title: Extraction and characterization of pectins from primary cell walls of edible açaí (Euterpe oleraceae) berries, fruits of a monocotyledon palm.
abstract: Açaí berries (Euterpe oleracea) are greatly consumed in Brazil and exported to other countries as a nutritional supplement, due to health benefits attributed to its consumption. However, the complete chemical structure of bioactive polysaccharides was not fully elucidated yet. In this work, we characterize pectic polysaccharides from açaí berries through monosaccharide composition, HPSEC, methylation and13C and1H/13C HSQC-DEPT-NMR analyses. A highly methoxylated homogalacturonan with a DM of 88% and Mw of 22kDa together with small amounts of a mannoglucan were found. Moreover, a type II arabinogalactan (Mw=45kDa) containing a backbone with high portions of 6-O-linked and 3,6-O-linked Galp chains rather than 3-O-linked Galp was also isolated and structurally characterized. The type II arabinogalactan was found as a side chain of a type I rhamnogalacturonan. These findings contribute to correlate the fine chemical structure with the previously reported action of açaí polysaccharides on innate immune response. Moreover, from the taxonomic point of view, the results bring new information about polysaccharide composition of primary cell walls of palms (Arecaceae), that despite being commelinid monocots, have a distinct cell wall composition.
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-980, Curitiba, PR, Brazil.
authors.forename: Thaisa Moro
authors.initials: TM
authors.lastname: Cantu-Jungles
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-980, Curitiba, PR, Brazil.
authors.forename: Marcello
authors.initials: M
authors.lastname: Iacomini
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-980, Curitiba, PR, Brazil.
authors.forename: Thales R
authors.initials: TR
authors.lastname: Cipriani
authors.affiliation: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-980, Curitiba, PR, Brazil. Electronic address: lucimaramcc@ufpr.br.
authors.forename: Lucimara M C
authors.initials: LM
authors.lastname: Cordeiro
mesh_terms: D002473:Cell Wall / Q000737:chemistry*; D065748:Euterpe / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D010368:Pectins / Q000302:isolation & purification*
chemical_list: D010368:Pectins
keywords: Arecaceae; Açaí berries; Highly methoxylated homogalacturonan; Palm fruits; Type II arabinogalactan