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 mo re informative than optical methods for the experimental conditions under s tudy. 5,5-Dimethyl-pyrroline-N-oxide (DMPO) and N-rert-butyl-alpha -phenyln itrone (PBN) were used as spin traps for the EPR studies. The results show that the scavenging ability of the carotenoids towards radical (OOH)-O-. co rrelates with their redox properties. (C) 2001 Elsevier Science Inc.