New and Uncommon Indole- and Imidazole-Alkylamines in Skins of Amphibians from Australia and Papua New Guinea

Extracts of the skin of some amphibians from Australia and Papua New Guinea contained, in addition to the usual 5-hydroxyindolealkylamines and histamine: a. two new, hitherto unknown indolealkylamines, i.e . O-sulphate of bufotenidine and 2-(3-indolyl)ethyltrimethylammonium, a quaternary ammonium base of tryptamine. The rare O-sulphate of bufotenine was also present, the occurrence of which had previously been demonstrated only in the skin of some South American toads; b. a series of uncommon imidazolealkylamines, such as N′-acetylhistamine, N′-methyl-histamine, N′,N′-dimethylhistamine, spinaceamine and 6-methylspinaceamine. It appears evident that amphibian skin continues to be an exceptionally rich source of aromatic amines.