1104-36-5Relevant articles and documents
Analytical- and preparative-scale isoelectric focusing separation of enantiomers
Glukhovskiy, Pavel,Vigh, Qyula
, p. 3814 - 3820 (1999)
Isoelectric focusing has been used to achieve the analytical- and preparative-scale separation of the enantiomers of amphoteric analytes. By considering the simultaneous multiple equilibria involved in the chiral recognition process, a model has been developed to describe the magnitude of the ΔpI value that develops between the enantiomers in the presence of a noncharged chiral resolving agent, such as a noncharged cyclodextrin. Theoretical analysis of the model indicates that three kinds of IEF enantiomer separations are possible: aniono-selective and cationo-selective, when only the identically charged forms of the enantiomers bind selectively to the resolving agent, and duo-selective, when the differently charged forms of the enantiomers bind selectively to the resolving agent. The model predicts that the ΔpI vs cyclodextrin concentration curves approach limiting ΔpI values which can be as large as 0.1, even when the binding constants of the enantiomers differ only by 10%. The parameters of the model can be readily determined by free solution capillary electrophoretic or pressure- mediated capillary electrophoretic experiments. The validity of the proposed model has been tested with hydroxypropyl β-cyclodextrin as resolving agent and dansyl phenylalanine as probe. Capillary IEF enantiomer separations have been achieved using both ampholytes and binary propionic acid-serine buffers (Bier's buffers). Preparative-scale IEF enantiomer separations with production rates as high as 1.3 mg/h have been achieved in an Octopus continuous free-flow electrophoretic system.
Enantiomeric Separation with Use of Stationary Phase Coated with Micellar Bile Salt for Microcolumn Liquid Chromatography
Hu, Wenzhi,Haraguchi, Hiroki
, p. 1967 - 1970 (1993)
A novel method for enantiomeric separation using an ODS stationary phase coated with bile salt micelles in high-performance liquid chromatography has been developed, where bile salt surfactants such as sodium cholate and sodium deoxycholate were used for micelle formation.The present method was applied to the separation of the enantiomers of 1,1'-binaphthyl-2,2'-diyl hydrogenphosphate (BNDHP) and N-dansylphenylalanine by using acetonitrile-water solution as the mobile phase.The dependence of the capacity factors and separation factors on the acetonitrile concentration in the mobile phase was examined for BNDHP enantiomers.These factors decreased with increasing acetonitrile concentration, which resulted in the change of separation characteristics of BNDHP enantiomers.Although BNDHP and N-dansylphenylalanine enantiomers were separated, similar enantiomers such as 2,2'-dihydroxy-1,1'-binaphthyl and other N-dansylamino acids were not separated in the present separation system.
Preparation and evaluation of a triazole-bridged bis(β-cyclodextrin)–bonded chiral stationary phase for HPLC
Shuang, Yazhou,Liao, Yuqin,Wang, Hui,Wang, Yuanxing,Li, Laisheng
, p. 168 - 184 (2019/11/25)
A triazole-bridged bis(β-cyclodextrin) was synthesized via a high-yield Click Chemistry reaction between 6-azido-β-cyclodextrin and 6-propynylamino-β-cyclodextrin, and then it was bonded onto ordered silica gel SBA-15 to obtain a novel triazole-bridged bis (β-cyclodextrin)–bonded chiral stationary phase (TBCDP). The structures of the bridged cyclodextrin and TBCDP were characterized by the infrared spectroscopy, mass spectrometry, elemental analysis, and thermogravimetric analysis. The chiral performance of TBCDP was evaluated by using chiral pesticides and drugs as probes including triazoles, flavanones, dansyl amino acids and β-blockers. Some effects of the composition in mobile phase and pH value on the enantioseparations were investigated in different modes. The nine triazoles, eight flavanones, and eight dansyl amino acids were successfully resolved on TBCDP under the reversed phase with the resolutions of hexaconazole, 2′-hydroxyflavanone, and dansyl-DL-tyrosine, which were 2.49, 5.40, and 3.25 within 30 minutes, respectively. The ten β-blockers were also separated under the polar organic mode with the resolution of arotinolol reached 1.71. Some related separation mechanisms were discussed preliminary. Compared with the native cyclodextrin stationary phase (CDSP), TBCDP has higher enantioselectivity to separate more analytes, which benefited from the synergistic inclusion ability of the two adjacent cavities and bridging linker of TBCDP, thereby enabling it a promising prospect in chiral drugs and food analysis.
A new chiral ligand exchange capillary electrophoresis system based on Zn(ii)-l-leucine complexes coordinating with β-cyclodextrin and its application in screening tyrosinase inhibitors
Su, Yuan,Mu, Xiaoyu,Qi, Li
, p. 55280 - 55285 (2015/02/05)
Tyrosinase plays a key role in melanin formation, and it is closely related to hyper pigmentation in animals and enzymatic browning in food. Thus, it is of great significance to screen inhibitors of tyrosinase. In this work, a new chiral ligand exchange-capillary electrophoresis (CLE-CE) system based on the coordination effect of Zn(ii)-l-leucine complexes and β-cyclodextrin (β-CD) was developed for screening the inhibitors of tyrosinase. The effects of the concentration of β-CD, buffer pH, the ratio of l-leucine to Zn(ii), and the complex concentration were investigated with Dns-d,l-tyrosine, Dns-d,l-valine and Dns-d,l-phenylalanine as the tested analytes. The optimum buffer conditions were composed of 100.0 mM boric acid, 5.0 mM ammonium acetate, 3.0 mM Zn(ii), 6.0 mM l-leucine and 4.0 mM β-CD at pH 8.2. It has been found that six pairs of Dns-d,l-AAs could be baseline-separated and five pairs of Dns-d,l-AAs were partly enantioseparated. Then the quantitative analysis of l-tyrosine was conducted and good linearity (r2 = 0.992) was obtained with a concentration ranging from 12.95 μM to 413.3 μM. A kinetics study of tyrosinase was realized, and the Km and Vmax were 636 μM and 312 μmol min-1 mg-1. Moreover, the proposed method was applied in screening the inhibitors of tyrosinase with four kinds of chalcones as the model inhibitors. The results demonstrated that the developed CLE-CE system was favorable for screening enzyme inhibitors, and showed great potential in related drugs discovery and clinical analysis in the future.
Clicked AC regioisomer cationic cyclodextrins for enantioseparation
Zhou, Jie,Liu, Yun,Lu, Yingying,Tang, Jian,Tang, Weihua
, p. 54512 - 54516 (2015/02/05)
Novel AC regioisomer cationic cyclodextrins have been successfully prepared with azide/alkyne click chemistry. The clicked CDs were explored for the enantioseparation of acidic racemates in capillary electrophoresis.
