
(+)-Anatoxin-a—(1R,6R)-5-acetyl-9-azabicyclo[4.2.1]non-4-ene—is an acute neurotoxin produced by cyanobacteria worldwide. In biological systems, it behaves similarly to acetylcholine, but it is not degraded by cholinesterase. Recent studies of anatoxin-a contamination of drinking water sources have been carried out in New York State; Quebec, Canada; southern France; and the Niger Delta in Africa.