Ingestion of gonyautoxins through consumption of mollusks contaminated by toxic algae can cause a human illness called paralytic shellfish poisoning (PSP).

Gonyautoxins are naturally produced by several marine dinoflagellates species (Alexandrium sp., Gonyaulax sp., Protogonyaulax sp.).

[1][2] The paralytic shellfish poisoning caused by these toxins is connected with dinoflagellate blooms known as “red tides”, even though the coloration of the water isn't a necessity.

In this process firstly the L-serine methyl ester is treated with aldehyde, so that it can react to close the ring structure.

GTX-2 is formed by incubating the product in an aqueous solution at pH 8, in order to make the epimerization at C11 still occur.

Shellfish can contain more than 10 micrograms of gonyautoxin per 100 gram weight, inducing that the consumption of a few mussels can already be fatal for human.

They can bind with high affinity at the site 1 of the α-subunit of the voltage dependent sodium channels in the postsynaptic membrane.

[1] Biotransformation in the human body occurs as a first phase detoxification by oxidizing the gonyautoxin molecule.

In the second phase detoxification step a glucuronidation takes place which produces glucuronic-GTX, which has an increased hydrophilicity in comparison to the GTX and can hence be excreted more easily.