南蛇藤昆虫拒食成分的研究(I)

南蛇藤昆虫拒食成分的研究（Ｉ）王明安,陈馥衡（北京农业大学应用化学系,北京,１０００９４）关键词南蛇藤,倍半萜,结构分析南蛇藤（Ｃｅｌａｓｔｒｕｓｏｒｂｉｃｕｌａｔｕｓ）是我国传统的低毒杀虫植物,其主要化学成分为倍半萜［１］．Ｓｍｉｔｈ等［２,３］对...     

茴藿香精油化学成分的研究

本文介绍采用毛细管气相色谱-质谱法研究了甘肃敦煌栽培的茴霍香精油的化学成分。色谱分离出30多个组分,质谱鉴定了25种化合物,占色谱流出峰总面积的97.87%。其中有19种化合物为该植物化学成分的首次报道。异薄荷酮(35.22)、茴香脑(24.30%)和长叶薄荷酮(16.66%)为该精油的主要成分。     

西伯利亚云杉松脂挥发油化学成分分析

1　引　　言西伯利亚云杉 (ＰｉｃｅａｏｂｏｖａｔａＬｅｄｅｂ .)是一种在中国仅产于新疆阿尔泰山脉 12 0 0～ 2 4 0 0ｍ高的中山带和亚高山带下部的一种古老的残遗植物 ,对研究第三纪末和第四纪初北方植物区系成分南迁及古地理、古气候有一定科研价值。但迄今为止 ,其松脂挥发油的化学成分分析却从未见报道。我们采集布尔津林场新鲜的云杉松脂 ,用水蒸汽蒸馏、有机溶剂萃取等方法获得 2 0 %～ 2 5%的精油 ,采用ＧＣ ＭＳ ＤＣ技术对其精油的化学成分进行了分析 ,色谱分离出 10 0个成分 ,根据质谱数据 ,经过ＨＰ 5988Ａ联机谱库检索 ,结合…     

A Study on 4,4′-Diaminobenzene Sulfonanilide (DABSA) and the Properties of Dyes Derived from DABSA

Ｓｉｎｃｅｂｅｎｚｉｄｉｎｅｉｓａｋｎｏｗｎｃａｒｃｉｎｏｇｅｎ ,ｉｄｅｎｔｉｆｙｉｎｇｐｏｔｅｎｔｉａｌｒｅｐｌａｃｅｍｅｎｔｓｆｏｒｂｅｎｚｉｄｉｎｅｈａｓｂｅｃｏｍｅａｎｉｍｐｏｒｔａｎｔｒｅｓｅａｒｃｈｐｒｏｊｅｃｔｉｎｃｏｌｏｒｃｈｅｍｉｓｔｒｙ .Ｏｎｅｏｆｔｈｅｃｏｍｐｏｕｎｄｓｅｘａｍｉｎｅｄｉｓ 4,4′ ｄｉａｍｉｎｏｂｅｎｚｅｎｅｓｕｌｆｏｎａｎｉｌｉｄｅ(ＤＡＢＳＡ) .ＡｓｅｒｉｅｓｏｆｄｙｅｓｄｅｒｉｖｅｄｆｒｏｍＤＡＢＳＡｈａｓｂｅｅｎｄｅｖｅｌｏｐｅｄａｎｄｃｏｍｍｅｒｃｉ…     

玫瑰花提取工艺、化学成分及其生物活性研究进展

玫瑰花具有重要的观赏和药用价值, 主要的化学成分有玫瑰精油、黄酮类、多糖类和酚酸类等, 具有心肌保护、抗氧化、抑菌、抗肿瘤、抗病毒、镇静催眠作用、调节血脂和降血糖等生物活性.玫瑰精油是高级香水、香料和化妆品不可取代的原料, 其提取工艺是工业研究的重点.对玫瑰花中的化学成分和生物活性进行了综述, 并重点总结了玫瑰精油的提取工艺、成分和生物活性, 为玫瑰花, 特别是玫瑰精油的研究和开发提供参考.     

