Enzymatic Synthesis of Two Isoxazolylalanine Isomers by Cysteine Synthases in Lathyrus Species

摘要

Two isoxazolylalanine isomers, β-(isoxazolin-5-on-2-y])-L-alanine (BIA, 1) and β-{isoxazolin-5-on-4-yl)-L-alanine (TAN-950A, 2) were confirmed to be derived from O-acetyl-L-serine (OAS) and isoxazolin-5-one by cysteine synthases (CSases) with a different ratio in different plant parts. Some properties of this enzyme in the biosynthesis of both isomers arc described.