An enantioselective study of β‐cyclodextrin and ionic liquid‐β‐cyclodextrin towards propranolol enantiomers by molecular dynamic simulations

Abstract

In this study, the enantioselectivity of β‐cyclodextrin and its derivatives towards propranolol enantiomers are investigated by molecular dynamic (MD) simulations. β‐cyclodextrin (β‐CD) have previously been shown to be able to recognize propranolol (PRP) enantiomers. To improve upon the enantioselectivity of β‐cyclodextrin, we propose the use of an ionic‐liquid‐modified‐β‐cyclodextrin (β‐CD‐IL). β‐CD‐IL was found to be able to complex R and S propranolol enantiomers with differing binding energies. The molecular docking study reveals that the ionic liquid chain attached to the β‐CD molecule has significant interaction with propranolol. The formation of the most stable complex occurred between (S)‐β‐CD‐IL and (S)‐propranolol with an energy of −5.80 kcal/mol. This is attributed to the formation of a hydrogen bond between the oxygen of the propranolol and the hydrogen on the primary rim of the (S)‐β‐CD‐IL cavity. This interaction is not detected in other complexes. The root mean‐squared fluctuation (RMSF) value indicates that the NH group is the most flexible molecular fragment, followed by the aromatic group. Also of note, the formation of a complex between pristine β‐CD and (S)‐propranolol is the least favorable.