Saxitoxin composition

Saxitoxin composition therefore originates as that of the local dinoflagellate population and evolves with time depending on the characteristics of the filter-feeders and subsequent consumers that accumulate and transform the toxins. 

Some Chemical Considerations Relevant to the Mouse Bioassay. Net toxicity, determined by mouse bioassay, has served as a traditional measure of toxin quantity and, despite the development of HPLC and other detection methods for the saxi-toxins, continues to be used. In this assay, as in most others, the molar specific potencies of the various saxitoxins differ, thus, net toxicity of a toxin sample with an undefined mixture of the saxitoxins can provide only a rough approximation of the net molar concentration. Still, to the extent that limits can be placed on variation in toxin composition, the mouse assay can in principle provide useful data on trends in net toxin concentration. However, the somewhat protean chemistry of the saxitoxins makes it difficult to define conditions under which the composition of a mixture of toxins will remain constant thus, attaining a reproducible level of mouse bioassay toxicity is difficult. It is therefore useful to review briefly some of the chemical factors that should be considered when employing the mouse bioassay for the saxitoxins or when interpreting results. Similar concepts will apply to other assays. 

In summary, analyses for the saxitoxins provide information that, in principle, is clear and readily interpreted while the design and interpretation of assays for the saxitoxins is complicate by the multiplicity of the toxins, their differing properties, and the variations in toxin composition that will be encountered. Assays, however, can in principle be very simple to perform while the presently available analyses for the saxitoxins require fairly complex equipment. 

Pharmaceutical local anesthetic composition employing saxitoxin US 4001413 (1977) STX Local anesthesia... 

Velzeboer RMA, Baker PD, Rositano J, Heresztyn T, Codd GA, Raggett SL (2000) Geographical patterns of occurrence and composition of saxitoxins in the cyanobacterial genus Anabaem (Nostocales, Cyanophyta) in Australia. Phycologia 39 395 07... 

---