Synthesis and molecular structure exploration of novel piperidin-4-one imine derivatives combined with DFT and X-ray: A new class of antioxidant and anti-inflammatory agents

Inflammation is one of the pertinent responses of the body, depending mainly on the process and factors involved in combating the oxidative species produced either by any infection or failure of the antioxidant pathways. In search of new compounds to exhibit antioxidant and anti-inflammatory activity here, we have successfully reported the synthesis of three novel compounds of Piperidin-4-one skeleton by adopting simple and convenient methods. Compound 1, (3, 3-dimethyl-2, 6-bis(3,4,5-trimethoxyphenyl) piperidin-4-one) was synthesized by one-pot Mannich condensation reaction having good yield (88 %). Furthermore in the next step highly functionalized imine derivatives, Compound 2 (3,3-dimethyl-2,6-bis (3,4,5-trimethoxyphenyl) piperidine-4-one) hydrazine carbothioamide) and Compound 3 (3,3-dimethyl-2,6-bis(3,4,5-trimethoxyphenyl) piperidin-4-one oxime) were prepared by the condensation reaction with thiosemicarbazide and hydroxylamine hydrochloride with compound 1, respectively. The structure of the compounds has been deduced by the combined use of modern spectroscopic and single crystal x-ray diffraction (XRD) techniques. in-silico ADMET studies predict pharmacokinetic properties and showed that compounds are non toxic on vital organs. The optimized geometry and reactivity parameters of compounds were further calculated based on the B3LYP/6-31G (d, p) density functional theory (DFT). The negative values of chemical potential follow the trend as 2 (-0.2101) > 3 (-0.2198) > 1(-0.2233) signifies that all compounds are reactive in nature as evident from in-vitro antioxidant and anti-inflammatory response were determined by using the DDPH assay and protein denaturation methods respectively. Compounds possess good radical scavenging activity having IC 50 values 30.392 μM (2), 37.802 (1) μM, and 72.285 (3) μM, and anti-inflammatory response in same manner indicating that 2 (71.3 %) is more active than compound 1 (43.5 %) and 3 (39.3 %) marking them as a potential antioxidant and anti-inflammatory agents.