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.