创新型化学科普设计与实践——以流行歌曲的化学密码为例

Chemistry is the force to transform nature. To let people have a proper understanding of chemistry, this popular science teaching team, based on the previously Finding Chemistry in Detective Conan, select creatively words from the lyrics of influential pop songs, such as "blue and white porcelain" and "bubble", as the hot problems for chemistry popular science teaching; based on the chemistry topic of each part, seven interactive episodes of popular science are designed, which are rich in content and popular with readers.     

Biotransformation of p‐Coumaric Acid (=(2E)‐3‐(4‐Hydroxyphenyl)prop‐2‐enoic Acid) by Momordica charantia Peroxidase

LC/MS³‐Guided biotransformation of p‐coumaric acid (=(2E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoic acid; CA) with H₂O₂/Momordica charantia peroxidase at pH 5.0 and 45° in the presence of acetone has resulted in the isolation of three CA trimers, triCA1 ( 1 ), triCA2 (trans‐ 2 ), and triCA3 (cis‐ 2 ), and seven CA dimers, diCA1–diCA7, i.e., 3 – 9 , among which seven (triCA1–triCA3 and diCA1–diCA4) are new compounds and three (diCA5–diCA7) are known compounds. The structures were established by 2D‐NMR such as HSQC, HMBC, and NOESY measurements. The possible mechanism for the formation of the products is also discussed (Schemes 1–3). This is the first time that the biotansformation of p‐coumaric acid catalyzed by peroxidase in vitro was achieved. Compounds triCA3 (cis‐ 2 ), diCA1 ( 3 ), diCA5 ( 7 ), and diCA7 ( 9 ) exhibit a stronger antioxidative activity than the parent CA.     

超声波作用下的烯醇硅醚环丙化反应的研究

研究了超声波作用下烯醇硅醚的环丙化反应(Simmons-Smith反应),发现在超声波和CuCl共同作用下,锌粉能有效地被活化。三甲基硅氧基环丙烷类化合物的产率可达56%～78%。同时,还研究了超声波功率、反应温度、溶剂、反应时间等对环丙化反应的影响。     

A Novel Protein Found in Selenium-rich Silkworm Pupas

Selenium(Se)is well known for its cancer-preventive function1.In our previous work,silkworm pupas from Ziyang county of Shanxi Province,one of the two largest Se-rich areas in China,was found to have Se content215times higher than that from Luoyang which is a normal region in China2.Meanwhile,Se-rich amino acids extracted from Ziyang pupas could efficiently induce the apoptosis of human hepatoma cells SMMC-7721.In order to find out the effective component responsible for this carcinostat…     

Fluorescence Quenching of Poly[2-methoxy-5-（2′-ethylhexoxy）-p-phenylene vinylene] （MEH-PPV） in Solutions

Fluorescence quenching processes of poly[2-methoxy-5-(2‘ethyl-hexoxy)-p-phenylene vinylene] (MEH-PPV) in solution by electron acceptors, O2 and acid, have been studied. Static quenching of the fluorescence from MEH-PPV by an electron acceptor (DDQ or TCNE) occurs due to electron transfer from MEH-PPV to the electron acceptor and this electron transfer quenching can be promoted by chloroform. Photooxidation takes place in the MEH-PPV solution and singlet oxygen is an intermediate in the photooxidation, according to the results of ESR spectroscopy. Acid also plays an important role in the fluorescence quenching process of MEH-PPV, by the protonation of the alkoxy groups in the molecular chain.     

Relative rate constants for the reactions of hydroxyl radicals and chlorine atoms with a series of aliphatic alcohols

Rate constants for the gas‐phase reactions of hydroxyl radicals and chlorine atoms with a series of alcohols have been determined by using the relative method. The experiments were performed at 295 ± 2 K and at 1 atmospheric pressure. The obtained values of the rate constants in units of 10^?12 cm³ molecule^?1 s^?1 are as follows:

DPH-环糊精纳米管状聚集体的计算机模拟

1,6-二苯基－1,3,5-己三烯（1,6-diphenyl-1,3,5-hexatriene）（简称DPH）不能与α-环糊精，但可以分别与β-、γ-环糊精通过超分子自组装作用形成纳米管状结构的聚集体.该文采用分子力学和分子动力学模拟对这些聚集体在中性和碱性下条件的理论模型进行了预测，并分析了其主客体间的非键相互作用以及氢键的形成情况.计算结果表明，在碱性条件下，环糊精分子间氢键的消失导致了纳米管状结构的解离；而空腔过小是α-环糊精和DPH之间不能形成纳米管状结构的原因.     

有机分子中引入二氟亚甲基方法的最新进展

本综述从直接氟化法和间接氟化法两个方面就近些年来在有机化合物中引入二氟亚甲基的方法进行了概括。直接氟化法中，主要介绍了利用亲核和亲电两类氟化试剂在分子中导入-CF~2-的一些最新进展；间接氟化法则主要介绍了一些新的含-CF~2-的合成砌块在合成二氟亚甲基化合物中的应用。     

Determination of resveratrol in red wine by solid phase extraction-flow injection chemiluminescence method

A sensitive flow injection chemiluminescence method has been developed for the detection of resveratrol in red wine based on the fact that resveratrol can greatly enhance chemiluminescence reaction between KMnO_4 and HCHO in sulfuric acid medium. Analytes were pre-concentrated on solid sorbents (C_(18) solid-phase extraction cartridges).Under the optimum conditions,the proposed method allows the measurement of resveratrol over the range of 1.32×10~(-8) to 1.32×10~(-5) mol/L with a detection limit of 3.30×10~(-9) mol/L,and the relative standard deviation for 1.32×10~(-5) mol/L resveratrol (n=11) is 3.8%.This method has been successfully applied for the determination of the resveratrol in red wine.Furthermore,the possible reaction mechanism was also discussed.     

亚烷基锡烯与乙烯环加成反应机理的理论研究

The mechanism of a cycloaddition reaction between singlet alkylidenestannylene and ethylene has been investigated with MP2/3-21 G^* and B3LYP/3-21 G* methods, including geometry optimization and vibrational analysis for the involved stationary points on the potential energy surface. Energies for the involved conformations were calculated by CCSD(T)//MP2/3-2 IG^* and CCSD(T)//B3LYP/3-21G^* methods, respectively. The results show that the dominant reaction pathway of the cycloaddition is that an intermediate (INT) is firstly formed between the two reactants through a barrier-free exothermic reaction of 39.7 kJ/mol, and the intermediate then isomerizes to a four-membered ring product (P2.1) via a transition state TS2.1 with a barrier of 66.8 kJ/mol.