A Thermodynamic Study of the Temperature-Dependent Elution Order of Cyclic α-Amino Acid Enantiomers on a Copper(II)−<scp>d</scp>-Penicillamine Chiral Stationary Phase

Schlauch, Michael; Frahm, A. W.

doi:10.1021/ac0009999

Cited by 44 publications

(19 citation statements)

References 24 publications

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“…[26][27][28] Besides complex formation, additional interactions (e.g., hydrogen bonding, hydrophobic interactions) may contribute to the separation of the enantiomers, and steric reasons may also have crucial effect on the elution order. 6 It can be assumed that the pencillamine (fixed on the silicagel) interacts with copper(II) through the amino and carboxyl groups, 11 while the stereoisomers of the analyte occupy the remaining two positions (the coordination of water molecules may be involved in the case of octahedral complex formations).…”

Section: Resultsmentioning

confidence: 99%

High‐performance liquid chromatographic enantioseparation of unusual secondary amino acids on a D‐penicillamine‐based chiral ligand exchange column

Ilisz¹,

Tourwé²,

Armstrong³

et al. 2006

Chirality

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The application of a chiral ligand-exchange column (CLEC) for the direct high-performance liquid chromatographic enantioseparation of unusual secondary amino acids using D-penicillamine-Cu(II) complex as chiral selector is reported. The amino acids investigated were pyrrolidine-2-carboxylic acid, piperidine-2-carboxylic acid, piperazine-2-carboxylic acid, morpholine-3-carboxylic acid, and thiomorpholine-3-carboxylic acid analogs. Chromatographic results are given as the retention, separation, and resolution factors. The chromatographic conditions were varied to achieve optimal separation. The elution sequence of the enantiomers was determined and in most cases the S isomer eluted before R.

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Section: Resultsmentioning

confidence: 99%

High‐performance liquid chromatographic enantioseparation of unusual secondary amino acids on a D‐penicillamine‐based chiral ligand exchange column

Ilisz¹,

Tourwé²,

Armstrong³

et al. 2006

Chirality

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“…[37][38][39][40][41][42][43][44] Silva Jr. et al 37 reportaram o estudo termodinâmico envolvido na separação dos fármacos quirias rolipram, omeprazol e bupivacaína, utilizando uma coluna quiral semipreparativa Kromasil CHI-TBB.…”

Section: Experimentosunclassified

Separação cromatográfica quiral de anestésicos a partir de soluções diluídas e concentradas em escala preparativa

Silva¹,

Barreto²,

Santana³

2009

Quím. Nova

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Recebido em 3/3/08; aceito em 31/10/08; publicado na web em 2/2/09 CHIRAL CHROMATOGRAPHIC SEPARATION OF ANESTHETICS FROM DILUTE AND CONCENTRATED SOLUTIONS UNDER PREPARATIVE SCALE. In this work the separation of the chiral anesthetic compounds ketamine and bupivacaine was development using two chiral stationary phases (CSP). Ketamine enantiomers were well separate in the polysaccharide-based CSP (microcrystalline cellulose triacetate -MCTA) while bupivacaine in the tartardiamide-based CSP (Kromasil CHI-TBB). In both cases, the effect of temperature was investigated under analytical conditions. An improvement in the separation performance with temperature was observed. Thermodynamic parameters were evaluated by the van't Hoff plot. We concluded that enthalpic effects controlled the retention in these chiral columns. The enantiomers of ketamine and bupivacaine were separated under overloaded conditions with a good performance.Keywords: enantiomer separation; chiral stationary phases; liquid chromatography. introduçãoA separação de isômeros ópticos é importante para o desenvolvimento e a manufatura de numerosos terapêuticos. No intuito de conferir a composição dos fármacos, bem como estudos farmacocinéticos e clínicos mais elaborados, a habilidade para obter quantidades destes isômeros ópticos separadamente tornou-se de essencial importância. Muitos fármacos são administrados como uma mistura racêmica. No organismo, a maioria dos enantiômeros se comporta como duas entidades diferentes; processos controlados pela estereosseletividade, tais como absorção do fármaco, distribuição, metabolismo e eliminação, podem diferir substancialmente entre os enantiômeros. Como exemplo clássico da importância da quiralidade na indústria farmacêutica, podemos citar o caso da talidomida. Na década de 60, a talidomida foi comercializada na sua forma racêmica como um sedativo, para aliviar náuseas matinais em gestantes. Esse medicamento foi retirado do mercado após ter sido constatado apresentar sérios efeitos colaterais. Estudos posteriores confirmaram que apenas o R-enantiômero possui a atividade sedativa desejada, enquanto que o S-enantiômero apresenta propriedades teratogênicas, levando a deformações congênitas em fetos, quando administrado em gestantes.2 Durante a última década, houve grande interesse quanto à obtenção de enantiômeros em sua forma opticamente pura, devido a razões científicas e econômicas, sendo a indústria farmacêutica a principal interessada. 3 Entre 1992 e 2000, o mercado mundial para compostos químicos opticamente puros aumentou de US$ 30 bilhões para uma estimativa de US$ 100 bilhões, com quase duas dúzias de companhias que se especializaram em separações quirais. 5 Rekoske 4 relatou que entre as 500 drogas mais vendidas no mundo, 269 já estavam sendo comercializadas como um único enantiômero.A cromatografia é um processo de separação baseado no equilíbrio de distribuição dos componentes entre duas diferentes fases: a estacionária e a móvel. O transporte seletivo é o resultado da tendência do sistema para evol...

