阴阳离子型表面活性剂双水相萃取色氨酸衍生物和牛血清白蛋白

溴化十二烷基三乙胺（Ｃ１２ＮＥ）和十二烷基硫酸钠（ＳＤＳ）在一定条件下混合可以形成具有清晰界面的两个水相，称为阴阳离子型表面活性剂双水相。作者研究了利用该双水相萃取３种色氨酸衍生物和牛血清白蛋白的可能性．文中采用工作曲线校正扣除表面活性剂背景的影响，萃取结果准确可信。     

A New β-Carboline Alkaloid and a New Derivate of Isoferulic Acid from Anemone altaica

A new β-carboline alkaloid, 4-（9H-β-carbolin-1-yl）-4-oxobutyric acid and a new derivate of isoferulic acid, （E）-3-（3-hydroxy-4-methoxyphenyl）acrylic acid carboxymethyl ester, were isolated from the roots of Anemone altaica. Their structures were determined on the basis of spectral data.     

Synthesis, Crystal Structure and Properties of [Co(1,3- bdoaH)_2·4H_2O]·4H_2O with Benzene-1,3-dioxyacetate Ligand

1INTRODUCTIONTheorganicaromaticcarboxylatemetalcom-plexeshavearousedmuchattentionandbeenwidelyinvestigated.However,thestrategyofdesignandsynthesisofthesecomplexesismostlyfocusedonrigidligands,suchasterephthalicacidandbenzenetricarboxylicacid,etc.[1～5].Theassemblyofcom-plexesbyusingflexiblearomaticcarboxylateli-gandsisfarlessdeveloped[6,.Phenylenedioxydia-7]ceticacids(bdoaH2)withbiologicalactivitiesandwideapplicationsinagriculture[8]areafamilyofmultidentateflexibleligandswithversatilebind…     

用丘氏气提定氮器测定植物中的氮

研究了用气提滴定法测定植物中氮的条件和方法．实验结果表明，与蒸馏法相比，方法简便安全，结果准确     

Electrospun nanofibers of poly（vinyl pyrrolidone）/Eu^3＋ and its photoluminescence properties

Nanofibers of poly（vinyl pyrrolidone） （PVP）/Eu^3＋ with diameters of 300-900 nm were prepared by using sol-gel processing and electrospinning technique. The products were characterized by scanning electron microscope （SEM）, Fourier transform infrared spectroscopy （FT-IR）, and photoluminescence （PL）. The results indicated that, Eu^3＋ was successfully embedded in the onedimensional hybrid nanofibers, and the PVP/Eu^3＋ hybrid nanofibers had favorable photoluminescence properties.     

Electron propagator theory study of N-/O-methylglycine conformers

The low-lying conformers of N-/O-methylglycine are studied by ab initio calculations at the B3LYP, MP3, and MP4(SDQ) levels of theory with the aug-cc-pVDZ basis set. The conformers having the intramolecular hydrogen bonds N-H...O=C or O-H...N are more stable than the others. Vertical ionization energies for the valence molecular orbitals of each conformer predicted with the electron propagator theory in the partial third-order quasiparticle approximation are in good agreement with the experimental data available in the literatures. The relative energies of the conformers and comparison between the simulated and the experimental photoelectron spectra demonstrate that there are at least three and two conformers of N- and O-methylglycine, respectively, in the gas-phase experiments. The intramolecular hydrogen bonding O-H...N effects on the molecular electronic structures are discussed for the glycine methyl derivatives, on the basis of the ab initio electronic structure calculations, natural orbital bond, and atoms-in-molecules analyses. The intramolecular hydrogen bonding O-H...N interactions hardly affect the electronic structures of the O-NH2-CH2-C(=O)-O-CH3 and alpha-methylated NH2-CH2-C(CH3)OOH conformers, while the similar intramolecular interactions lead to the significantly lower-energy levels of the highest occupied molecular orbitals for the N-(CH3-NH-CH2-COOH) and beta-methylated (NH2-CH2-CH2-COOH) conformers.     

