西藏罗花挥发油GC-MS分析

西藏罗花(Incarvillea younghusbandii)又名角蒿和西藏角蒿,为紫葳科角蒿属植物,主要生长于我国海拔3 500～5 400 m的青藏高原[1].该植物与同属的两头毛(I.arguta)和密生波罗花(I.compacta)等共同作为传统藏药材"欧曲"用于治疗胃病、黄疸、消化不良、月经不调、高血压、肺出血等疾病[1].     

基于化学计量学结合ICP-MS的党参道地性的研究及安全评价

微量元素与中药的功效和安全性密切相关,也是药材道地性研究的一部分,为探讨党参中重金属元素的安全性、风险性及道地性的相关性。本文采用电感耦合等离子体质谱法（ICP-MS）及原子荧光光谱法(AFS)测定来源于甘肃、山西、湖北、四川等产区的39批党参药材中的20种元素的含量,结果结合化学计量学分析对党参产区进行差异判别。通过单因子污染指数法和内梅罗综合污染指数法对其进行安全性评价,通过健康风险基于暴露量、危害指数法和暴露限值法对其进行风险评估。结果表明,重金属在各自范围内线性关系良好,加样回收率,仪器精密度和重复性良好,其中 Ba、Sr、Mn的含量最高。主成分分析显示39批药材分为三类,同一产区的党参能较好的聚在一起,元素含量差异与产区分布有一定规律,其中Cs、Ga、As、Co、Li、Pb、Hg、Se、V、Mn为关键的差异标志物,为产地元素特征分析鉴别提供依据。安全评价结果为39批党参药材污染等级为安全,但风险评估后DS-31、DS-32、DS-34、DS-36及 DS-37在人体长期蓄积中具有健康风险。结论：本研究方法高效、准确、简便,结合化学计量学可以对党参进行有效的产地判别,评价党参中元素的安全性及风险性,为党参道地性及健康评价提供了科学依据。     

DFT Study on Two C4N12O4 Isomers with Pagodane- and Isopagodane-like Structures

1 INTRODUCTION Pagodane (Fig. 1) first synthesized[1] in 1983 has been studied by Prinzbach and coworkers for more than twenty years[2, 3]. Described as a waxy solid melting without decomposition and stable to at least 600 ℃ in gas phase, pagodane is interesting for its exotic structure and as an introduction to the family of substituted dodecahedranes[2]. Owing to its unu- sual structure, pagodane has provided experimenters and theorists with a challenge to characterize and cal- culate …     

大孔吸附树脂纯化绵阳产绞股蓝总皂苷的研究

绞股蓝别名"七叶胆","五叶参"等,为葫芦科植物绞股蓝的全草 [1].民间用以治疗咳嗽、痰喘、慢性气管炎、传染性肝炎等病.绞股蓝提取物具有明显的抗疲劳、抗衰老、降血脂、预防冠心病、抑制肿瘤细胞生长及延长细胞寿命的作用[2].绞股蓝的主要药效成分为绞股蓝皂苷,现已分离出80余种与人参皂甙有类似骨架的达玛烷型绞股蓝皂甙(gypenosides ,GPs) [3-8].据报道绞股蓝皂苷具有明显的抗肿瘤作用,并且对神经、血液、循环、内分泌系统和消化系统等多方面疾病具有防治作用[2].     

黄芪中铅的初级形态分析

黄芪是我国盛名的大宗传统中药材,也是常用的中药及食疗药膳品.关于黄芪的研究较多,但主要集中于有机成分与药理作用的研究.中草药药效不仅同药材中的有机成分有关,与微量元素之间关系已被越来越多的研究所证实[1,2].因此对中药微量元素的研究仅仅提供元素总量的信息是不够的,更需要对金属元素的存在化学形态进行分析[3].中药中微量元素的形态分析属一新研究领域,文献报道较少[4-7].本实验选取不同产地的黄芪药材,采用微波消解样品,氢化物发生-电感耦合等离子体原子发射光谱法(HG-ICP-AES)[8],对不同产地黄芪中重金属铅进行了形态分析,这对药材道地性研究,质量控制具有积极的意义.     

