Shellfish poisons, structure toxicity

Cyanobacterial toxins (both marine and freshwater) are functionally and chemically a diverse group of secondary chemicals. They show structure and function similarities to higher plant and algal toxins. Of particular importance to this publication is the production of toxins which appear to be identical with saxitoxin and neosaxitoxin. Since these are the primary toxins involved in cases of paralytic shellfish poisons, these aphantoxins could be a source of PSP standards and the study of their production by Aphanizomenon can provide information on the biosynthesis of PSP s. The cyanobacteria toxins have not received extensive attention since they have fewer vectors by which they come in contact with humans. As freshwater supplies become more eutrophicated and as cyanobacteria are increasingly used as a source of single cell protein toxic cyanobacteria will have increased importance (39). The study of these cyanobacterial toxins can contribute to a better understanding of seafood poisons. 

The consumption of shellfish (scallops and mussels) harvested during late spring to early summer fiom the northeastern region of Japan quite often results in what is commonly known as diarrhetic shellfish poisoning. An initial chemical investigation of the toxic mussels resulted in the identification (86) of okadaic acid [108], dinophysistoxin 1 (DTXj) [109] and two toxins of unknown structures. In a later study (87), chemical structures of three new polyether toxins, dinophysistoxin- 3 (DTX3)[110], pectenotoxin-1 [111 ] and pectenotoxin-2 [112] were reported. 

Paralytic shellfish poisoning toxins consist of a group of toxin components, the structures of which are similar to each other. Since Schantz et al. [3] succeeded in determining the chemical structure of saxitoxin (STX), various derivatives of STX have been isolated from toxic dinoflagellates and toxin-contaminated shellfish [4-16]. Currently, more than 20 components are known [17]. 

Structure, nomenclature and occurrence ASP is a less common type of poisoning. It occurs after ingestion of shellfish contaminated by a specific toxic amino acid referred to as domoic acid (10-247), a naturally occurring neuroexcitatory toxin produced primarily by the marine diatom Pseudonitzschia multiseries, which is widespread... 

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