Synthesis, characterization, structures and antioxidant activity of nicotinoyl based organoselenium compounds

A series of nicotinoyl based organoselenium compounds, [2-NC5H3(3-COOH)Se]2 (1), [2-NC5H3(3-CO)Se–Se] (2), [2-NC5H3(3-CONH2)Se]2 (3), [2-NC5H3(3-CONHPh)Se]2 (4), [2-NC5H3(3-CONHpyrimidine)Se]2 (5), [2-NC5H3(3-CONHPh)SeBr] (6) and [2-NC5H3(3-CONHPh)SeI] (7) have been synthesized and characterized by absorption, IR, NMR (1H, 13C{1H}, 77Se{1H}) and mass spectrometry. The crystal structures of [2-NC5H3(3-CO)Se–Se] (2) and [2-NC5H3(3-CONHPh)Se]2 (4) have been determined. The structure of (4) revealed the existence of two intra-molecular Se⋯X (X = O and N) interactions, as a result of this, C–Se–Se–C torsion angle is unusually large (180°). The GPx mimicking activity of these compounds has been evaluated using methods based on 1H NMR spectroscopy and HPLC. Free radical scavenging ability of the compounds was examined by DPPH and deoxyribose assay. All these studies indicated that the compound (3) not only showed highest GPx activity but also has a very good free radical scavenging ability thus making it a novel structure for development of nicotine based antioxidants.

Several nicotinoyl based organoselenium compounds were synthesized and characterized. The compound [2-NC5H3(3-CONHPh)Se]2 showed existence of intra-molecular Se…X (X = O and N) interactions. The GPx mimicking activity and free radical scavenging ability of these compounds was evaluated. The compound [2-NC5H3(3-CONH2)Se]2 exhibited highest GPx activity and free radical scavenging ability.Figure optionsDownload as PowerPoint slideHighlights
► Nicotinamide based organoselenium compounds showing intra-molecular Se⋯X non-bonding interactions have been synthesized.
► These compounds exhibit excellent antioxidant and GPx mimicking activity.
► Efficient radical scavenging ability of nicotinamide selenides was observed.