title: Structural Characterization of New Peptide Variants Produced by Cyanobacteria from the Brazilian Atlantic Coastal Forest Using Liquid Chromatography Coupled to Quadrupole Time-of-Flight Tandem Mass Spectrometry.
abstract: Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by these organisms, peptides are by far the most frequently described structures. In this work, liquid chromatography/electrospray ionization coupled to high resolution quadrupole time-of-flight tandem mass spectrometry with positive ion detection was applied to study the peptide profile of a group of cyanobacteria isolated from the Southeastern Brazilian coastal forest. A total of 38 peptides belonging to three different families (anabaenopeptins, aeruginosins, and cyanopeptolins) were detected in the extracts. Of the 38 peptides, 37 were detected here for the first time. New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra. Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.).
authors.affiliation: Faculty of Pharmaceutical Science, University of São Paulo, Avenida Lineu Prestes 580, Bl-17-05508-900 São Paulo, SP, Brazil. miriam.sanz.roldan@usp.br.
authors.forename: Miriam
authors.initials: M
authors.lastname: Sanz
authors.affiliation: Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, 13400-970 Piracicaba, SP, Brazil. apdini@cena.usp.br.
authors.forename: Ana Paula Dini
authors.initials: AP
authors.lastname: Andreote
authors.affiliation: Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, 13400-970 Piracicaba, SP, Brazil. fiore@cena.usp.br.
authors.forename: Marli Fatima
authors.initials: MF
authors.lastname: Fiore
authors.affiliation: Faculty of Pharmaceutical Science, University of São Paulo, Avenida Lineu Prestes 580, Bl-17-05508-900 São Paulo, SP, Brazil. fadorr@usp.br.
authors.forename: Felipe Augusto
authors.initials: FA
authors.lastname: Dörr
authors.affiliation: Faculty of Pharmaceutical Science, University of São Paulo, Avenida Lineu Prestes 580, Bl-17-05508-900 São Paulo, SP, Brazil. ernani@usp.br.
authors.forename: Ernani
authors.initials: E
authors.lastname: Pinto
mesh_terms: D001938:Brazil; D002853:Chromatography, Liquid / Q000379:methods*; D000458:Cyanobacteria / Q000378:metabolism*; D065928:Forests; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010455:Peptides
keywords: Brasilonema; Desmonostoc; HPLC-ESI-QTOF-MS; Nostoc; aeruginosin; anabaenopeptolin; cyanobacteria; cyanopeptolin; mass spectrometry; peptides; structural elucidation