A Novel Pectenotoxin, PTX-12, in Dinophysis Spp. and Shellfish from Norway

Abstract

Two novel pectenotoxins (PTXs) were detected by LC-MS in solid phase extracts of net hauls taken at Flødevigen, Norway, in June 2002 that were dominated by Dinophysis acuminata and Dinophysis norvegica. The new compounds were isolated as minor components from a large collection of a Dinophysis acuta-dominated bloom obtained from Skjer, Sognefjorden, Norway, in October 2002. LC-MS and NMR analyses revealed that the new components, 36S-PTX-12 and 36R-PTX-12, occurred as a pair of equilibrating diastereoisomers differing from PTX-2 in that they contained an exocylic olefinic methylene rather than a methyl group at C-38. Analyses of shellfish extracts revealed that PTX-12 accumulated in Norwegian blue mussels (Mytilus edulis) and cockles (Cerastoderma edule), along with PTX-12 seco acids occurring as a complex mixture of diastereoisomers. LC-MS analysis of algal cells picked from the net haul from Flødevigen revealed that PTX-12 predominated in D. acuta and D. norvegica, whereas PTX-2 was the predominant pectenotoxin in D. acuminata. Preliminary observations indicate that the relative contents of PTX-2 and PTX-12 vary between sites and years in Norway, even within a single species of Dinophysis. Our data also suggest that heterotrophic dinoflagellates may accumulate toxins from their prey.

Distribution of Dinophysis species and their association with lipophilic phycotoxins in plankton from the Argentine Sea

“…Nevertheless, transmission through the food web to heterotrophic species cannot be excluded as the proximal source of this toxin in the larger cell size-fraction. The presence of PTX has been detected in isolated cells of the heterotrophic dinoflagellates Protoperidinium divergens, Protoperidinium depressum, and Protoperidinium crassipes that were previously observed to feed on Dinophysis spp., suggesting that transfer of toxin to these heterotrophs had occurred (Miles et al, 2004).…”

The Biosynthesis of Polyketide Metabolites by Dinoflagellates

“…2) (Miles et al, 2004c). It had been believed that the hydrolysis of the PTXs was an enzymatic process in the digestive glands of shellfish; however PTX-2-seco acid and 7-epi-PTX-2-seco acid were also isolated from Dinophysis acuta .…”

Growth and bioactive secondary metabolites of arctic Protoceratium reticulatum (Dinophyceae)

“…Besides the possible toxic effects of YTX, it has been suggested that YTX may act as a defense against grazers as feeding rates by copepods were significantly reduced in the presence of YTX (Makino et al, 2008). Yessotoxin has been found in bivalves and phytoplankton samples in many places around the world (Paz et al, 2008), with records from Norway (Ramstad et al, 2001;Miles et al, 2004) and the Russian White Sea (Vershinin et al, 2006), indicating a subarctic and arctic occurrence. A future expansion in distribution and an increase in bloom formation potential of toxin producing species such as P. reticulatum will have a significant impact, as marine products are assumed to be of increasing economic importance for Greenland and other arctic and subarctic regions.…”