Enantiomeric resolution of kielcorin derivatives by HPLC on polysaccharide stationary phases using multimodal elution

Abstract

Analytical HPLC methods using carbamate chiral stationary phases of polysaccharide derivatives were developed for the enantiomeric resolution of five racemic mixtures of xanthonolignoids: rac-trans-kielcorin C, rac-cis-kielcorin C, rac-trans-kielcorin D, rac-trans-isokielcorin D, and rac-trans-kielcorin E. The separations were evaluated with the stationary phases cellulose tris-3,5-dimethylphenylcarbamate, amylose tris-3,5-dimethylphenylcarbamate, amylose tris-(S)-1-phenylethylcarbamate, and amylose tris-3,5-dimethoxyphenylcarbamate under normal, reversed-phase, and polar organic elution conditions. Chiral recognition of those chiral stationary phases, the influence of mobile phases on the enantiomers separation, and the effects of structural features of the solutes on the chiral discrimination observed are discussed. The best performance was achieved on an amylose tris-3,5-dimethylphenylcarbamate phase. Polar organic conditions gave shorter retention factors and better resolutions and were a valuable alternative to the alcohol-hexane or reversed-phase conditions.

Multimilligram enantioresolution of sulfoxide proton pump inhibitors by liquid chromatography on polysaccharide-based chiral stationary phase

“…The use of these chiral phases has been previously demonstrated on many occasion [28][29][30][31][32][33][34], as in the direct separation of multimilligram quantities of gossypol enantiomers using tris-3,5-dimethylphenylcarbamate cellulose phase on the reversed mode of elution, with efficient recovery for the enantiomers (80%) [35]. Sousa et al [36] also showed the versatility of these polysaccharide phases, under polar organic conditions, in the separation of the xanthonolignoids enantiomers in multimilligram scale.…”

Enantiomeric Mixtures in Natural Product Chemistry: Separation and Absolute Configuration Assignment

“…To meet this end, chiral screening technologies have been pursued using either traditional columns (5 μm fully porous particles) [ 49 , 54 , 55 , 56 , 57 , 58 ] or multi-column parallel screening [ 59 ], as well as other advanced technologies for increasing high throughput and efficiency [ 60 , 61 ]. The ultraviolet (UV) detector is still the most used, but chiral detectors based on polarimetry or ECD has become a tendency for e.r.…”

“…They were first introduced back in 1984 [ 65 , 66 ] and since then, a large variety of derivatives of cellulose and amylose coated to silica have been successfully employed [ 67 ]. The polysaccharide-based coated phases are used under normal, reverse, or polar organic elution modes [ 55 , 68 ], however modifiers such as acetone, ethyl acetate, dichloromethane, dimethyl sulfoxide and methyl t -butyl ether cannot be used due to the solubility of the chiral selectors in these solvents [ 68 , 69 ]. To overcome these problems, despite reducing their chiral recognition ability, polysaccharide-based chiral selectors have been immobilized to silica gel as a gain in technology [ 48 , 56 , 67 ].…”

“…To avoid immiscibility problems with the eluents, one should go first to 100% EtOH. Methanol (MeOH) or acetonitrile (ACN) are the solvents of choice, or mixtures of them [ 55 , 84 ]. Reversed elution mode should also be explored.…”

Análise enantiosseletiva de fármacos: contribuições da cromatografia líquida de alta eficiência e eletroforese capilar

“…Um outro grupo, do Instituto de Química da Universidade Federal de São Carlos, atua no desenvolvimento de novas fases estacionárias quirais e modos de separação e, mais recentemente, em aplicações na análise de fármacos quirais em materiais biológicos. As publicações mais recentes desse grupo [130][131][132][133][134] também atestam sua importante contribuição na análise enantiosseletiva empregando HPLC.…”