Probing the structural properties, binding mode and intermolecular interactions of herbacetin against H1N1 neuraminidase using vibrational spectroscopic, quantum chemical calculation and molecular docking studies

Herbacetin (HBN) is an antiviral agent of H1N1 influenza virus which was reported to inhibit H1N1 neuraminidase (NA) enzyme with IC50 value of 8.9 mu M. The research exploration for HBN was conducted via quantum chemical calculations and spectroscopic techniques. The experimental vibrational FT-IR and FT-Raman spectra of the HBN molecule were obtained, and it was compared with theoretical method utilizing quantum chemical calculations through DFT approach employing basis sets 6-31G(d,p) and 6-311G(d,p). The MEP, NBO, global and local reactivity descriptors were carried out to describe the reactivity, selectivity and stabilization of the HBN molecule. The electronic characteristics namely UV-Vis and HOMO-LUMO were computed through TD-DFT method which was correlated with experimental spectral analysis. The total, partial and overlap population density of states (DOS) were carried out to confirm the molecular orbital contributions. The drug likeness and ADMET predictions were analysed to reveal the biological behaviour of the HBN. Furthermore, the molecular docking investigation is to find the best fit orientation: binding mode, inhibition constant and intermolecular interactions among HBN and NA enzyme. The ligand molecule fits very well in the NA active site cavity. Hence, the HBN molecule exhibits good biological activity, and it can be served as a prospective drug for H1N1 influenza A virus. [GRAPHICS] .