Antioxidative activity of a zinc-chelating substance in coffee.
Coffee brew contains a brownish zinc-chelating polymer designated ApV. ApV was prepared from the precipitate formed in a solution of instant coffee by adding ZnCl(2) and purified using ion-exchange and cellulose column chromatographies. The antioxidative activities of ApV and related compounds were evaluated in this study. The free-radical scavenging activity of ApV estimated by ABTS assay was at a similar level to that of instant coffee, while the O(2)(-) scavenging activity of ApV, which is superoxide dismutase-like activity, was lower than that of instant coffee. The hydroxyl-radical scavenging activity of ApV was higher than that of instant coffee, and the auto-oxidation of linoleic acid was more strongly inhibited by ApV than by caffeic acid.
Wen
Xu
X
Department of Nutrition and Food Science, Ochanomizu University, Tokyo, Japan.
Takenaka
Makiko
M
Murata
Masatsune
M
Homma
Seiichi
S
D000042:Absorption; D000975:Antioxidants / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D003069:Coffee / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry; D007202:Indicators and Reagents; D019787:Linoleic Acid / Q000737:chemistry; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
D000975:Antioxidants; D002614:Chelating Agents; D003069:Coffee; D016166:Free Radical Scavengers; D007202:Indicators and Reagents; D019787:Linoleic Acid; D013482:Superoxide Dismutase; D015032:Zinc