Regenerable Radical‐Trapping and Preventive Selenazolonamine Antioxidants

Selenazolonamines 10 a – d with free amine (‐NH 2 ) group, a new series of preventive and radical‐trapping antioxidants were synthesized from their corresponding diselenides. The radical‐trapping antioxidant capacity of compounds 10 a – d was determined in a chlorobenzene/water membrane‐like model system in which azo ‐initiated peroxidation of linoleic acid was carried out in the lipid phase. The regeneration occurred in the aqueous ascorbic acid as co‐antioxidant, which could regenerate the antioxidants and enhance their inhibition times. The best antioxidant 10 d substituted with para ‐NMe 2 a strong electron‐donating group quenched the peroxyl radicals more efficiently than α‐tocopherol almost 5.5‐fold longer inhibition time. The novel selenazolonamines 10 a – d and their derivatives exhibited good preventive i. e. glutathione peroxidase‐like activity in the coupled reductase assay. Based on 77 Se NMR spectroscopy, a catalytic cycle for 10 d , involving diselenide, selenosulfide, and selenol as intermediates was proposed. The mechanism for quenching of peroxyl radicals for 10 d was also considered to be involved via proton‐coupled electron transfer reaction.