Separation of Orthophthalaldehyde/Ethanethiol Derivatives of Taurine and Closely Eluting Amino Acids by High Performance Liquid Chromatography

Abstract

In studies of the reverse phase, HPLC analysis of amino acids employing precolumn derivatization with o-phthalaldehyde and ethanethiol, it was shown that α-amino-n-butyric acid, β-amino-isobutyric acid and taurine coeluted in the acetonitrile/aqueous phosphate solvent system. By using a ternary solvent system of acetonitrile/tetrahydrofuran/aqueous phosphate buffer and efficient 5- and 10-μm octadecylsilane packings, the co-elution problem has been resolved. This modified chromatographic system is now being used to quantitatively determine taurine and other closely eluting amino acids in a variety of physiological fluids in order to clarify the role of taurine in human development.     

七氟丁酰氨基酸正丁酯的GC/MS分析

本文报道了19种蛋白质氨基酸的七氟丁酰正丁酯衍生物的GC/MS分析方法;优选了衍生反应条件;建立了GC分离、定量分析方法,最小检测量为0.1ng;研究了衍生物的EI质谱数据,确定了可作为定性依据的特征离子;测定了儿童用复方氨基酸注射液及儿童血清样品,得到了满意的结果。     

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

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蛋白质水解液中氨基酸组成的定量分析

以氯甲酸－9－芴基甲酯（FMOC－Cl）为柱前衍生化试剂在液相色谱上分离17种常见氨基酸的衍生物并测定其摩尔吸光系数。用绝对分析法和标准曲线法对标准氨基酸溶液进行了定量分析，除组氨酸外两种方法测定结果的相对偏差为5．00％以内。对氨基酸的稳定性进行了模拟水解实验，发现在110℃/24h的水解条件下，丝氨酸等不稳定氨基酸的降解较在150℃/1.5h条件下小。用绝对分析法测定测定了牛胰岛素不同水解条件下水解液中氨基酸的含量，大部分氨基酸的相对收率都接近100％。     

高血压患者血浆中游离氨基酸的柱前衍生HPLC法测定

以2,4-二硝基氯苯为衍生化试剂,建立了反相高效液相色谱法测定人血浆中22种游离氨基酸的方法.衍生化产物用Kromasil C18柱分离,梯度洗脱,紫外检测波长为360 nm.在所研究的浓度范围内,22种氨基酸的线性关系良好(r>0.99),日内精密度(RSD)为1.7% ～4.1%,日间精密度(RSD)为2.8% ～6.9%,方法回收率为90% ～106%.用建立的方法对高血压病人和正常人血浆中的游离氨基酸进行测定,并将测定结果进行主成分分析及判别分析,结果表明高血压病人与正常人血浆中的氨基酸存在显著差异,分类判别率为94.4%.     

Acylation of Amino Acids with Dextran Derivatives

The conditions of N-acylation of amino acids with carboxymethyl dextran ethyl ester and with carboxymethyl and carboxyethyl dextran azides were studied.     

手性羟酸和氨基酸类化合物的构效关系研究

构造了用于手性参数衍生的距离矩阵和扩展的距离矩阵, 并且观察了与羟酸类和氨基酸类化合物手性薄层色谱保留指数的相关性, 得到了具有启示性的结果. 引进了扩展的eAm指数和连乘指数, 以及综合运用了三种算法. 所得参数进行了多元回归分析, 得到了单一变量和变量组合的分析结果. 与多元回归分析相比较, 运用人工神经网络法, 使结果得到了较大的改善. 所引进的方法对于化合物构效关系研究具有普遍可用性.     

胶束电动毛细管色谱分离氨基酸和磷酸化氨基酸

本文报道了胶束电动毛细管色谱分离、汞灯诱导荧光电荷耦合器件检测分析氨基酸和磷酸化氨基酸的 4-氟 - 7-硝基苯 - 2 - 口恶 - 1 ,3-丫唑衍生物。研究表明 ,在 p H9.35的 1 0 mmol/L硼砂和 1 0 mmol/L十二烷基硫酸钠的电泳缓冲介质中 ,5种氨基酸和 3种磷酸化氨基酸在 1 0 min内完全分离 ,检测灵敏度为 1 .2 1× 1 0 - 8～ 5 .2 1×1 0 - 8mol/L ,分离效率达 7.3× 1 0 5～ 3.0× 1 0 5/m理论塔板数 ,结果令人满意     

Preparation of Saccharin Derivatives of Amino Acids as Potential Peptidomimetic Building Blocks

We present a useful route for the preparation of saccharin derivatives of amino acids. Sixteen new compounds, saccharin-derived amino acids, were synthesized, all of them bearing additional functional groups either at the 5- or 6-position of the saccharin skeleton, thus rendering the compounds more amenable to functionalization.     

