these proteins were measured by differential pulse voltammetry. His-33 and Trp-59 were identified by^1HNMR as the binding sites of the platinum complex in the modified cytochrome c derivatives. Trp-59 was a conserved amino acid connected with the heme through hydrogen bond, which had not been modified by other transition metal complexes. The platinummodified cytochrome c derivatives might be valuable in exploring the role of the aromatic amino acids, especially Trp-59, in electron transfer.
