Abstract
Seven known compounds, pyrroside B (1), swertisin (2), isovitexin (3), isoswertiajaponin (4), vomifoliol (blumenol A) (5), (6S,9R)-roseoside (6) and angelicoidenol (7) were isolated from the methanol (MeOH) extract of the aerial part of Piper elongatum VAHL. and their structures were identified on the basis of physical and spectral data. In addition, the antioxidative activity of 1–4 was evaluated by the ferric thiocyanate method. All these compounds showed stronger antioxidative activity than that of α-tocopherol. Furthermore, the scavenging effects on 1,1-diphenyl-2-picrylhydrazyl (DPPH), the antihyaluronidase and the antityrosinase activities of 1–4, asebogenin (8), 2′,6′-dihydroxy-4′-methoxydihydrochalcone (9), 3-geranyl-4-methoxybenzoic acid (10), 3-geranyl-4-hydroxybenzoic acid (11), nervogenic acid (12) and 2,2-dimethyl-6-carboxyl-8-prenyl-chromene (13), which were previously isolated from the MeOH extract were evaluated. Compounds 4, 8 and 9 showed higher radical scavenging effect than that of L-cysteine, and 4, 8 and 11 exhibited stronger inhibition effect on the activation of hyaluronidase than that of tranilast. Compound 8 indicated almost the same antityrosinase activity as that of kojic acid.
