Study on the liquid membrane oscillation of water/oil/water system containing TTAB and picric acid

The liquid membrane oscillation of a novel water （aqueous tetradecyl trimethyl ammoniumbromide, TTAB and alcohol solution）/oil （picric acid in chloroform solution）/water （aqueous glucose solution） system was investigated. By using homemade device, the curves of various liquid membranes oscillation with different concentration of TTAB and picric acid, types of alcohol and other organic solvents at different temperature were measured. The results show that the water （aqueous 7 mmol/L of TTAB and 0.5 mol/L of n-propanol solution）/oil （0.5 mmol/L of picric acid in chloroform solution）/water （aqueous glucose solution） system performed sustained and stable oscillation at 30 ℃. And the novel system can recognise added amino acid.     

穿过液膜的自发电势振荡

An artificial membrane consisting of pricramic acid in nitrobenzene was used as an oil phase imposed between two aqueous phases. The right one contained trimethyl-slearylammonium chloride and aicohol; and the left contained sucrose solution (or H_2O). We found that this system exhibited rhythmic oscillation of electrical potential. The amplitude of the oscillations was between 20—150 mV. The oscillations were observed even when ethyl alcohol was absent in the aqueous of trimethylslearylammonium Chloride, and the increase in amplitude of oscillation with time was found to be less in the presence of sucrose. Some of the expremental results have been explained.     

盐水振荡与液膜振荡耦合

为进一步增大盐水振荡产生的电势差,并使盐水振荡可逆，该文将液膜振荡与盐水振荡耦合，组成一个耦合的振荡器.实验结果发现:(1)由于两振荡器耦合形成共振，所以此耦合振荡器的振幅明显增大; (2)耦合后的化学振荡器变为可逆振荡器.耦合振荡机理如下:扩散过程中形成的缔合物存于油相，难溶于水，通电后缔合物发生解离，因此造成反扩散，形成可逆振荡，且可逆程度及逆反应产生的电势差（即振幅）大大提高，扩展了盐水振荡在二次电池开发方面的应用.     

Syntheses of Nucleoside Derivatives Containing Fmoc- or Trityl-protected Amino Acids

Facile direct esterification reactions between 2‘, 3‘-O-isopropylidene-nucleosides and Fmoc- or trityl-protected amino acids via N, N-dicyclohexyl-carbodiimide(DCC) mediated condensation are described. These reactions offer a mild and convenient method to synthesize aminoacylated nucleoside derivatives.     

Liquid Membrane Transport Behavior of Functional Substituted Crown Ethers for Amino Acids

Crown compounds offer a variety of interesting functions based on their specific bindings of organic guest species1,2. In particular, they can act as carriers in ion- extraction, membrane transport, and phase-transfer reactions. In contrast to the large variety of synthetic ionophores for cation transport, there are only a few examples of synthetic anion transport ionophores. Therefore, it appears highly desirable to search for a new class of ionophores with excellent transport abilities fo…     

Liquid Chromatography Detertmination of Amino Acids by Pre-Column Fluorescence Derivatization with Acridone-N-acetyl Chloride

AminoacidsareimPortantconstituentSofmostlivingorganisms.Separationsandquantitativedetendnationsofandnoacidsbymeansofnewfluorescencereagentsforpre-columnorpost-columnderivatizationinRI,-HPLCarestillanactivefiled.InformationonderivahzationtechniquesforaminocomPoundshasbeencompiledbyBlanlandbyKnaPP'.Severalfluorescentderivatizationreagents'-'havebeendevelopedforthedeterminationofaminocomPounds.oPAmethodoffersgreatersensitivity,butisonIylimitedtoprimaryandnoacids.PIB-ClmethodisnotaPpropri…     

A Facile Synthesis of N-Phosphoryl Amino Acids Containing Hydroxy Group

three kinds of N-(diisopropyloxyphosphoryl) amino acids containing hydroxyl group were prepared in high yield by using diisopropyl phosphite as the phosphorylating agent, sodium hypochlorite as the chlorinating agent and tetrabutyl ammonium bromide as the phase transfer catalyst in basic aqueous media.     

