Determination of the free radical scavenging activity of dihydropyran-2,4-diones.

The antioxidant activities of four synthetic dihydropyran-2,4-diones have been established through the determination of their abilities to inhibit free radicals using DPPH(*) as the stable radical. Whilst all of the compounds exhibited high inhibition percentages, the most active member of the group was 6-phenyl-dihydropyran-2,4-dione. The antioxidant activity of the dihydropyran-2,4-diones is reported here for the first time and extends our knowledge of the range of valuable biological activities associated with this group of compounds.