Polyether antibiotic. Major factor in antibiotic complex isolated from Streptomyces cinnamonensis. Discovery and isolation: Haney, Hoehn, Antimicrob. Agents Chemother. 1967, 349. Production: Haney, Hoehn, US 3501568 (1970 to Lilly). Structure: Agtarap et al., J. Am. Chem. Soc. 89, 5737 (1967). Crystal structure studies: Lutz et al., Helv. Chim. Acta 53, 1732 (1970); ibid. 54, 1103 (1971). Fermentation studies: Stark et al., Antimicrob. Agents Chemother. 1967, 353. Chemistry: Agtarap, Chamberlin, ibid. 359. Stereocontrolled total synthesis: T. Fukuyama et al., J. Am. Chem. Soc. 101, 262 (1979); D. B. Collum et al., ibid. 102, 2117, 2118, 2120 (1980). 13C-NMR study: J. A. Robinson, D. L. Turner, Chem. Commun. 1982, 148. Biosynthesis: Day et al., Antimicrob. Agents Chemother. 4, 410 (1973). Review: Stark, “Monensin, A New Biologically Active Compound Produced by a Fermentation Process”, in Fermentation Advances, Pap. Int. Ferment. Symp., 3rd, 1968, D. Perlman, Ed. (Academic Press, New York, 1969) pp 517-540.