THERMAL ISOMERIZATION OF N-OXALYL DERIVATIVES OF DIAMINO ACIDS

Article abstract of DOI:10.1016/0031-9422(93)85034-O

The neurotoxic constituent of the legmure Lathyrus sativus, β-N-oxalyl-α,β-diaminopropionic acid, was thermally isomerized to an equilibrium mixture (60/40) containing the non-toxic α-N-oxalyl-α,β-diaminopropionic acid.The same equilibrium mixture was established by starting with the α isomer but required longer time. α- and γ-N-Oxalyl-α,γ-diaminobutyric acids also underwent thermally induced isomerization with α-γ, or γ-α migration of the oxalylgroup. δ-N-oxalylornithine and ε-N-oxalyllysine did not isomerize under these conditions.The observation that the higher homologes do not undergo isomerization suggest the intramolecular nature of the reaction. Key Word Index: Lathyrus sativus; α- and β-N-oxalyl-α,β-diaminopropionic acid; α-, γ-N-oxalyl-α,γ-diaminobutyric acids; δ-N-oxalylornithine; ε-N-oxalyllysine; neurotoxins; thermal isomerization.