Oxo-Carotenoids as Efficient Superoxide Radical Scavengers.

The electron-deficient carotenoids with conjugated carbonyl groups would destabilize the resulting carotenoid (cationic) radicals, and thus the loss of H• or a single electron from the polyene would not be a main mechanism of action for antioxidant activity. Although -carotene was demonstrated to be a very potent antioxidant by DPPH and ABTS assays, the oxo-carotenoids exhibit superior antioxidant activity than the natural carotenoid in the superoxide radical scavenging assay. On the other hand, the electron-deficient oxo-carotenoids would readily accept an electron [[15]] or form an adduct [[16]] from superoxide radical to produce carotenoid anionic radical, which means oxo-carotenoids are better antioxidants than -carotene (3). Keywords: antioxidant; apocarotenal; carotenoid; oxo-carotenoid; superoxide radical EN antioxidant apocarotenal carotenoid oxo-carotenoid superoxide radical N.PAG N.PAG 15 08/29/22 20220801 NES 220801 1. [Extracted from the article]