“…Pent-4-enoic acid is the simplest hypoglycaemic fatty acid structurally related to methylenecyclopropylacetic acid, the active metabolite of hypoglycin from the fruit of the ackee, Blighia sapida. Ingestion of unripe ackee fruits may cause vomiting sickness, a disease characterized by severe hypoglycaemia (Anderson et al, 1958;De Renzo et al, 1958;von Holt, 1966;Senior & Sherratt, 1968a,b;Sherratt et al, 1971) and probably by isovaleric-acidaemia (Tanaka et al, 1972). Both pent-4-enoic acid and hypoglycin are thought to cause hypoglycaemia by impairing gluconeogenesis secondarily to inhibiting fatty acid oxidation (Senior, 1967;Sherratt et al, 1971) and pent-4-enoic acid has been used to demonstrate the dependence of gluconeogenesis on fatty acid oxidation in perfused rat liver (Ruderman et al, 1968;Toews et al, 1970;Williamson et al, 1970;Menahan & Williams, 1971).…”