Relationship structure-antioxidant activity of hindered phenolic compounds
- Autores: X. C. Weng, Y. Huang
- Localización: Grasas y aceites, ISSN-e 1988-4214, ISSN 0017-3495, Vol. 65, Nº 4, 2014
- Idioma: español
- Enlaces
- Dialnet Métricas: 2 Citas
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Resumen
The relationship between the structure and the antioxidant activity of 21 hindered phenolic compounds was investigated by Rancimat and DPPH· tests. 3-Tert-butyl-5-methylbenzene-1,2-diol is the strongest antioxidant in the Rancimat test but not in the DPPH· test because its two hydroxyl groups have very strong steric synergy. 2,6-Ditert-butyl-4-hydroxy-methylphenol exhibits a strong antioxidant activity as 2,6-ditertbutyl- 4-methoxyphenol does in lard. 2,6-Ditert-butyl-4- hydroxy-methylphenol also exhibits stronger activity than 2-tert-butyl-4- methoxyphenol. The methylene of 2,6-ditert-butyl-4-hydroxy-methylphenol can provide a hydrogen atom to active free radicals like a phenolic hydroxyl group does because it is greatly activated by both the aromatic ring and hydroxyl group. Five factors affect the antioxidant activities of the phenolic compounds:
how stable the phenolic compound free radicals are after providing hydrogen atoms; how many hy drogen atoms each of the phenolic compounds can provide; how fast the phenolic compounds provide hydrogen atoms; how easily the phenolic compound free radicals can combine with more active free radicals, and whether or not a new antioxidant can form after the phenolic compound provides hydrogen atoms.