悬浮液进样-火焰原子吸收光谱法测定地黄中锌和锰

怀地黄、怀山药、怀牛膝、怀菊花合称"四大怀药",是享誉海内外的名贵中药材,其中,怀地黄有"以邑供天下"的威名,素有"怀参"之美称[1].中药材的性味功能与微量元素具有一定相关性,特别是微量元素锌和锰与人体多种酶有关,对于调节人体的生理机能有独特的作用.对锌、锰元素含量的测定为此药材的品质、疗效提供科学依据.在样品分析中,前处理是一个重要步骤,怀地黄(包括生地黄、干地黄、熟地黄)的预处理方法通常有干法(灰化)、湿法(加酸消化)及微波消化法,前两种方法消化时间长、操作环节多,被测元素丢失或被污染的机会多;后种方法溶样不完全,重现性易受影响.悬浮液进样一原子吸收光谱法测定粮食、茶叶、中草药中微量元素已有报道[2-5].本法采用悬浮液进样处理怀地黄样品,并用火焰原子吸收光谱法测定地黄中锌和锰.     

联吡啶还原合成吡啶基四氢吡啶和吡啶基六氢吡啶

吡啶基四氢吡啶衍生物(Ⅰ)和吡啶基六氢吡啶衍生物(Ⅱ)是α受体和HT1A受体类似物的结构组成部分,应用在药物合成中[1].Ⅰ和Ⅱ可通过环化反应、烷基化反应或联吡啶还原合成[2].环化反应或烷基化反应路线较长,且易形成含不饱和哌啶基吡啶的混合物,需要进一步的还原或纯化[2a];用Ni合金还原联吡啶只能直接合成吡啶基六氢吡啶,且反应时间长,收率低[2d];N-氧化联吡啶还原合成吡啶基六氢吡啶收率低,不适用于大量合成[2e].     

中药佩兰化学成分研究

佩兰为芳香化湿类中药,属于菊科(Compositae)泽兰属(Eupatorium)植物,为一年生或多年生草本植物,全国各地皆产[1].作为芳香化湿药,佩兰具有化湿醒脾、祛暑辟秽的功效,主治湿温暑病,以及因过食甜腻厚味以致脾热结聚、口甘舌腻等病症[2].佩兰还有活血化瘀、调经利尿[3]和抗流感病毒之疗效[4].为提高健康人群对非典型肺炎的抵抗能力,佩兰在"非典"期间由全国著名中医专家开出的中药方中频频出现.     

党参及其水提取物的红外光谱研究

采用傅里叶变换红外光谱法,并结合二阶导数红外光谱法,研究了党参原药材及其水提取物所含化学成分的红外谱图整体变化规律。结果表明,党参水提取物中主要为糖类成分,含有935、868、817、779cm-1等一系列糖环的振动吸收峰,通过谱峰的指认可以判定党参水提取物中主要含有甘露糖、果糖和葡萄糖等单糖;水提取物药渣中则是提取后剩余的淀粉、纤维素、木质素等原药材的基体成分和一些不易溶于水的酯类、酮类和芳香类成分。     

油脂皂化反应实验的改进

高职基础化学中羧酸及其衍生物一章里有一个实验"油脂的皂化反应",传统实验是用猪油与氢氧化钠进行皂化反应,经过加热、回流、盐析、过滤等步骤制得肥皂[1].因所需仪器及操作步骤较复杂,在日常生活中较难利用.为了使化学实验更贴近生活,更能激起学生学习化学的兴趣,我们将传统的油脂皂化反应实验改进为制备如今非常流行的手工皂.市售的一般肥皂在制造过程中已将皂化产生的甘油作为副产物分离,而手工皂含有天然的甘油,保湿效果超凡,且对肌肤十分温和.此外,还可以根据个人皮肤特点添加各种花草、精油、药材等[2].手工皂因其具有天然、纯净、环保的优点越来越受到人们的推崇.     

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。     

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。     

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.     

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.     

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。