Applying magnetic substrates, magnetized perpendicular to the surface, we were able crystallize from racemic solution pure conglomerates of several molecules. The resolution is based on spin-dependent charge reorganization (SDCR) effect. By having two surfaces with opposite magnetization, it was possible simultaneously each surface a different enantiomer. method does not require any seeding or ...

Carvedilol is administered as a racemic mixture of the R(+)- and S(-)-enantiomers, although it was demonstrated that the two enantiomers exhibit different pharmacological effects and stereoselective pharmacokinetics. The aim of this study was the evaluation of several native and derivatized cyclodextrines as chiral selectors for the separation of carvedilol enantiomers. Stereoselective interact...

est, because the biologically effective chiral drug is either of enantiomers and the antipode is regarded as the impurity showing sometime high toxicity. Recently, the HPLC with chiral stationary phases (CSPs) has been extensively used to achieve the direct enantiomer separation. Crown ether, first introduced by Pedersen in 1967, was shown by Cram et al. to resolve enantiomers by the host-guest...

■ ■ Reliable and reproducible measurement of the enantiomeric and/or diastereomeric ratios. IN T RO DU C T IO N The development of analytical methods for the separation of chiral compounds is important in many areas of research, as it is well known that different enantiomers are selectively biologically active. Biochemical reactions can be diastereo or enantioselective. While one isomer may del...

In recent years there has been considerable interest in the synthesis and separation of enantiomers of organic compounds especially because of their importance in the biochemistry and pharmaceutical industry. High-performance liquid Chromatography is a very useful method for the direct separation of enantiomers. However, about 30−40 years ago, commercially available chiral stationary phases wer...

2-(2,3-anthracenedicarboximido)cyclohexane derivatives (AC) have been known as the evolutionary diastereomerizing reagents for enantiomer discrimination in HPLC with ODS. However, a substantial separation of diastereomers can be observed only at lower temperatures, such as -40 degrees C. Therefore, in this work, poly(octadecyl acrylate)-grafted silica, ODAn was applied as an alternative station...

The chromatographic resolution of pregabalin enantiomers has been often achieved by derivatization of the molecule, in order to reach enough sensitivity at low concentrations of the minor enantiomer present in the active principle. In the present article, the development and optimization of two liquid chromatographic methods are presented for the direct resolution of pregabalin enantiomers on a...

A simple and sensitive RP-HPLC method for the determination of omeprazole R-enantiomer (ROME) and omeprazole S-enantiomer (S-OME) in bulk drug samples and pharmaceutical formulations has been developed and validated. The separation of R-OME and S-OME was achieved on a chiral AGP column using UV detector at 301 nm. The mobile phase consisted of 0.025 mol L di sodium hydrogen phosphate/ acetonitr...

A novel enantioseparational monolithic stationary phase for binaphthol based on a molecular imprinting method was introduced and evaluated in capillary electrochromatography (CEC). The monolithic stationary was prepared by the in situ copolymerization of methacrylic acid and ethylene glycol dimethacrylate in a porogenic solvent (toluene or toluene-isooctane) in the presence of an imprinting mol...

The direct enantioseparation of a novel aminothiazolecarboxamide fungicide, ethaboxam, on polysaccharide-derived chiral stationary phases (CSPs) is described. Good resolution is achieved with several polysaccharide-derived CSPs. Chiralcel OD (OD-H) and Chiralpak AS are excellent for direct enantiomer separation of ethaboxam. The elution behavior and the effects of eluent composition on the reso...