Antioxidant, antimicrobial activities and characterization of phenolic compounds from buriti (Mauritia flexuosa L. f.) by UPLC-ESI-MS/MS

Mauritia flexuosa L. f. is a native palm tree from the South American Amazon rainforest commercialized in food, cosmetics and medicine. This paper reported the antioxidant, antimicrobial activities and characterization of phenolics from buriti leafs, trunk and fruit extracts. The total phenolics of the buriti extracts ranged from 378.07 +/- 3.12 to 86.89 +/- 3.15 mg GAEq/100 g and flavonoid content ranged from 567.16 +/- 1.15 to 246.84 +/- 1.11 mg QUEREq/100 g. The antioxidant activity assays with EC50, of 12.28 +/- 0.022 to 19.58 +/- 0.064 mg/mL revealed the antioxidant capacity of M. flexuosa extracts. Results of the antimicrobial tests against some pathogenic bacteria revealed its strong ability to inhibit the growth of pathogen with low MIC values, where the best results were found with the leaf extract against the pathogen Pseudomonas aeruginosa (MIC 50 mu g/mL). The characterization of the phenolic compounds using Ultra Performance Liquid Chromatography coupled to Electrospray Ionization Tandem Mass Spectrometry (UPLC-ESI-MS/MS) was based on CID experiments of the observed precursors, thus 13 compounds were tentatively identified ((+)-catechin, caffeic acid hexoside, chlorogenic acid, quercetin, narigenin, myricetin, vitexin, scoparin, rutin, cyanidin-3-rutinoside, cyanidin-3-glucoside, (-)-epicatechin and kaempferol). These results indicate that antioxidant and antimicrobial activities in buriti phenolic extracts are quite potent and implicate the presence of compounds with potent free-radical-scavenging activity. (C) 2013 Elsevier Ltd. All rights reserved.