Structural analysis and molecular docking study of pachypodostyflavone: A potent anti-onchocerca

Abstract

In order to get a better insight into the intermolecular interactions in the solid state of the naturally occurring flavone derivative, pachypodostyflavone, its single crystal X-ray diffraction was performed and analysed. Structural analysis revealed that the compound crystallises in the monoclinic space group P21/c with a = 23.910(1), b = 13.256(1), c = 8.044(1) Å, β = 94.96(1), Z = 4. An experimental and theoretical investigation of pachypodostyflavone is presented, combining the use of vibrational spectroscopies (IR, NMR and UV–visible) with density functional theory (DFT) that employs hybrid B3LYP exchange correlation functional with 6–311++G(d,p) as basis set. HOMO-LUMO, MEP, and NBO analysis was investigated and reactivity descriptors were calculated. Analysis of chemical reactivity indicates that the compound is more reactive in water, which is a good indicator for clinical preparations. Thermodynamic properties viz., heat capacity, entropy, and enthalpy change of title molecule at various temperatures are presented. Additionally, molecular docking results revealed that pachypodostyflavone structure strongly binds to the parasitic worm Onchocerca volvulus by relative binding affinity of –7.00 kcal mol–1.