Why heptakis(2,3-di-O-acetyl)-β-cyclodextrin can separate terbutaline enantiomers better than β-cyclodextrin: nonbonding and hydrophobic interactions

Recognition in the Domain of Molecular Chirality: From Noncovalent Interactions to Separation of Enantiomers

“…1331 The same trend emerged in the modelling studies involving HP-1432,1446−1449 and CM-β-CD. 1433,1450−1453 In the last few years, molecular modelling of HDA, 1280,1454 HDAS, 1334,1455−1459 HDMS β-CD, 1457 and HMDS β-CD 1334 has been performed in several cases by comparing the affinity of these substituted CDs and the corresponding native macrocycle toward chiral analytes. In most cases, the modelling evidenced that substitution at the rims of CDs may enhance the interaction ability of the host and favor the differentiation between diastereomeric complexes through steric repulsion, whereas in some cases the binding modes of enantiomers with native CDs tend to be similar because of the poor flexibility of the host, which limits its discrimination capability.…”

“…For instance, the following strategies were used so far to deal with the modelling of S-β-CD and related complexes: (a) the question is neglected, or the CD is considered as a single isomer; , (b) a structure representing one of the possible structures is randomly generated; (c) different isomeric forms are selected and modelled considering an ensemble of isomers; (d) some authors argue that it is not reliable to model mixtures of CDs . The same trend emerged in the modelling studies involving HP- ,− and CM-β-CD. ,− In the last few years, molecular modelling of HDA, , HDAS, ,− HDMS β-CD, and HMDS β-CD has been performed in several cases by comparing the affinity of these substituted CDs and the corresponding native macrocycle toward chiral analytes. In most cases, the modelling evidenced that substitution at the rims of CDs may enhance the interaction ability of the host and favor the differentiation between diastereomeric complexes through steric repulsion, whereas in some cases the binding modes of enantiomers with native CDs tend to be similar because of the poor flexibility of the host, which limits its discrimination capability.…”

Application of Molecular Dynamics Simulations in the Analysis of Cyclodextrin Complexes

“…Here, two approaches are available. Either the classic method of simulating one guest with one CD, and checking for any selectivity among the tested CDs, as in the case of terbutaline enantiomers [178]. Or, in a more complicated approach, a channel or walls are formed out of multiple CDs; in this way, a kind of chromatographic column is simulated.…”

How areN-methylcarbamates encapsulated by β-cyclodextrin: insight into the binding mechanism

“…Many previous studies focused on the structure and various interactions of hostguest systems in aqueous solution. [26][27][28][29] In 2016, Ling et al combined 1 H NMR, isothermal titration calorimetry and DFT calculations to explore the effect of different substituents on the stability of inclusion complexes of N-benzyl-trimethylsilylmethylammonium cations with cucurbit [7]uril (CB [7]). 26 They found a competition between the following two factors: (1) the solvation of the ammonium unit in the free guests by water, and (2) the Coulombic attraction between the ammonium unit and the rim of CB [7] in the complexes.…”

“…the non-covalent interaction and solvent effect. 28,29 Promecarb (PC), bendiocarb (BC), carbaryl (CY), and carbofuran (CF) are widely used N-methylcarbamate insecticides in agriculture, 30 but their residues can also contaminate water sources, making their impact on the environment and human health a concern. Thence, rapid, reliable and highly selective analytical techniques are required to quantify these residues.…”