超临界流体色谱法分离手性药物

对超临界流体色谱技术（SFC）在手性药物分离方面的研究与应用状况做了评述,对超临界流体色谱手性分离的分离方式、操作条件及影响因素作了介绍。     

负电性和中性环糊精在毛细管电泳手性分离中的协同效应

１引言环糊精及其电中性衍生物（二甲基－β－环糊精（ＤＭ－β－ＣＤ）、三甲基－β－环糊精（ＴＭ－β－ＣＤ）、羟丙基－β－环糊精（ＨＰ－β－ＣＤ））是毛细管电泳（ＨＰＣＥ）手性分离中最常采用的手性选择剂,带电环糊精是ＨＰＣＥ手性分离中另一类重要的手性选择剂,它的带电性质使其在手性拆分过程中起到非常重要的作用。本文分别考察了带电的磺丁基－β－环糊精（ＳＢＢ－β－ＣＤ）与电中性的ＤＭ－β－ＣＤ、ＴＭ－β－ＣＤ以及ＨＰ－β－ＣＤ等３种双环糊精体系的手性拆分性能,研究了双环糊精在手性分离中所体现出的协同效应…     

双手性选择单元手性固定相的研究进展

手性固定相（chiral stationary phase,CSP）作为手性色谱分离的核心技术,在手性化合物的识别和分离中得到广泛应用。以双手性选择单元结合作为CSP是近些年的研究热点,研究表明,两种手性选择单元相结合的CSP可增加手性识别位点,显著提高分离效果。本文介绍了近几年双手性选择单元手性固定相在手性分离中的研究进展,并对其发展前景进行了展望。     

超分子化学方法研究环糊精的手性识别

本文论述了环糊精（ｃｙｌｄｅｘｔｒｉｎ，ＣＤ）的主体结构，并引进了超分子化学和概念，讨论了基于ＣＤ的特殊结构及在手性分离中的分子识别机理。     

分子模型在对映体分离的手性识别机理研究中的应用

本文对分子模型及其在手性色谱分离机理研究中的应用作了综述。     

莨菪烷型生物碱薄层原位表面增强拉曼光谱

１引　言薄层色谱（ＴＬＣ）已广泛用于中药成分的分离与分析，但在薄层原位无法获得分离后各化合物的分子结构信息；表面增强拉曼光谱（ＳＥＲＳ）可高灵敏度获得单一组分的分子振动光谱，将以上技术联用，可在混合物微量分离的原位获得化合物的分子结构信息，本文用ＴＬＣ－ＳＥＲＳ对洋金花注射液中莨菪烷型生物碱进行了探索。２　实验部分２．１　仪器与试剂ＦＴ－Ｒａｍａｎ９１０光谱仪（Ｎｉｃｏｌｌｅｔ公司），Ｎｄ：ＹＶＯ４激光器，激光波长１０６４ｎｍ；三用紫外分析仪（上海分析仪器厂）。硅胶ＣＦ２５４（青岛海洋化工厂）；…     

微径高效液相色谱法分离三唑类手性化合物的对映体

 采用微径高效液相色谱技术在手性纤维素色谱柱上分离了一系列 1 1,2 ,4 三唑类手性化合物。比较了微径液相色谱与传统液相色谱的分离结果 ,研究了化合物的苯环上不同取代基及取代基位置对分离的影响 ,并探讨了分离机理。     

气相色谱法用于观察手性醇合成中的对映体选择性自动诱导效应

在手性醇合成中,采用非手性柱气相色谱（ＣＣ）分析,结合反应前后诱导物和产物的比旋光度测定,简单方便地计算了比旋光增量;以这种方法,成功地观察到了手性化合物选择性自动诱导效应。     

