| 摘要 |
NEW MATERIAL:An antibiotic KA-6643-B shown by the formula and its salt. USE:An antibiotic effective against Gram-positive and Gramnegative bacterial, and effective against bacteria having resistance to various kinds of beta-lactam antibiotics. PROCESS:A streptomyces sp KC-6643(FERM-P 4467) is cultured aerobically at 3-35 deg.C, preferably at 27-33 deg.C by liquid cultivation, especially deep part cultivation, and the culture solution is subjected to centrifugation or filtration to remove the mold. The culture filtrate is made to flow through a basic anion exchange resin, and substance KA-6643 is adsorbed. The substance KA-6643 is eluted with s salt solution or an aqueous methanol solution of salt. The solution is made to flow a strongly basic ion exchange resin, and the substance FA-6643 is eluted by changing a salt concentration in a buffer solution of phosphoric acid stepwise. The substance KA-6643-A is eluted at early stage, and the substance KA-6643-B shown by the formula is then eluted. Both substance are separated. |
