“包埋”极性官能团固定相对碱性化合物分离的热力学研究

以苯、吡啶、尼古丁和普鲁卡因为探测因子,考察了酰胺型、胺型、醚型和酯型4种"包埋"极性官能团的新型键合固定相对碱性化合物在流动相pH值分别为3.0和7.0时的热力学焓变.实验结果表明,新型固定相由于烷基分子链中"嵌入"极性官能团,因此在流动相pH为3.0时温度对碱性溶质的保留影响相互差异较大.在流动相pH为7.0时,根据Van′t Hoff方程计算出4种待测物质从流动相转移到固定相上的ΔH0,从ΔH0的绝对值大小、相关系数以及实际的分离效果可以发现,在分离强碱性物质时,若实验条件一样,则分离效果是酰胺型和胺型＞酯型固定相＞醚型固定相,但它们均优于传统的固定相.     

Two cobalt(II) 5-aminoisophthalate complexes and their stable supramolecular microporous frameworks

Two stable supramolecular microporous cobalt(II) polymers, namely [Co(HAIP)2]n.3nH2O (1) and [Co(AIP)(H2O)]n (2), AIP = 5-aminoisophthalate, were hydrothermally synthesized and characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric analyses, and variable-temperature magnetic susceptibility measurements. The two complexes are constructed from the same Co2(CO2)2 SBU, which is extended into a 1D chain in 1 and a 2D layer in 2. As a result, 1 and 2 are 2D and 3D coordination polymers, respectively. The 3D supramolecular network of complex 1 is held up by strong hydrogen bonds formed between carboxylate groups and shows very high stability when the free H2O molecules are removed, indicating an extraordinarily stable H-bonding system. Upon water ligands being liberated, complex 2 becomes a stable microporous solid with coordination-unsaturated Co centers. The behavior of the susceptibility curve of 1 suggests the occurrence of an interesting intrachain antiferromagnetic coupling between the Co(II) ions and the presence of a significant orbital contribution, whereas the features of 2 indicate an antiferromagnetic coupling with T(N) = 3.5 K and a long-range antiferromagnetic order with a field-induced magnetic transition.     

在盐的水溶液中非电解质活度系数的研究(Ⅺ)——正丙酸和正丁酸在苯和盐水溶液间的分配

在25℃下分别测定正丙酸和正丁酸在苯相和纯水相中的分配比,以及在苯相和盐水溶液中的分配比,从而求出酸的活度系数。所用的盐有氯化锂、氯化钠、氯化钾、氯化锶、氯化钡、溴化锂、溴化钠、溴化钾等八种。对弱酸算出了未解离部分的活度系数。在所用盐浓度(0-1mol/l)范围内,作lgf_u-C_s图,都呈直线。比较直线的斜率,对正丙酸为:SrCl₂>BaCl₂>LiCl≈NaCl>LiBr≈NaBr>KCl>KBr。对正了酸为:SrCl₂>BaCl₂>NaCl≈LiC₁>NaBr≈KCl≈LiBr>KBr.指出小离子盐对小脂肪酸盐效应主要是静电力作用。     

Simultaneous determination of ampicillin, cefoperazone, and sulbactam in pharmaceutical formulations by HPLC with beta-cyclodextrin stationary phase

An accurate and reproducible method for the simultaneous determination of ampicillin (AMP), sulbactam (SUL), and cefoperazone (CFP) in pharmaceutical formulations by using HPLC with beta-CD stationary phase was developed. It involved the use of the added tetraethylammonium acetate (TEAA) reagent, pH, and methanol as the significant parameters to find the optimum separation condition. A high resolution and selectivity of analytes was obtained by running the mobile phase in methanol-5 mM TEAA buffer = 35:65 (v/v, pH 4.5) at 280 nm. The mean recoveries ranged from 96.6 to 103.3% for AMP in the synthetic mixture, 97.6 to 103.0% for SUL, and 97.0 to 104.0% for CFP. The low LOD (<1.8 microg/mL) and low CV (<0.9%) assured that this method was sensitive and reproducible. The assay of analytes in commercial products exhibited that it was convenient and reproducible for routine analyses of these components in sterilized H(2)O, saline, or 5% dextrose injection solutions.     