Thermodynamics of Transfer of Amino Acids from Water to Aqueous Sodium Sulfate

Abstract

The solubilities of amino acids at 288.15, 298.15 and 308.15K in water and aqueous sodium sulfate have been determined as a function of electrolyte concentration (0.5, 1.0, 1.5 mol/kg of water). It has been observed that sodium sulfate renders amino acids less scluble. The free energies of transfer of amino acids from water to aqueous sodium sulfate have been calculated from the solubility data. The enthalpies and entropies of transfer have also been estimated. The solubility and the thermodynamics of transfer data manifest that sodium sulfate generates favourable interaction between nonpolar groups of amino acids. If applied to proteins, it seems to stabilize the protein native globular structure by enhancing the intramolecular nonpolar-nonpolar group interactions.     

含手性双环胍的氨基酸受体的合成

报道含有手性双环胍，氮杂冠醚及萘甲酰基３个分子识别点的芳香族氨基酸人工受体的合成。     

水溶性聚合物和两亲聚合物19．磺化液体聚丁二烯──种新型液膜用表面活性剂

一种新的聚工二烯型表面活性剂ＬＹＦ经液体聚了二烯磺化方法制备而得，并应用于液膜分离研究之中。发现无论内水相是酸性还是碱性，由该表面活性剂制得的Ｗ／Ｏ型乳状液在稳定性、溶胀率和破乳诸方面均具有令人满意的综合性能。为深入了解液膜的稳定性，我们测定了处于两种水相间的双分子膜的强度。发现由ＬＹＦ所形成的双分子膜具有最大的膜强值，优于聚异丁烯型的表面活性剂ＥＣＡ４３６０和ＥＭ３０１．     

纳滤膜分离技术分离纯化多肽和氨基酸

综述了近十年来纳滤膜技术在氨基酸和多肽分离与纯化方面的研究进展。多肽和氨基酸的纳滤分离过程受溶液物化性质、氨基酸和多肽分子尺寸、所带电荷以及膜孔径、膜带电状态等多种因素的影响,建立该过程的分离机理模型、组合并优化分离条件是当前研究的热点。     

反萃分散组合液膜分离提取氨基酸

建立了分离提取蛋氨酸、亮氨酸、苯丙氨酸和色氨酸的磷酸二（2-乙基己基）酯(D2EHPA) 煤油-HCl反萃分散组合液膜体系,考察了料液相pH值、载体D2EHPA浓度、液膜相与反萃相体积比、反萃相组成、料液相与反萃分散相流速、传输时间以及支撑膜重复使用次数对氨基酸渗透系数和传输效率的影响。 在优化的条件下,建立的反萃分散组合液膜体系对4种氨基酸均可以获得大于35%的传输效率,其中色氨酸和亮氨酸的传输效率超过了79%,且传输效率呈Et,Trp＞Et,Leu＞Et,Phe＞Et,Met的趋势。 支撑膜重复使用25次,对氨基酸的传输效率没有明显改变。建立的液膜体系对考察的氨基酸展示了较高传输效率和优越的传输选择性,是一种简单和环境友好的分离技术。     

葡萄酒中游离氨基酸的高效液相色谱法测定

采用邻苯二甲醛衍生化法衍生葡萄酒中的游离氨基酸，以反相高效液相色谱法对葡萄酒中１８种氨基酸进行了测定，方法简单、迅速，２５ｍｉｎ即可完成１８种氨基酸的分离。精密度及回收率实验结果令人满意。     

Determination of Amino Acidsas Their N-Hydroxy-succinimidyl-3-indolylacetate Derivatives by Reversed-phase HPLC

ＤｅｔｅｒｍｉｎａｔｉｏｎｏｆＡｍｉｎｏＡｃｉｄｓａｓＴｈｅｉｒＮ┐Ｈｙｄｒｏｘｙ┐ｓｕｃｃｉｎｉｍｉｄｙｌ┐３┐ｉｎｄｏｌｙｌａｃｅｔａｔｅＤｅｒｉｖａｔｉｖｅｓｂｙＲｅｖｅｒｓｅｄ┐ｐｈａｓｅＨＰＬＣ＊ＱＩＵＰｅｉ－ｈｏｎｇ＊＊（Ｄｅｐａｒｔｍｅ...     

