酸性外消旋联苯类药物在纤维素-三(3,5-二甲基苯基氨基甲酸酯)固定相上的直接拆分

合成了纤维素 三 ( 3,5 二甲基苯基氨基甲酸酯 ) (CDMPC)衍生物 ,并将其涂敷于自制的球形硅胶上 ,制备出用于高效液相色谱手性拆分的固定相。在正相条件下 ,用该固定相对 5种酸性外消旋联苯类药物进行了直接拆分 ,并考察了流动相组成和样品结构对保留和拆分的影响 ,讨论了固定相对样品的作用模式。结果表明 ,在正己烷 /异丙醇流动相体系中加入少量三氟乙酸 ,可对外消旋羧酸类化合物进行有效的手性拆分。     

禾草灵对映体在纤维素-三(3,5-二甲基苯基氨基甲酸酯)手性固定相上的拆分

将纤维素-三(3,5-二甲基苯基氨基甲酸酯)(CDMPC)涂敷于自制的球形氨丙基硅胶上,制备了手性固定相.在正相条件下,用高效液相色谱法在该固定相上直接拆分了农药禾草灵的外消旋体,并系统地选用了多种二元及三元流动相体系对样品进行拆分.实验结果表明,流动相中不同的醇类改性剂及其含量的不同对样品保留时间和立体选择性有不同程度的影响,选用异丙醇改性剂时样品的拆分效果较好,在三元流动相体系正己烷/异丙醇/乙醇中可以实现对禾草灵外消旋体快速有效的拆分.     

支链淀粉-三(苯基氨基甲酸酯)手性固定相的制备及对外消旋环酮和环醇的直接拆分

在参照文献基础上，合成并制备了支链淀粉－三（苯基氨基甲酸酯）手性固定相，以此手性固定相为基础，利用高效液相色谱首次直接拆分了３种外消旋环酮和一种外消旋环醇，并考察了流动相中异丙醇含量对拆分的影响。     

氟环唑外消旋体在纤维素-三(3,5-二甲基苯基氨基甲酸酯)手性固定相上的高效液相色谱法拆分

在纤维素-三(3,5-二甲基苯基氨基甲酸酯)（CDMPC）手性固定相上,分别采用正相、反相及极性有机相色谱模式对氟环唑外消旋体进行了拆分,并考察了流动相组成在手性识别中对手性分离的影响。氟环唑在Chiralcel OD-H手性色谱柱（填充CDMPC手性固定相）上采用反相色谱模式,以甲醇-水(体积比为80∶20)为流动相,获得了最佳的拆分,其两对对映异构体的分离度Rs分别为1.64和6.50。     

联苯类对映体在直链淀粉类手性固定相上的高效液相色谱法直接拆分

 涂敷直链淀粉 三 (3,5 二甲基苯基氨基甲酸酯 )于自制的球形氨丙基硅胶上 ,制备了手性固定相。用该固定相直接拆分了一系列外消旋联苯类保肝药物 ,考察了一系列伯醇 (乙醇、正丙醇、正丁醇 )和异丙醇等流动相改性剂对保留和立体选择性的影响 ,讨论了固定相对样品的作用机理。     

高效液相色谱法拆分雷喏嗪

用高效液相色谱法(HPLC)在正相条件下,用自制的涂敷直链淀粉-三(3,5-基苯基氨基甲酸酯)(ADMPC)手性固定相直接拆分了高效低毒的抗心绞痛药物雷喏嗪外消旋体(Ranolazine),并考察了二元及三元流动相体系对样品分离的影响,结果表明,三元流动相中的拆分结果远远好于二元流动相,流动相中不同种类醇改性剂及含量对样品保留时间和立体选择性有不同程度的影响．     

柱前衍生高效液相色谱法测定四氢噻唑-2-硫酮-4-羧酸的光学纯度

用苯胺对四氢噻唑-2-硫酮-4-羧酸(TTCA)进行柱前衍生,将其衍生物在手性固定相上拆分,通过二极管阵列紫外检测器和在线旋光检测仪对其衍生物进行检测,建立了一种拆分TTCA消旋体、测定TTCA光学纯度的新方法。以正己烷和乙醇或异丙醇为流动相,在DNB-Leucine手性固定相上对TTCA衍生物进行了拆分,并考察了流动相组成和柱温对其衍生物分离的影响,获得较优分析条件,分离因子大于1.2。非手性试剂苯胺柱前衍生化法测定(R)-TTCA的光学纯度与旋光度方法比较,结果一致,相对偏差小于1.34%。     

高效液相色谱手性固定相法直接拆分外消旋雷诺嗪

在反相以及正相争件下，利用自制的涂敷型纤维素-三（3，5-二甲基苯基氨基甲酸酯）手性固定相直接拆分了外消旋雷诺嗪，并考察了不同流动相对手性拆分的影响，特别是醇类物质对拆分影响。结果表明，醇的立体结构、极性对雷诺嗪的手性拆分均有影响。实验结果显示无论在正相条件下还是在反相条件下，涂敷型纤维素-三（3，5-二甲基苯基氨基甲酸酯）手性固定相均可以很好的拆分外消旋体雷诺嗪。     

