A non-proteinogenic L-alpha-amino acid that is L-norleucine which is substituted at position 5 by an oxo group and at position 6 by a diazo group. It is as inhibitor of various glutamine-utilising enzymes. ChEBI: 6-diazo-5-oxo-L-norleucine is a non-proteinogenic L-alpha-amino acid that is L-norleucine which is substituted at position 5 by an oxo group and at position 6 by a diazo group. It is as inhibitor of various glutamine-utilising enzymes. It has a role as a bacterial metabolite, an analgesic, an antibacterial agent, an antiviral agent, an antineoplastic agent, an EC 6.3.5.5 [carbamoyl-phosphate synthase (glutamine-hydrolysing)] inhibitor, an EC 6.3.4.2 [CTP synthase (glutamine hydrolyzing)] inhibitor, an EC 6.3.5.3 (phosphoribosylformylglycinamidine synthase) inhibitor, an EC 6.3.5.2 [GMP synthase (glutamine-hydrolysing)] inhibitor, an antimetabolite, a glutamine antagonist, an apoptosis inducer, an EC 2.4.2.14 (amidophosphoribosyltransferase) inhibitor, an EC 3.5.1.2 (glutaminase) inhibitor, an EC 6.3.5.1 [NAD(+) synthase (glutamine-hydrolysing)] inhibitor and an EC 6.3.5.4 [asparagine synthase (glutamine-hydrolysing)] inhibitor. It is a non-proteinogenic L-alpha-amino acid, a diazo compound and a ketone. It is a tautomer of a 6-diazo-5-oxo-L-norleucine zwitterion.