Theoretical Investigation of the Complexation Reaction of Procaine-hydrochloride by β-cyclodextrin

Document Type: Regular Article

Authors

Laboratory of Physical Chemistry of Macromolecular and Biological Interfaces (LCPMIB), Faculty of Sciences, University of Mascara Mustapha Stambouli, BP 305, Road of Mamounia Mascara, 29000 Algeria

10.22036/pcr.2020.205547.1691

Abstract

Abstract. . Quantum-chemical calculations were performed to study the complexation of drug molecule procaine hydrochloride with beta cyclodextrin (β-CD) in the gas phase and in water. The inclusion process was optimized by the semi empirical method PM3 and the obtained complex structure was further refined by ONIOM method (DFT: PM3). It is found that (B3LYP/6-31G(d,p) : PM3) provides the best energy minimum for the complex, compared to M06-2X and WB97XD functional. Given the energy profile, the configuration of the complex formed indicates that the benzene ring is completely included in the hydrophobic cavity of the β-CD. The thermodynamic parameters analysis has shown that the procaine/β-CD complexation is enthalpically favorable, and the complex is well structured. Natural bond orbital (NBO) analysis indicates that no hydrogen bond interaction exists, and the procaine/β-CD complex is mainly stabilized by Van der Waals forces. 1D 1H NMR spectra analysis shows that the procaine molecule penetrates into the cavity of this CD with the aromatic ring.

Graphical Abstract

Theoretical Investigation of the Complexation Reaction of Procaine-hydrochloride by β-cyclodextrin

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