Cicutoxin
Cicutoxin is a poisonous polyyne and alcohol found in various plants, such as the highly toxic water hemlock (Cicuta species). It is a natural product structurally related to the oenanthotoxin of hemlock water dropwort.
It causes death by disruption of the central nervous system. It is a potent, noncompetitive gamma-aminobutyric acid (GABA) receptor antagonist. In humans, cicutoxin rapidly produces symptoms of nausea, emesis and abdominal pain, typically within 60 minutes of ingestion. This can lead to tremors, seizures, and death. LD50(mouse; i.p.) ~9 mg/kg