FREE RADICAL SCAVENGING CAPACITY OF CAROTENOIDS

HERRERA, ELISA; MONTENEGRO, MARIANA; NAZARENO, MÓNICA

Los Cocos, Córdoba

Conferencia; 9TH Latin American Conference on Physical Organic Chemistry.; 2007

Carotenoids pigments are abundant in many fruit, and vegetables and they play a important protective role against disease, in particular, cancer, heart disease, macular degeneration and cataracts. This effect is owed to carotenoids capacity of scavenger reactive oxygen species (ROS) such as singlet oxygen 1O2, superoxide anion O2·-, hydroxyl radical HO· and peroxyl radical ROO· acting as antioxidants. A way of determination this antioxidant activity is by study of the intrinsic capacity of compound to trap free radical denominate Antiradical Activity. In this work we study the radial cation stable ABTS·+ scavenging capacity of un series of carotenoids derivates of b-carotene in organic medium and aqueous micell medium. Radical ABTS·+ was generated by reaction of ABTS [2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] with potassium persulfate. The results obtained show that for the series of carotenoids studied the capacity antiradical aforesaid as Antiradical Power (ARP) decrees with the addition of polar groups (e.g. carbonyl and hydroxyl groups) onto the ring b-ionone, possibly due to their electron withdrawing effects, and with the decrease of number of conjugated double bonds. For all the series was observed an ARP smaller in the aqueous micell medium, which would be able due to the interaction of the carotenoides with the molecules of surfactant.