New Chiral Calixarene Derivatives： Syntheses and Their Chiral Recognition Toward Amino Acids by UV-Vis Spectroscopy

Three novel types of chiral calixarene derivatives 5, 8, and 10 were designed and synthesized by introducing chiral units to parent calixarenes. Their chiralities were confirmed by rotational analysis. Chiral recognition properties of these host compounds towards L- and D-threonine were studied by UV-Vis spectroscopy. The results indicated that calixarene derivatives 5 and 8 exhibited good chiral recognition capabilities toward L- or D-threonine. Although calixarene derivative 10 had no evident chiral recognition ability, the supramolecules of calixarene derivative 10 with L- or D-threonine showed a hypochromic effect or hyperchromic effect respectively. Therefore, calixarene derivative 10 might serve as a good chiral UV-indicator.     

The Biosynthesis of Aromatic Amino Acids and its Regulation

Microorganisms synthesize the aromatic amino acids phenylalanine, tyrosine, and tryptophan, as well as the related compounds p-aminobenzoic acid, tetrahydrofolic acid, p-hydroxybenzoic acid, ubiquinone, vitamin K, and nicotinic acid, by a highly branched route passing through shikimic acid. The biosynthesis is not regulated in the same way in all the organisms studied. The regulation is strongly dependent on the ability of the enzymes involved to be resolved into isozymes, their ability to be inhibited, and their activation, repression, and induction.     

含氨基磺化聚芳醚酮砜质子交换膜的制备与性能

通过四元缩聚的方法合成了带有氨基的磺化度可控的磺化聚芳醚酮砜共聚物(Am-SPAEKS). 采用红外光谱和核磁共振谱表征了Am-SPAEKS共聚物的结构. 该共聚物膜具有较好的热性能、尺寸稳定性、较高的质子传导率和阻醇能力. 在80℃时Am-SPAEKS-1膜的质子传导率达到0.0894 S/cm, 而其甲醇渗透系数在25℃时为0.24×10^-6 cm²/s, 低于相同温度下SPAEKS膜(0.87×10^-6 cm²/s)和Nafion膜(2×10^-6 cm²/s). 结果表明, Am-SPAEKS膜能够满足质子交换膜燃料电池(PEMFC)的使用要求.     

双吲哚烯类受体对氨基酸的比色识别作用

设计合成了一系列3,3′-双吲哚烯类受体分子,应用紫外-可见吸收光谱研究了该类受体对二十种天然氨基酸分子的识别作用. 结果表明,在乙腈-水溶液中,双吲哚烯受体分子可以通过其氢键受体位点的质子化作用比色识别天冬氨酸、谷氨酸等酸性氨基酸;而硝基取代的双吲哚烯受体分子则通过其氢键供体位点的去质子化作用比色识别精氨酸、赖氨酸等碱性氨基酸. 在乙腈-水的中性缓冲溶液体系中,硝基取代的双吲哚烯类受体分子通过与巯基发生亲核加成反应高选择性比色识别半胱氨酸和同型半胱氨酸.     

柱前手性衍生色谱法拆分DL—氨基酸时流动相的影响

本文利用邻苯二甲醛和Ｎ－乙酰－Ｌ－半胱氨酸作柱前手性衍生化试剂，经反相高效液相色谱法拆分ＤＬ－氨基酸对映体，研究了流动相组成对出峰顺序和分离效果的影响。     

Rapid Determination of Amino Acids in Ginseng by High Performance Liquid Chromatography and Chemometric Resolution

Ginseng is one of the most important traditional Chinese medicines and functional foods.A method for the fast determination of amino acids in ginseng samples using high performance liquid chromatography（HPLC） was developed,in which strong isocratic elution was employed for simplifying the separation and speeding up the analysis.All amino acids were eluted within 3 min with the chromatogram composed of overlapped peaks from the interferences.Then,non-negative immune algorithm（NNIA） was adopted to resolve the chromatographic signals of the components from the chromatogram measured.The results show that the signals of the amino acids can be correctly extracted by NNIA and the signal extracted can be used for the quantitative analysis.The method was validated via determining six amino acids of four different samples of ginseng.The recoveries of the spiked samples are in a range of 96.6％-106.3％.