2007 年 13 巻 4 号 p. 366-371
Four phenolic compounds were isolated from Japanese butterbur (Petasites japonicus) by preparative RP-HPLC technique, and were identified as chlorogenic acid (CGA), fukinolic acid (FA), 3,5-dicaffeoyl quinic acid, and 3,4,5-tricaffeoyl quinic acid. Since the antioxidant activity of FA among these four compounds has not been reported in detail, we investigated the scavenging activity of FA against several active oxygens and radicals, compared with CGA, gallic acid (GA) and epigallocatechin gallate (EGCG), using ESR spectroscopy. The order of potency of scavenging superoxide anion, nitric oxide (NO) and DPPH was EGCG>FA>CGA. The order of potency of scavenging hydroxyl radical was EGCG>FA>GA. FA inhibited the lipopolysaccharide-stimulated NO production and inducible NO synthase protein and mRNA expression by mouse macrophage-like cells Raw 264.7 more potently than CGA. The present study suggests the usefulness of FA as an antioxidant.