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.

Presentación del documental "Paciente" en el Instituto Caro y Cuervo. Plano general sentados en butacas dando la espalda a la pantalla. De izquierda a derecha, Jorge Caballero, cineasta colombiano, autor de "Paciente"; e Iván Guarnizo, editor del documental.

Presentación del documental «Paciente» en el Instituto Caro y Cuervo. Plano medio de perfil, de izquierda a derecha, Jorge Caballero, cineasta colombiano, autor de «Paciente»; e Iván Guarnizo, editor del documental.

Presentación del documental "Paciente" en el Instituto Caro y Cuervo. Plano medio de perfil, de izquierda a derecha, Jorge Caballero, cineasta colombiano, autor de "Paciente"; e Iván Guarnizo, editor del documental.

Plano general de Cristina Aranda Gutiérrez, cofundadora de Mujeres Tech; de pie, durante su presentación: «No somos princesas consumidoras. Somos reinas de la tecnología».

Plano americano, de izquierda a derecha: Ana Roca Gadea, jefa de la biblioteca Álvaro Mutis del Instituto Cervantes de Estambul; Isabel Blanco Pardo, directora de la Red de Bibliotecas Municipales de A Coruña; José Antonio Gómez Hernández, profesor de Biblioteconomía de la Universidad de Murcia; Carme Fenoll i Clarabuch, jefa del Servicio de Bibliotecas de la Generalitat de Catalunya; Yolanda de la Iglesia Sánchez, jefa de Departamento de Bibliotecas y Documentación del Instituto Cervantes.

Plano general de Félix Serrano, director del Instituto Nacional de Tecnologías Educativas y Formación del Profesorado (INTEF); y moderador del debate, de pie ante el atril.

La sede del Instituto Cervantes de Madrid celebra la IX Jornada Profesional de la RBIC. Plano general que muestra a los ponentes del segundo panel, «Es misión de los bibliotecarios empoderar», de izquierda a derecha; el moderador, José Antonio Gómez Hernández, profesor de Biblioteconomía de la Universidad de Murcia; Ana Roca Gadea, jefa de biblioteca Álvaro Mutis, Instituto Cervantes de Estambul; Carme Fenoll i Clarabuch, jefa del Servicio de Bibliotecas de la Generalitat de Catalunya; Isabel Blanco Pardo, directora de la Red de Bibliotecas Municipales de A Coruña.

La sede del Instituto Cervantes de Madrid celebra la IX Jornada Profesional de la RBIC. Plano general que muestra a los ponentes del primer panel, «Vertientes del empoderamiento: variedad de destinos», de izquierda a derecha: Félix Serrano, director del Instituto Nacional de Tecnologías Educativas y Formación del Profesorado (INTEF); Montserrat Guitert Catasús, profesora de la Universitat Oberta de Catalunya; Cristina Aranda Gutiérrez, cofundadora de Mujeres Tech; Víctor Sampedro, catedrático del Departamento de Comunicación de la Universidad Rey Juan Carlos de Madrid; y Sofía de Roa, alumna egresada de la Universidad Rey Juan Carlos.