Calycanthine, the principal alkaloid of the order Calycanthaceae, has been isolated from a species of the genus Psychotria, and is a central nervous system toxin, causing convulsions.

Crenulatin has dual- direction effects on apoptosis of cerebral microvascular endothelial cells, inhibitive effect in 25 mg/L and stimulative effect in 100 mg/L group, respectively; the mechanism is related to the alterations of Fas/Bcl-2 expression and caspase-3 activity.

Atracurium besylate is a non-depolarizing neuromuscular blocking agent with short duration of action. Its lack of significant cardiovascular effects and its lack of dependence on good kidney function for elimination provide clinical advantage over alternate non-depolarizing neuromuscular blocking agents.