Chromatography of methyl derivatives of 5-ethyl-5-phenyl-2-thiobarbituric acid

Bojarşki, Jacek; Kubaszek, M.; Bartoń, H.; Chmiel, Elżbieta

doi:10.1016/0021-9673(94)80143-6

Cited by 3 publications

(5 citation statements)

References 6 publications

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“…This enantiomer indeed was eluted first. 7 The sum of differences in stability is much higher for this compound than for the others. This is in agreement with the experiment, because the difference in experimental retention times (t R ) between its enantiomers is also the highest (see Table 5).…”

Section: Correlation With Chromatographic Datamentioning

confidence: 98%

“…The mobile phase was composed of aqueous saturated ␤-CD solution, 96% ethanol, 0.1 M Na 2 HPO 4 , and 0.1 M NaH 2 PO 4 (80:10:7.5:2.5). 7 The pH of the mobile phase (7.00 ± 0.01) was close to the pK a values of the compounds and under these conditions both neutral and anionic forms exist in the mobile phase.…”

Section: Experimental Conditionsmentioning

confidence: 98%

“…6 In this work, semiempirical calculations were used to confirm the results of chiral chromatography for other compounds of this type, i.e., 5-ethyl-5-phenyl-2-methylthio-4,6(3H,5H)-pyrimidinedione (compound B), 5-ethyl-5-phenyl-3-methyl-2-methylthio-4,6-(3H,5H)-pyrimidinedione (compound C), and 1,5-diethyl-5-phenyl-2-thiooxo-4,6-(1H,3H,5H)-pyrimidinedione (compound D). 7 …”

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confidence: 97%

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Enantioselective chromatography of alkyl derivatives of 5‐ethyl‐5‐phenyl‐2‐thiobarbituric acid studied by semiempirical AM1 method

Zborowski

Żuchowski

2002

Chirality

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Complexation of alkyl derivatives of 5-ethyl-5-phenyl-2-thiobarbituric acid (2-thiophenobarbital) enantiomers by beta-cyclodextrin was investigated by the AM1 method. The inclusion complexes of beta-cyclodextrin with neutral and anionic forms of these enantiomers have been modeled and energetically optimized. The chiral discrimination of enantiomers was analyzed in terms of differences in the interaction energies. The calculated interaction energies between each enantiomer of the investigated 2-thiobarbiturates and beta-cyclodextrin confirm the ability of beta-cyclodextrin to act as a mobile phase additive in reversed-phase HPLC to separate enantiomers by liquid chromatography and rationalize their order of elution.

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Section: Correlation With Chromatographic Datamentioning

confidence: 98%

Section: Experimental Conditionsmentioning

confidence: 98%

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confidence: 97%

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Enantioselective chromatography of alkyl derivatives of 5‐ethyl‐5‐phenyl‐2‐thiobarbituric acid studied by semiempirical AM1 method

Zborowski

Żuchowski

2002

Chirality

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“…Aboul-Enein and Serignese 1994 Chromatography of methyl derivatives of 5-ethyl-5-phenyl-2-thiobarbituric acid. Bojarski et al 1994 Use of a macrocyclic antibiotic as the chiral selector for enantiomeric separation by TLC.…”

Section: Huang and LI 1995mentioning

confidence: 99%

Application of thin-layer chromatography in enantiomeric chiral analysis—an overview

Aboul‐Enein

El-Awady

Heard

et al. 1999

Biomed. Chromatogr.

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Several chiral drugs are produced and administered as pure enantiomers, whereas many others, especially of synthetic origin, are used mainly in the form of racemates. The biological and pharmacological activity of chiral compounds depends on their configuration. The racemic drugs may exhibit quite different activity from the optically pure drugs. Often only one of the enantiomers is pharmacologically active and/or even can be toxic. Since numerous enantiomers have been shown to behave differently from at least one point of view, whether pharmacokinetic, pharmacodynamic, toxicological or interaction, there seems to be hardly any exception to the general rule that a racemate cannot be considered as a single drug entity. A variety of chromatographic methods have been developed for optical resolution recently. Usually direct separation of the enantiomers is carried out on HPTLC chiral precoated plates or on plates impregnated with chiral substances. TLC techniques are a developing branch of separation and quantitation of drugs, both in pharmaceutical dosage forms and in biological material. This review presents an overview of the current successful enantioseparations of drugs by TLC and their potential in the analysis of the drug racemates. Copyright © 1999 John Wiley & Sons, Ltd.

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“…Therefore, enantiospecific analysis of these compounds are of current interest [14]. The enantiomers of some thiobarbiturates were separated by HPLC by adding b-CD to the mobile phase [15] and on a cellulose tris-(4-methylbenzoate) chiral stationary phase (Chiralcel OJ-R) under reversed-phase conditions [16]. The enantioseparation of N-methyl-2-thiophenobarbital with b-CD was recently rationalized by semiempirical AM1 calculations [17].…”

Section: Introductionmentioning

confidence: 99%

Enantioseparation of chiral thiobarbiturates using cyclodextrin-modified capillary electrophoresis

2001

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The racemates of several chiral thiobarbiturates were separated by using different cyclodextrins in capillary electrophoresis (CE). Six neutral and negatively charged cyclodextrins 1 (CDs) were employed as chiral separators whereof five led to successful separation of enantiomeric thiobarbiturate pairs. The CDs used were the native alpha-CD, beta-CD, gamma-CD, and heptakis-(2,6-di-O-methyl)-beta-cyclodextrin (HDM) as well as heptakis-(2,3-di-O-methyl-6-sulfato)-beta-cyclodextrin (HDMS) and heptakis-(2,3-di-O-acetyl-6-sulfato)-beta-CD (HDAS). Five of the six chiral thiobarbiturates studied could be resolved at a basic pH value of 9.4 and a phosphate buffer concentration of 100 mM in a fused-silica capillary. Structurally related substances showed a similar behavior in separation: 1 and 2 bearing the center of chirality in the side chain at C5 can be best separated using gamma-CD, the N-alkyl-substituted compounds 3 and 4 as well as the N/S-dialkyl-substituted compound 5 could be resolved with HDM. Using the neutral CDs, the migration times were relatively small (< 11 min). 3 and 4 could be also resolved by means of the negatively charged HDMS. In the latter case, the migration time is twice as long as with HDM.

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Chromatography of methyl derivatives of 5-ethyl-5-phenyl-2-thiobarbituric acid

Cited by 3 publications

References 6 publications

Enantioselective chromatography of alkyl derivatives of 5‐ethyl‐5‐phenyl‐2‐thiobarbituric acid studied by semiempirical AM1 method

Enantioselective chromatography of alkyl derivatives of 5‐ethyl‐5‐phenyl‐2‐thiobarbituric acid studied by semiempirical AM1 method

Application of thin-layer chromatography in enantiomeric chiral analysis—an overview

Enantioseparation of chiral thiobarbiturates using cyclodextrin-modified capillary electrophoresis

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