中药川白芷化学成分的研究

中药川白芷为伞形科当归属杭白芷 (Ａｎｇｅｌｉｃａｄａｈｕｒｉｃａ (Ｆｉｓｃｈ .ｅｘＨｏｆｆｍ .)Ｂｅｎｔｈ .ｅｔＨｏｏｋ .ｃｖｈａｎｇ ｂａｉｚｈｉＨｏｒｔ)的干燥根。川白芷为我国传统中药 ,主治头疼、鼻炎、癣症等疾病。现代药理实验表明白芷中所含的呋南香豆素具有平喘、降压、抗菌、解痉、光敏、活化交感系激素等多种药理作用[1] 。已有文献对白芷的化学成分进行了研究 ,发现白芷中主要含香豆素成分[2～ 4] 。四川遂宁产川白芷为道地白芷 ,其药性好 ,为进一步研究其活性成分 ,本文对遂宁产川白芷进行化学成分研究。共分离、…     

最新电化学技术应用文献摘引

能量存储与转移2 0 0 0年日本国家项目中大尺寸锂离子二次电池的研发　ＴｏｓｈｉｋａｔｓｕＴａｎａｋａ ,ＫａｚｕｈｉｒｏＯｈｔａ,ＮｏｂｏｒｕＡｒａｉ,ＪｏｕｒｎａｌｏｆＰｏｗｅｒＳｏｕｒｃｅｓ ,Ｖｏｌ.97＿98( 0 ) 2 0 0 1 ,2～ 6宇航用锂离子电池　Ｒ .Ａ .Ｍａｒｓｈ ,Ｓ .Ｖｕｋｓｏｎ ,Ｓ .Ｓｕｒａｍｐｕｄｉ,Ｂ .Ｖ .Ｒａｔｎａｋｕｍａｒ,Ｍ .Ｃ .Ｓｍａｒｔ,Ｍ .Ｍａｎｚｏ ,Ｐ .Ｊ.Ｄａｌｔｏｎ ,ＪｏｕｒｎａｌｏｆＰｏｗｅｒＳｏｕｒｃｅｓ,Ｖｏｌ.97＿98( 0 ) 2 0 0 1 ,2 5～ 2 7用稻壳制备的锂离子电池高容量碳　Ｇ…     

舞花姜的化学成分

舞花姜（Ｇｌｏｂｂａｒａｃｅｍｏｓａｓｍｉｔｈ）为姜科舞花姜属植物,产于我国南部、西南部等地。其根和果实在民间药用,有健胃、消炎的功能,用于治疗胃炎、消化不良、急慢性肾炎等［１］。尚未见有关舞花姜属植物化学成分和药理活性的研究报道,为此我们对其地下部分的化学成分进行了研究。乙醇提取物的石油醚可溶部分经硅胶柱和萄聚糖凝胶柱层析分离得到五个化合物,经光谱鉴定为木栓酮（ｆｒｉｅｄｅｌｉｎ１）,ｃｙｃｌｏｅｕｃａｌｅｎ－ｏｌ（２）、３－羟基－豆甾－５烯－７－酮（３－ｈｙｄｒｏｘｙ－ｓｔｉｇｍａｓｔ－５－…     

桂花精油化学成分研究

用水蒸汽蒸馏法对江苏产桂花精油进行了提取, 并用GC-MS联用仪对其有效成分进行了测定. 结果表明: 江苏产桂花精油的香味成分主要是萜烯、醇类、氧化芳樟醇类、 5-己基二氢呋喃-2-酮、紫罗兰酮类、邻苯二甲酸酯类, 其中邻苯二甲酸酯类含量最大. 对水蒸汽蒸馏后的桂花水溶液进行萃取和GC-MS测试, 进一步证实了邻苯二甲酸酯的存在. 与其它产地的桂花精油化学成分比较, 其主要的香味成分基本相同, 但邻苯二甲酸酯含量不同, 这一研究结果表明: 研究不同产地的香料香味成分时需要将多种提取方法结合;对现有应用于化妆品和食用香精的桂花精油是否含有邻苯二甲酸酯需作进一步的研究.     

GC-MS方法分析杨梅果实精油中香气成分

采用气相色谱一质谱联用技术分析鉴定了木叶、东魁及黑炭3种新鲜杨梅果实精油样品的化学成分,并对三者成分进行对比分析.木叶梅果实精油中鉴定出55个化合物,以单萜类成分为主;东魁梅果精油中鉴定出49个化合物,以倍半萜烯和烷烃类成分为主;黑炭梅果精油中鉴定出化合物48种,以倍半萜烯和烷烃类成分为主.木叶杨梅中富含单萜而缺少倍半萜烯,这可能是其香气浓且易腐烂原因.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

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.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

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.