[Assessment of antioxidant activity of natural compound by water- and lipid-soluble antioxidant factor].

We evaluated the antioxidant activity of natural compounds in water-soluble and lipid-soluble phases and found that ferulic acid, quercetin and caffeic acid showed stronger activity in the water-soluble phase. Various fractions isolated from Bidens pilosa showed this activity mainly in the water-soluble phase. Antioxidant activity in the lipid-soluble phase of propolis depended on the lipophilic extraction.