BUSCADOR RECOLECTA

Maitotoxins (MTXs) are among the most potent toxins known. These toxins are produced by epi-benthic dinoflagellates of the genera Gambierdiscus and Fukuyoa and may play a role in causing the symptoms associated with Ciguatera Fish Poisoning. A recent survey revealed that, of the species tested, the newly described species from the Canary Islands, G. excentricus, is one of the most maitotoxic. The goal of the present study was to characterize MTX-related compounds produced by this species. Initially, lysates of cells from two Canary Island G. excentricus strains VGO791 and VGO792 were partially purified by (i) liquid-liquid partitioning between dichloromethane and aqueous methanol followed by (ii) size-exclusion chromatography. Fractions from chromatographic separation were screened for MTX toxicity using both the neuroblastoma neuro-2a (N2a) cytotoxicity and Ca2+ flux functional assays. Fractions containing MTX activity were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) to pinpoint potential MTX analogs. Subsequent non-targeted HRMS analysis permitted the identification of a novel MTX analog, maitotoxin-4 (MTX4, accurate mono-isotopic mass of 3292.4860 Da, as free acid form) in the most toxic fractions. HRMS/MS spectra of MTX4 as well as of MTX are presented. In addition, crude methanolic extracts of five other strains of G. excentricus and 37 other strains representing one Fukuyoa species and ten species, one ribotype and one undetermined strain/species of Gambierdiscus were screened for the presence of MTXs using low resolution tandem mass spectrometry (LRMS/MS). This targeted analysis indicated the original maitotoxin (MTX) was only present in one strain (G. australes S080911_1). Putative maitotoxin-2 (p-MTX2) and maitotoxin-3 (p-MTX3) were identified in several other species, but confirmation was not possible because of the lack of reference material. Maitotoxin-4 was detected in all seven strains of G. excentricus examined, independently of their origin (Brazil, Canary Islands and Caribbean), and not detected in any other species. MTX4 may therefore serve as a biomarker for the highly toxic G. excentricus in the Atlantic area.

Maitotoxins (MTXs) are among the most potent toxins known. These toxins are produced by epi-benthic dinoflagellates of the genera Gambierdiscus and Fukuyoa and may play a role in causing the symptoms associated with Ciguatera Fish Poisoning. A recent survey revealed that, of the species tested, the newly described species from the Canary Islands, G. excentricus, is one of the most maitotoxic. The goal of the present study was to characterize MTX-related compounds produced by this species. Initially, lysates of cells from two Canary Island G. excentricus strains VGO791 and VGO792 were partially purified by (i) liquid-liquid partitioning between dichloromethane and aqueous methanol followed by (ii) size-exclusion chromatography. Fractions from chromatographic separation were screened for MTX toxicity using both the neuroblastoma neuro-2a (N2a) cytotoxicity and Ca2+ flux functional assays. Fractions containing MTX activity were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) to pinpoint potential MTX analogs. Subsequent non-targeted HRMS analysis permitted the identification of a novel MTX analog, maitotoxin-4 (MTX4, accurate mono-isotopic mass of 3292.4860 Da, as free acid form) in the most toxic fractions. HRMS/MS spectra of MTX4 as well as of MTX are presented. In addition, crude methanolic extracts of five other strains of G. excentricus and 37 other strains representing one Fukuyoa species and ten species, one ribotype and one undetermined strain/species of Gambierdiscus were screened for the presence of MTXs using low resolution tandem mass spectrometry (LRMS/MS). This targeted analysis indicated the original maitotoxin (MTX) was only present in one strain (G. australes S080911_1). Putative maitotoxin-2 (p-MTX2) and maitotoxin-3 (p-MTX3) were identified in several other species, but confirmation was not possible because of the lack of reference material. Maitotoxin-4 was detected in all seven strains of G. excentricus examined, independently of their origin (Brazil, Canary Islands and Caribbean), and not detected in any other species. MTX4 may therefore serve as a biomarker for the highly toxic G. excentricus in the Atlantic area.

La Asociación Bernardo de Gálvez y el Instituto Cervantes presentan el libro «Bernardo de Gálvez. Héroe recuperado», de Manuel Olmedo y Francisco Cabrera, en el salón de actos de la sede central del Instituto Cervantes. Plano medio de Rafael Rodríguez-Ponga Salamanca, secretario general del Instituto Cervantes, en el atril.

La Asociación Bernardo de Gálvez y el Instituto Cervantes presentan el libro «Bernardo de Gálvez. Héroe recuperado», de Manuel Olmedo y Francisco Cabrera, en la sede central del Instituto Cervantes. Plano medio de Miguel Ángel Gálvez, presidente de la Asociación cultural Bernardo de Gálvez y Gallardo Conde de Gálvez, en el atril.

La Asociación Bernardo de Gálvez y el Instituto Cervantes presentan el libro «Bernardo de Gálvez. Héroe recuperado», de Manuel Olmedo y Francisco Cabrera, en la sede central del Instituto Cervantes. Plano medio de Francisco de la Torre, alcalde de Málaga, en el atril.

La Asociación Bernardo de Gálvez y el Instituto Cervantes presentan el libro «Bernardo de Gálvez. Héroe recuperado», de Manuel Olmedo y Francisco Cabrera, en la sede central del Instituto Cervantes. Plano general, de izquierda a derecha, XXX; Francisco de la Torre, alcalde de Málaga;Rafael Rodríguez-Ponga Salamanca, secretario general del Instituto Cervantes;Miguel Ángel Gálvez, presidente de la Asociación cultural Bernardo de Gálvez y Gallardo Conde de Gálvez; Beatriz Hernanz Angulo, directora de Cultura del Instituto Cervantes; y Manuel Olmedo Checa, historiador, en la Caja de las Letras del Instituto Cervantes.

Presentación del libro «Diario de Argónida», de José Manuel Caballero Bonald, en la sede central del Instituto Cervantes. Plano general, de izquierda a derecha, Beatriz Hernanz Angulo, directora de Cultura del Instituto Cervantes; Víctor García de la Concha, académico de la Real Academia Española y exdirector del Instituto Cervantes; José Manuel Caballero Bonald, poeta; Pedro Tabernero, crítico de literatura y editor; Juan Manuel Bonet, director del Instituto Cervantes; Luis Manuel Fernández, pintor; y Rafael Rodríguez-Ponga Salamanca, secretario general del Instituto Cervantes, en la Caja de las Letras del Instituto Cervantes.

Presentación del libro «Diario de Argónida», de José Manuel Caballero Bonald, en el salón de actos de la sede central del Instituto Cervantes. Plano medio, de izquierda a derecha, Luis Manuel Fernández, pintor; José Manuel Caballero Bonald, poeta; Víctor García de la Concha, académico de la RAE y exdirector del Instituto Cervantes; y Pedro Tabernero, crítico de literatura y editor, sentados en el salón de actos de la sede central del Instituto Cervantes.

Presentación del libro «Diario de Argónida», de José Manuel Caballero Bonald, en el salón de actos de la sede central del Instituto Cervantes. Plano medio de Juan Manuel Bonet, director del Instituto Cervantes, leyendo en el atril.

Presentación del libro «Diario de Argónida», de José Manuel Caballero Bonald, en el salón de actos de la sede central del Instituto Cervantes. Plano medio, de izquierda a derecha, Luis Manuel Fernández, pintor; José Manuel Caballero Bonald, poeta; y Víctor García de la Concha, académico de la RAE y exdirector del Instituto Cervantes, sentados en el salón de actos de la sede central del Instituto Cervantes.