高配位双环氮氧杂有机锡化合物在二甲亚砜溶剂中的酸性解离常数

本文报道了在DMSO溶剂中利用Bordwell指示剂重迭法测定六种高配位双环氮氧杂有机锡化合物的α-CH的酸性离解常数(pKa)的方法, 并对配合物的结构与其α-CH酸性的关系进行了讨论。     

Studies on the Phase Properties of Winsor Ⅰ-Ⅲ Type Microemulsions with Dielectric Relaxation Spectroscopy

The dielectric relaxation spectroscopy （DRS） of Winsor I -Ⅲ microemulsions for nonionic surfactant octyl polyglucoside CsG1.46/1-butanol/cyclohexanedwater system was studied. The experiment shows that the permittivity decreases with the increase in the frequency and clear dielectric relaxation phenomena were observed. Permittivity obviously decreases with the change of the microstructure of the microemulsion, W/O, B.C. and O/W can be distinguished by the permittivity.     

Determination of binding sites in carboplatin-bound cytochrome c using electrospray ionization mass spectrometry and tandem mass spectrometry

Interaction of carboplatin with cytochrome c (Cyt. c) has been investigated by electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS). ESI-MS studies revealed that the ring-opened adducts of carboplatin with Cyt. c were formed in the stoichiometric ratio of 1:1 and 2:1 at pH 5.0 and 37 degrees C and in the stoichiometric ratio of 1:1 only at pH 7.0 and 37 degrees C. It was also found that Cyt. c could be cleaved by carboplatin at pH 2.5 and 50 degrees C. The cleaved fragments of Cyt. c were determined by ESI-MS and MS/MS analysis to be Glu66 approximately Met80, Ac-Gly01 approximately Met65, Glu66 approximately Glu104, Ac-Gly01 approximately Met80 and Ile81 approximately Glu104. The carboplatin prefers to anchor to Met65 first, then to Met80. To further confirm the binding site of Met, AcMet-Gly was used as the model molecule to investigate its interaction with carboplatin and its hydrolysis reaction. On the basis of species detected during the reaction monitored by ESI-MS, a possible pathway of the cleavage reaction was proposed.     

Synthesis of a novel 18β-glycyrrhetinic acid derivative

A novel compound, biotinylated 18β-glycyrrhetinic acid (BGA), was synthesized. It is a compound of 18β-glycyrrhetinic acid linked with biotin. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 266–267, May–June, 2006. An erratum to this article is available at .     

Assembly and Dissociation of Α-Cyclodextrin [2]Pseudorotaxanes with α,ω-Bis(N-(N,N′-dimethylethylenediamine)alkane Threads

A series of novel bischelate bridging ligands, CH₃NH(CH₂)₂N(CH₃)(CH₂) _n N(CH₃)(CH₂)₂NHCH₃ (n = 9, 10, 11, and 12) were synthesized as hydrochloride salts and characterized by elemental analyses, electrospray mass spectrometry, and ¹H and ¹³C NMR spectroscopy. These ligands form [2]pseudorotaxanes with α-cyclodextrin (α-CD) and the stability constants have been determined from ¹H NMR titrations in D₂O. The kinetics and mechanism of the assembly and dissociation of a [2]pseudorotaxane in which α-CD has been threaded by the CH₃NH₂(CH₂)₂N(CH₃)(CH₂)₁₂N(CH₃)(CH₂)₂NH₂CH ₃ ²⁺ ligand were determined in aqueous solution using ¹H NMR spectroscopy. A weak inclusion of the dimethylethylenediamine end group precedes the passage of the α-CD onto the hydrophobic dodecamethylene chain.     

Estimation of isoelectric points of human plasma proteins employing capillary isoelectric focusing and peptide isoelectric point markers

Synthetic UV-detectable peptide pI markers were used to estimate isoelectric point (pI) values of proteins separated by capillary isoelectric focusing (CIEF) followed by cathodic mobilization in the absence of denaturing agents. The pI calculation and quantitative analysis of purified proteins showed the feasibility of these peptides as pI markers and internal standards in CIEF separation of proteins. Estimation of pI values of major proteins in human plasma was performed using the peptide pI markers, and the values were compared with those previously obtained by gel isoelectric focusing (IEF). Sera of immunoglobulin G (IgG) myeloma patients, which showed characteristic peaks of myeloma IgG in their CIEF patterns, were also subjected to the analysis and the pI values of the myeloma proteins have been estimated.     

Investigations on adsorption potentiometry-part VIII. Determination of ultratrace copper in food by derivative adsorption chronopotentiometry

An electroanalytical method, based on derivative chronopotentiometry of the copper complex with 4-[(4-diethylamino-2-hydroxyphenyl) azo]-5-hydroxy-naphthalene-2,7-disulphonic acid (Beryllon III) accumulated on the surface of a hanging mercury drop electrode, for determining trace copper in food has been developed. The dependence of the peak height of reduction of the copper complex on the preconcentration time and preconcentration potential are discussed. Optimum experimental conditions include 0.01 M HOAc, 0.01M NaOAc, 1.0 x 10(-6) Beryllon III and a preconcentration potential of 0.10 V (vs. SCE). Under these conditions the detection limit and the linear range are 4 x 10(-11)M and 6 x 10(-11) -4 x 10(-7)M, respectively. The method was applied to samples of digested rice.     

Dye-sensitized solar cells based on composite solid polymer electrolytes

The ionic conductivity of polymer electrolytes and their interfacial contact with dye-attached TiO2 particles were enhanced markedly by the addition of amorphous oligomer into polymer electrolytes, resulting in very high overall energy conversion efficiency.     

Synthesis and manganese complexes of pentagonal bipyramidal ligands: N,N′-disubstituted pentaaza macrocycles

Two novel heptadentate ligands, pentaaza macrocycles with two pendant xpyridyl and phenol groups, were prepared and the crystal structure of the manganese(II) complex of N,N′-bis(2-pyridylmethyl)-pentaaza macrocycle revealed a pentagonal bipyramidal geometry.     

酶联免疫吸附法直接测定血清雌二醇

本合成了３种不同载体蛋白的雌二醇抗原，研究了载体蛋白免疫原性对雌二醇抗体产生的影响。应用酶联免疫吸附分析法测定了血清中雌二醇，浓度范围为５－１６０ｎｇ／ｍｌ（１．８×１０＾－＾８－５．９×１０＾－＾７ｍｏｌ／Ｌ）．ＲＳＤ％小于１０．％，检测限为１．９７ｎｇ／ｍｌ，相当于９８．５ｐｇ／孔（按空白平均值的二倍标准偏差计算）。另外，本还建立了一种用考马斯亮蓝Ｇ－２５０测定半抗原与蛋白结合比的方法，提