Pectenotoxin-2 seco acid: a toxin converted from pectenotoxin-2 by the NewZealand Greenshell mussel, Perna canaliculus

Comparison of pectenotoxin (PTX) profiles of toxic dinoflagellate Dinophysi s acuta, Greenshell mussels (Perna canaliculus) and Blue mussels (Mytilus g alloprovincialis) collected from Wedge Point, Queen Charlotte Sound, New Ze aland was carried out by liquid chromatography-mass spectrometry with turbo -ionspray ionization. Although the major PTX homologue in D. acuta was pect enotoxin-2 (PTX2), both Greenshell and Blue mussels contained pectenotoxin- 2 seco acid (PTX2SA) as the predominant toxin. More than 90% of PTX2 isolat ed from D. acuta was rapidly converted to PTX2SA and its epimer 7-epi-pecte notoxin-2 seco acid (7-epi-PTX2SA) in the Greenshell mussel extracts. The c onversion from PTX2 to PTX2SA and 7-epi-PTX2SA was not observed in phosphat e buffers at various pH ranging from 4.1 to 9.1. These findings indicate th at PTX2SA and 7-epi-PTX2SA are not artifact toxins resulting from hydrolysi s of PTX2, but arise from the conversion of PTX2 by mussel tissues. (C) 200 0 Elsevier Science Ltd. All rights reserved.