title: Microcystin-LR Detected in a Low Molecular Weight  Fraction from a Crude Extract of Zoanthus sociatus.
abstract: Cnidarian constitutes a great source of bioactive compounds. However, research involving peptides from organisms belonging to the order Zoanthidea has received very little attention, contrasting to the numerous studies of the order Actiniaria, from which hundreds of toxic peptides and proteins have been reported. In this work, we performed a mass spectrometry analysis of a low molecular weight (LMW) fraction previously reported as lethal to mice. The low molecular weight (LMW) fraction was obtained by gel filtration of a Zoanthus sociatus (order Zoanthidea) crude extract with a Sephadex G-50, and then analyzed by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry (MS) in positive ion reflector mode from m/z 700 to m/z 4000. Afterwards, some of the most intense and representative MS ions were fragmented by MS/MS with no significant results obtained by Protein Pilot protein identification software and the Mascot algorithm search. However, microcystin masses were detected by mass-matching against libraries of non-ribosomal peptide database (NORINE). Subsequent reversed-phase C18 HPLC (in isocratic elution mode) and mass spectrometry analyses corroborated the presence of the cyanotoxin Microcystin-LR (MC-LR). To the best of our knowledge, this finding constitutes the first report of MC-LR in Z. sociatus, and one of the few evidences of such cyanotoxin in cnidarians.
authors.affiliation: CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal. danydguezperez@gmail.com.|Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal. danydguezperez@gmail.com.
authors.forename: Dany
authors.initials: D
authors.lastname: Domínguez-Pérez
authors.affiliation: Department of Experimental and Clinical Peptide Chemistry, Hanover Medical School (MHH), Feodor-Lynen-Straße 31, D-30625 Hannover, Germany. aara259@gmail.com.
authors.forename: Armando Alexei
authors.initials: AA
authors.lastname: Rodríguez
authors.affiliation: Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal. hosorio@ipatimup.pt.|Ipatimup, Institute of Molecular Pathology and Immunology of the University of Porto, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal. hosorio@ipatimup.pt.|Department of Pathology and Oncology, Faculty of Medicine, University of Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal. hosorio@ipatimup.pt.
authors.forename: Hugo
authors.initials: H
authors.lastname: Osorio
authors.affiliation: CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal. joana_passo@hotmail.com.
authors.forename: Joana
authors.initials: J
authors.lastname: Azevedo
authors.affiliation: Faculty of Biology, University of La Habana, 25 St 455, CP 10400 La Habana, Cuba. edapasaron@gmail.com.
authors.forename: Olga
authors.initials: O
authors.lastname: Castañeda
authors.affiliation: CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal. vmvascon@fc.up.pt.|Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal. vmvascon@fc.up.pt.
authors.forename: Vítor
authors.initials: V
authors.lastname: Vasconcelos
authors.affiliation: CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal. aantunes@ciimar.up.pt.|Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal. aantunes@ciimar.up.pt.
authors.forename: Agostinho
authors.initials: A
authors.lastname: Antunes
mesh_terms: D000818:Animals; D037421:Anthozoa; D045424:Complex Mixtures / Q000032:analysis* / Q000737:chemistry; D008387:Marine Toxins; D052998:Microcystins / Q000032:analysis*; D008970:Molecular Weight
chemical_list: D045424:Complex Mixtures; D008387:Marine Toxins; D052998:Microcystins; C057862:cyanoginosin LR
keywords: microcystins;   MC‐LR;   Sephadex  G50;   Zoanthus  sociatus;   cnidarian;   zoanthidea;    MALDI‐TOF/TOF