Acivicin is a fermentation product of Streptomyces; it is a glutamine analog. Acivicin inhibits γ-glutamyl transferase, CTP synthetase, GMP synthetase, and FGAM synthetase, preventing purine synthesis. Acivicin exhibits anticancer and antifungal activity, although its potential chemotherapeutic benefit is limited by high CNS toxicity. Acivicin inhibits the growth of pancreatic cancer cells and, separately, the growth of Alternaria, Magnaporthe, and Botrytis.