以β-环糊精及其衍生物为手性选择剂毛细管电泳拆分几种药物的旋光对映体

在毛细管电泳中，采用β－环糊精（β－ＣＤ）及其衍生物为手性选择剂对扑尔敏、异丙嗪、二氧异丙嗪和氧氟沙星对映体进行了分离。优化了分离条件；讨论了环糊精空腔边缘与溶．质分子作用的基团的种类和分离效果的联系，通过计算手性分离的热力学常数比较了不同手性选择剂对扑尔敏对映体的分离能力。最后，讨论了乙腈在手性分离中的作用。     

对映体的气相色谱分析Ⅱ．手性芳香二级醇的分离测定

在手性毛细管柱Ｃｈｉｒａｓｉｌ－Ｌ－Ｖａｌ（玻璃柱）、ＣＹＤＥＸ－β－全甲基化β－环糊精（交联弹性石英柱）上考察了苯乙醇腈、１－苯基－１－乙醇、１－苯基－１－丙醇、１－苯基－２,２－二甲基－１－丙醇、１－（４－氯苯基）－１－乙醇芳香二级醇对映体分离的色谱行为。并测定了一系列不对称合成实际样品中对映体过量值（即ｅ．ｅ．值）。     

Enhanced chromatographic resolution of amine enantiomers as carbobenzyloxy derivatives in high-performance liquid chromatography and supercritical fluid chromatography

The carbobenzyloxy (cbz) protecting group is evaluated for it's potential to enhance the resolution of chiral amine enantiomers using high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). A series of cbz derivatives of commercially available racemates was prepared and analyzed by enantioselective chromatography using a variety of mobile phases and polysaccharide and Pirkle-type chiral stationary phases (CSPs). The cbz-derivatized product consistently demonstrated enhanced chiral resolution under HPLC and SFC conditions. Improved selectivity and resolution combined with an automated preparative HPLC or SFC system can lead to the rapid generation of highly purified enantiomers of desirable starting materials, intermediates or final products.     

超临界流体色谱与高效液相色谱分离手性化合物的比较

超临界流体色谱(SFC)分离具有速度快、分离效率高、溶剂消耗少等优点,近年来在手性化合物的分离分析中得到诸多应用。本文对比研究了涂覆型多糖手性色谱柱在SFC和高效液相色谱(HPLC)上拆分24种手性化合物的差异。通过比较这些化合物在色谱柱上的保留时间和选择因子等发现多数化合物在SFC上的分离效率要高于其在HPLC上的分离效率,但HPLC对轴手性化合物的分离效率要优于SFC。SFC和HPLC的分离表现出一定的互补性,随着苯环侧链烷基的碳数增加,化合物在SFC上的保留逐渐增强,而在HPLC的保留却逐渐减弱。叶菌唑在使用SFC和HPLC分析时出现了洗脱顺序反转的现象。这些结果为SFC手性拆分提供了参考。     

Enantiomeric separation of proton pump inhibitors on new generation chiral columns using LC and supercritical fluid chromatography

The enantioselectivity of proton pump inhibitors, namely, omeprazole, lansoprazole, rabeprazole, pantoprazole, tenatoprazole, and ilaprazole were studied using new generation chiral packing materials: CHIRALPAK IA, CHIRALPAK IB, and CHIRALPAK IC. Two versatile techniques, HPLC and supercritical fluid chromatography (SFC) were used in this study. CHIRALPAK IC has shown superior selectivity under both LC and SFC conditions, whereas CHIRALPAK IA has shown good selectivity in SFC when compared to LC under primary screening conditions. The chiral recognition ability in LC and SFC modes were found to be in the order CHIRALPAK IC > CHIRALPAK IA > CHIRALPAK IB. In addition to diode array detection, chiral detection was carried out using a laser polarimeter and the elution orders were found to be the same in both LC and SFC elution modes. Mobile phase modifiers and column temperature effects were also studied. In SFC, modifiers (cosolvent) elution strength was found to be in the order ethanol > methanol > 2‐propanol > acetonitrile. In both LC and SFC, a decrease in retention and increase in resolution with an increase in temperature was noticed for all the proton pump inhibitors.     

