高效液相色谱法同时测定忍冬中7种成分

建立了在不同时间段内转换使用不同波长同时测定忍冬花和叶中7种化学成分(绿原酸、咖啡酸、芦丁、木犀草苷、异绿原酸A、异绿原酸B、异绿原酸C)的高效液相色谱分析方法,同时应用该方法分析了忍冬花、忍冬老叶和新叶中成分含量的差异。色谱柱为Agilent Eclipse Plus C18(250 mm×4.6 mm, 5 μm);流动相为0.3%甲酸水溶液(A)和乙腈(B),梯度洗脱,流速1 mL/min;采用VWD紫外检测器转换波长(330 nm、350 nm)检测。应用所建立的方法测定忍冬新叶中绿原酸、木犀草苷含量分别为2.572%、1.498‰,均比药典中规定的含量高,有必要进一步的研究和开发利用。该方法准确、简便、灵敏度高,适用于忍冬中7种化学成分含量的同时测定和忍冬的质量控制及综合评价。     

绿原酸分子印迹电化学传感器的制备及其性能分析

应用分子印迹技术,以绿原酸为模板分子,邻苯二胺为功能单体,利用循环伏安法在玻碳电极表面构建了绿原酸的电化学传感器。采用差分脉冲伏安法,研究了此传感器的分析性能,建立了以K3[Fe(CN)6]为电子传递媒介的对绿原酸的间接分析方法。在8.0×10-7~2.0×10-5mol/L范围内,绿原酸的浓度与K3[Fe(CN)6]的相对峰电流变化呈较好的线性关系,检出限为1.4×10-7mol/L。将其用于实际样品清肝利胆口服液中绿原酸的测定,回收率为101.6%~105.5%。     

高效液相色谱化学发光抑制检测法测定烟草中的绿原酸和芸香苷

1 引言绿原酸和芸香苷是烟草中含量最多、最重要的多酚类化合物,发展绿原酸和芸香苷的高灵敏度和高选择性的分析方法对于烟叶质量的控制、植物生理的研究具有重要意义.基于绿原酸、芸香苷对鲁米诺化学发光的抑制作用,首次建立了绿原酸、芸香酸的高效液相色谱化学发光抑制检测法.该法灵敏度高、选择性好,用于烟草样品中绿原酸与芸香苷的测定,结果令人满意.     

光谱法研究绿原酸与人血清白蛋白的相互作用

利用荧光光谱法研究了绿原酸与人血清白蛋白(HSA)的相互作用,考察了不同温度下绿原酸与HSA的结合常数KA和结合位点数n,并研究了Cu2+、Al3+、Ca2+、Pb2+等金属离子对绿原酸与HSA结合性质的影响。基于Frster偶极-偶极非辐射能量转移机理确定了荧光给体HSA与受体绿原酸间的结合距离。     

薄层色谱法分析葵花仁粕中的绿原酸

 以聚酰胺薄膜为固定相、体积分数为 36 %的乙酸溶液为流动相 ,研究建立了薄层色谱分离测定葵花仁粕中绿原酸的方法。绿原酸样品溶液上行展开 8 5cm ,其Rf 值为 0 6 1。绿原酸的检测量在 0 0 5 μg～ 0 6 μg范围内 ,其斑点的面积与绿原酸的检测量具有良好的线性关系。绿原酸的回收率为 97 5 3 % ,不同薄层板之间的RSD为2 5 7% ,最低检出限为 0 0 2 5 μg。在以体积分数为 70 %的乙醇溶液为萃取剂、搅拌振荡萃取时间为 30min的条件下 ,以该方法测定萃取液中绿原酸的含量和葵花仁粕中绿原酸的残留量 ,确定了最佳萃取次数。     

杜仲叶中绿原酸提取分离工艺条件的研究

对杜仲叶绿原酸的提取分离进行研究.探讨了水以及不同浓度乙醇、甲醇和丙酮水溶液作为提取溶剂对绿原酸得率的影响,采用正交实验方法对影响绿原酸提取率的主要因素进行分析,并采用大孔树脂对其分离.结果表明,50℃水提绿原酸得率比较高,其得率为1.06%,从而确定水作为绿原酸提取溶剂;水提杜仲叶绿原酸的最佳工艺条件为:温度60℃,料液比1∶16,pH4,提取时间3h,所筛选的GC-I树脂是吸附分离绿原酸的最佳吸附剂,吸附最佳pH值为3,吸附流速为3BV/h;本实验条件下得到粗产品纯度为30.88%,收率为76.51%.     

HPLC法同时测定忍冬叶中9种活性成分的研究

为了有效利用忍冬植株,建立了同时检测忍冬叶中新绿原酸、绿原酸、咖啡酸、芦丁、木犀草苷、金丝桃苷、异绿原酸C、木犀草素和槲皮素9种活性成分含量的HPLC分析方法,并用于忍冬叶中活性成分的定量测定,为忍冬叶多指标质量评价标准提供理论依据和方法参考.     

金银花中绿原酸的酶法提取工艺优化

采用酶法优化提取金银花中的绿原酸,考察纤维素酶酶的用量、酶解时间、酶解温度及回流提取温度对绿原酸含量的影响;用高效液相色谱法(HPLC)测定绿原酸含量。用纤维素酶法提取金银花可提高绿原酸得率。酶法提取最佳条件为:加入纤维素酶3.0%,在46℃下酶解4 h,再在56℃下浸提1 h;其绿原酸含量为3.57%。     

绿原酸对脱氧鸟苷酸氧化性羟基加合物的快速修复

利用脉冲辐解时间分辨吸收光谱技术 ,研究了中草药金银花中的有效成分———绿原酸对羟基自由基与脱氧鸟苷酸形成氧化性加成自由基的修复作用 .发现绿原酸不仅能有效地清除羟基自由基 ,而且通过电子转移快速修复羟基与脱氧鸟苷酸所形成的氧化性加成自由基 ,自身变为反应性很低的绿原酸酚氧自由基 .探讨了反应机理 ,测出了绿原酸修复脱氧鸟苷酸氧化性羟基加成产物的反应速率常数 .     

阻抑催化褪色光度法测定痕量绿原酸

在盐酸介质中 ,绿原酸能灵敏地阻抑铁 催化过氧化氢还原亮绿SF的褪色指示反应 ,据此建立了测定痕量绿原酸的阻抑 催化动力学光度分析方法。该方法测定绿原酸的线性范围为 0～ 0 .12mg/L ;检出限为4 .2× 10 -6g/L。对浓度为 0 .0 8mg/L绿原酸标准溶液 6次平行测定的相对标准偏差为 3.8% ;回收率为 93.4 %～ 10 5 %。考察了反应的最佳条件和动力学参数 ,探讨了反应机理。该方法应用于金银花浸取液中绿原酸含量的测定 ,结果满意     

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。     

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.     

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。     

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。