Synthesis, characterization, structures and GPx mimicking activity of pyridyl and pyrimidyl based organoselenium compounds

Pyridyl and pyrimidyl based organoselenium compounds have been synthesized and characterized by analytical and spectroscopic techniques. Molecular structures of 2,2′-dipyrimidyl diselenide (1b), 2,2′-dipyrimidyl selenide (2b) and 2-pyrimidyl seleno ethanoic acid (3d) have been determined by single crystal X-ray diffraction analyses. The 3d is associated in the solid state through hydrogen bonding between carboxylic acid proton and N2 of the pyrimidyl ring of an adjacent molecule. The in vitro GPx-like catalytic activity for these compounds was evaluated by 1H NMR and HPLC methods where H2O2 was reduced by dithiothreitol (DTTred) and glutathione (GSH) as a thiol cofactor, respectively, in the presence of catalytic amounts of organoselenium compounds. The electron density around selenium atom (–SeSe– or –Se–) which is reflected by 77Se{1H} NMR chemical shifts, has been found to be one of the crucial factors in influencing their overall GPx like activity.

A series of pyridyl- and pyrimidyl-selenides were synthesized. Their GPx mimicking catalytic activity has been evaluated by 1H NMR spectroscopy and HPLC method. The electron density around Se atom influences the overall GPx activity of these compounds.Figure optionsDownload as PowerPoint slideHighlights
► N-heterocyclic organoselnium compounds exhibit GPx like activity.
► Their activity is influenced by the electron density around selenium atom.
► pymSeCH2COOH forms an infinite chain through hydrogen bond.
► Dipyrimidyl diselenide exhibits weak Se⋯N non-bonding interaction.