title: Chemical composition of Argentinean propolis collected in extreme regions and its relation with antimicrobial and antioxidant activities.
abstract: This paper reveals, for the first time, the functional properties of propolis from an extreme region of Argentine (El Rincón, Province of Catamarca, Argentina), as well as the isolation and identification of bioactive compounds. The antioxidant activity was determined by the ABTS method and beta-carotene bleaching. The antibacterial activity was determined on methicillin resistant Staphylococcus aureus (MRSA) by the microdilution method and bioautographic assays. Twelve compounds were isolated and identified by NMR spectroscopy. The main bioactive compounds were 2',4'-dihydroxy-3'-methoxychalcone (3), 2',4'-dihydroxychalcone (9), 2',4',4-trihydroxy-6'- methoxychalcone (8), 5-hydroxy-4',7-dimethoxyflavone (4), 4',5-dihydroxy-3,7,8-trimethoxyflavone (10) and 7-hydroxy- 5,8-dimethoxyflavone (11). All compounds were active against clinical isolates (MIC50 10 microg/mL) and displayed antioxidant activity (SC50 values of 20 microg/mL). The MIC and SC50 values of the isolated compounds were lower than those obtained with crude propolis extracts, chloroform sub-extracts and isolated fractions.
authors.affiliation: Facultad de Bioquímica, Química y Farmacia, Ayacucho 471, Universidad Nacional de Tucumán, 4000 San Miguel de Tucumán, Argentina.
authors.forename: Nancy
authors.initials: N
authors.lastname: Vera
authors.forename: Eliana
authors.initials: E
authors.lastname: Solorzano
authors.forename: Roxana
authors.initials: R
authors.lastname: Ordoñez
authors.forename: Luis
authors.initials: L
authors.lastname: Maldonado
authors.forename: Enrique
authors.initials: E
authors.lastname: Bedascarrasbure
authors.forename: María I
authors.initials: MI
authors.lastname: Isla
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D001118:Argentina; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D011429:Propolis / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000975:Antioxidants; D011429:Propolis