NOBORITOMYCINS A AND B, NEW POLYETHER ANTIBIOTICS

• Published in: Journal of antibiotics Vol. 31; no. 9; pp. 820 - 828
• Main Authors: KELLER-JUSLÉN, CAMILLA, KING, HAMILTON D., KUHN, MAX, LOOSLI, HANS-RUDOLF, WARTBURG, ALBERT VON
• Format: Journal Article
• Language: English
• Published: Japan JAPAN ANTIBIOTICS RESEARCH ASSOCIATION 1978
• Subjects: Anti-Bacterial Agents - biosynthesis; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Chemical Phenomena; Chemistry; Ethers - biosynthesis; Ethers - isolation & purification; Ethers - pharmacology; Fermentation; Ionophores - isolation & purification; Magnetic Resonance Spectroscopy; Microbial Sensitivity Tests; Streptomyces - classification; Streptomyces - metabolism
• ISSN: 0021-8820; 1881-1469
• DOI: 10.7164/antibiotics.31.820

Noboritomycins A and B, two new polycyclic ionophoric polyethers were isolated from a strain of Streptomyces noboritoensis. The crystal structure and absolute configuration of noboritomycin A were established by X-ray analysis of its silver salt C43H63O14Ag. Noboritomycin A is the first metabolic polyether possessing two carboxylic acid functions on the carbon backbone (C-31), namely a free acid and an additional carboxylic acid ethylester group. An unusual spiroketal system as well as a salicylic acid chromophore represent further remarkable elements. Noboritomycin A shows in this respect a structural relationship to salinomycin and lasalocid respectively. Comparison of physico-chemical data, in particular the interpretation of the 1H- and 13C-NMR spectra, revealed that noboritomycins A and B are structurally closely related, noboritomycin B carrying an ethyl substituent on the aromatic ring in the place of a methyl group present in noboritomycin A. Both metabolites exhibit activity against Gram-positive bacteria and against Eimeria tenella (chicken coccidiosis).