Carotenoids as antioxidants: Spin trapping EPR and optical study

The role of several natural and synthetic carotenoids as scavengers of free radicals was studied in homogeneous solutions. A set of free radicals: (OH)-O-., (OOH)-O-., and (CH3)-C-. were generated by using the Fenton reaction in dimethyl sulfoxide. It was shown that the spin trapping technique is more informative than optical methods for the experimental conditions under study. 5,5-Dimethyl-pyrroline-N-oxide (DMPO) and N-rert-butyl-alpha -phenylnitrone (PBN) were used as spin traps for the EPR studies. The results show that the scavenging ability of the carotenoids towards radical (OOH)-O-. correlates with their redox properties. (C) 2001 Elsevier Science Inc.