硅胶键合手性配体交换色谱固定相拆分α-氨基酸

用简易的方法制备了铜(Ⅱ)—L—羟脯氨酸键合手性固定相；在所制备的手性固定相上，用配体交换色谱法研究了pH值、温度、中心离子浓度及流速对α—氨基酸对映体拆分的选择性和分离度的影响，选择了合理的色谱分离条件；结果表明，该固定相在配体交换模式下，可对部分常见氨基酸进行良好分离。     

α-氨基酸在L-脯氨酸手性配体交换色谱固定相上的分离

合成了L-脯氨酸硅胶键合手性配体交换色谱固定相，并用于α-氨基酸的直接光学分离，详细考察了流动相pH值、金属离子浓度、流速、柱温以及进样量等因素对分离效果的影响，从而进一步优化了色谱分离条件。     

单分散树脂键合手性配体交换色谱固定相拆分DL-氨基酸

以单分散交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为基质合成了L-脯氨酸键合手性配体交换固定相,并用于DL-氨基酸的直接光学拆分,考察了流动相pH值、金属离子浓度、流速及温度等因素对DL-氨基酸对映体拆分的影响。结果表明,该固定相在配体交换色谱模式下可对多对DL-氨基酸进行良好的拆分。     

L-羟基脯氨酸键合手性配体交换色谱固定相的制备及手性拆分

合成出了L—羟基脯氨酸键合手性配体交换固定相，用元素分析和红外光谱对固定相进行了表征。该固定相在反相条件下，以水作流动相，对DL—氨基酸对映异构体有良好的拆分能力。     

一种新型手性配体交换色谱键合固定相

采用气相或液相色谱法拆分氨基酸对映体通常一化过程,费时而麻烦,而且有可能发生消旋,影响分析结果,手性配体交换色谱法是拆分氨基酸和羟基酸对映体的一种有效方法,其选择性高,不需柱前衍生。Davankov等对此方法进行了评述。此法大都采用刚性环状结构的光活性脯氨酸或羟基脯氨酸键合相作为柱填料,Jeanneret-Gris等曾采用1,2,3,4－四氢－3－异喹啉羧酸接枝的聚丙烯酰胺相拆分氨基酸对映体。     

L-苯丙氨酸键合手性配体交换色谱固定相的制备及手性拆分

合成了L-苯丙氨酸键合手性配体交换固定相，用元素分析和红外光谱对固定相进行了表征；该固定相在反相条件下对DL-氨基酸对映体有良好的拆分能力。     

新型手性配体交换色谱固定相的合成及其对DL-氨基酸的拆分

将β-(3,4-环氧环己基)乙基三甲氧基硅烷与硅胶反应,得到环氧化硅胶中间体,然后与L-异亮氨酸反应,再与铜离子进行配位,最后得到一种新型配体交换固定相。用DL-氨基酸对该固定相进行了色谱评价,同时探讨了分离机理。研究结果表明,该固定相在配体交换模式下,可对DL-氨基酸进行良好分离。     

α-羟基酸在不同的手性配体交换色谱固定相上分离性能的考察

合成了L-羟基脯氨酸，L-脯氨酸，L-苯丙氨酸3种硅胶链合手性配体交换色谱固定相，并用于α-羟基酸的直接光学分离，取得了较为满意的结果。对不同的手性配体交换色谱固定相的分离性能进行了比较，并详细考察了流动相pH值、金属离子浓度、柱温等因素对分离效果的影响，从而进一步优化了色谱分离条件。     

β-氨基酸对映体在键合型配体交换色谱固定相上的分离

制备了以L-α-氨基酸为手性配体和球型多孔硅胶为基质的键合型手性配体交换色谱固定相,用于β-氨基酸对映体的拆分。考察了硅胶基质、配体、流动相pH值、中心金属离子浓度和流动相阴离子等因素对5种β-苯丙氨酸对映体分离的影响,由此确立最佳色谱分离条件为以BaseLine硅胶为基质键合L-羟脯氨酸的手性固定相,5.0mmol/L和pH4.6的CuSO4溶液为流动相,紫外检测波长为254nm。在此条件下5种β-氨基酸对映体均可在35min内得到分离,分离因子在1.49~1.77之间。结果表明该方法操作简便,成本低廉,可用于β-氨基酸对映体的分离和分析。     

L-异亮氨酸型配体交换固定相对DL-氨基酸的拆分研究

用自制的新型L-异亮氨酸配体交换固定相在配体交换模式下对11种DL-氨基酸进行了拆分研究,详细考察了流动相中铜离子浓度、甲醇含量、流速及温度对拆分效果的影响,并探讨了可能的拆分机理。研究结果表明:流动相中高浓度的铜离子不利于DL-氨基酸的拆分;增加流动相中甲醇的含量,降低流动相流速以及提高色谱柱温度均可改善拆分效果。     

Chromatographic Enantioseparation of Ten Amino Acid Amide Derivatives on Three Polysaccharide-Based Chiral Stationary Phases

Enantioseparation of ten kinds of amino acid amide derivatives bearing aniline moieties on three polysaccharide-based chiral stationary phases (CSPs) was first systematically investigated. The chromatographic experiments were performed in the normal phase mode, namely, with n-hexane and 2-propanol as mobile phase. The effects of chiral columns, concentration of 2-propanol and column temperature on the enantioseparation were studied in detail. These compounds can be well resolved on Chiralcel OD-H column with the resolution above 1.5. Enantioseparation mechanism of chiral analytes and the CSPs are proposed based on the thermodynamic analysis of the experimental data. Our study establishes a simple, fast and efficient analytical method for amino acid amide derivatives by chiral HPLC, and provides a reference for enantioseparation of chiral amino acid amide derivatives and similar chiral compounds.     

