Methylene cyclopropyl alanine and congeners isolated from the unripe edible fruit of the AKEE plant (BLIGHIA SAPIDA). Hypoglycin B is the gamma-glutamyl congener of hypoglycin A. They are very toxic and teratogenic, causing a syndrome called Jamaican vomiting sickness that includes a fall in blood glucose due to the interference of FATTY ACIDS and LEUCINE metabolism which leads to VOMITING, liver damage, CONVULSIONS and DEATH.