Antioxidant activity of chlorophylls and their derivatives

Autor(es)

Lanfer-Marquez‚ U. M. ; Barros‚ R. ; Sinnecker‚ P.

• Tipo de documento: Artigo Científico
• Fonte: Food Research International; v. 38, n. 8/9, p. 885-891, Oct.-Nov. 2005.
• Área do conhecimento: Ciências Agrárias - Ciência e Tecnologia de Alimentos
• Assunto(s): Antioxidantes Clorofila

Resumo

The antioxidant activity of six natural isolated chlorophyll derivatives and Cu-chlorophyllin was investigated by measuring their protective action against lipid oxidation. For this, the β-carotene bleaching method and the stable radical 2,2-diphenyl-1-picryldrazyl (DPPH) scavenging assay were employed. The results obtained by the β-carotene bleaching method showed that all chlorophyll derivatives presented a dose-dependent response. Pheophorbide b and pheophytin b were the strongest natural antioxidant compounds, whose activities were comparable to BHT. The high antioxidant activity found for pheophorbide b, in comparison to pheophorbide a, demonstrated the importance of the aldehyde group for functionality. On the other hand, by the DPPH assay, all natural pigments showed low antioxidant activity when compared to Trolox. Cu-chlorophyllin, tested by both methods, presented a higher antioxidant activity than that of natural chlorophylls, showing the importance of the nature of the chelated metal in the porphyrin ring. The mechanism of antioxidant activity displayed by the natural chlorophyll derivatives does not seem to be based on the ability to donate hydrogen but maybe, on the protection of linoleic acid against oxidation and/or preventing decomposition of hydroperoxides. (AU)

• Processo FAPESP: 02/01145-8 - Derivados incolores da degradacao da clorofila durante a maturacao e secagem de sementes de soja.
• Beneficiário: Patricia Sinnecker
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 03/08733-5 - Influencia da temperatura de secagem de soja no modelo de degradacao da clorofila: catabolitos esverdeados e incolores.
• Beneficiário: Ursula Maria Lanfer Marquez
• Modalidade de apoio: Auxílio à Pesquisa - Regular