Either of two related toxins occurring naturally in the unripe fruit of the ackee, Blighia sapida, typically causing severe vomiting if ingested. More fully "hypoglycin A", "hypoglycin B".
The hypoglycins are amino acids related to lysine and containing a cyclopropane ring. Formulae: (hypoglycin A) C₇H₁₁NO₂; (hypoglycin B) C₁₂H₁₈N₂O₅.
1950s. From hypoglyc- + -in.