CP-78,545, a new monocarboxylic acid ionophore antibiotic related to zincophorin and produced by a Streptomyces.Dirlam JP, Belton AM, Chang SP, Cullen WP, Huang LH, Kojima Y, Maeda H, Nishiyama S, Oscarson JR, Sakakibara T, et al.J Antibiot (Tokyo). 1989 Aug;42(8):1213-20. doi: 10.7164/antibiotics.42.1213.

Isolation and characterization of antibiotic X-14547A, a novel monocarboxylicacid ionophore produced by Streptomyces antibioticus NRRL 8167.Westley JW, Evans RH Jr, Sello LH, Troupe N, Liu CM, Blount JF.J Antibiot (Tokyo). 1979 Feb;32(2):100-7. doi: 10.7164/antibiotics.32.100.