二阶导数差示脉冲极谱法用于醋酸氟氢可的松的定量研究

用二阶导数差示脉冲极谱法对醋酸氟氢可的松进行了定量分析。在０．００１ｍｏｌ／Ｌ硫酸＋乙醇＋水（１＋２５＋２４）的底液中，醋酸氟氢可的松于－０．３４０Ｖ（ｖｓＡｇ／ＡｇＣｌ）处出现一良好的二阶导数差示脉冲极谱峰，在５～１４０μｇ／ｍＬ范围内，醋酸氟氢可的松的浓度与其二阶导数差示脉冲极谱峰幅值呈线性关系，检测限为０．４ｎｇ／ｍＬ。本法操作简便、快速、灵敏、结果准确。     

Solution-phase preparation of a 560-compound library of individual pure mappicine analogues by fluorous mixture synthesis

Solution-phase mixture synthesis has efficiency advantages and favorable reaction kinetics. Applications of this technique, however, have been discouraged by the difficulty in obtaining individual, pure final products by using conventional separation and identification processes. Introduced here is a new strategy for mixture synthesis that addresses the separation and identification problems. Members of a series of organic substrates are paired with a series of fluorous tags of different chain lengths. The tagged starting materials are then mixed and taken through a multistep reaction process. Fluorous chromatography is used to demix the tagged product mixtures on the basis of the fluorine content of the tags to provide the individual pure components of the mixture, which are detagged to release the final products. The utility of fluorous mixture synthesis is demonstrated by the preparation of a 560-membered library of analogues of the natural product mappicine. A seven-component mixture is carried through a four-step mixture synthesis (two one-pot and two parallel steps) to incorporate two additional points of diversity onto the tetracyclic core. Methods for analysis and purification of the intermediates are established for the quality control of the mixture synthesis.     

化学模式识别技术评价中药厚朴质量的研究

本文对不同产地和市售的二十四种厚朴药材及饮片的萃取液进行了高效液相色谱、气相色谱及紫外光谱分析;对所得数据用主成分分析进行分类,概括出不同样品化学成分的异同,认为大叶木兰可做为厚朴的代用品,而在陕西安康购得的样品不应做厚朴使用,后者经生药学鉴定为厚朴伪品凹叶木兰。化学模式识别技术可为寻找药材的代用品、评价中药质量及鉴定伪劣药材提供依据。     

Synthesis, crystal structure of bis(arylamido)lanthanide methyl complexes and their catalytic behavior for the polymerization of methyl methacrylate

Reactions of [N(C₆H₃i-Pr₂-2,6)(SiMe₃)]₂LnCl(THF) (Ln=Nd, Yb) with two equivalents of MeLi in a mixture solution of toluene and Et₂O gave [N(C₆H₃i-Pr₂-2,6)(SiMe₃)]₂LnCH₃(μ-CH₃)Li(THF)₃·PhCH₃ (Ln=Nd (1), Yb (2)) in good isolated yields as crystalline solids. The single-crystal structural analysis of 2 revealed that the coordination geometry of ytterbium ion is best described as a distorted pseudo-tetrahedron. Both 1 and 2 are active for the polymerization of methyl methacrylate to give syndiotactic-rich and high molecular weight polymers (M_n>10⁴) with relatively narrow molecular weight distributions (M_w/M_n<2).     

光声量热法测定辅酶B12的光解量子产率

时间可分辨的光声最热法（Time－resolvedphotoacousticcalorimetry；简称PAC）是研究脉冲激光诱发的快速光化学和光生物化学反应过程动力学和热力学信息的一种有效方法[1－5]。本文采用压电陶瓷圆管同时作为样品油和换能器组成的PAC探测系统[6]，以波长λ＝355nm的脉冲激光（脉冲宽度8ns，脉冲重复频率10Hz）为光源激发辅酶B12甲醇溶液；研究其解量子产率，获得了满意的结果．1实验被测溶液注入两端用石英玻璃封口的压电陶瓷圆管内腔，激光束透过石英窗照射溶液（如图］所示）为标定被测样品的非辐射放热量，利用能在极短的时间内（＜l…     

冠醚配合物的研究XV.若干席夫碱及仲胺型双冠醚和碱金属离子的配位反应

本文运用微量电导滴定及计算机拟合技术，研究了若干席夫碱及仲胺型双冠醚和碱金属离子的配位反应，测定了配合物的组成及稳定常数，并对实验结果进行了讨论。     

Determining PPARγ-ligand binding affinity using fluorescent assay with cis-parinaric acid as a probe

Upon the study of small-molecules binding to proteins, the traditional methods for calculating dissociation constants (Kd and Ki) have shortcomings in dealing with the single binding site models. In this paper, two equations have been derived to solve this problem. These two equations are independent of the total concentration or initial degree of saturation of receptor and the activity of the competitive molecule. Through nonlinear fitting against these two equations, Kd value of a probe can be obtained by binding assay, and Ki value of a ligand can be obtained by competitive assay. Moreover, only the total concentrations of receptor([R]t), ligand([L]t) and probe([P]t) are required for the data fitting. In this work, Ki values of some typical ligands of PPARγ were successfully determined by use of our equations, among which the Ki value of PPARγ-LY171883 was reported for the first time.     

王冠高聚物担载四核钴羰基簇催化剂的醛化反应活性

本文用二苯并-18-冠-6高聚物作因相化载体,通过化学健合,合成了担载的四核钴羰基簇催化剂Crown-Co_4。,并对该催化剂进行了元素分析、红外光谱及X射线光电子能谱(XPS)等方面的测试分析;还考察了不同温度、不同极性溶剂及不同类型烯烃对醛化活性的影响。实验证明,该催化剂对直链端位烯烃的醛化活性高于均相的苯基-四核钴羰基簇催化利Ph-Co_4。。二苯并-18-冠-6高聚物载体能明显改善催化性能。     

以Δpe 表示的一次加入标准法计算公式和数值表

本文提出一个以(10~(△pe)-1)~(-1)对△pe表示的离子选择电极一次加入标准法结果处理数值表。该表简单明了,不含电极斜率因素,适用于具有各种斜率的电极和不同价态离子的测定。     

用辐射交联方法测定含氟聚合物分子量FEP分子量的测定

本文提出并研究了用辐射交联方法测定难溶高聚物的分子量问题。不同熔融指数FEP共聚物,辐射交联后,其凝胶化剂量随熔融指数增大而增高。由高温弹模测得FEP的交联G值为1.2。由交联G值和凝胶化剂量计算得FEP的,它与熔融指数的关系为log∞3.5log(1/Ml)·该结果与一般高聚物的本体粘度与分子量关系相一致。