Isolation and Structure Elucidation of New and Unusual Saxitoxin Analogues from Mussels

Abstract

Chemical analyses of plankton and highly toxic mussel samples collected in eastern Canada during an intense bloom of the dinoflagellate Alexandrium tamarense established the presence of a complex mixture of paralytic shellfish poisoning (PSP) toxins. Application of a newly developed technique, hydrophilic interaction liquid chromatography-mass spectrometry, confirmed the identities of the known toxins and revealed the presence in the mussels of five saxitoxin analogues (M1-M5) that were not present in the plankton. Four of these compounds were isolated and their structures established by tandem mass spectrometry, 1D- and 2D-NMR spectroscopy, and chemical interconversion experiments. One of these was found to be 11beta-hydroxysaxitoxin (M2), while the other three were found to be new saxitoxin analogues, namely, 11beta-hydroxy-N-sulfocarbamoylsaxitoxin (M1), 11,11-dihydroxy-N-sulfocarbamoylsaxitoxin (M3), and 11,11-dihydroxysaxitoxin (M4). Compound M5 remains unidentified because of insufficient material for characterization.

Towards tailored assays for cell-based approaches to toxicity testing

“…Multiple structural features, however, determine transcriptional responses involving the estrogen receptor system at the level of ligands, receptor forms, and transcriptional co-factors/activators contributing to changes in the transcription of selected genes (see, for instance, Shiau et al, 1998; McKenna duced in the eU (eU, 2011), efforts aimed at the development of cell-based methods has continued, as they are considered of higher value for some purposes. efforts in this area are supported by the recognition that naturally contaminated materials often include many distinct analogues (MacKenzie et al, 2002;Aasen et al, 2005;Dell'Aversano et al, 2008;Rehmann et al, 2008) of varying potency, pinpointing the need to quantify the full series of compounds with toxicological relevance. A second line of intervention recognizes that contamination of seafood by microalgal toxins has been evolving over the years, and novel or atypical contaminations have been detected (Moore and Scheuer, 1971;Hu et al, 1995;Deeds and Schwartz, 2010;ledreux et al, 2012).…”

A roadmap for hazard monitoring and risk assessment of marine biotoxins on the basis of chemical and biological test systems

“…More than 57 different analogues of Stx have been described (Dell'Aversano et al, 2008;Wiese et al, 2010). PSP toxins have been detected in european, North American, and Japanese waters, as well as in Chile, South Africa, Australia, and other countries (Pitcher et al, 2007;Krock et al, 2007;Robertson et al, 2004).…”

<strong>Computational model of adsorption for paralytic shellfish poisoning toxins (PSTs) on graphene surface.</strong>

“…Saxitoxin (STX) was the first PSTs identified and isolated [2] and it is the most toxic. To date, more than 57 STX analogues are known [1,3] and they can be divided into three families based on structural differences in their functional groups: the carbamate family includes saxitoxin (STX), neosaxitoxin (NEO) and the gonyautoxins (GTX1-4); the decarbamoyl family includes decarbamoyl-gonyautoxins (dcGTX1-dcGTX4) and decarbamoyl-saxitoxins (dcSTX, dcNEO); the N-sulfocarbamoyl toxins include GTX5, GTX6 (also called B1 and B2, respectively) and C toxins (C1-4). In recent years, a novel group were identified and named GC toxins (GC1-6) [4].…”