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

Abstract

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.

Capillary electrophoretic separation and theoretical study of inclusion complexes of sulfobutyl ether β‐cyclodextrin with estrogens

“…Such a correlation suggests that both cis and trans orientations may occur simultaneously because the estrogen can enter the cavity from either side of the cavity [26]. Similar correction has also been observed for the enantioselective separation of sulfurcontaining chiral compounds with ␤-CD using reversed-phase high-performance liquid chroma- tography (HPLC) [27]. Unlike in CE, a compound eluted earlier in HPLC formed a more stable guesthost complex with ␤-CD than a compound eluted later.…”

“…Unlike in CE, a compound eluted earlier in HPLC formed a more stable guesthost complex with ␤-CD than a compound eluted later. The stabilization energies calculated using semiempirical AM1 method were consistent with the order of elution of the compounds studied [27].…”

Chiral recognition of Propranolol enantiomers by β-Cyclodextrin: Quantum chemical calculation and molecular dynamics simulation studies

“…PM3 performs better than AM1 in biochemical systems due to its dealing better with hydrogen bonding [10]. Exclusively MNDO [11], semi-empirical CNDO [12,13], AM1 [14,15], PM3 [16,17], or DFT [18] methods have been applied in Cyclodextrin quantum chemical calculations.…”

Effect of external electric field on Cyclodextrin-Alcohol adducts: A DFT study

“…[4][5][6][7][8][9][10][11][12][13][14][15][16] Different methods are used to understand the host-guest interactions in larger systems like complexes of CDs or their derivatives. [7][8][9][10][11][12][13][14][15] Recently we have studied CD-alcohol interactions using QM-MM method. 16 An intermediate value of interaction energy indicates that the rate of adsorption of alcohols on CD membrane is governed by the host-guest interaction.…”