Azaserine is a tumor-inhibiting antibiotic isolated from a species of Streptomyces that functions as a glutamine analog. At 25 μM, it inhibits the glutamine-dependent amidotransferases involved in nucleotide biosynthesis, phosphoribosylformylglycinamidine synthetase and glucosamine-6-phosphate isomerase. Azaserine also inhibits the hexosamine biosynthetic pathway, which shunts excessive intracellular glucose into the biosynthesis of UDP-N-acetylglucosamine and the formation of O-linked glycoproteins. Azaserine has been shown to protect against hyperglycemic endothelial damage through its antioxidant effects.
