Sumanene as a delivery system for 5-fluorouracil drug – DFT, SAPT and MD study

Abstract

In this work, density functional theory (DFT) and symmetry-adapted perturbation theory (SAPT) calculations, together with molecular dynamics (MD) simulations, were used to study the interaction between sumanene molecule and 5-fluorouracil (5-FU). 5FU is a known and frequently employed cytostatic drug. To better understand the effects of the curvature of sumanene, we have also considered the interaction between 5-FU and coronene, a sumanene's relative with planar geometry. DFT calculations at B3LYP-D3/6-31G(d,p) level of theory were used to obtain information on binding energies and identify and visualize the noncovalent interactions between the 5-FU and the sumanene/coronene. DFT calculations revealed that 5-FU binds to sumanene's concave side much stronger than to its convex side. The strengths of noncovalent interactions explained the obtained trends in the binding energies. The SAPT0 calculations helped reveal the essential physical contributions to the interaction energies. The importance of the electrostatic component was emphasized in the case of adsorption from sumanene's concave side. Molecular electrostatic potential was compared between the sole molecules and complexes. Simulation of the UV spectra was performed to evaluate whether the binding of 5FU to sumanene could be tracked and monitored by UV spectroscopy. Last but not least, MD simulations were performed to check the influence of temperature on the interaction between sumanene and 5FU. It was established that an increase in temperature significantly decreases the interaction between sumanene and 5FU.