Chiral separations in sub- and supercritical fluid chromatography

Sub- and supercritical fluid chromatography (SFC) received more and more attention in pharmaceutical analysis during the last years. Especially for chiral separations, this technique is becoming increasingly popular. This review gives an overview of most chiral separation applications using SFC, covering the literature from 2000 on.     

Two-dimensional supercritical fluid chromatography/mass spectrometry for the enantiomeric analysis and purification of pharmaceutical samples

A new analytical two-dimensional supercritical fluid chromatography/mass spectrometry system (2D SFC/SFC/MS) has been designed and implemented to enhance the efficiency and quality of analytical support in drug discovery. The system consists of a Berger analytical SFC pump and a modifier pump, a Waters ZQ 2000 mass spectrometer, a set of switching valves, and a custom software program. The system integrates achiral and chiral separations into a single run to perform enantiomeric analysis and separation of a racemic compound from a complex mixture without prior clean up. The achiral chromatography in the first dimension separates the racemate from all other impurities, such as un-reacted starting materials and by-products. Mass-triggered fractionation is used to selectively fractionate the targeted racemic compound based on its molecular weight. The purified racemate from the achiral chromatography in the first dimension is then transferred to the chiral column in the second dimension to conduct the enantiomeric separation and analysis. A control software program, we coined SFC2D, was developed and integrated with MassLynx to retrieve acquisition status, current sample information, and real time mass spectrometric data as they are acquired. The SFC2D program also monitors the target ion signal to carry out mass-triggered fractionation by switching the valve to fractionate the desired peak. The 2D SFC/SFC/MS system uses one CO(2) pump and one modifier pump for both first and second dimension chromatographic separations using either gradient or isocratic elution. Similarly, a preparative 2D SFC/SFC/MS system has been constructed by modifying an existing Waters preparative LC/MS system. All components except the back pressure regulator are from the original LC/MS system. Applications of the 2D SFC/SFC/MS methods to the separation and the analysis of racemic pharmaceutical samples in complex mixtures demonstrated that an achiral separation (in first dimension) and a chiral separation (in second dimension) can be successfully combined into a single, streamlined process both in analytical and preparative scale.     

Supercritical fluid chromatography as a tool for enantioselective separation; A review

Supercritical fluid chromatography (SFC) has become popular in the field of enantioselective separations. Many works have been reported during the last years. This review covers the period from 2000 till August 2013. The article is divided into three main chapters. The first one comprises a basic introduction to SFC. The authors provide a brief explanation of general principles and possibilities of this method. The advantages and drawbacks are also listed. Next part deals with chiral separation systems available in SFC, namely with the commonly used chiral stationary phases. Properties and interaction possibilities of the chiral separation systems are described. Recent theoretical papers are emphasized in this chapter. The last part of the paper gives an overview of applications of enantioselective SFC in analytical chemistry, in both analytical and preparative scales. Separation systems and conditions are summed up in tables so that they provide a helpful tool for analysts who search for a particular method of analysis.     

Integration of supercritical fluid chromatography into drug discovery as a routine support tool. Part I. fast chiral screening and purification

Supercritical fluid chromatography (SFC) has been implemented within our group as a purity assessment and purification tool to complement high performance liquid chromatography (HPLC) for diastereomer and chiral separations. Using a novel strategy, rapid chiral screening has been implemented using short columns, high flow rates and fast gradients. A primary screen delivers a separation assessment using one solvent modifier (methanol) and four columns (Chiralpak AD-H and AS-H, and Chiralcel OD-H and OJ-H) run serially in a total of 24 min. A secondary screen then uses ethanol and isopropanol (IPA) modifiers across the same columns. The screens can be combined to run a sequence of samples overnight where each racemate is analysed over 80 min. The fast analytical screening and optimisation process enables rapid identification of the purification method. Furthermore, subsequent preparative chiral SFC has decreased the overall sample turnaround time for the Medicinal Chemist, delivering high fraction purities and acceptable recoveries, substantial operational cost savings and increased flexibility with respect to large scale purification feasibility in comparison to HPLC. SFC has been so successful it is now used as the primary method for chiral analysis and purification within our laboratory.     

