Synthesis, spectral, quantum chemical, biological, molecular docking and mathematical investigations of piperidin-4-one oxime picrates

Abstract

By using spectroscopic techniques, the 3,5-diethyl-2r,6c-diarylpiperidin-4-one oxime picrates (DDPPOP and DDMPPOP) were characterised by elemental analysis, FT-IR, 1H, 13C and 2D NMR and mass spectral techniques. The compounds follow a normal chair conformation with all substituents orientated equatorially, as indicated by the reported chemical shifts and coupling constants from the NMR spectral data. The optimised molecular structures of the title compounds were done by using DFT method with B3LYP/6-311++G(d,p) theory. According to the calculated first hyperpolarizability (β0) values of the compounds display non-linear optical (NLO) behaviour. The molecule may have undergone intra-molecular charge transfer, according to the HOMO–LUMO transition. The reactive sites of the title molecule was analysed by using the Molecular Electrostatic Potential (MEP) surface. The Mulliken atomic charges were calculated by using same basis set. The antibacterial and antifungal activity of the title compounds was examined by biological study. Docking studies were thoroughly conducted to establish knowledge regarding the molecular interactions between protein and this compound. This study is further developed and uses the idea of graph colouring in mathematical computation to support the molecular structure we created using NMR spectroscopy.