The migrastatin family: discovery of potent cell migration inhibitors by chemical synthesis

The first asymmetric total synthesis of (+)-migrastatin (1), a macrolide natural product with anti-metastatic properties, has been accomplished. Our concise and flexible approach utilized a Lewis acid-catalyzed diene aldehyde condensation (LACDAC) to install the three contiguous stereocenters and the trisubstituted (Z)-alkene of migrastatin (2 + 3 --> 21). Construction of the two remaining stereocenters and incorporation of the glutarimide-containing side chain was achieved by an anti-selective aldol addition of propionyl oxazolidinone 28 to angelic aldehyde 27, followed by a Horner-Wadsworth-Emmons (HWE) coupling of 32 with glutarimide aldehyde 5. Finally, the assembly of the macrocycle was realized by a highly (E)-selective ring-closing metathesis (35 --> 37). Utilizing the power of diverted total synthesis (DTS), a series of otherwise inaccessible analogues was prepared and evaluated for their potential as tumor cell migration inhibitors in several in vitro assays. These studies revealed a dramatic increase in activity when the natural motif was considerably simplified, presenting macrolactones 45 and 48, as well as macrolactam 55, macroketone 60, and CF(3)-alcohol 71 as promising anti-metastatic agents.     

Michael-Addition Reaction of Malononitrile with α,β-Unsaturated Cycloketones Catalyzed by KF／Al2O3

A series of KF/Al2O3 catalyzed Michael-addition reactions between malononitrile and α,β-unsaturated cycloketones in DMF solution were studied. At room temperature, 2-cyano-3-aryl-3-(1,2,3,4-tetrahydronaphthalen-1-one-2-yl) propionitrile derivatives were synthesized by the reaction between 2-arylmethylidene-1,2,3,4-tetra-hydronaphthalen-1-one and malononitrile. However, if the temperature was increased to 80℃, 2-amino-3-cyano-4-aryl-4H-benzo[h]chromene derivatives were obtained in high yields. When the α,β-unsaturated ketones were replaced by 2,6-biarylmethylidenecyclohexanone or 2,5-biarylmethylidenecyclopentanone, another series of 2-amino-3-cyano-4H-pyran derivatives was isolated successfully. The structures of the products were confirmed by X-ray diffraction analysis.     

系列单取代烷氧基-2-羟丙基-β-环糊精的合成与表征

以环氧氯丙烷和脂肪醇为原料, 通过相转移催化法合成了乙基、正丙基、正丁基和正戊基缩水甘油醚(1～4), 并利用所合成的缩水甘油醚和β-环糊精为原料, 分别在弱碱水溶液(1.5%)和强碱水溶液(30%)中制备并用硅胶柱分离出单2位取代的乙氧基、丙氧基、丁氧基和戊氧基-2-羟丙基-β-环糊精(1a～4a)和单6位取代的丙氧基、丁氧基和戊氧基-2-羟丙基-β-环糊精(2b～4b), 利用薄层色谱、红外光谱、差热扫描量热分析、质谱和核磁共振等手段对所合成的产品进行了表征.     

Grape tissue-based electrochemical sensor for the determination of hydrogen peroxide

The use of grape tissue as a source of catalase for the determination of hydrogen peroxide is reported. A slice of grape tissue attached to the membrane of a Clark-type oxgen sensor was used to monitor the oxidation of hydrogen peroxide by catalase. At the steady state, the sensor responds linearly to hydrogen peroxide in the concentration range 1 × 10^?5–5 × 10^?4 M. The response time (T₉₀) was of the order of 1 min for this sensor. No interference was observed from ethanol, amino acids, glucose and lactic acid. The long-term stability of the grape tissue sensor was much better than previously reported immobilized enzyme and liver tissue-based hydrogen peroxide sensors.