First detection of Pectenotoxin-11 and confirmation of OA-D8 diol-ester in Dinophysis acuta from European waters by LC–MS/MS Gemita Pizarro a, * , Beatriz Paz b , Jose ´ M. Franco b , Toshiyuki Suzuki c , Beatriz Reguera a a Instituto Espan ˜ol de Oceanografı ´a, Centro Oceanogra ´fico de Vigo, Apdo. 1552, E-36200 Vigo, Spain b Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, 36080 Vigo, Spain c Tohoku National Fisheries Research Institute, 3-27-5 Shinhama Shiogama, Miyagi 985-0001, Japan article info Article history: Received 12 March 2008 Received in revised form 10 September 2008 Accepted 16 September 2008 Available online 27 September 2008 Keywords: Dinophysis acuta DSP-toxins Okadaic acid Dinophysistoxins OA-D8 diol-ester Dinophysistoxin-2 Pectenotoxins LC–MS/MS abstract During November 2005, a dense bloom of Dinophysis spp. dominated (>97%) by Dinophysis acuta in the Galician Rı ´as Baixas (NW Spain), provided a unique opportunity to describe the full toxin profile – including toxins that represent a low percentage and escape detection in analyses of single-cell isolates – in plankton concentrates rich in this species. Detection and identification of toxins were carried out by liquid chromatography coupled to mass spectrometry (LC–MS/MS), a method that is based on their retention times (RT) and the fragmentation patterns of their mass spectra. OA-D8 diol-ester and PTX11 were detected in co-occurrence with okadaic acid analogues (OA, DTX2) and PTX2 in plankton concentrates dominated by D. acuta. The presence of a PTX11-isomer, which was suggested to be PTX13 or a novel PTX11-isomer, released in the sea water, was also confirmed in samples obtained after deployment of passive samplers (SPATT) in situ at the time of the D. acuta bloom maximum. The amount of PTX11 per cell of D. acuta, estimated as PTX2 equivalents, ranged between not detected and 2.2 pg cell 1 , and represented a maximum of 2.9% of the total toxin content. The variation in PTX11 content per cell of D. acuta, during a daily cycle, followed the same pattern than that of PTX2, with maxima at 21:00 and 03:00 h (dark hours), but the amounts per cell were one order of magnitude lower. This is the first report of PTX11, together with the confirmation of OA-D8 diol-ester in D. acuta populations from Europe. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction Diarrhetic shellfish poisoning (DSP) is a severe gastro- intestinal illness caused by consumption of shellfish contaminated with toxins produced by planktonic dino- flagellates of the genus Dinophysis spp. (Yasumoto et al., 1980) and epiphytic species of the genus Prorocentrum spp. (Bauder et al., 1996). Okadaic acid (OA), dinophysistoxin-1 (DTX1) and dinophysistoxin-2 (DTX2) are the main toxins responsible for the DSP syndrome (Yasumoto et al., 1985). The co-occurrence of OA and DTX2 has only been reported in D. acuta populations from Spain, Ireland and Portugal (James et al., 1999; Ferna ´ ndez et al., 2001; Vale and Sampayo, 2000), whereas those from Norway and Sweden present a combination of OA, DTX1 and DTX2 (Miles et al., 2004b; Rundberget et al., 2007; Johansen, 2008). Several derivatives of okadaic acid and its esters, the OA diol-esters, have been reported from Prorocentrum spp. cultures (Yasumoto et al., 1987; Hu et al., 1995a, b; Sua ´ rez- Go ´ mez, 2005; Cruz et al., 2006). One of these derivatives, the OA-D8 diol-ester, was found in field populations of D. acuta from New Zealand (Suzuki et al., 2004) and its presence detected in populations of the same species from Galicia (Pizarro et al., 2008). * Corresponding author. Instituto de Fomento Pesquero, Enrique Abello, 0552 Punta Arenas, Chile. Tel.: þ56 61 211 424; fax: þ56 61 214 648. E-mail address: gpizarro@ifop.cl (G. Pizarro). Contents lists available at ScienceDirect Toxicon journal homepage: www.elsevier.com/locate/toxicon 0041-0101/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.toxicon.2008.09.001 Toxicon 52 (2008) 889–896