支链淀粉—三（苯基氨基甲酸酯）手性固定相的制备及对外消旋环酮和环醇的直？

在参照文献基础上上，合成并制备了支链淀粉－三（苯基氨基甲酸酯）手性固定相，以此手性固定相为基础，利用高效液相色谱首次直接拆分了３种外消旋环酮和一种外消旋环醇，并考察了流动相中异丙醇含量对拆分的影响。     

聚甲基丙烯酸葡萄糖酯及聚甲基丙烯酸纤维二糖酯高效液相色谱手性固定相的性能测评

首先合成了甲基丙烯酸葡萄糖酯和甲基丙烯酸纤维二糖酯,然后通过甲基丙烯酸-3-(三甲氧基硅基)丙酯分别聚合在硅胶上,并将其作为高效液相色谱手性固定相。分别以正己烷-异丙醇(体积比为90:10)、正己烷-异丙醇-三乙胺(体积比为90:10:0.2)和正己烷-异丙醇-三氟乙酸(体积比为90:10:0.2)溶液作为流动相,对15种包含醇类、胺类、酰胺类和酮类的外消旋体化合物进行手性拆分。拆分结果表明,葡萄糖和纤维二糖聚合物固定相对大多数醇类和胺类以及部分酰胺类和酮类外消旋体化合物有较好的手性识别能力,并且二者的手性识别能力还具有一定的互补性。该研究表明,单糖和二糖聚合物固定相可成为一类新型的高效液相色谱手性固定相。     

高效液相色谱法拆分外消旋药物联苯双酯及其衍生物

合成并制备了纤维素-三（3,5-二甲基苯基氨基甲酸酯）手性固定相,利用高效液相色谱法首次直接拆分了5种外消旋联苯类药物,考察了流动相组成,样品结构对保留和拆分的影响。     

Direct optical resolution of the enantiomers of axially chiral compounds by high-performance liquid chromatography on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase

Summary The enantiomeric separation of nineteen biphenyl dimethyl dicarboxylate derivatives has been examined by HPLC on a chiral statonary phase prepared by coating aminopropylated silica gel with cellulose tris-(3,5-dimethylphenylcarbamate). It was found that trifluoroacetic acid (TFA) has a dominant effect on chiral separation for acidic compounds. The percentage of 2-propanol in the mobile phase does not have a large effect on the anantioselectivity but the separation was dramatically influenced by the kind of alcohol in the mobile phase. The effect of temperature on the chiral separation is also discussed. Most of the enantiomers investigated could be resolved satisfactorily.     

流动相组成对外消旋阿苯达唑亚砜对映体拆分的影响

涂敷直链淀粉-三(3,5-二甲基苯基氨基甲酸酯)(ADMPC)于自制的球形氨丙基硅胶上,制备了一种手性固定相。采用高效液相色谱法(HPLC),在正相条件下用该固定相直接拆分了广谱驱虫药物阿苯达唑的代谢产物阿苯达唑亚砜(albendazole sulfoxide, ABZSO)的外消旋对映体。系统地选用了多种二元及三元流动相体系对样品进行拆分,结果表明,流动相中不同种类的醇改性剂及其含量的不同对样品的保留时间和立体选择性有不同程度的影响,甲醇、乙醇等作改性剂用于拆分样品的效果较好;采用三元流动相体系正己烷-     

高效液相色谱手性固定相法直接拆分4种吲哚类衍生物

将纤维素-三(3,5-二甲基苯基氨基甲酸酯)(CDMPC)涂敷于自制的球形氨丙基硅胶上,制备成了纤维素-三(3,5-二甲基苯基氨基甲酸酯)手性固定相(CDMPC-CSP)。利用正相高效液相色谱,在该固定相上对新合成的4种吲哚类衍生物对映体进行了手性拆分。通过选择不同结构和浓度的醇类改性剂,优化了色谱分离条件,同时探讨了醇的结构和浓度对于对映体拆分和保留的影响。结果表明,适合Ⅱ~Ⅳ号样品拆分的醇类改性剂分别为正丁醇、乙醇和乙醇,而适合Ⅰ号样品的醇类改性剂为乙醇和正丙醇组成的混合体系。在优化的各流动相体系下,4种吲哚类衍生物的对映体都得到了很好的分离。在此基础上计算了它们的对映体过量值(e.e.值)。实验结果令人满意,表明高效液相色谱手性固定相法是拆分这类化合物的一种理想方法。     