Parallel supercritical fluid chromatography/mass spectrometry system for high-throughput enantioselective optimization and separation

An automated parallel four-column supercritical fluid chromatography (SFC)/MS system to perform high-throughput enantioselective chromatographic method development and optimization is described in this paper. The initial screening was performed in parallel on four chiral SFC columns over several buffer conditions. Optimization of the separation of enantiomers was achieved on a single chiral column. The screening and optimization were accomplished in a fully automated, user-independent manner. Incorporation of column control valves in front of each chiral column allowed the system to switch from parallel four-column screening mode to single-column optimization mode. To facilitate the process, a custom software program, we termed, intelligent parallel optimization for chiral SFC separation (IPOCSS), was developed in-house. The custom software monitored each of the runs in real-time, processed each data set, and by incorporating user-defined criteria (e.g., resolution of the two enantiomer chromatographic peaks), selected the next set of experiments and automatically optimized the enantioseparation. This new approach, combining parallel SFC/MS screening and intelligent software-controlled method optimization, has resulted in a streamlined, high-throughput tool for enantioselective method development, which has been applied successfully to enantioseparations in support of drug discovery.     

Comparison of supercritical fluid chromatography and liquid chromatography for the separation of urinary metabolites of nobiletin with chiral and non-chiral stationary phases

Nobiletin (NOB), a polymethoxylated flavone found in sweet orange (Citrus sinensis) peel, is currently recognized as a promising anti-inflammatory and anti-tumor agent. It is believed that, by undergoing metabolic biotransformation in vivo, nobiletin is demethylated by hepatic P450 enzymes, yielding multiple hydroxylated metabolites. However, it has not been possible to date to separate the two demethylated nobiletin metabolites, 3'-demethyl-NOB and 4'-demethyl-NOB (regio-isomers) on reversed-phase liquid chromatography (RPLC). Additionally, both display similar mass spectrometric fragmentation, resulting in difficulties to identify the dominant metabolite. A successful separation method was developed by utilizing supercritical fluid chromatography (SFC) with chiral stationary phase. The separation was also attempted with normal-phase liquid chromatography (NPLC) in both chiral and non-chiral modes. Chromatographic separation for the two nobiletin metabolites was superior by SFC than by LC, especially using chiral stationary phase. By comparing the SFC profile of the synthesized standards, the major nobiletin metabolite in mouse urine was identified as 4'-demethyl-NOB, with the concentration of 28.9 microg/mL.     

Chromatographic resolution of closely related species: Drug metabolites and analogs

In this study, we investigate the separation of a variety of mixtures of drugs, metabolites, and related analogs including representatives of the carbamazepine, methylated xanthine, steroid hormone, nicotine, and morphine families using several automated chromatographic method development screening systems including ultra high performance liquid chromatography, core–shell HPLC, achiral supercritical fluid chromatography (SFC), and chiral SFC. Of the 138 column and mobile phase combinations examined for each mixture, a few chromatographic conditions afford the best overall performance, with a single achiral SFC method (4.6 × 250 mm, 3.0 μm GreenSep Ethyl Pyridine, 25 mM isobutylamine in methanol/CO₂) affording good separation for all samples. Four of these mixtures were also resolved by achiral SFC on the Luna HILIC and chiral SFC Chiralpak IB columns using methanol or ethanol with 25 mM isobutylamine as polar modifiers. Modifications of standard chromatography screening conditions afforded fast separation methods (from 1 to 5 min) for baseline resolution of all components of each of these challenging sets of closely related compounds.