粪箕笃生物碱化学成分的研究

从粪箕笃的根茎中分得五种莲花氏烷型生物碱,其中两种为新化合物,分别命名为粪箕笃碱(2)及粪箕笃酮碱(3)。其他三种分别鉴定为已知的stephaboune(1),stephabyssine(4)及prostephabyssine(5)     

悼柳大纲学长

聆教罗城四十秋,忘年交笃气相投。     

甲基硫酸新斯的明的ICP-AES测定

研究了电感耦合等离子体原子发射光谱法间接测定甲基硫酸新斯的明，在溶液pH为5.0，四苯硼钠过量时可完全沉淀甲基硫酸新斯的明，测定滤液中的四苯硼钠可以计算得到甲基硫酸新斯的明的含量；方法简单快速，回收率在95％-101％之间，相对标准偏差为1.8％。     

斯替宁碱的合成方法研究进展

具有1H-吡咯并[1,2-a]氮杂和多取代全氢吲哚结构的斯替宁碱是百部生物碱的代表性结构,其多环结构和连续的七个手性中心对不对称合成化学极具挑战性.按斯替宁碱合成中使用的关键方法分类,对斯替宁碱的合成研究进展进行了综述.     

间接原子吸收光谱法测定甲基硫酸新斯的明

建立了原子吸收光谱法间接测定甲基硫酸新斯的明的方法。在pH5．0溶液中，当四苯硼钠过量时可完全沉淀甲基硫酸新斯的明，在滤液中加入过量的KCl沉淀剩余的四苯硼钠，再测定滤液中的过量的钾，可以计算得到甲基硫酸新斯的明的质量分数。方法回收率在97％～103％之间，相对标准偏差为1．5％。     

3—芳酰基乙基斯德酮在浓盐酸中的分离反应

3－芳酰基乙基斯德酮与过量浓盐酸在乙酸酯中于室温下反应，生成3－芳酰基乙基斯德酮的盐酸盐，而将3－芳酰基乙基乙基斯德酮与不同量的盐酸在乙酸乙酯中回流，则得到1－芳酰基乙基－3－芳基吡唑啉，此外，33－芳酰基乙基－4－溴斯德酮在类似条件下分解得到的相应的1－氯甲酰吡唑啉。     

吸附型“人工肝”辅助材料的制备及其性能研究：（Ⅳ）VD共聚物？…

本文选择醋酸乙烯酯／二乙烯苯共聚物（ＶＤ）及其醇解物（ＳＶＤ）为亲水性吸附剂,考察了它们笃水溶液及血清中芳香氨基酸（ＡＡＡ）的吸附性能,实验结果表明：ＳＶＤ比ＶＤ吸附ＡＡＡ的功效高,该吸附剂不权在水溶液及在血清中选择性吸附ＡＡＡ较高,血清相容性亦良好。     

氢氧化镧钠米线对多倍斯伏安响应的增敏作用及其应用

氢氧化镧钠米线修饰碳糊电极对多倍斯伏安响应有明显的增敏作用,其特征是多倍斯一对氧化还原峰的峰电流增大和峰电位差减小。这种增敏作用是由于氢氧化镧钠米线修饰电极有效面积的增大以及氢氧化镧钠米线与多倍斯间的化学作用。基于多倍斯在氢氧化镧钠米线修饰碳糊电极上灵敏的氧化峰,用线性扫描伏安法测定多倍斯,线性范围是3.0×10^-10～1.0×10^-8 mol·L^-1,检测限达5×10^-11mol·L^-1。     

贺涅斯米扬诺夫院士六十寿辰

9月9日杰出的学者和科学组织者,苏联科学院院长亚历山大·尼古拉也维奇·涅斯米扬诺夫院士已满六十岁了。最卓越的有机化学家之一——А.Н.涅斯米扬诺夫在自己创造性的工作中,将经典的俄罗斯有机化学学派的伟大传统(Н.Н.齐宁、А.М.布特列洛夫、В.В.马尔柯夫尼柯夫、Н.Д.泽林斯基等等)与基于电子观念的新的现代科学方向巧妙地结合了起     

有机元素微量分析——Ⅰ.普雷格耳-杜馬斯(Pregl-Dumas)微量定氮法

一、引言有机化合物中氮元素的測定,多半采用普雷格耳杜馬斯法,凱达尔(Kjeldahl)法和催化氫化三种方法。由于普雷格耳-杜馬斯法操作簡单,迅速,尤其是近年来經过不断的改进,在分析的准确度方面,得到了很大的提高;因此,使用較为广泛。其基本原理,可以簡单地用下式表示: 有机含氮化合物(?)N_2+氮的氧化物+GO_2+     

