N-(4-甲基苯甲酰基)苯甘氨酸手性固定相的合成及对多种手性化合物的拆分

合成了N-(4-甲基苯甲酰基)苯甘氨酸手性固定相,采用湿法装柱(250mm×2.0mm i.d.),在V(正己烷)∶V(异丙醇)=90∶10的高效液相色谱正相色谱条件下,测得理论塔板数为40800m-1,该柱成功地分离了醇类、胺类、氨基酸的对映异构体以及一些手性药物。结果表明:所拆分的16种手性化合物,有12种手性化合物得到基线分离,最好的分离度Rs=4.66,表现出良好的手性分离性能。     

α-酸糖蛋白手性柱对56种手性化合物的拆分

采用α-酸糖蛋白手性固定相(Chiral-AGP),固定流动相pH、流速,化合物样品浓度,考察酸性、碱性、中性手性化合物和21个氨基酸在α-酸糖蛋白手性柱上的拆分情况.应用高效液相色谱法,α-酸糖蛋白手性柱对上述手性样品拆分,一共有8个中性化合物、3个碱性化合物、6个酸性化合物和5个氨基酸得到手性对映分离.探讨了α-酸糖蛋白手性柱对酸性、中性、碱性样品的拆分能力并进行对比,结果证明α-酸糖蛋白手性柱拆分中性化合物和酸性化合物效果最好,拆分碱性化合物和氨基酸效果不好,为α-酸糖蛋白手性柱适合于拆分哪一类型的手性化合物提供参考.     

乙酸丁酸纤维素手性固定相的制备及对手性化合物的拆分

将乙酸丁酸纤维素涂敷在硅烷化的硅胶上制备了涂渍型高效液相色谱固定相,在40MPa压力下将所得固定相装入色谱柱.在正相的条件下,对20种手性化合物进行拆分,包括醇类,胺类,氨基酸类手性化合物以及外消旋体药物,有13种手性化合物得到了较好的分离.     

替考拉宁高效液相色谱手性固定相的制备研究

替考拉宁属于大环抗生素,具有半篮状结构和多个手性中心,是常见的手性识别材料,广泛应用于对映体的色谱手性分离分析.本文研究了以替考拉宁为手性识别剂,采用键合的方法制备得到9种高效液相色谱手性固定相,用于苯甘氨酸和对羟基苯甘氨酸的拆分研究,并且考察了重现性和稳定性及进样量对拆分结果的影响.实验结果表明,9种手性固定相均具有拆分苯甘氨酸及对羟基苯甘氨酸的能力.     

新型L-羟脯氨酸聚合物键合手性固定相的制备及对手性化合物的拆分

以单分散亲水性交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为载体,制备新型L-羟脯氨酸聚合物键合高效手性配体交换固定相。该固定相在配体交换分离模式下,以0.2mol/LNaAc和0.1mmol/LCu(Ac)2水溶液(pH5.2)为流动相,柱温为30℃～50℃,对衍生和非衍生的D,L-氨基酸和α-羟基酸等9种手性化合物进行了高效液相色谱拆分。详细考察了流动相pH值、温度、流速和进样量对手性分离的影响,选择了合适的色谱分离条件。结果表明,所拆分的9种手性化合物,有5种手性化合物能得到基线分离,最好的分离因子α=2.32。     

海藻糖、龙胆二糖、蜜二糖键合硅胶手性固定相的制备和性能

合成了海藻糖、龙胆二糖、蜜二糖三种二糖类键合硅胶高效液相色谱手性固定相,采用湿法装柱制备了色谱柱．在高效液相色谱正相条件下,该类固定相对醇类、胺类、氨基酸类对映异构体以及一些手性药物表现出了一定的拆分效果．特别是海藻糖固定相在所拆分的9种手性化合物中,有6种手性化合物能得到较好的分离,表现出较好的手性分离性能．并且手性固定相之间具有较好的互补性．     

醋酸纤维素液相色谱固定相的制备与手性拆分

在均相条件下合成了醋酸纤维素,将其涂渍在修饰硅胶表面,制备了涂渍型高效液相色谱固定相.在40MPa压力下将所得固定相装入色谱柱.在高效液相色谱正相色谱条件下,对包括醇类、羧酸类、胺类、氨基酸类及药物类的16种新型手性化合物进行了拆分试验,结果有6种手性化合物得到了分离,效果良好.     

