title: Phlorotannins as radical scavengers from the extract of Sargassum ringgoldianum.
abstract: To screen algal phlorotannins with antioxidative activities, 50% ethanol extracts of 25 Japanese marine algae were evaluated. Scavenging activity against superoxide anion radicals was frequently found with a high content of total phenolic compounds. Among these, the extract from the brown seaweed, Sargassum ringgoldianum, showed the strongest scavenging activity. The active fraction contained a mixture of high molecular weight polyphenols, phlorotannins that were found to be polymerized bifuhalol, as analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The scavenging activity of the fraction against superoxide anion radicals was estimated to be 1.0 microg/ml (IC(50)), which were approximately five times stronger than that of catechin.
authors.affiliation: Suntory Research Center, Suntory, Ltd., Wakayamadai 1-1-1, Shimamoto-cho, Mishima-gun, Osaka, 618-8503, Japan. Masaaki_Nakai@suntory.co.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakai
authors.forename: Norihiko
authors.initials: N
authors.lastname: Kageyama
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakahara
authors.forename: Wataru
authors.initials: W
authors.lastname: Miki
mesh_terms: D056890:Eukaryota / Q000737:chemistry / Q000378:metabolism; D005419:Flavonoids / Q000032:analysis; D016166:Free Radical Scavengers / Q000032:analysis*; D010636:Phenols / Q000032:analysis; D059808:Polyphenols; D044647:Sargassum / Q000737:chemistry* / Q000378:metabolism*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D013481:Superoxides / Q000378:metabolism*; D013634:Tannins / Q000378:metabolism*
chemical_list: D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D059808:Polyphenols; D013634:Tannins; D013481:Superoxides