Resolution of enantiomers by HPLC on cellulose derivatives

Ichida, Akito; Shibata, Tsugumichi; Okamoto, Ichiro; Yuki, Yoichi; Namikoshi, Hajime; Toga, Yuzo

doi:10.1007/bf02687754

Cited by 198 publications

(81 citation statements)

References 9 publications

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“…Several compounds were resolved on CTA-I [102,103]. Okamoto's group [104,105] prepared cellulose triacetate in a different way and coated macroporous aminopropylsilanized silica gel with the biopolymer. It was observed that the enantioselectivity on this phase, called CTA-II, was completely different from that of CTA-I.…”

Section: Direct Methodsmentioning

confidence: 99%

“…It was observed that the enantioselectivity on this phase, called CTA-II, was completely different from that of CTA-I. Similarly, cellulose tribenzoate and other cellulose ester phases were prepared [105,106]. Contrary to the inclusion mechanism proposed for CTA-I, the main interactions were assumed to be hydrogen bondings and dipole-dipole interactions on this type of phases [107].…”

Section: Direct Methodsmentioning

confidence: 99%

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Chiral separation by chromatographic and electromigration techniques. A Review

Gübitz

Schmid

2001

Biopharm & Drug Disp

226

135

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This review gives a survey of different chiral separation principles and their use in high-performance liquid chromatography (HPLC), gas chromatography (GC), supercritical fluid chromatography (SFC), thin-layer chromatography (TLC), capillary electrophoresis (CE) and capillary electrochromatography (CEC) highlighting new developments and innovative techniques. The mechanisms of the different separation principles are briefly discussed and some selected applications are shown.

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Section: Direct Methodsmentioning

confidence: 99%

Section: Direct Methodsmentioning

confidence: 99%

Chiral separation by chromatographic and electromigration techniques. A Review

Gübitz

Schmid

2001

Biopharm & Drug Disp

226

135

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“…O primeiro derivado de polissacarídeo largamente usado, desenvolvido por Hesse e Hagel 31 , foi o triacetato de celulose (CTA-I), preparado por acetilação da celulose microcristalina em benzeno, que mostrou altas habilidade de reconhecimento quiral e capacidade. Outro tipo de fase estacionária com habilidade de reconhecimento quiral completamente diferente foi desenvolvido pelo grupo de Okamoto, através do recobrimento de partículas de sílica com a fase CTA-I [32][33][34] . A análise dessa fase indicou que a microcristalinidade não é essencial para o reconhecimento quiral 35 .…”

Section: Fases Estacionárias Quirais Baseadas Em Derivados De Polissaunclassified

