SAXITOXIN Property

Boiling point:

440.62°C (rough estimate)

Density 

1.3010 (rough estimate)

refractive index 

1.6400 (estimate)

storage temp. 

−20°C

pka

13.32±0.50(Predicted)

optical activity

+13320 (H2O)

EPA Substance Registry System

Saxitoxin (35523-89-8)

Safety

Hazard Codes 

T+

Risk Statements 

26/27/28

Safety Statements 

36/37/39-45

RIDADR 

UN 3462 6.1/PG 1

WGK Germany 

3

Toxicity

During seasons when dinoflagellates “bloom,” filter-feeding shellfish become contaminated with accumulated toxin and are toxic when eaten. STX blocks nerve membrane sodium channels in nanomolar concentrations when applied externally. STX competes with tetrodotoxin (TTX) for binding to sodium channels. The mechanism of action on nerves is the same as that of TTX, although recovery from STX block occurs slightly faster than that after TTX block. The i.p. LD50 in mice is 10 μg/kg. Symptoms in humans within 30 min of ingestion include tingling and burning in face, lips, tongue, and eventually the whole body, parathesia followed by numbness, ataxia, general motor incoordination, confusion, and headache. Death due to respiratory paralysis occurs within 12 h. Treatment is restricted to symptoms. There is no antidote, and emesis is advisable. Artificial respiration is given if neces_x0002_sary. Prostigmine methylsulfate (1 mL of 1:2000 solution, i.v.) is helpful.

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H300Fatal if swallowed

H310Fatal in contact with skin

H330Fatal if inhaled

Precautionary statements

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P262Do not get in eyes, on skin, or on clothing.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

P271Use only outdoors or in a well-ventilated area.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P284Wear respiratory protection.

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

P302+P350IF ON SKIN: Gently wash with plenty of soap and water.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P310Immediately call a POISON CENTER or doctor/physician.

P320Specific treatment is urgent (see … on this label).

P321Specific treatment (see … on this label).

P322Specific measures (see …on this label).

P330Rinse mouth.

P361Remove/Take off immediately all contaminated clothing.

P363Wash contaminated clothing before reuse.

P403+P233Store in a well-ventilated place. Keep container tightly closed.

P405Store locked up.

P501Dispose of contents/container to..…

SAXITOXIN Chemical Properties,Usage,Production

Description

First recognized in 1957 by Shantz et al. in the butter clam Saxidomus giganteus, saxitoxin is a naturally occurring toxin that is synthesized by various marine dinoflagellates and cyanobacteria. It is used in neurochemical and molecular biology research, but regulatory concerns have focused on its weaponization and potent toxicological effects on animals and humans. Saxitoxin causes paralytic shellfish poisoning (PSP) in humans and other animals; whales having ingested organisms contaminated with the toxin have died just hours after exposure. In humans, PSP can occur as a result of consuming shellfish or other seafood in which saxitoxin has accumulated. While effects have been documented worldwide, the sources of contaminated seafood have been identified as primarily the west and east coasts of the United States.
To date, more than 30 different saxitoxin analogs have been identified. These include pure saxitoxin (STX), neosaxitoxin (neoSTX), the gonyautoxins (GTX), and decarbamoylsaxitoxin (dc-STX); of these, STX, 6NeoSTX, GTX1, and dc-STX seem to be the most toxic. The term saxitoxin typically refers to this collection of compounds produced naturally by cyanobacteria.
Saxitoxin is far more potent than the classic puffer fish toxin tetrodotoxin, and is one of only two naturally occurring Schedule 1 chemical warfare agents (the other is ricin). In 1970, President Nixon ordered stocks of the toxin destroyed in compliance with U.N. agreements on biological weapons; however, the Central Intelligence Agency revealed in 1975 that there was a remaining supply, which was distributed to research facilities by the National Institutes of Health in order to study neurological diseases.

Chemical Properties

Crystalline solid; soluble in water and me thanol; forms dihydrochloride with HCl.

Uses

As a Schedule 1 controlled substance under the Chemical Weapons Convention of 1993, the use of saxitoxin is extremely limited outside of weaponized forms. Its use as a chemical reagent in research is its other important use, as it has been instrumental in experiments to elucidate the mechanisms involved in sodium channels used in cellular communication.

Uses

Mussel poison; clam poison; paralytic shellfish poison; gonyaulax toxin. These poisonous shellfish have been connected to instances of toxic”red-tides” where the high concentration of algae discoloring the water were of the Gonyaulax genus. Used as a too

Uses

Saxitoxin is an alkaloid of nonplant origin.It is the neurotoxic constituent of dinoflagel lates (Gonyaulax catenella and G. excavata)the so-called “red tide” found along the U.S.coast. Shellfish, clams, and scallops consumethis and become extremely poisonous forhuman consumption.

Definition

ChEBI: An alkaloid isolated from the marine dinoflagellates and cyanobacteria that causes paralytic shellfish poisoning.

Health Hazard

Saxitoxin is an extremely toxic substance.It binds to sodium channels and the blocksnerve membrane. In humans, ingestion ofthis compound can produce tingling andburning in the lip, tongue, face, and thewhole body within an hour. This is fol lowed by numbness, muscular incoordina tion, confusion, headache, and respiratoryfailure. Death may occur within 12 hours.
LD50 value intraperitoneal (mice): 0.005mg/kg
LD50 value oral (mice): 0.26 mg/kg
Intravenous administration of 1 mL of1:2000 solution of prostigmine methylsulfatehas been reported to be effective againstsaxitoxin poisoning (Hodgson et al. 1988).

Environmental Fate

Dinoflagellates (flagellate protists, plankton) are primarily responsible for the biosynthesis of saxitoxin, and bioaccumulation tends to occur in several shellfish such as mussels, clams, scallops, and cockles. Broth made from shellfish can harbor saxitoxin as well due to its stability at normal cooking temperatures. Consumption of the shellfish leads to toxicity in humans, while consumption of other organisms in which saxitoxin has accumulated (up the food chain, for example) has historically affected other animals such as whales.
Data describing the environmental fate of saxitoxin is extremely limited. There have been some studies investigating the absorption/desorption capacities of various soils for the compound, but more exhaustive studies are yet to be reported.

Toxicity evaluation

Saxitoxin interrupts nerve transmissions by binding to voltagegated sodium channels. Positively charged guanidinium groups of saxitoxin interact with negatively charged carboxyl groups at a site on the sodium channel (in a one-to-one ratio) of neurons and muscle cells, resulting in blocked action potentials and interrupted transmissions. The inactivation of vasomotor nerves along with vascular smooth-muscle relaxation follows and hypotension can additionally occur. When muscles in the respiratory or cardiovascular system are affected, death can result.
Intraperitoneal inoculation with STX extract in the freshwater fish Hoplias malabaricus resulted in a variety of systemic effects culminating in oxidative stress observed in the brain, leading to lipid, protein, and DNA damage. Although the exposure in this study was subchronic, apoptotic cellular processes were implicated.

References

Schantz et al., J. Arner. Chern. Soc., 97, 1238 (1975)