Deformation density components analysis of fullerene-based anti-HIV drugs.

Deformation density analysis is performed on fullerene-based anti-HIV agents to investigate the influence of charge redistribution on the capability of binding to HIV enzymes. Two types of HIV inhibitors including malonic acid- and amino acid-type C60 derivatives are considered to study. Total deformation density and its components including orbital relaxation and kinetic energy pressure are obtained for C60 derivatives. The deformation natural orbitals for each component of deformation density are assessed and their amounts of charge displacement are quantified to evaluate the binding affinity of HIV inhibitors. The results show that the orbital relaxation plays a more prominent role in deformation of electron density of studied compounds. Among the considered drugs, the amino acid-type derivatives, N-(carboxymethyl)-2,5-dicarboxylic fulleropyrrolidines, show the most charge displacement. Moreover, the investigation into the deformation density of amino acid-type functional groups on C60 reveals that the connection of functional groups to the 5,6-ring junction results more displaced charge than the connection to the 6,6-ring junction.