摘要 |
A new acidic polycyclic ether antibiotic UK-58,852 has the formula: <IMAGE> +TR <IMAGE> wherein R and R1 are both hydrogen, and can be prepared by the submerged aerobic propagation in aqueous nutrient media of Actinomadura sp. ATCC 39697. The antibiotic and its cationic salts are active against a variety of microorganisms and are effective in controlling coccidiosis, enteritis, swine dysentery and theileriosis as well as being effective in promotion of growth and/or improving efficiency of feed utilization in swine and ruminants. Two minor components, wherein R is H and R1 is CH3 and wherein R and R1 are both CH3, have also been isolated from the fermentation. |