Phenylpropanoid and phenylisoprenoid metabolites from Asteraceae species as inhibitors of protein carbonylation

► Plant phenolics inhibit carbonylation of albumin induced by hypochlorite or peroxynitrite. ► Known antioxidant potency does not correlate the effect against peroxynitrite. ► The dihydroflavonol, 7-methylaromadendrin is the most potent agent in leukocyte carbonylation.