Quantum chemical computations, fluorescence spectral features and molecular docking of two biologically active heterocyclic class of compounds

Abstract

This work is an effort for determination of excited and ground state values of dipole moments and also for quantum chemical computation of two biologically active heterocyclic class of compounds namely of 3-[2-Oxo-2-(2-oxo-2H-chromen-3-yl)-ethylidene]-1,3-dihydro-indol-2-one (3OCE) and 3-[2-Oxo-2-(3-oxo-3H-benzo[f]chromen-2-yl)-ethylidene]-1,3-dihydro-indol-2-one (3OBC). Redshift is displayed by both the compounds with some enhancement in polarity of solvent. The selected molecules show comparatively more polar nature in excited state than in ground state, and this is indicated by large dipole moment in the excited state. DFT calculations with B3LYP/6?311+G (d, p) basis sets using compound's quantum chemical property such as analysis of frontier molecular orbital were used for studying chemical reactivity and kinetic stability of selected compounds. MEP, NBO and Mulliken charges are further studied. The compounds exhibit great amount of energy for stabilization, which is depicted as transfer of proton showed by natural bond orbital (NBO) analysis within the selected donor-acceptor. The indices of electrophilicity and local softness of solute compounds being used is calculated with the help of Fukui function. In order to observe the biophysical properties of the compounds, molecular docking studies performed with periplasmic proteins (PDB ID: 2IPM and 2IPL).