Salamanders and newts

In 1964, the structure of tetrodotoxin (XXIV) was finally elucidated by analysis of a variety of chemical. X-ray crystallographic, and spectral data (187-190). One key reaction was the facile conversion to 2-amino-6-hydroxymethyl-8-hydroxyquinazoline (XXV). Natural tetrodotoxin is levorotatory, with an [a] of -S.S (3.3, D2O). Tetrodotoxin is accompanied in certain salamanders and newts of the family Salamandridae by 4,9-anhydrotetrodotoxin, 4-epitetrodotoxin, 6-epitetrodotoxin, and 11-deoxy-tetrodotoxin, as well as trace amounts of 4,9-anhydro-4-epitetrodotoxin,... 

Hofrichter, Robert. Amphibians The World of Frogs, Toads, Salamanders and Newts. Toronto Firefly Books, 2000. Zug, George R., Laurie J. Vitt, and Janalee P. Caldwell. Herpetology An Introductory Biology of Amphibians and Reptiles. 2nded. New York Academic Press, 2001. 

Two orders of amphibia have been studied the Anura (frogs, toads) and Urodela or Caudata (tailed amphibia, including salamanders and newts). The urodeles are the more primitive of the two orders. 

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