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“…Other evidence from GC has mainly been reported by Schurig's group [5][6][7][8]. Because of the narrow temperature range used in liquid chromatography (LC), there are only a few observations on temperature-induced inversion of elution order [9][10][11][12]; for example, Pirkle [9] reported this phenomenon when using a brush-type column to separate enantiomers of a phenylethylamine derivative in 1993. The experimental temperature was in the range of -25 to 50°C.…”

Section: Introductionmentioning

confidence: 99%

Reversal of Elution Order between Enantiomers of Binaphthol on an Immobilized Polysaccharide-Based Chiral Stationary Phase

et al. 2011

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Enantioseparation of 1,1 0 -bi-2-naphthol (BINOL) was performed on an immobilized polysaccharide-based chiral stationary phase (CSP), Chiralpak IA, in the normalphase mode. The effects of polar modifier in the mobile phase and column temperature on retention, enantioseparation, and elution order were investigated. An interesting reversal of elution order for BINOL was observed. When ethanol was used as a polar modifier, R-BINOL was eluted first with marginal enantioseparation. Excellent enantioseparation was obtained when ethanol was replaced by 1-propanol, and S-BINOL was eluted first, this effect being retained with 2-butanol, 1-butanol, 1-pentanol or 1-hexanol as the modifier. When isoamyl alcohol was used, reversal of elution order was again observed, i.e., R-BINOL eluted first with marginal enantioseparation, similar to the case of ethanol. When cyclohexanol and cyclopentanol were used, R-BINOL was still eluted first, but enantioseparation was as good as with 1-propanol as the modifier. This is the first report of large enantioseparation obtained in both elution orders for a given selector/selectant system. A retention model based on stoichiometric displacement theory for retention (SDT-R) was investigated to fit the chromatographic data. The reason for solvent-induced reversal of elution order was elucidated based on a derivation of the retention model. Reversal of elution order for BINOL induced by the content of isoamyl alcohol was also predicted based on the model and confirmed by experiment.

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A Thermodynamic Study of the Temperature-Dependent Elution Order of Cyclic α-Amino Acid Enantiomers on a Copper(II)−d-Penicillamine Chiral Stationary Phase

Cited by 44 publications

References 24 publications

High‐performance liquid chromatographic enantioseparation of unusual secondary amino acids on a D‐penicillamine‐based chiral ligand exchange column

High‐performance liquid chromatographic enantioseparation of unusual secondary amino acids on a D‐penicillamine‐based chiral ligand exchange column

Separação cromatográfica quiral de anestésicos a partir de soluções diluídas e concentradas em escala preparativa

Reversal of Elution Order between Enantiomers of Binaphthol on an Immobilized Polysaccharide-Based Chiral Stationary Phase

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