Encapsulation investigation of molnupiravir drug guest using cucurbituril hosts through the DFT approach

The geometrical structures of cucurbit[n]uril (CB[n], n = 5–8 and their complexes with molnupiravir (MLP) drug have been investigated using the DFT computations. The complexation energies and electronic properties of CB[n]/MLP complexes were also computed. The host–guest interactions in the complexation are occurred through the of dipole–dipole interactions which are the hydrogen bonds between the O−H or N−H of molnupiravir and oxygen atoms of CB[n]s. The CB[n]/MLP host–guest complexation in both gas and water are found to be an exothermic reaction with negative complexation energy values. By means of the NBO analysis and MEP contours, the partial charge transfers from CB[n]s to molnupiravir are displayed. After drug complexation, the electronics properties of CB[n]s are significantly changed. This means that CB[n]s can act as a host for appropriately molnupiravir guest, even in aqueous solution.