Japanese puffer fish

Tetrodotoxin is one of the most powerful non-protein neurotoxins known. It occurs in the liver and ovaries of the Japanese puffer fish, Sphoerides rubripes and S. phyreus, and its lethal effects have been known for centuries, although it was isolated in crystalline form... 

Lastly, tetrodotoxin, the Japanese puffer fish toxin, is a polyhydroxylated reduced 2-aminoquinazoline derivative that has attracted a lot of interest, and a number of asymmetric total syntheses have recently been published <2003JA8798, 2003JAl 1510, 2004AGE4782, 2005CRV4537>. 

Tetrodotoxin, an extremely poisonous heterocycle present in Japanese puffer fish (various species of Spheroides), exerts its action by blocking the sodium ion channels in the peripheral nervous system. Chemically it has an adamantane-like structure, namely octahydro-12 - (hydroxymethyl) - 2 - imino-5,7,9,1 Oa-dimethano- 10aH-[ 1,3] -dioxo-cino-[6,5-d]pyrimidine-4,7,10,11,12-pentol. When chemically dehydrated, it rehydrates in dilute acid.73 Methanol, and ammonia, can add similarly. Because 2-amino-1,6-dihydropyrimidine forms the central part... 

Yamaguchi F, Brenner S. Molecular cloning of 5-hydroxytiyptamine (5-HT) type 1 receptor genes from the Japanese puffer fish, Fugu rubripes. Gene 1997 191 219-223. 

The highly toxic guanidinium alkaloid tetrodotoxin was first isolated from the Japanese puffer fish, Fuga rubipes. In the early 1960s, a guanidinium alkaloid was isolated from eggs of the California newt Taricha torosa and named tarichatoxin (185). It proved identical with tetrodotoxin from puffer fish (186 see Ref. 5 for a historical review). Tetrodotoxin and other guanidinium toxins, namely, chiriquitoxin and the zetekitoxins, have been shown to occur in other amphibians. 

Aparicio, S., Morrison, A., Gould, A., et al. (1995) Detecting conserved regulatory elements with the model genome of the Japanese puffer fish, Fugu rubripes. Proc. Natl. Acad. Sci. USA 92, 1684-1688. 

Several natural products contain the quinazoline structure, e.g. the quinazoline alkaloids obtained from rutaceae (e.g. arborine 24). Tetrodotoxin 25 derived from decahydroquinazoline and found in the Japanese puffer fish is one of the strongest nonproteinogenic neurotoxins. 

A hypotensive red alkaloid isolated from the Brazilian plant Hortia arborea England was called hortiamine. One of the most potent nonprotein neurotoxin tetrodotoxin was isolated from certain varieties of the Japanese puffer fish. Several quinazoline derivates show antimalarial properties against Plasmodium gallinace-um. The most effective was 6-chloro-2-ethyl-3,4-dihydro-4-oxo-3-/7-pyrimidin-2 -ylsulfa-moylphenylquinazoline [28]. 

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