流动相对百树菊酯高效液相色谱手性分离的影响

在一种由N－3,5二硝基苯甲酸苯基甘氨酸衍生而成的Pirkle1-A型手性固定相上分离百树菊酯的8个立体异构体,通过选用不同的醇作为流动相的强溶剂,研究二元体系中流动相组分对保留值和选择性的影响。结果表明：对同一种组分的流动相,增加流动相的强度会缩短溶质的保留时间,且对非对映体的选择性影响比较大,而对对映体的选择性影响却不大,作为强溶剂的醇的结构不同会对异构体的分高度及峰形产生影响,二级醇或三级醇作强溶剂时的分高度好于一级醇,小分子醇作强溶剂时的峰形好于较大分子醇。     

Separation of the enantiomers of 4-aryl-7,7-dimethyl- and 1,7,7-trimethyl-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-diones by chiral HPLC

Summary Analytical HPLC methods using derivatized cellulose chiral stationary phases have been developed for separation of the enantiomers of 25 racemic 4-aryl-7,7-dimethyl- or 1,77-trimethyl-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-diones, condensed derivatives of dihydropyrimidines. The enantiomers of the compounds were resolved by normal-phase chromatography on silica-based cellulose tris(3,5-dimethylphenylcarbamate) (Chiralcel OD) and amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD) columns with mobile phases consisting of mixtures ofn-hexane and an alcohol (2-propanol, ethanol, or methanol) in different proportions. The mobile phase and the chiral stationary phase were varied to achieve the best resolution. The effect of the concentration of alcohol in the mobile phase was studied. The resolution obtained on the two columns was complementary.     

Enantioseparation of Novel Chiral Tetrahedral Clusters on an Amylose Tris-(3,5-dimethylphenylcarbamate) Chiral Stationary Phase by Normal Phase HPLC

Introduction In recent years, chiral transition metal cluster has at-tracted a great deal of interests due to its potential ap-plication in asymmetric catalytic reaction.1-3 Producing catalysis for asymmetric induction using a rigid chiral framework would not only bring a basically conceptual breakthrough in the asymmetric catalysis, but also en-rich the methodology in the design of new chiral cata-lysts.4 So far, a lot of chiral clusters have been re-ported,5-9 but only a few of them have bee…     

Separation of the four pairs of enantiomers of vincamine alkaloids by enantioselective high-performance liquid chromatography

The four enantiomeric pairs of vincamine group alkaloids were separated by HPLC using Chiralpak AD as chiral stationary phase (CSP) and various n-hexane-2-propanol and n-hexane-ethanol mobile phases. (+)-cis-Vincamine, which is used in pharmaceutical preparations, is eluted much faster than its optical isomer, with separation factors of 2.4 and 3.5, respectively in these mobile phases. Other CSPs gave negative results. A chiral recognition mechanism is proposed and circular dichroism spectra of the individual enantiomers are presented.     

Comparison of Coated and Immobilized Chiral Stationary Phases Based on Amylose tris-[(S)-α-Methylbenzylcarbamate] for the HPLC Enantiomer Separation of α-Lipoic Acid and Its Reduced Form

The couple of chiral sulfur compounds α-lipoic acid (ALA)/α-dihydrolipoic acid (DHALA) has attracted considerable attention in recent years owing to its remarkable anti-inflammatory and antioxidant properties. It is well known that the chirality of the C6 plays a key role in determining the biological activity of ALA. The natural occurring (R)-ALA enantiomer is an essential cofactor for key oxidative metabolism enzyme complexes and, after oral administration of the racemic mixture, it shows higher plasma concentration than (S)-ALA. Differently, the in vivo enantioselective action difference between the enantiomers of DHALA has not yet been studied. This lacking is perhaps due to the unavailability of analytical methods capable of determining the enantiomeric composition of biological samples during pharmacokinetic and pharmacodynamic events. In the present work, the direct and baseline enantioresolution of both chiral acids by HPLC on two amylose-derived chiral stationary phases is presented. The proposed chiral enantioselective protocol, therefore, does not require pre- or on-column derivatization. The performance of the coated Chiralpak AS-H CSP and the new immobilized Chiralpak IH-3 CSP, which have the same chiral selector amylose tris-[(S)-α-methylbenzylcarbamate], were compared using conventional normal-phase mobile phases containing ethanol or 2-propanol as alcoholic solvents and a fixed percentage of trifluoroacetic acid. Nonconventional eluents containing dichloromethane, ethyl acetate, and 2-methyltetrahydrofuran as organic cosolvents were applied in the separation of the enantiomers of two carboxylic acids on the immobilized Chiralpak IH-3 CSP. The effect of the column temperature was carefully evaluated in order to improve enantioselectivity. Adequate amounts of enantiomers were isolated by an analytical-size Chiralpak IH-3 column and submitted to chiroptical measurements. The absolute configuration assignment of the isolated enantiomers was determined by a multidisciplinary procedure based on the comparison of the experimental and calculated chiroptical properties.