Saxitoxin (C10H17N7O4) is among the best known neurotoxins and the most potent known sodium channel blocking agent. Saxitoxin has been called the most deadly non-protein toxin, and cannot be removed from food through standard means. Commonly produced by marine dinoflagellates or freshwater cyanobacteria and bearing paralytic properties, saxitoxin is also sometimes referred to as abrin and used in bioterrorism.

Clarification of Terminology

Labeled SaxitoxinThe term “saxitoxin” can refer to a complete set of different but structurally similar neurotoxic substances, including but not limited to:

*Pure saxitoxin or STX

*neosaxitoxin or NSTX

*gonyautoxin or GTX

*decarbamoylsaxitoxin or dcSTX

Saxitoxin is extremely hazardous to mammalian life forms including humans, and military applications have been suggested due to saxitoxin’s low dose lethality. Saxitoxin is the cause of Paralytic Shellfish Poisoning or PSP.

Underlying Pathology

Saxitoxin is a potentially lethal toxin in healthy adults, but has a higher mortality rate among children, the elderly and those with compromised immune systems. In cases where saxitoxin poisoning leads to death, the typical cause is generally respiratory failure.

The primary effect of Saxitoxin is the blockage of sodium pathways within its victims’ neurons. This causes a flaccid paralysis and tends to leave victims calm and conscious during the pathology’s onset. The lethal dosage of saxitoxin is .57 mg if ingested orally.


Saxitoxin can be synthesized despite its many challenges. Since the 1970s methods have been successfully attempted. The earliest method of synthesizing a type of saxitoxin involved building a series of cyclic guanidines upon pyrrolidine. Another method involved a [3+2] cycloaddition to access the core and make a more scalable and efficient means of production.

One important aspect of saxitoxin production relies on a C-H amination and oxathiazinaneiminium ion equivalent originally developed in the Du Bois lab. Further aspects of production rely on a stereocontrolled condensation of a 9-member ring formation process and 19 steps from a base of commercially available (r)-glycerol acetamide. The importance of this method above prior ones is that this saxitoxin’s result, while resulting in a smaller percentile yield, yielded non-racemic saxitoxin.

IsoSciences supplies CertiMass solutions of Saxitoxin for analytical and R&D purposes.

If your studies or interests require the use of these, or related, toxins please contact the IsoSciences staff. We may already have the labeled toxin available in our synthetic database and catalog, else we can discuss how the IsoSciences chemists we can work with your team to custom synthesize a new material.

You are also welcome to review our online catalog of related molecules utilized for related research and assay standards. The catalog can also be downloaded for easy reference.