Study of molecular interactions by hydrogen bond of charged forms of makaluvamines and complex stability with H2O and glutamic acid (Glu Ac) by the theory of the functional of density (B3LYP)

This work was undertaken to understand the mode of interaction of makaluvamines, a class of marine pyrroloiminoquinone alkaloids isolated from sponges of the genus Zyzzya, used in the treatment of several human cancer cell lines. This analysis was done by the quantum chemistry method. First, we used electrostatic potential (ESP) to reveal the different sites that accept and donate hydrogen bonds (HB) of charged forms (protonated and methylated) of makaluvamines (at level B3LYP/6-311++G(d,p)). In a second step, we studied the interactions by hydrogen bond between these molecules and water molecule on the one hand (at level B3LYP/6-311++G(d,p)) and on the other hand glutamic acid a protein residue of topoisomerase II (at level B3LYP/6-31+G(d,p)). Finally, we calculated the corrected BSSE interaction energies and estimated the relative stability of the formed complexes.