Etude de l'activité anti oxydante de Gelidium Sesquipedale par chromatographie liquide haute performance.

This work lies within the scope of the valorization of the extracts of sesquipedalian Rhodophycées Gelidium as antioxydants. The method applied to measure this activity is that of the trapping of the free radicals by using the 1,1'-diphenyl-2 - picrylhydrazyl (DPPH°) and the follow-up of the reaction was carried out by colorimetry and Liquid Chromatography High efficiency. The results obtained show that the extracts of Gelidium sesquipedale have a significant antioxidant activity, inhibition of 50% of oxidation of the radical has been achieved by using a dilution of 100 times of the extracts. The characterisation of molecules responsible for this biological activity has shown that extracts of Gelidium sesquipedale are rich in phenolic compounds, ascorbic acid and functions thiols. The levels recorded for these molecules are of the order of 8.71 ± 6.1 mg/g of EAG after crushing for the total polyphenols, 5.35 ± 4.77 mg/ml for the ascorbic acid, and 8.65 ± 1.12 mg/ml of equivalent of N- acetylcysteine conjugate for the functions thiols. [ABSTRACT FROM AUTHOR]