共价有机框架材料TpBD-（NH2）2-D-（-）-α-苯甘氨酸用作高效液相色谱手性固定相的研究

该文采用溶剂热法合成了一种共价有机框架材料（COFs）TpBD-（NO2）2,将TpBD-（NO2）2还原为TpBD-（NH2）2后用D-（－）-α-苯甘氨酸对其进行手性修饰得到手性COFs材料TpBD-（NH2）2-D-（－）-α-苯甘氨酸。对TpBD-（NO2）2、TpBD-（NH2）2及TpBD-（NH2）2-D-（－）-α-苯甘氨酸3种COFs材料进行表征,并采用“网包法”制备了TpBD-（NH2）2-D-（－）-α-苯甘氨酸手性固定相。为考察该固定相的分离性能,将其用于制备高效液相色谱（HPLC）手性柱,并使用正己烷－异丙醇（体积比9∶1）和甲醇－水（体积比9∶1）为流动相,实现了13种手性化合物和5种苯系位置异构体的分离。且该色谱柱具有较好的重现性。实验表明TpBD-（NH2）2-D-（－）-α-苯甘氨酸用作HPLC固定相用于手性物质和苯系位置异构体分离具有良好的研究意义。     

高效液相色谱法对二氢吡喃酮衍生物的手性拆分

介绍了利用手性chiralcel OD和chiralpak AD柱在高效液相色谱上对一系列二氢吡喃酮衍生物进行手性拆分，获得了良好的分离结果，考察了部分对映体在这两种柱上的色谱行为。实验表明手性化合物与手性柱之间存在着化学作用与空间作用，两者的共同作用决定了分离结果。     

高效液相色谱使用两种类型的纤维素-三(对甲基苯甲酸酯)固定相手性拆分非洛地平的比较

以高效液相色谱手性固定相法对非洛地平(FEL)进行手性拆分。分别采用两种类型的纤维素-三(对甲基苯甲酸酯)手性柱Chiralcel OJ-R和Chiralcel OJ-H进行比较实验,以正己烷-异丙醇(90:10, v/v)为流动相,考察了流动相、柱温对保留及手性拆分的影响。实验显示,两柱拆分FEL的van’t Hoff图均发生了转折,在高温区域为焓驱动,在低温区域为熵驱动。两柱在温度升高时拆分FEL的分离度均提高,其中OJ-H的分离度优于OJ-R。两种手性柱对FEL具有相似的拆分机理。     

Effects of chromatography conditions on intact protein separations for top-down proteomics

A chiral stationary phase (CSP) has been prepared by chemically bonding a chiral pseudo-18-crown-6 type host having a 1-phenyl-1,2-cyclohexanediol unit to 3-aminopropyl silica gel. The chiral column was prepared by the slurry-packing method in a stainless steel HPLC column. Normal mobile phases can be used with this CSP in contrast to conventional dynamic coating type CSPs. Enantiomers of 20 out of 30 amino compounds, including 20 amino acids, 2 amino acid methyl esters, 6 amino alcohols, and 2 lipophilic amines, were efficiently separated on columns with this CSP. It is noteworthy that 15 amino compounds out of 30 were separated with better separation factors and shorter retention times compared to the corresponding CSP having pseudo-18-crown-6 with 1-phenyl-1,2-ethanediol as a chiral unit. In view of the correlation between the enantiomer selectivities observed in chromatography and those obtained in gas phase FABMS-EL methods and solution phase titrations, chiral recognition in the host-guest interaction likely contributes to enantiomer separation.     

Preparation and evaluation of a chiral stationary phase covalently bound with a chiral pseudo-18-crown-6 ether having a phenolic hydroxy group for enantiomer separation of amino compounds

In order to develop a chiral stationary phase (CSP), which has even higher separation ability than the corresponding commercially available crown ether based CSP (OA-8000 having a pseudo-18-crown-6 ether with an OMe group as a selector), chemically bonded type CSP having a phenolic OH group on a crown ring was developed. Normal mobile phases with or without acid additive can be used with this OH type CSP in contrast to the conventional OMe type CSP which has a neutral chiral selector. Enantiomers of 25 out of 27 amino compounds, including 20 amino acids, 5 amino alcohols, and 2 lipophilic amines, were efficiently separated on a column with this CSP. Nine amino compounds out of 27 were separated with better separation factors than the corresponding OMe type CSP. It is noteworthy that the chromatography on this CSP exhibited excellent enantiomer-separations for amines and amino alcohols when triethyl amine was used as an additive in the mobile phase. Comparison of enantiomer separation ability on this OH type of CSP and on the OMe type of CSP and correlation between the enantioselectivity in chiral chromatography and that of the corresponding model compounds in solution imply that the chiral separation arose from chiral recognition in host guest interactions.     

