Chiral ionic liquid interface as a chiral selector for recognition of propranolol enantiomers: A molecular dynamics simulations study

Abstract

The interfacial complexation of 1-butyl-3-methylimidazolium (T-4)-bis[(αS)-α-(hydroxy-O) benzeneacetato-κO] borate, a non-halogenated chiral ionic liquid, with propranolol enantiomers is studied by using classical Molecular Dynamics (MD) Simulations. This kind of halogen-free chiral ionic liquid is recently synthesized and experimental results show that it is a suitable candidate for chiral discrimination of propranolol enantiomers. But the mechanism behind this discrimination is not understood yet. The importance of chiral recognition is that the activity of enantiomers is different in biological environments. So chiral separation is a vital issue for the pharmaceutical industry. The micro structure, molecular orientation, density profiles and dynamical properties of propranolol systems are investigated. The number of hydrogen bonds and strength of interactions in S-propranolol/CIL system is greater than R-propranolol/CIL system, leading to the more stability of S-propranolol/CIL system by 9.93× 104 kJ/mol. The results promise the ability of this chiral ionic liquid as a chiral discriminator for propranolol enantiomers and other chiral drugs.