Detection and Identification of Spirolides in Norwegian Shellfish and Plankton

Abstract

Mussels sampled in the spring of 2002 and 2003 from Skjer, a location in Sognefjord, Norway, tested positive in the mouse bioassay for lipophilic toxins. The symptoms, which included cramps, jumping, and short survival times (as low as 4 min), were not characteristic of toxins previously observed in Norway. A survey of the algae present at the aquaculture sites showed that the toxicity correlated with blooms of Alexandrium ostenfeldii. Up to 2200 cells/L were found at the peak of one bloom. In Canadian waters, this alga is known to be a producer of the cyclic imine toxins, spirolides. Analysis of mussel extracts from Skjer in the spring of 2002 and 2003, using liquid chromatography tandem mass spectrometry, revealed the presence of several new spirolides. The same compounds were also found in algal samples dominated by A. ostenfeldii, which had been sampled from Skjer in February 2003. A large-scale extraction of mussel digestive glands and chromatographic fractionation of the extracts allowed the isolation and structure elucidation of the main spirolide, 20-methyl spirolide G, with a molecular weight of 705.5. This is the first confirmed occurrence of spirolides in mussels and plankton from Norway.

LC-MS-MS aboard ship: tandem mass spectrometry in the search for phycotoxins and novel toxigenic plankton from the North Sea

“…The related group of macrocyclic imine toxins known as spirolides and originating from the dinoflagellate Alexandrium ostenfeldii was detected at some stations. Cultured isolates of A. ostenfeldii may produces a diversity of spirolides [13,14], but only 20-methylspirolide G and to a lesser extent 13-desmethylspirolide C were found in the North Sea field plankton samples. Somewhat surprisingly, spirolides A, B, C, D, and G were completely absent.…”

Identification of gymnodimine D and presence of gymnodimine variants in the dinoflagellate Alexandrium ostenfeldii from the Baltic Sea

“…Spirolides A, C, and 13-desmethylspirolide C were isolated from A. ostenfeldii cultures (Nova Scotia, Canada) and their structures were determined (Hu et al, 2001). Subsequently, various spirolide analogues have been isolated and structurally characterized from A. ostenfeldii (Aasen et al, 2005;MacKinnon et al, 2006a;Roach et al, 2009;Ciminiello et al, 2010). Several unknown analogues have also been described together with known spirolides (Sleno et al, 2004;Almandoz et al, 2014;Tillmann et al, 2014;Rundberget et al, 2011).…”

Current Techniques for Detecting and Monitoring Algal Toxins and Causative Harmful Algal Blooms

“…LC-MS/MS has therefore become the norm and the standard method for algal toxin for both quantitative and qualitative measurement -providing extremely low detection limit and unequivocal and definite structural information to search for new toxins. LC-MS/MS has allowed the detection of spirolider (a cyclic imine toxin), 20-methyl spirolide G in Norwegian shellfish and planktons samples [73]. Combined with the use of chemical degradation and derivatization, MS/MS was able to detect several toxic peptides from blue-green algae at the nanomole level, including two additional toxins that were thought to belong to a family of sevenresidue cyclic peptides, a cyclic imine toxin, having the general structure cyclo-D-Ala-L-Xaa-erythro-,B-methyl-D-isoaspartic acid-LYaa-Adda-D-isoglutamic acid-N-methyldehydroalanine, where Xaa and Yaa represent variable amino acids of the L configuration and Adda is 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid [74].…”