title: Optimization of Ultrasound-assisted Extraction of Phenolic Compounds from Myrcia amazonica DC. (Myrtaceae) Leaves.
abstract: BACKGROUND
  Myrcia amazonica. DC is a species predominantly found in northern Brazil, and belongs to the Myrtaceae family, which possess various species used in folk medicine to treat gastrointestinal disorders, infectious diseases, and hemorrhagic conditions and are known for their essential oil contents.
  
  
  METHODS
  This study aimed applied the Box-Behnken design combined with response surface methodology to optimize ultrasound-assisted extraction of total polyphenols, total tannins (TT), and total flavonoids (TF) from M. amazonica DC.
  
  
  RESULTS
  The results indicated that the best conditions to obtain highest yields of TT were in lower levels of alcohol degree (65%), time (15 min), and also solid: Liquid ratio (solid to liquid ratio; 20 mg: 5 mL). The TF could be extracted with high amounts with higher extraction times (45 min), lower values of solid: Liquid ratio (20 mg: mL), and intermediate alcohol degree level.
  
  
  CONCLUSIONS
  The exploitation of the natural plant resources present very important impact for the economic development, and also the valorization of great Brazilian biodiversity. The knowledge obtained from this work should be useful to further exploit and apply this raw material.
  
  
  CONCLUSIONS
  Myrcia amazonica leaves possess phenolic compounds with biological applications;Lower levels of ethanolic strength are more suitable to obtain a igher levels of phenolic compouds such as tannins;Box-Behnken design indicates to be useful to explore the best conditions of ultrasound assisted extraction. Abbreviation used: Nomenclature ES: Ethanolic strength, ET: Extraction time, SLR: Solid to liquid ratio, TFc: Total flavonoid contents, TPc: Total polyphenol contents, TTc: Total tannin contents.
authors.affiliation: Laboratory of PD&I of Bioproducts, School of Pharmacy, Federal University of Goiás, Jataí, Brazil.
authors.forename: Mariana Cristina
authors.initials: MC
authors.lastname: de Morais Rodrigues
authors.affiliation: Laboratory of PD&I of Bioproducts, School of Pharmacy, Federal University of Goiás, Jataí, Brazil.
authors.forename: Leonardo Luiz
authors.initials: LL
authors.lastname: Borges
authors.affiliation: Department of Pharmaceutical Sciences, Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
authors.forename: Frederico Severino
authors.initials: FS
authors.lastname: Martins
authors.affiliation: Laboratory of Bioprospecting and experimental Biology, Department of Natural Resources of Amazônia, Federal University of Oeste do Pará, Santarém - PA, Brazil.
authors.forename: Rosa Helena V
authors.initials: RH
authors.lastname: Mourão
authors.affiliation: Laboratory of PD&I of Bioproducts, School of Pharmacy, Federal University of Goiás, Jataí, Brazil.
authors.forename: Edemilson Cardoso
authors.initials: EC
authors.lastname: da Conceição
keywords: Box–Behnken; Myrcia amazônica; flavonoids; polyphenols; tannins