Antibiotic substance produced by various Streptomyces species. It is an inhibitor of enzymatic activities that involve glutamine and is used as an antineoplastic and immunosuppressive agent.

Synonyms: 0, LL-D05139a, 87299V3Q9W, Azaserine, L-Serine, diazoacetate (ester), O Diazoacetyl L serine, Azeserine, O-Diazoacetyl-L-serine