Identification of 19-epi-okadaic Acid, a New Diarrhetic Shellfish Poisoning Toxin, by Liquid Chromatography with Mass Spectrometry Detection

Okadaic acid (1) (OA) and its congeners are mainly responsible for diarrhetic shellfish poisoning (DSP) syndrome. The presence of several OA derivatives have already been confirmed in Prorocentrum and Dinophysis spp. In this paper, we report on the detection and identification of a new DSP toxin, the OA isomer 19-epi-okadaic acid (2) (19-epi-OA), isolated from cultures of Prorocentrum belizeanum, by determining its retention time (RT) and fragmentation pattern using liquid chromatography coupled with mass spectrometry (LC–MS/MS).Versión del editor3,471

Identificación y caracterización por LC-MS de derivados del Ácido Okadaico en cultivos de Prorocentrum belizeanum

En el presente estudio, las principales toxinas producidas por el dinoflagelado Prorocentrum belizeanum (Ácido okadaico, DTX-5c y 7- hidroximetil-2-metilen-octa-4,7-dienil okadaato) fueron analizadas en un sistema de cromatografía líquida acoplado a espectrometría de masas (LCMS), lo que permitió determinar los tiempos de retención (tR) respectivos y los patrones de fragmentación asociados. Como una muestra de la aplicabilidad de la metodología empleada, diversas muestras provenientes de cultivos in vitro de P. belizeanum fueron analizadas.Versión del edito

Identification and characterization of DTX-5c and 7-hydroxymethyl-2-methylene-octa-4,7-dienyl okadaate from Prorocentrum belizeanum cultures by LC–MS

The main toxins produced by the dinoflagellate Prorocentrum belizeanum, DTX5c and 7-hydroxymethyl-2methylene-octa-4,7 dienyl okadaate, were studied by liquid chromatography-coupled with ion trap mass spectrometry (LC–MS/MS). Their retention times (RTs) and fragmentation patterns were established, in particular those of DTX5c, as there is a lack of data about these water soluble OA sulphated derivatives. As an application of the LC–MS methodology, a sample of the toxic P. belizeanum culture was analysed for these metabolites. Both metabolites were detected in cells as majority compounds, whereas levels of these compounds in the culture media were undetectable.Versión del editor2,924

Characterisation of okadaic acid related toxins by liquid chromatography coupled with mass spectrometry

In the Diarrhetic Shellfish Poisoning (DSP) phenomena, the parent toxins, namely okadaic acid (OA) and/or dinophysistoxin-2 (DTX2), are predominantly found esterified. Therefore, a toxicity assessment of a sample can only be performed after an alkaline hydrolysis step in order to recover the parent molecules in their free form. The presence of several OA diol esters has already been confirmed in Prorocentrum lima and Prorocentrum belizeanum cultures. This paper reports on the analysis of OA diol esters using liquid chromatography coupled with mass spectrometry (LC–MS/MS), and establishes a method for their detection and identification based upon their retention times (RT) and the fragmentation patterns of their mass spectra.Versión del editor2,924