title: Antioxidant and antimutagenic polyisoprenylated benzophenones and xanthones from Rheedia acuminata.
abstract: Dichloromethane extract of the stem bark of Rheedia acuminata yielded three benzophenones with antioxidant activity, the new one named acuminophenone A (1), guttiferone K (2) and isoxanthochymol (3), along with the known xanthones formoxanthone C (4) and macluraxanthone (5). The structures were established through interpretation of their spectroscopic data, the stereochemistry of compounds (1) and (2) were resolved by experimental and computational experiments and their antioxidant activities were measured using the DPPH, ABTS and TEAC assays. The antioxidant results showed that metabolites 1, 4 and 5 had a better antioxidant activity than the reference compound quercetin. In addition, we evaluate the mutagenicity and antimutagenicity of the CH2Cl2 extract as well as of the free radical scavenger compounds 1, 4 and 5 by the AMES Salmonella/microsomal test. No mutagenicity was found in the CH2Cl2 extract using Salmonella typhimurium strains TA98, TA100, TA102, TA1537 and TA1538, with or without S9 metabolic activation. The pure compounds neither showed mutagenicity in TA 102 strain and the most important result was the strong reduction of mutagenic effect induced by hydrogen peroxide in S. typhimurium TA102, with or without S9, showed by the compounds 1 (more than 93%) and 4 (more than 88%) at 0.02 microg/plate.
authors.affiliation: Instituto de Investigaciones Químicas, Universidad Mayor de San Andrés, CP 303, La Paz, Bolivia. giovyalmanza@yahoo.com.ar
authors.forename: Giovanna R
authors.initials: GR
authors.lastname: Almanza
authors.forename: Raúl
authors.initials: R
authors.lastname: Quispe
authors.forename: Patricia
authors.initials: P
authors.lastname: Mollinedo
authors.forename: Gloria
authors.initials: G
authors.lastname: Rodrigo
authors.forename: Odette
authors.initials: O
authors.lastname: Fukushima
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Villagomez
authors.forename: Bjorn
authors.initials: B
authors.lastname: Akesson
authors.forename: Olov
authors.initials: O
authors.lastname: Sterner
mesh_terms: D016587:Antimutagenic Agents / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D001577:Benzophenones / Q000737:chemistry* / Q000494:pharmacology*; D001713:Biphenyl Compounds; D028084:Clusiaceae / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010851:Picrates; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D012475:Salmonella / Q000187:drug effects; D044004:Xanthones / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D016587:Antimutagenic Agents; D000975:Antioxidants; D001577:Benzophenones; D001713:Biphenyl Compounds; D010851:Picrates; D044004:Xanthones; C004931:1,1-diphenyl-2-picrylhydrazyl