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

Bonato¹,

Jabor²,

Gaitani³

2005

Quím. Nova

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Recebido em 2/7/04; aceito em 6/10/04; publicado na web em 17/2/05 ENANTIOSELECTIVE ANALYSIS OF DRUGS: CONTRIBUTIONS OF HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND CAPILLARY ELECTROPHORESIS. The demand for analytical methods suitable for accurate and reproducible determination of drug enantiomers has increased significantly in the last years. High-performance liquid chromatography (HPLC) using chiral stationary phases and capillary electrophoresis (CE) are the most important techniques used for this purpose. In this paper, the fundamental aspects of chiral separations using both techniques are presented. Some important aspects for the development of enantioselective methods, particularly for the analysis of drugs and metabolites in biological samples, are also discussed.Keywords: chiral drugs; high-performance liquid chromatography; capillary electrophoresis. INTRODUÇÃOPor razões econômicas e dificuldades de ordem prática nos processos de produção, a maioria dos fármacos quirais obtidos por vias sintéticas é comercializada como racemato, ou seja, mistura contendo quantidades iguais dos dois enantiômeros 1 . No entanto, existem inúmeros exemplos de fármacos que apresentam atividades farmacológicas estereosseletivas (propriedades farmacodinâmicas), conseqüência de interações com receptores biológi-cos, que são altamente específicas 2 . Um exemplo clássico que não pode ser esquecido é o da talidomida. Somente depois das investigações da contribuição das propriedades estereosseletivas desse fármaco, é que foi possível estabelecer que as propriedades teratogênicas da talidomida, que causaram deformidades físicas em recém nascidos cujas mães fizeram uso desse fármaco durante a gravidez, estavam relacionadas com o enantiômero (-)-(S)-3 . Infelizmente, em estudos posteriores foi constatada a inversão de configuração não apenas in vitro mas também in vivo da talidomida 4,5 , evidenciando que se o enantiômero (+)-(R)-puro tivesse sido administrado, teria sido parcialmente convertido no isômero responsável pelo efeito teratogênico. Exemplos menos drásticos que esse são bastante comuns, nos quais as diferenças existentes entre os dois enantiômeros podem ser qualitativas ou quantitativas, sendo que, nesse último caso, o enantiômero mais ativo é chamado de eutômero enquanto que ao outro dá-se o nome de distômero 6 . Estudos têm mostrado que β-bloqueadores, propranolol é um exemplo, se ligam estereosseletivamente a receptores β-adrenérgicos e que os enantiômeros (-)-são os principais responsáveis pela atividade β-bloqueadora dessa classe de fármacos 7 . Adicionalmente, quando um fármaco quiral é administrado como racemato, os dois enantiômeros podem apresentar os processos de absorção, distribuição, metabolização e excreção (disposição cinética) de forma estereosseletiva [8][9][10][11] . Desses processos, a estereosseletividade é mais significativa no metabolismo, devido ao envolvimento do sistema enzimático. Dentre os inúmeros exemplos, pode-se destacar o verapamil; o enantiômero ativo (-)-(S) é preferencialmente metabolizado ...

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“…46 From this study, I thought that polysaccharides, especially cellulose and amylose, which are highly stereoregular and commercially available and are easily modified, would be suitable polymers for preparing practically useful CSPs for HPLC. After some experiments on cellulose esters at Daicel 47 and in my group, 48 in 1984, I attempted to prepare cellulose trisphenylcarbamate (CTPC) as the CSP. When we examined the CTPC-coated silica gel, we immediately noticed its high chiral-resolving power, 49 and then we began to study the effect of substituents on HIGHLIGHTthe phenyl group.…”

Section: Development Of Chiral Stationary Phases (Csps) For High-perfmentioning

confidence: 99%

(−)‐Sparteine: The compound that most significantly influenced my research

Okamoto

2004

J. Polym. Sci. A Polym. Chem.

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A chiral diamine alkaloid, (−)‐sparteine (Sp), has been found to be very effective as a ligand for Grignard reagents when used for the enantiomer‐selective polymerization of racemic RS‐1‐phenylethyl methacrylate. The enantiomeric excess of the initially polymerized monomer is 93%, and at about a 60% conversion, nearly optically pure R‐monomer is recovered. This enantiomer selectivity is today the highest in polymer chemistry. Triphenylmethyl methacrylate (TrMA) is a unique monomer that gives a highly isotactic polymer even during radical polymerization. When TrMA is polymerized with the Sp complex with n‐butyllithium in toluene at −78 °C, an optically active, isotactic polymer [poly(triphenylmethyl methacrylate) (PTrMA)] with a one‐handed helical conformation is obtained. The helical structure is maintained even at room temperature in solution. Analogous helical polymethacrylates that show various conformational changes have also been found. One‐handed helical PTrMA exhibits high chiral recognition to a variety of racemates as a chiral stationary phase (CSP) for high‐performance liquid chromatography. This finding has led to the development of very powerful CSPs based on polysaccharides, such as cellulose and amylose. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4480–4491, 2004

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Resolution of enantiomers by HPLC on cellulose derivatives

Cited by 198 publications

References 9 publications

Chiral separation by chromatographic and electromigration techniques. A Review

Chiral separation by chromatographic and electromigration techniques. A Review

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

(−)‐Sparteine: The compound that most significantly influenced my research

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