title: Melanogenesis inhibitory and free radical scavenging activities of diarylheptanoids and other phenolic compounds from the bark of Acer nikoense.
abstract: Melanogenesis inhibitory and free radical scavenging activities of nine cyclic (1-9) and one acyclic diarylheptanoids (10), and two phenolic compounds, (+)-rhododendrol (11) and (+)-catechin (12), isolated from the ethyl acetate-soluble fraction of the MeOH extract of the bark of Acer nikoense MAXIM. (Aceraceae) were examined. Upon evaluation of compounds 1-12 on the melanogenesis in the B16 melanoma cells, two compounds, 2 and 8, exhibited marked inhibitory activity with 55.6% and 46.8% reduction, respectively, of melanin content at 25 microg/ml without inhibition of cell proliferation. In addition, upon an evaluation of eleven compounds, 1-7 and 9-12 against the scavenging activities of free radicals (against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical), compound 12 (IC(50) 9.0 microgM) followed by compounds 1, 3, 4, and 6 (IC(50) 40.2-44.0 microgM) showed potent scavenging activities.
authors.affiliation: College of Science and Technology, Nihon University, Kanda Surugadai, Tokyo, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Akazawa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Akihisa
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Taguchi
authors.forename: Norihiro
authors.initials: N
authors.lastname: Banno
authors.forename: Risa
authors.initials: R
authors.lastname: Yoneima
authors.forename: Ken
authors.initials: K
authors.lastname: Yasukawa
mesh_terms: D031002:Acer / Q000737:chemistry*; D000818:Animals; D036381:Diarylheptanoids / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology*; D008543:Melanins / Q000096:biosynthesis*; D051379:Mice; D010636:Phenols / Q000494:pharmacology*; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*
chemical_list: D036381:Diarylheptanoids; D016166:Free Radical Scavengers; D008543:Melanins; D010636:Phenols; D010936:Plant Extracts