3-氨基环己基甲酸和cis-3-氨基环己烯基-5-甲酸立体异构体的合成

通过手性胺拆分方法，从3-环己烯基甲酸出发分别合成得到了3-氨基环己基甲酸（ACHC）的四个立体异构体，以及cis-5-氨基-3-环己烯基甲酸（ACHEC）的二个立体异构体。     

Synthesis of alkoxymethyl derivatives of resorcinarene via the Mannich reaction catalysed with iminodiacetic acid

The conditions of a simple synthesis of tetra(alkoxymethyl) derivatives of resorcinarene via the Mannich reaction catalysed with iminodiacetic acid are described. A possibility of high yield synthesis of such derivatives for the selected straight-chain alcohols is shown. A possible mechanism of this reaction is suggested.     

Effect of drug-loading methods on drug load, encapsulation efficiency and release properties of alginate/poly-L-arginine/chitosan ternary complex microcapsules

The drug-loaded alginate/poly-L-arginine/chitosan ternary complex microcapsules were prepared by mixing method, absorption method and the combined method of mixing and absorption, respectively. The effect of drug-loading methods on drug load, the encapsulation efficiency and the release properties of the complex microcapsules were investigated. The results showed that the absorption process is a dominating factor to greatly increase the drug load of Hb into microcapsules. Upon loading Hb into microcapsules by combined method of mixing and absorption, the drug load (19.9%) is up to the maximum value, and the encapsulation efficiency is 93.8%. Moreover, the drug release is a zero-order kinetics process for the ternary complex microcapsules made by mixing. For the complex microcapsules made by absorption, the drug release is a first-order kinetics. However, for the complex microcapsules made by combining the mixing and the absorption, the drug release obeys a first-order kinetics during the first eighteen hours, changing afterwards to a zero-order kinetics process. Effect of drug-loading methods on drug load and encapsulation efficiency of alginate/poly-L-arginine/chitosan ternary complex microcapsules.     

Selective Electroanalytical Assay for Cysteine at a Boron Doped Diamond Electrode

The electrochemical oxidation of the cysteine‐quinone adduct has been examined as a means of providing an electroanalytical cysteine specific detection protocol. The appliance of square‐wave voltammetry allowed 0.5 μM as a limit of detection. The effects of various biologically relevant interferences including other thiols were studied and found to present no change in the voltammetric profile. The practical applicability and efficiency of the methodology was probed through the determination of cysteine concentration in growth tissue medium.     

Rapid quantification of HIV protease inhibitors in human plasma by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

HIV protease inhibitors are important antiretroviral drugs which have substantially reduced the morbidity and mortality associated with HIV-1 infection. Recent data have shown relationships between plasma concentrations of the protease inhibitors and clinical response, which makes therapeutic drug monitoring valuable. We have developed and validated an assay, using liquid chromatography coupled with electrospray tandem mass spectrometry (LC/MS/MS), for the routine quantification of the six licensed protease inhibitors (amprenavir, indinavir, lopinavir, nelfinavir, ritonavir and saquinavir) and the pharmacologically active nelfinavir metabolite M8 in plasma. The sample pretreatment consisted of protein precipitation with a mixture of methanol and acetronitrile using only 100 microl of plasma. Chromatographic separation was performed on an Inertsil ODS3 column (50 x 2.0 mm i.d., particle size 5 microm), with a quick stepwise gradient using an acetate buffer (pH 5) and methanol, at a flow rate of 0.5 ml min(-1). The analytical run time was 5.5 min. The use of a 96-well plate autosampler allowed batch sizes up to 150 patient samples. The triple-quadrupole mass spectrometer was operated in the positive ion mode and multiple reaction monitoring was used for drug quantification. The method was validated over the concentration ranges 0.01-10 microg ml(-1) for indinavir and saquinavir, 0.1-10 microg ml(-1) for amprenavir, 0.05-10 microg ml(-1) for nelfinavir and ritonavir, 0.1-20 microg ml(-1) for lopinavir and 0.01-5 microg ml(-1) for M8. Saquinavir-d(5) and indinavir-d(6) were used as internal standards. The coefficients of variation were always <10% for both intra-day and inter-day precisions for each compound. Mean accuracies were also between the designated limits (+/-15%). The validated concentration ranges proved to be adequate in daily practice. This robust and fast LC/MS/MS assay is now successfully applied for routine therapeutic drug monitoring and pharmacokinetic studies in our hospital.     

