Protein synthesis inhibitor with antibiotic and antitumor activity. Isoln from fermentation broth of Streptomyces sparsogenes var sparsogenes: S. P. Owen et al., Antimicrob. Agents Chemother. 1962, 772; GB 974541 (1964 to Upjohn); from S. cuspidosporus: E. Higashide et al., Takeda Kenkyusho Nempo 25, 1 (1966), C.A. 66, 54238q (1967). Characterization and purification: A. D. Argoudelis, R. R. Herr, Antimicrob. Agents Chemother. 1962, 780. Structural elucidation: P. F. Wiley, F. A. MacKellar, J. Org. Chem. 41, 1858 (1976). Total synthesis: H. C. J. Ottenheijm et al., ibid. 46, 3273 (1981); R. M. J. Liskamp et al., ibid. 5408. HPLC determn in plasma and urine: B. Winograd et al., J. Chromatogr. 275, 145 (1983). Pharmacokinetics and toxicology: Z. Zylicz et al., Cancer Chemother. Pharmacol. 20, 115 (1987). Ribosomal binding studies: E. Lazaro et al., Antimicrob. Agents Chemother. 35, 10 (1991). Biosynthetic studies: R. J. Parry et al., J. Am. Chem. Soc. 114, 5946 (1992). Review of chemistry and biological activity: H. C. J. Ottenheijm et al., Prog. Med. Chem. 23, 220-268 (1986).