Preparation and application of a new ligand exchange chiral stationary phase for the liquid chromatographic resolution of alpha-amino acid enantiomers

A new liquid chromatographic ligand exchange CSP has been prepared by covalently bonding (S)-N,N-carboxymethyl undecyl leucinol monosodium salt onto silica gel and employed in resolving various alpha-amino acids. The new CSP was quite good in resolving various a-amino acids and the resolution results were dependent on the type and content of organic modifier in the mobile phase. From these results, a chiral recognition model using a lipophilic interaction between the tethering alkyl group of the CSP and the substituent at the chiral center of alpha-amino acids was proposed. The liquid chromatographic resolution of alpha-amino acids on the new CSP was also found to be dependent on the Cu(II) concentration in the mobile phase and the column temperature.     

A chiral stationary phase with special hydrophobic framework for ligand-exchange chromatography

A novel chiral stationary phase (CSP1) for ligand-exchange chromatography (CLEC) was prepared by firstly using dimethyl- chlorosilane as an endcapping reagent for decreasing residual silanol group on the surface of silica gel,and then introducing L-Pro as a chiral selector and hydrophobic octyl group to the silica gel surface simultaneously.The enantioseparations of 14 DL-amino acids on CSP1 were achieved with the enantioselectivityαranging from 1.09 to 2.44 and the resolution Rs being between 0.8 and 6.3.The chromatographic performances of CSP1 with the bonded phase (CSP2) prepared using reference method were compared.The results showed that the column efficiency and resolution Rs of chiral stationary phase could be improved by using the above modifying method.     

Preparation and application of a new modified liquid chromatographic chiral stationary phase based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid

As an effort to improve the chiral recognition efficiency of a previously reported chiral stationary phase (CSP) based on (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic acid, a new CSP was prepared by simply replacing the amide N-H hydrogens of the tethering groups of the old CSP with methyl groups. The new CSP was superior to the old one in the resolution of racemic primary amines. However, in the resolution of alpha-amino acids and amino alcohols, the new and the old CSPs were complementary with each other. The elution orders on the new CSP were sometimes opposite to those on the old one. Consequently, the chiral recognition mechanism on the new CSP was presumed to be different from that on the old one. The chiral recognition behavior of the new CSP were investigated with four selected analytes and found to be dependent to some extent on the content of organic and acidic modifiers in aqueous mobile phase and the column temperature.     

Preparation and application of a chiral stationary phase based on (+)-(1 8-crown-6)-2,3,11,12-tetracarboxylic acid without extra free aminopropyl groups on silica surface

A crown ether-based chiral stationary phase (CSP) without extra aminopropyl groups on the surface of silica gel was newly prepared by bonding (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid to silica gel. The new CSP was applied to the resolution of various racemic alpha-amino acids, amines, and amino alcohols. The chiral recognition efficiency of the new CSP was generally superior to that of the original CSP containing unreacted residual aminopropyl groups on the surface of silica gel in terms of the separation (alpha) and the resolution factors (Rs). The retention behaviors of analytes on the new CSP with the variation of the content of organic and acidic modifiers in aqueous mobile phase were consistent with those on the original CSP in the resolution of alpha-amino acids, but somewhat different in the resolution of racemic amines and amino alcohols from those on the original CSP and the difference was rationalized by the lipophilicity difference of the two CSPs. The effect of the column temperature on the chromatographic resolution behaviors on the new CSP was consistent with that on the original CSP.     