反相高效液相色谱测定依替巴肽注射液中氨基酸的含量

采用异硫氰酸苯酯为柱前衍生化试剂,结合反相高效液相色谱技术,建立了定量分析依替巴肽注射液中氨基酸组分的检测方法。优化色谱条件,选用Agilent XDB-C18色谱柱(5μm,150 mm×4.6 mm),以0.1 mol/L醋酸钠(冰醋酸调至pH 6.0)-乙腈(90∶10)为流动相A,乙腈为流动相B,梯度洗脱方式,检测波长为254 nm,流速为1.0 mL/min,进样体积为5μL,柱温为30℃。结果表明,在优化条件下,各氨基酸能实现有效分离,且在1.23～3.68 mmol/L浓度范围内,各氨基酸的线性关系良好,相关系数(r)为0.999 1～0.999 6。该方法显示了良好的准确性、重复性、稳定性及选择性,能对依替巴肽注射液中的氨基酸实现准确定量分析。     

Analysis of Taurine in Blood Plasma of Epileptic Patients Using an Improved Isocratic HPLC Method for Amino Acids

Abstract

An efficient, reversed-phase HPLC method is described in which 21 derivatized amino acids were isocratically separated in less than 90 minutes. An internal standard was used to improve precision and accuracy. The method, which separated taurine from α-, β-, and γ-aminobutyric acids, was used to quantify taurine levels in 83 blood plasma samples. A statistical comparison was made between taurine levels found in the plasma of epileptic and non-epileptic children.     

Dimethylsilicon(IV) Derivatives of Amino Acids

Reactions of dichlorodimethylsilane with the sodium salt of amino acids in 1:2 molar ratio led to the formation of a new series of dimethylsilicon(IV) complexes of general formula, Me 2 SiL 2 [L = anion of amino acids, viz. glycine (HGly), L-methionine (L-MethH), DL- f -alanine (DL- f -AlaH) L-leucine (L-LeuH), L-valine (L-ValH) and D-phenylalanine (D-PheH)]. The complexes have been characterized by elemental analyses, molar conductance, and electronic spectra, and the bonding in these complexes is discussed in terms of their infrared, 1 H and 13 C NMR spectra. A distorted octahedral structure with trans methyl groups has been tentatively suggested for the complexes. The complexes, found soluble in DMSO, have been tested in vitro against various bacteria, viz. Escherichia coli , Pseudomonas putida-2252 , Aeromonas formicans , Staphylococcus aureus-740 , and fungi, viz. Aspergillus niger ORS-4, Aureobasidium pullulans-1991 , Verticillium dahliae-2063 , and Penicillium notatum-1348 .     

苯基异硫氰酸酯衍生氨基酸的高效液相色谱分析

苯基异硫氰酸酯衍生氨基酸的高效液相色谱分析杨扬,秦强,郭伟忠（江苏石油化工学院应化系常州２１３０１６）１前言采用苯基异硫氰酸酯（ＰＩＴＣ）衍生氨基酸并用高效液相色谱测定的报道国外较多￣［１－４］。该法的优点是ＰＩＴＣ与氨基酸、亚氨基酸都能反应生成ＰＴ...     

Synthesis of Some Novel Benzylidenehydantoins: Amino Acids Derivatives

5-Benzylidenehydantoin reacts with chlorosulfonic acid to give the corresponding p-sulfonyl chloride. Condensation of the latter with amino acids leads to sulfonylamino acid derivatives, which on coupling with glycine methyl ester hydrochloride in THF-Et₃N using the dicyclohexylcarbodiimide method furnish the desired dipeptide methyl esters. The spectral data of the compounds are briefly discussed.     

Chiral HPLC of Amino Acids Using Chemically Modified Chitosan as the Stationary Phase

The chiral recognition ability of chitosan is enhanced by chemical modifications. For example, chitosans modified with phenylcarbamate or cyclodextrin were used as good stationary phases for the chiral HPLC separation of aromatic alcohols or amino acid derivatives2>, respectively. We report here the preparation of chitosans having an a -amino acid moiety in the glucosamine unit and their chiral recognition behavior toward a -amino acids under ligand-exchange chromatographic separation mode.     

Facile Synthesis of Novel Amino Acids Derivatives as Potential Antibacterial Agents using Sustainable Materials

Following the principles of green chemistry, cardanol derivatives have been used as renewable, low‐cost, and available natural starting materials to construct a variety of protected and unprotected amino acids derivatives. The reaction of cardanol derivatives with different phthaloylamino acids including glycine, alanine, phenylalanine, and valine in the presence N,N'‐ dicyclohexylcarbodiimide (DCC ) as coupling reagent afforded high yields of the target compounds. Deprotection of phthaloylamino acids derivatives was achieved by heating with hydrazine hydrate. The chemical structures of all products were confirmed by spectral data (IR , MS , ¹H NMR , ¹³C NMR ) and elemental analyses. Antibacterial evaluation of the synthesized products was performed, which exhibited potent to weak activity in comparison with a standard drug.     

Pre-Column Derivatization in HPLC of Amino Acids and Peptides

Abstract

The development of high preformance liquid chromatography with permanently bonded non-polar, so called reversed phase packings has been useful in the separation of a variety of peptides and amino acid derivatives. Limits to the detectability of underivatized substances are on the order of several nanomolar. Sensitivity enhancement became very important for the analysis and determination of peptide hormones, their metabolites and fragments, trace constituents and amino acids existing in very little quantity in biological and clinical samples. Therefore chemical derivatization techniques have been introduced into HPLC, too. By derivatization not only sensitivity enhancement, but selectivity can be achieved.     

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.     

New Conjugates of Di- and Trichlorocyclopentenones with Amino Derivatives of Adamantane and Amino Acids

Reactions of di- and trichlorocyclopentenones with adamantan-1-amine, 1-(adamantan-1-yl)ethanamine, and amino acids (histidine, L-proline, L-methionine methyl ester hydrochloride) afforded the corresponding enamino ketones.