ACETYLENIC AMINO ACIDS FROM EUPHORIA LONGAN

Three amino acids containing an acetylenic bond have been newly characterized from seed of Euphoria longan. Structures were assigned, largely on the basis of hydrogenation, NMR and mass spectrometric studies, as follows: 2-amino-4-methylhex-5-ynoic acid, 2-amino-4-hydroxymethylhex-5-ynoic acid, and 2-amino-4-hydroxyhept-6-ynoic acid. The possible biogenetic relationships existing between the two branched-chain C7 compounds and other olefinic and cyclopropyl amino acids isolated earlier from species of the allied Aesculus and Blighia genera are discussed. © 1970.