Preparation of a new doubly tethered chiral stationary phase based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid and its application

A new doubly tethered chiral stationary phase (CSP) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was prepared by attaching the second tethering group to silica gel through a carbon atom of the first tethering group of the corresponding singly tethered CSP, which was previously developed in our laboratory. The new doubly tethered CSP was applied successfully to the resolution of various racemic alpha-amino acids, amines and amino alcohols containing a primary amino group. In most cases, the chiral recognition efficiency of the new doubly tethered CSP was superior to that of the corresponding singly tethered one in the resolution of alpha-amino acids, amines and amino alcohols. In the resolution of some racemic primary amino compounds, the new doubly tethered and the corresponding singly tethered CSPs were complementary with each other. The chiral resolution behaviors on the new doubly tethered CSP were examined with the variation of the type and content of organic and acidic modifiers in aqueous mobile phase and the column temperature. The chiral resolution behaviors on the new doubly tethered CSP were generally quite similar to those on the corresponding singly tethered CSP. The stability of the new doubly tethered CSP was greater than that of the corresponding singly tethered CSP.     

Quinine Derivative Bonded the Hybrid Mesoporous Silicas Chiral Stationary Phase: Preparation and Application in Liquid Chromatography

A novel chiral stationary phase (QN‐APEPMOs) was synthesized by immobilizing quinine derivative (QN) onto spherical ammoniapropyl‐functionalized ethane‐bridged periodic mesoporous organosilicas (APEPMOs). The mesoporous material was prepared by a one‐step co‐condensation of 1,2‐bis (triethoxysilyl) ethane (BTSE) and 3‐ammoniapropyl triethoxysilane (KH‐550) using cetyltrimethyl‐ammoniumchlorine (C₁₈TACl) as a template with the aid of ethanol (co‐solvent) in basic medium. And O‐9‐(tert‐butyl carbamoyl) quinine derivative was immobilized on APEPMOs particles through the vinylic double bond. All of the products were characterized. The results showed that APEPMOs were perfect substrates for chiral stationary phase (CSP) and quinine moieties have been successfully immobilized onto the silica gel. To evaluate the chiral discrimination ability of the synthesized CSP, some analytes have been investigated on QN‐APEPMOs in high performance liquid chromatography (RP‐HPLC) in reversed phase. Three acidic compounds were baseline separated. The results demonstrated that QN‐APEPMOs had high selectivity for acidic compounds such as: carboxylic and sulfonic acids. And the reproducibility of the chiral column was good, while the stability was not very good.     

Chromatography of B prostaglandins on beta-cyclodextrin silica: application to analysis of major E prostaglandins in human seminal fluid

A new chiral stationary phase (CSP) was developed for the direct optical resolution of enantiomeric amino acid derivatives. The CSP was readily prepared by a three-step reaction carried out in a pre-packed aminopropylsilyl silica gel column. In the first step, a solution of disuccinimido carbonate (DSC) was delivered through the pre-packed column to give a succinimido carbamyl aminopropylsilyl-bonded, activated-carbamate type silica gel (ACsil) column. Through the column was then delivered a solution of pentaethylenehexamine to afford a polyamine-bonded column. Finally, a solution of optically active succinimido (S)- or (R)-naphthylethyl carbamate was delivered through the polyamine column, to give a naphthylethylurea multiple-bonded CSP. p-Bromophenylcarbamyl derivatives of enantiomeric protein amino acids were resolved on these CSPs by elution with an aqueous mobile phase. Simultaneous analysis of these amino acid enantiomers by means of gradient elution was also accomplished.     

Preparation of a new chiral stationary phase for HPLC based on the (R)- 1-phenyl-2-(4-methylphenyl)ethylamine amide derivative of (S)-valine and 2-chloro-3,5-dinitrobenzoic acid: enantioseparation of amino acid derivatives and pyrethroid insecticides

A novel chiral stationary phase (CSP) for HPLC was prepared by bonding (R)-1-phenyl-2-(4-methylphenyl)ethylamine amide derivative of (S)-valine to aminopropyl silica gel through a 2-amino-3,5-dinitro-1-carboxamido-benzene unit. The CSP was used for the separation of some amino acid derivatives and pyrethroid insecticides by chiral HPLC. Satisfactory baseline separation required optimization of the variables of mobile phase composition. Use of dichloromethane as modifier in the mobile phase gave baseline separations of amino acid derivatives. The two enantiomers of fenpropathrin and four stereoisomers of fenvalerate were baseline separated using hexane-dichloromethane-ethanol as mobile phase. The results show that the enantioselectivity of the new CSP is better than Pirkle type 1-A column for these compounds. Only partial separations were observed for the stereoisomers of cypermethrin and cyfluthrin, which gave even and eight peaks, respectively.