Guanitoxin
Guanitoxin (GNT), formerly known as anatoxin-a(S) "Salivary"[lower-alpha 1][1], is a naturally occurring cyanotoxin commonly isolated from cyanobacteria (specifically of the genus Anabaena) and causes excess salivation in mammals via inhibition of acetylcholinesterase.[2] Guanitoxin is structurally a cyclic N-hydroxyguanine organophosphate with a phosphate ester moiety.
Names | |
---|---|
IUPAC name
(5S)-5-[(Dimethylamino)methyl]-1-{[hydroxy(methoxy)phosphoryl]oxy}-4,5-dihydro-1H-imidazol-2-amine | |
Identifiers | |
3D model (JSmol) |
|
ChemSpider | |
KEGG | |
PubChem CID |
|
UNII | |
CompTox Dashboard (EPA) |
|
| |
| |
Properties | |
C7H17N4O4P | |
Molar mass | 252.211 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Infobox references | |
Toxicity and treatment
The main mechanism of action for guanitoxin is by irreversibly inhibiting the active site of acetylcholinesterase leading to excess acetylcholine in the parasympathetic and peripheral nervous systems; inducing poisoning via nicotinic and muscarinic cholinergic receptor stimulation.[3] Treatment of afflicted case by atropine has attested to suppress the muscarinic mediated toxicity; which prevents the namesake salivation that similarly reacts to prevent the toxin's other poisoning symptoms which include lacrimation, urinary incontinence and defecation. Atropine will not, however, counter another mechanism of the compounds toxicity as it also mediates a nicotinic adverse toxicity affecting muscle tremors, fasciculation, convulsions and respiratory failure.
See also
- Anatoxin-a – a cyanotoxin that shares near to same active mechanism and also relates to same cyanobacteria genera, but with a different chemical structure
References
- Fiore, Marli Fátima; de Lima, Stella Thomaz; Carmichael, Wayne W.; McKinnie, Shaun M.K.; Chekan, Jonathan R.; Moore, Bradley S. (2020). "Guanitoxin, re-naming a cyanobacterial organophosphate toxin". Harmful Algae. Elsevier BV. 92: 101737. doi:10.1016/j.hal.2019.101737. ISSN 1568-9883. PMID 32113603.
- "Anatoxin-a".
- Hyde, E. G.; Carmichael, W. W. (1991). "Anatoxin-a(s), a naturally occurring organophosphate, is an irreversible active site-directed inhibitor of acetylcholinesterase (EC 3.1.1.7)". Journal of Biochemical Toxicology. 6 (3): 195–201. doi:10.1002/jbt.2570060305. PMID 1770503.
- (The "(S)" its name stands for 'salivary' indicating its manner of affliction to distinguish it from a toxin having otherwise the same conventional name. cf. "See also" for aforementioned compound of shared nomenclature.)