Synthesis of α-Ketoglutaramic acid.

α-Ketoglutaramic acid (KGM, α-ketoglutaramate), also known as 2-oxoglutaramic acid (OGM, 2-oxoglutaramate), is a substrate of ω-amidase, also known as Nitrilase 2 (NIT2), and is essential for studying the canonical role of ω-amidase, as well as its role in multiple diseases. Until now, KGM used for biological studies has been prepared most often by the enzymatic oxidation of l-glutamine using snake venom l-amino acid oxidase, which provides KGM as an aqueous solution, containing by-products including 5-oxoproline and α-ketoglutarate. The enzymatic method for KGM preparation, therefore, cannot provide pure product or an accurate percent yield evaluation. Here, we report a synthetic method for the preparation of this important substrate, KGM, in 3 steps, from l-2-hydroxyglutaramic acid, in pure form, in 53% overall yield.