New esters of okadaic acid in seawater and blue mussels (Mytilus edulis).

Marine algal toxins of the okadaic acid (OA) group can occur as diol esters and sulfated diol esters in algae and as fatty acid esters in shellfish. Several of these ester forms have been identified, but the most common procedure for detecting OA group toxin esters is by measuring the increase in parent toxin after alkaline hydrolysis. Use of this alkaline hydrolysis method led to the discovery of high levels of conjugates of OA and dinophysistoxins-2 (DTX2) in seawater and of OA, DTX1, and DTX2 in blue mussel hepatopancreas (HP) from Flødevigen, Norway, during a bloom of Dinophysis spp.

Profiles and levels of fatty acid esters of okadaic acid group toxins and pectenotoxins during toxin depuration. Part I: brown crab (Cancer pagurus).

In 2002, two outbreaks of diarrhetic shellfish poisoning (DSP) occurred in Norway, which was later confirmed to be caused by the consumption of brown crab (Cancer pagurus) contaminated predominantly by esters of okadaic acid (OA) after feeding on toxic blue mussels (Mytilus edulis). In addition to OA-group toxins, pectenotoxins (PTXs) are commonly detected in the toxin-producing algae (i.e.

Profiles and levels of fatty acid esters of okadaic acid group toxins and pectenotoxins during toxin depuration. Part II: blue mussels (Mytilus edulis) and flat oyster (Ostrea edulis).

Bivalve molluscs accumulate toxins of the okadaic acid (OA) and pectenotoxin (PTX) groups, which are frequently found in Dinophysis spp. Transformation of the OA-group toxins into fatty acid ester derivatives (often designated "DTX3") is common in many bivalve species but the degree to which these toxins are transformed vary between species, and is also depending on the parent toxin involved. In this paper, detailed profiles and levels of fatty acid esters of OA, DTX1, DTX2 and PTX2 SA were studied in blue mussels (Mytilus edulis) and European flat oysters (Ostrea edulis), collected during a bloom of Dinophysis spp.

Characterization of fatty acid esters of okadaic acid and related toxins in blue mussels (Mytilus edulis) from Norway.

Marine algal toxins of the okadaic acid group can occur as fatty acid esters in blue mussels, and are commonly determined indirectly by transformation to their parent toxins by alkaline hydrolysis. Some data are available regarding the identity of the fatty acid esters, mainly of palmitic acid (16:0) derivatives of okadaic acid (OA), dinophysistoxin-1 (DTX1) and dinophysistoxin-2 (DTX2). Other fatty acid derivatives have been described, but with limited mass spectral data.

Structural confirmation and occurrence of azaspiracids in Scandinavian brown crabs (Cancer pagurus).

In 2005 and 2006, azaspiracids were for the first time detected in brown crabs (Cancer pagurus) from the west coast of Sweden and the north and north-west coast of Norway. Azaspiracids are marine toxins that have been detected in blue mussels in Europe in recent years. On some occasions, they have been responsible for human intoxications with symptoms similar to those occurring by consumption of shellfish contaminated with okadaic acid group toxins.

Identification of fatty acid esters of pectenotoxin-2 seco acid in blue mussels (Mytilus edulis) from Ireland.

Pectenotoxins from marine dinoflagellates of the genus Dinophysis are rapidly hydrolyzed by many shellfish to give pectenotoxin-2 seco acid, which isomerizes to 7-epi-pectenotoxin-2 seco acid. Three series of fatty acid esters of pectenotoxin-2 seco acid (PTX-2 seco acid) and 7-epi-PTX-2 seco acid were detected by LC-MS analysis of extracts from blue mussels (Mytilus edulis) from Ireland. The locations of the fatty acid ester linkages were identified by a combination of LC-MSn in positive- and negative-ion modes, LC-MS analysis of the products from reaction of the esters with sodium periodate, and NMR analysis of purified samples of the two most abundant ester derivatives.

Diarrhetic shellfish poisoning by okadaic acid esters from Brown crabs (Cancer pagurus) in Norway.

In 2002 several hundred people were taken ill after eating self-harvested brown crabs (Cancer pagurus) in the southern part of Norway. The symptoms were similar to diarrhetic shellfish poisoning (DSP) although with a somewhat delayed onset. This happened at the same time as an unusual early bloom of Dinophysis acuta had lead to high amounts of DSP toxins in blue mussels (Mytilus edulis) in the same area.

A novel pectenotoxin, PTX-12, in Dinophysis spp. and shellfish from Norway.

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.