An L-glutamine diazo analogue amino acid antibiotic isolated from a species of the bacterial genus Streptomyces with potential antineoplastic activity. Diazooxonorleucine inhibits several glutamine-dependent biosynthetic pathways involved in the the syntheses of D-glucosamine phosphate, purines and pyrimidines. This agent inhibits phosphate-activated glutaminase, a key enzyme for the synthesis of releasable glutamine, depleting cells of this essential amino acid and reducing their capacity to proliferate. Check for active clinical trials using this agent. (NCI Thesaurus)