Host-Guest Interactions of α−Mangostin with (α,β,γ)−Cyclodextrins: Semi-Empirical Quantum Mechanical Methods of PM6 and PM7

Abstract

Objective: This study aimed to investigate the molecular interactions, geometrical properties, encapsulation process and calculated energy of the inclusion complexes system between α−mangostin (guest) with α−cyclodextrin, β−cyclodextrin and γ-cyclodextrin (hosts) in an aqueous environment using the semi-empirical quantum mechanical methods of PM6 and PM7. Materials and Methods: Molecular docking simulation and semi-empirical quantum mechanical calculations of PM6 and PM7 were employed to identify the molecular interactions between α−mangostin and three types of cyclodextrin. Results: The inclusion complex formation energy values of all α−mangostin/cyclodextrin that obtained by the semiempirical PM7 method were significantly lower than complexation energy obtained by the semi-empirical PM6 method. Conclusion: The inclusion complex of α−mangostin/γ−cyclodextrin is the most favorable pathway of inclusion complex formation of α−mangostin with cyclodextrin because it has the highest negative value of free binding energy (ΔG) and complexation energy (ΔE) compared to α−mangostin/α−cyclodextrin and α−mangostin/ β−cyclodextrin. Key words: Alpha mangostin, Cyclodextrin, Host-guest interactions, PM6, PM7.