多孔介质中气体水合物降压分解的分形理论研究

通过将水合物的分解过程看作是无固态产物层生成的气固反应过程, 结合粒径缩小的收缩核反应模型和分形理论, 建立了多孔介质中水合物降压分解的分数维动力学模型, 提出了基于水合物分解实验数据计算多孔介质分形维数的方法. 分别利用前人的甲烷水合物和CO2水合物降压分解实验数据, 对上述分数维动力学模型进行了验证. 计算结果表明, 用提出的方法所计算得到的多孔介质分形维数与前人的测定结果基本符合; 对甲烷水合物和CO2水合物的降压分解过程, 提出的分数维动力学分解模型得出了和实验结果基本一致的预测, 绝对平均误差(AAD)小于10%.     

Enantioselective synthesis of beta-aryl-gamma-amino acid derivatives via Cu-catalyzed asymmetric 1,4-reductions of gamma-phthalimido-substituted alpha,beta-unsaturated carboxylic acid esters

A series of chiral beta-aryl-substituted gamma-amino butyric acid derivatives were synthesized in good enantioselectivities via the Cu-catalyzed asymmetric conjugate reduction of gamma-phthalimido-alpha,beta-unsaturated carboxylic acid esters using Cu(OAc)2 x H2O as a catalyst precursor, (S)-BINAP as a ligand, PMHS as a hydride source, and t-BuOH as an additive. The methodology has been applied successfully to the enantioselective synthesis of a chiral pharmaceutical, (R)-baclofen.     

Side-by-side comparison of disposable microchips with commercial capillary cartridges for application in capillary isoelectric focusing with whole column imaging detection

Simple-structured, well-functioned disposable poly(dimethylsiloxane) (PDMS) microchips were developed for capillary isoelectric focusing with whole column imaging detection (CIEF-WCID). Side-by-side comparison of the developed microchips with well-established commercial capillary cartridges demonstrated that the disposable microchips have comparable performance as well as advantages such as absence of lens effect and possibility of high-aspect-ratio accompanied with a dramatic reduction in cost.     

迭代Suzuki偶联反应合成全氟环丁基芳基醚齐聚物的研究

对迭代Suzuki偶联反应合成全氟环丁基芳基醚齐聚物的方法进行了研究, 并合成了全氟环丁基芳基醚齐聚物. 首先从对溴苯酚出发, 合成了含有一个全氟环丁基芳基醚结构单元的中间体3. 芳基硼酸与中间体3进行Suzuki偶联反应, 得到了含有一个全氟环丁基芳基醚结构单元的硼酸. 重复与中间体3进行Suzuki偶联反应, 从而合成了全氟环丁基芳基醚二聚体和三聚体. 最后通过热环化二聚反应合成了全氟环丁基芳基醚三聚体、五聚体和七聚体.     

IVSPlat 1.0: an integrated virtual screening platform with a molecular graphical interface

Background  

The virtual screening (VS) of lead compounds using molecular docking and pharmacophore detection is now an important tool in drug discovery. VS tasks typically require a combination of several software tools and a molecular graphics system. Thus, the integration of all the requisite tools in a single operating environment could reduce the complexity of running VS experiments. However, only a few freely available integrated software platforms have been developed.     

A new feruloyl amide derivative from the fruits of Tribulus terrestris

A new feruloyl amide derivative, named tribulusamide C, was isolated from the fruits of Tribulus terrestris. Its structure was determined on the basis of spectroscopic analysis including IR, 1-D-, 2-D-NMR and HR-ESI-MS. The structure of tribulusamide C was characterised by a unit of pyrrolidine-2,5-dione, which distinguished it from other lignanamides previously isolated from the fruits of T. terrestris.