Sparsomycin is a bacterial metabolite and a nucleoside analog of uracil that has been found in S. sparsogenes and has diverse biological activities.1,2,3 It is active against KB carcinoma cells, Gram-positive and Gram-negative bacteria, and fungi.4 Sparsomycin is an inhibitor of peptidyl transferase that interferes with tRNA binding to the A-site of the peptidyl transfer center and increases the binding of peptidyl-tRNA to the P-site.2 It inhibits protein synthesis in bacteria, archaea, and eukaryotes.2,3 Sparsomycin reduces tumor growth in a P388 mouse leukemia model and in a Walker 256 carcinosarcoma rat model.5

|1. Ottenheijm, H.C., van den Broek, L.A., Ballesta, J.P., et al. Chemical and biological aspects of sparsomycin, an antibiotic from Streptomyces. Prog. Med. Chem. 23, 219-268 (1986).|2. Wilson, D.N. The A-Z of bacterial translation inhibitors. Crit. Rev. Biochem. Mol. Biol. 44(6), 393-433 (2009).|3. Lazaro, E., Van den Broek, L.A., San Felix, A., et al. Chemical, biochemical and genetic endeavours characterizing the interaction of sparsomycin with the ribosome. Biochimie 73(7-8), 1137-1143 (1991).|4. Owen, S.P., Dietz, A., and Camiener, G.W. Sparsomycin, a new antitumor antibiotic. I. Discovery and biological properties. Antimicrob. Agents Chemother. 1962, 772-779 (1963).|5. Zylicz, Z., Wagener, D.J., van Rennes, H., et al. In vivo antitumor activity of sparsomycin and its analogues in eight murine tumor models. Invest. New Drugs 6(4), 285-292 (1988).