title: Color variation assay of the anthocyanins from Açai Fruit (Euterpe oleracea): a potential new dye for vitreoretinal surgery.
abstract: OBJECTIVE
  The goals of this study were to determine the potential for use of the natural anthocyanins from the açai fruit (Euterpe oleracea) during vitreoretinal surgery and the ideal physicochemical properties of the dye.
  
  
  METHODS
  We evaluated the color variations of the dye at different pHs and osmolarities with or without the use of mordants as a potential new tool for internal limiting membrane peeling. The extracts of anthocyanin from the açai fruit were analyzed by spectrophotometry to determine the degree of color variations associated with various pHs and osmolarities. The experiments were conducted in test tubes filled with tryptophan soya media and Petri dishes prepared with agar media.
  
  
  RESULTS
  We observed various shades of green, red, and purple in the extracts of the anthocyanin dye at different pHs and osmolarities. The assay to adjust the anthocyanin solution similar to the physiologic retinal environment (osmolarity, 300 mOsm; pH, 7.00) resulted in a shade of purple that may be useful to stain the intraocular microstructures during vitreoretinal surgery. The physicochemical property of the purple anthocyanin solutions from the açai fruit was observed at physiologic pH and osmolarity.
  
  
  CONCLUSIONS
  Anthocyanins from the açai fruit may be useful to enhance visualization of the intraocular microstructures during vitreoretinal surgery.
authors.affiliation: 1 Department of Ophthalmology, Vision Institute (IPEPO), Federal University of São Paulo , São Paulo, Brazil .
authors.forename: Cristiane Siqueira
authors.initials: CS
authors.lastname: Peris
authors.forename: Emmerson
authors.initials: E
authors.lastname: Badaro
authors.forename: Magno Antonio
authors.initials: MA
authors.lastname: Ferreira
authors.forename: Acácio Alves Souza
authors.initials: AA
authors.lastname: Lima-Filho
authors.forename: Eber Lopes
authors.initials: EL
authors.lastname: Ferreira
authors.forename: Andre
authors.initials: A
authors.lastname: Maia
authors.forename: Eduardo Buchele
authors.initials: EB
authors.lastname: Rodrigues
authors.forename: Michel Eid
authors.initials: ME
authors.lastname: Farah
authors.forename: Maurício
authors.initials: M
authors.lastname: Maia
mesh_terms: D000872:Anthocyanins / Q000008:administration & dosage / Q000737:chemistry* / Q000302:isolation & purification; D028023:Arecaceae / Q000737:chemistry*; D002102:Cadaver; D003116:Color; D004396:Coloring Agents / Q000008:administration & dosage / Q000737:chemistry* / Q000302:isolation & purification; D005123:Eye / Q000737:chemistry* / Q000473:pathology; D005638:Fruit / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D028321:Plant Preparations / Q000008:administration & dosage / Q000737:chemistry* / Q000302:isolation & purification; D013194:Staining and Labeling; D057586:Vitreoretinal Surgery
chemical_list: D000872:Anthocyanins; D004396:Coloring Agents; D028321:Plant Preparations