Interaction of propylthiouracil, an anti-thyroid drug with boron nitride nanotube: a DFT study

Abstract

A theoretical study was performed on the adsorption of propylthiouracil (PTU) on the outer surface of boron nitride nanotube (BNNT). In this investigation, the BNNTs with (5,5), (6,6) and (7,7) chiralities were selected. The PTU molecule was located on the outer surface of BNNT in perpendicular and parallel modes. After the relaxation of whole system, the energy values and optimum distances in two different configurations were calculated. According to calculations, the adsorption of PTU upon the outer wall of BNNT was thermodynamically favorable. It was revealed that the adsorption of PTU through its S atom on the outside of BNNT with (5,5) chirality is the most stable state with the adsorption energy of − 6.30 kcal/mol. In addition, the adsorption process also effects on the HOMO–LUMO levels such that a slight increase in HOMO value and a considerable decrease in LUMO value was observed for both of Drug@BNNTs groups in these systems. Therefore, the energy gaps (Eg) between HOMO and LUMO are reduced, indicating the greater strength of intermolecular bond. Moreover, the reactivity and the stability of the Drug@BNNTs complexes were evaluated to determine the magnitude of the chemical reactivity descriptors including electrophilicity, chemical potential, and global hardness index. According to the results, BNNTs can be employed as a carrier for drug delivery purposes to transport the PTU as anticancer drug in the biological systems. This theoretical study was investigated in the presence and absence of water as solvent. In this study, the adsorption of propylthiouracil (PTU) on the outer surface of boron nitride nanotube (BNNT) with (5,5), (6,6) and (7,7) chiralities was investigated by density functional theory (DFT). The results revealed that BNNTs can be applied as carrier for drug delivery purposes to transport the PTU as anti-thyroid drug into target tissues.