Application of Sulfated Cyclodextrins to Chiral Separations by Capillary Zone Electrophoresis

Stalcup, Apryll M.; Gahm, Kyung H.

doi:10.1021/ac950764a

Cited by 247 publications

(141 citation statements)

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“…However, during the last decades the most important analytical applications of cyclodextrins and micellar media were focused on separation techniques, mostly HPLC or capillary zone electrophoresis (CZE) and their variants. In particular, the progress in chiral separation have been boosted by the use of cyclodextrins [85,119,120]. …”

Section: Analytical Applications Advantages Resulting From the Use Ofmentioning

confidence: 99%

Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

Lerner¹,

Martín²

2000

Analusis

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Introduction Molecular luminescence of analytes in organized media or in supramolecular complexes of cyclodextrinsThe photophysical and photochemical behaviour of molecules complexed to cyclodextrins (CD) is generally different from their behaviour in solution. The first observations in the field were qualitative and were related to the increased stabilisation of labile molecules, mostly drugs, against photodegradation when complexed to natural cyclodextrins [1]. Complexation by CD's was then the preferred subject for those involved in supramolecular chemistry and drug vectorisation techniques [2] as well as in separation techniques [3][4][5]. Stabilization of a molecule against photochemical degradation is still very important in the field of pharmaceutical sciences. A recent example is the stabilisation of promazine as an inclusion complex with β-cyclodextrin [6]. Other photochemists were attracted quite early to this field of research and initiated studies, which were mostly photophysical in nature [7,8]. The key observation was that the formation of supramolecular complexes of analytes with cyclodextrins (CDs) resulted in an increase of their fluorescence quantum yield or even in the appearance of room temperature phosphorescence (RTP) [9][10][11][12]. This enhancement has been used to increase the sensitivity and the selectivity in both luminescence and chromatographic techniques [13-15].We will not say more about RTP with CDs as the subject will be developed in another contribution in the same issue of this Journal. However RTP is also observed in the solubilization of analytes in micellar colloïdal solutions and this field will be reviewed hereunder.These properties have been used to develop analytical techniques, which combine the selectivity of complexation with an enhanced emission [16][17][18][19]. In this way an improvement in the detection limits is obtained in many separation techniques such as HPLC, capillary electrophoresis (CE) or planar chromatography. Furthermore these molecular interactions allow to reveal or to stabilize new molecular forms or to turn species which are normally non-emitting into luminescent ones. All these aspects are reviewed hereunder after a short summary on the nature of the intermolecular interactions, which lie at the heart of these effects. Nature of the interactions between an analyte and a CD or a micelleWithout going into a thorough analysis of the origin of the interactions which exist between molecules in dense media which concern us here, it seems useful to recall the most important factors which should be taken into account when any type of luminescence, fluorescence or phosphorescence is involved.

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Section: Analytical Applications Advantages Resulting From the Use Ofmentioning

confidence: 99%

Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

Lerner¹,

Martín²

2000

Analusis

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“…Entre os derivados carregados de CDs disponíveis comercialmente, destacam-se a β-CD carboxilada, a β-CD sulfobutiléter e a β-CD sulfatada. Essas CDs estão sendo cada vez mais citadas na literatura, em um grande número de separações quirais para compostos de diferentes classes 81,[84][85][86][87][88][89][90][91][92][93][94][95] . A separação de enantiômeros empregando os derivados de CDs depende não apenas do tipo de CD e de sua concentração, mas também de outras características como grau de substituição e posição em que os substituintes se encontram.…”

Section: Separação De Enantiômeros Por Ceunclassified

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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“…Among functionalized CDs, sulfated CDs are recognized as being the best effective selectors, especially when they were used in CE as chiral additives. [19][20][21][22] Theoretically, it is likely to be excellent if the sulfated CDs are used in HPLC or CEC for enantiomeric separation. Surprisingly, very few studies related to sulfated CDs used in HPLC and CEC have been reported.…”

Section: Introductionmentioning

confidence: 99%

Enantiomeric Separation by Capillary Electrochromatography on a Sulfated Poly β-Cyclodextrin Modified Silica-based Monolith

2010

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Application of Sulfated Cyclodextrins to Chiral Separations by Capillary Zone Electrophoresis

Cited by 247 publications

References 32 publications

Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

Luminescence in organized media and supramolecular interactions:physicochemical aspects and applications

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

Enantiomeric Separation by Capillary Electrochromatography on a Sulfated Poly β-Cyclodextrin Modified Silica-based Monolith

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