Synthesis and properties of fluorous arenes and triaryl phosphorus compounds with branched fluoroalkyl moieties (“split pony tails”)

Most compounds designed for immobilization in fluorous media feature linear pony tails of the formula (CH₂)_m(CF₂)_n−1CF₃ [(CH₂)_mR_fn]. This paper presents a first-generation approach to compounds with branched or “split” pony tails of the formula (CH₂)_lCH[(CH₂)_mR_fn]₂. Allyl tri(n-butyl)tin is reacted twice with perfluorooctyl iodide (R_f8I; first, photochemical, 78-81%; second, thermal with radical initiator, 71%; 13-18 g scales) to give the secondary alkyl iodide ICH(CH₂R_f8)₂ (3). A subsequent Ni(Cl)₂(PPh₃)₂-catalyzed reaction with allyl tri(n-butyl)tin yields the branched alkene H₂CCHCH₂CH(CH₂R_f8)₂ (74%). A palladium-catalyzed Heck coupling with OP(p-C₆H₄Br)₃ gives the fluorous phosphine oxide OP(p-C₆H₄CHCHCH₂CH(CH₂R_f8)₂)₃ (84%), and Pd/C-catalyzed hydrogenation affords OP(p-C₆H₄(CH₂)₃CH(CH₂R_f8)₂)₃ (>99%). Reduction with SiHCl₃ gives P(p-C₆H₄(CH₂)₃CH(CH₂R_f8)₂)₃, which is protected as the air-stable borane adduct H₃B·P(p-C₆H₄(CH₂)₃CH(CH₂R_f8)₂)₃ (9, 64%). The CF₃C₆F₁₁/toluene partition coefficient of 9 is much higher than that of the analog with p-(CH₂)₃R_f8 groups (96.6:3.4 versus 37.3:62.7). The iodide 3 is unreactive towards PAr₃ at 175-250 °C. However, a CuBr-catalyzed reaction with C₆H₅MgBr gives C₆H₅CH(CH₂R_f8)₂, which also exhibits a high partition coefficient (97.9:2.1).     

Physicochemical and structural properties of bacteriostatic sulfonamides: Theoretical study

A theoretical study at the Hartree–Fock and density functional theory levels is performed on sulfonamide‐type bacteriostatic compounds with the aim to provide an insight into their structure–activity relationship. The basicity of the p‐amino group is analyzed by means of the proton affinities and the protonation energies, showing that molecules presenting bacteriostatic activity are less basic, i.e., they are characterized by larger protonation energies and smaller proton affinities. The acidity of the amide group is analyzed through the deprotonation energy. The results reveal that the more acidic molecules present a larger bacteriostatic activity. This result is also confirmed from a study of bond orders. A bond order analysis of the amide group suggests that the electron attracting group in these molecules is responsible for the increase in acidity. The charge of the SO₂ group is also shown to be affected by the presence of the electron attracting group and consequently related to the acidity of the molecules. A geometric analysis shows that structures in which the amino group is more coplanar with respect to the benzenic ring possess larger bacteriostatic activity. A conformational analysis of these molecules illustrates that active molecules have relatively larger torsion energy barriers. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 165–172, 2003     

四核钼簇合物的配体取代反应及产物Mo4S4(μ-OAc)2(dtp)4的晶体结构

标题化合物(Ⅰ)经由Mo₄S₄(μ-dtp)₄(Ⅱ)[dtp=S₂P(OEt)₂]和Ni(OAc)₂反应而得。(Ⅰ)晶体属单斜晶系,空间群P2/c,a=13.176(4),b=11.699(3),c=18.526(4)Å,β=116.11(3)°,V=2564(3)ų,Z     

偏钛酸型锂离子交换剂固相合成反应动力学

偏钛酸型锂离子交换剂固相合成反应动力学钟辉＊郭灵虹（成都理工学院应用化学系成都６１００５９）（四川联合大学分析测试中心成都）关键词偏钛酸锂，离子交换剂，合成，固相反应动力学１９９７－０８－２５收稿，１９９７－１２－１０修回四川省应用基础研究基金资助项...     

Preparation of Y2Ba4Cu7O15-δ Superconductor without High Oxygen Pressure

The synthesis of bulk Y₂Ba₄Cu₇O_15-δ superconductor at atmospheric oxygen pressure via solid state sintering is reported. Temperature ranging from 860 to 890 °C as well as time interval over 2 to 15 days were used to investigate the formation of the Y₂Ba₄Cu₇O_15-δ phase. A time-temperature profile characterizing the conditions for the preparation of Y₂Ba₄Cu₇O_15-δ phase suggests the optimal condition to be sintering at 890 °C for over 10 days. Detailed results of X-ray diffraction, electrical resistivity, iodometric titration and magnetization measurements are described.