Adsorption of cytarabine and gemcitabine anticancer drugs on the BNNT surface: DFT and GD3-DFT approaches

Abstract

In this work, at first, in order to find the most stable conformers of the two types of anticancer cytarabine (CYT) and gemcitabine (GEM) drugs, the potential energy curves for rotation around the C1′-N bond were explored at M06-2X/6–311 + + G(2d,2p) level of theory. Adsorption of the most stable conformers of CYT and GEM drugs on the BNNT surface was explored. Depending on the orientation of CYT and GEM drugs on the outside surface of the BNNT, two different types of drug-BNNT adsorption complexes (A and B) were found on the potential energy surface. Dispersion corrected adsorption energies at M06-2X/6–31 + G(d)-GD3 level were in the range − 19.7 to − 26.1 kcal mol−1 for A1–A4 and − 21.7 to − 24.6 kcal mol−1 for B1–B4. The results show that adsorptions of CYT and GEM drugs on the BNNT surface in the water solvent are energetically favorable process. The structural and electronic density properties, charge transfer values, global reactivity descriptors and the molecular electrostatic potential maps of the drug-BNNT complexes were evaluated. It is anticipated that the complex formation accompanied by charge transfer between BNNT and drugs and the decrease in the HOMO − LUMO energy gap. The NCI (non-covalent interaction) analysis shows the role and importance of the cooperative π − π stacking and H-bonding interactions on the adsorption of drugs on the BNNT surface.