Heats of formation and kinetics of decomposition of nitroalkanes

Heats of formation of solid, liquid, and gaseous nitroalkanes have been shown mostly to obey group additivity. Group values have been obtained for carbon atoms attached to one, two, and three nitro groups. The heat of formation of 1,1,1,3,5,5,5,-heptanitropentane, either solid or liquid, cannot be fitted to the scheme, even allowing for gauche effects. The differences between observed and estimated values for 1,1,1-fluorodinitroalkanes and 1,2-dinitroethane are larger than expected and should be further investigated. Activation energies have been calculated for decomposition by five-center elimination of HONO from mononitro- and dinitroalkanes using thermochemistry and estimated activation energies for the reverse reactions. The key data for these estimates were previously reported activation energies for the decomposition of nitroethane and 1,2-dinitropropane. The calculations also gave values for the heats of formation (in kcal/mole) of nitroethylene 12.4, and 1-nitropropylene 5.6, and 2-nitropropylene 1.6. Activation energies were calculated for the competing unimolecular reaction, C? N bond fission, from thermochemistry and previously reported activation energies for the decomposition of 1,1- and 2,2-dinitropropane. Comparison of Arrhenius parameters for the two competing processes, namely, HONO and C? N bond fission, shows that, for the geminate dinitroethanes and dinitropropanes, C? N bond fission is faster about 370°K and, for the mononitroalkanes and for all the mononitroalkanes and dinitroalkanes, C? N bond fission is faster above 770°K.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

Mechanism of reactions of photocatalytic synthesis of chlorohydrins

A mechanism of photocatalytic synthesis of chlorohydrins from olefins and peroxo complexes of titanium (IV) is proposed. It consists of formation of radical-containing complexes, their reactions with olefins, and decomposition of the α-oxides obtained by hydrogen chlorides. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prosp. Nauki, 252039 Kiev, Ukraine. Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 33, No. 1, pp. 17–21, January–February, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

栽培草莓品种果实香气特性研究

通过对4个不同栽培草莓(Fragaria ananassa Duch．)品种果实糖和氨基酸测定及香气的GC-MS分析,结果表明：不同品种间氨基酸和糖含量不同,氨基酸含量由高到低依次为丰香、瓦尔达、哈达和全明星;哈达、丰香、全明星和瓦尔达4个品种果实分别检测出39、46、37和44种香气成分,各占总峰面积98.52％、99.15％、98.77％和95.4l％,检测成分的多少与氨基酸总量显著正相关,相关系数为0.967;哈达有5种独有的成分,丰香有9种独有的成分,全明星有3种独有的成分,瓦尔达有2种独有的成分,4个品种共有的成分有19种。     

化学单元教学设计的探索

论述了单元教学是落实化学新课程三维目标的基本教学过程,同时对教学单元的含义、教学单元的选择与建构、化学单元教学设计及其意义进行了阐述。     

Investigation of the influence of technological factors on quality of basic brands of HPPE

The comparative analysis of the molecular mass distribution, temperatures and heat effect of phase transitions, degree of crystallinity of defect materials and matrix polyethylene film were carried out. Possible reasons of deterioration of the quality of polyethylene on stages of its synthesis, transportation, storage, and processing were determined.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Phospholipids of the seeds of two species of Erysimum

Summary The phospholipid complexes of the seeds ofErysimum diffusum andE. sylvestris have been investigated. It has been found that the amount of phospholipids in the seeds ofE. diffusum is lower than in those ofE. sylvestris, but their qualitative compositions are similar. The fatty-acid compositions of the triglycerides and of the total phospholipids of the two plants investigated have been studied. It has been established that the total phospholipids of the species ofErysimum under consideration and individual fractions of them differ by the degree of saturation and the qualitative and quantitative composition of the acids that they contain and, consequently, the phospholipids present in greatest amount differ in their molecular compositions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 623–627, September–October, 1977.     

Composition of the complex of biopolymers of the cell walls of the grape

The complex of high-molecular-weight substances of the cell walls of the grape has been studied. It has been shown that the complex contains polysaccharides, proteins, and phenolic substances presumably linked through O-glycosidic bonds."Magarach" Scientific-Research Institute of Wine-Making and Wine-Growing, Yalta, M. V. Frunze Simferopol' State University, Khimiya Prirodnykh Soedinenii, No. 5, pp. 564–567, September–October, 1984.