title: Bromophenols from the marine red alga Polysiphonia urceolata with DPPH radical scavenging activity.
abstract: Three new (1-3) and three known (4-6) bromophenols were isolated and identified from the marine red alga Polysiphonia urceolata. On the basis of extensive analysis of spectroscopic data, the structures of these compounds were determined to be 7-bromo-9,10-dihydrophenanthrene-2,3,5,6-tetraol (1), 4,7-dibromo-9,10-dihydrophenanthrene-2,3,5,6-tetraol (2), 1,8-dibromo-5,7-dihydrodibenzo[ c,e]oxepine-2,3,9,10-tetraol (3), urceolatol (4), 3-bromo-4,5-dihydroxybenzaldehyde (5), and 3,5-dibromo-4-hydroxybenzaldehyde (6). Each of the isolated compounds was evaluated for alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical scavenging activity, and all were found to be potent, with IC50 values ranging from 6.1 to 35.8 microM, compared to the positive control, butylated hydroxytoluene (BHT), with an IC50 of 83.8 microM.
authors: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China.
authors: Ke
authors: K
authors: Li
authors: Xiao-Ming
authors: XM
authors: Li
authors: Nai-Yun
authors: NY
authors: Ji
authors: Bin-Gui
authors: BG
authors: Wang
mesh_terms: D001713:Biphenyl Compounds; D002084:Butylated Hydroxytoluene / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D006842:Hydrocarbons, Brominated / Q000737:chemistry / Q000302:isolation & purification*; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D010851:Picrates / Q000494:pharmacology; D000461:Rhodophyta / Q000737:chemistry*; D014357:Trypsin / Q000378:metabolism
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006842:Hydrocarbons, Brominated; D010851:Picrates; D002084:Butylated Hydroxytoluene; C004931:1,1-diphenyl-2-picrylhydrazyl; D014357:Trypsin