Resolution of the Optical Isomers of Underivatisized Amino Acids on Chemically Bonded Chiral Phases by Ligand Exchange Chromatography

Abstract

A method for the direct separation of racemates by HPLC is described. A chiral stationary phase is synthesized, suitable for ligand exchange chromatography. L-proline is chemically bonded to silica gel via 3-glycidoxypropyltrimethoxysilane. The bonded support is loaded with Cu(II) ions as a complexing agent. Complete resolution of amino acid racemates can be obtained in less than ten minutes. α-values up to 3.5 are observed.     

Silica Immobilised Chloro- and Amido-Derivatives of Eremomycine as Chiral Stationary Phases for the Enantioseparation of Amino Acids by Reversed-Phase Liquid Chromatography

Macrocyclic glycopeptide antibiotics immobilized on silica are one of the effective classes of stationary phases for chiral recognition and HPLC separation of a wide range of optically active compounds. Enantioselectivity primarily depends on the chemical structure of the chiral ligand, immobilization chemistry, and separation conditions. In the present work, three new chiral stationary phases (CSPs) based on macrocyclic antibiotic eremomycin were prepared and investigated for enantioseparation of amino acids. Two eremomycin derivatives, including simple non-substituted amide and bulky adamantyl amide, provided important information on the role of the carboxylic group in the eremomycin structure in the chiral recognition mechanism concerning amino acid optical isomers. One more CSP having a chlorine atom in the same position elucidates the role of the first aromatic ring in the eremomycin structure as a crucial point for chiral recognition. CSP with immobilized chloreremomycin was the most successful among the phases prepared in this work. It was additionally investigated under various separation conditions, including the type and content of the organic solvent in the eluent, the effects of different additives, and the concentration and pH of the buffer. Importantly, an efficient enantioselective separation of amino acids was achieved with pure water as the eluent.     

新型手性配体交换色谱固定相的制备及应用

 合成了 2 -(2 -羟基 -3 -烷氧基 )丙基 -(S) -1 ,2 ,3 ,4-四氢 -3 -异喹啉羧酸手性选择子 ,制备了两种新型涂渍手性配体交换色谱固定相 ,拆分了某些 DL-氨基酸 ,比较了 DL-氨基酸在两种手性相上的色谱分辨。     

Enantioseparation of 1-Phenyl-1,2,3,4-tetrahydroisoquinoline on Polysaccharide-Based Chiral Stationary Phases

The enantiomers of 1-phenyl-1,2,3,4-tetrahydroisoquinoline have been directly separated on polysaccharide-based chiral stationary phases (CSPs). The normal phase separation of (S)- and (R)-1-phenyl-1,2,3,4-tetrahydroisoquinoline was accomplished by screening of the immobilized Chiralpak IC column with different eluents. The effect of mobile phase type on retention, selectivity and resolution was studied. 2-Propanol or ethanol/n-hexane/ethanolamine mixtures were applied as mobile phases by screening of following polysaccharide-based immobilized (Chiralpak IA, Chiralpak IC) and coated (Lux Cellulose-1, Lux Cellulose-2, Lux Amylose-2) CSPs. Polar organic and reversed-phase conditions were also tested for direct enantioseparation of 1-phenyl-1,2,3,4-tetrahydroisoquinoline.     

手性固定相法分离芳香醇及芳酯对映体

在自制的涂敷型CDMPC和Pirkle型（S,S）-Whelk-O 1、（R,R）-DNB-DPEDA两类手性柱上,对1-苯乙醇、1-苯-1-丙醇及2-苯基丙酸甲酯进行了对映体分离。分别考察了在流动相正己烷中不同极性醇类添加剂、醇的浓度对这些溶质手性分离的影响,并研究了溶质的体积大小及立体结构因素对手性分离的影响,由此探讨了这两类手性柱对这些化合物手性识别的机理,发现在（S,S）-Whelk-O 1和（R,R）-DNB-DPEDA柱上溶质与固定相之间主要是吸引作用,而CDMPC手性识别的关键是溶质的体积大小、尤其是空间结构在手性空腔中的空间适应性,氢键作用对于CDMPC手性固定相的手性识别并不重要。     

HPLC Enantioseparation of Novel Spirobrassinin Analogs on the Cyclofructan Chiral Stationary Phases

A novel series of nine chiral analogs of spirobrassinin, which have potential biological activity, was separated for the first time on three different derivatized cyclofructan chiral stationary phases in the normal phase mode. The effects of mobile phase composition, the type and concentration of polar modifier, additives, and the analyte structure on the retention and enantioseparation were studied. The results proved that for cyclofructan-based chiral stationary phases, the R-naphthylethyl carbamate cyclofructan 6 provides the best separation efficiency for the analyzed compounds. The effect of temperature on the separation was also investigated and the corresponding thermodynamic parameters were evaluated from linear Van’t Hoff plots (lnk or lnα versus 1/T). It was found that the enantioseparation was enthalpy controlled. In addition, the elution order of the enantiomers was determined in all the cases.     

去甲万古霉素键合手性固定相在反相条件下拆分氨基酸类衍生物

使用合成的大环抗生素-去甲万古霉素键合手性固定相(NVC-CSP),在反相条件下直接拆分了4种丹酰化氨基酸对映异构体,并系统考察了缓冲溶液pH值、有机改性剂用量、温度以及流速对对映体拆分的影响。研究结果表明,在反相条件下,疏水作用和静电作用是影响溶质保留和手性选择性的重要因素,其手性识别的机理类似于蛋白质类手性固定相。