| 摘要 |
NEW MATERIAL:A compound A40A of the formula (the configuration of the pyran is S at the hemiketal 2, S at the carbon atom 4 having an OH group, and S at the carbon atom 6 having the pentadienyl side chain), its salt or ester. USE:Antibiotics effective against Gram-positive and limited Gram-negative bacteria, and growth accelerators for animals. PROCESS:Strains of Streptomyces lavendulae MA-4758(ATCC 31312) are cultured aerobically in an aqueous nutrient medium containing assimilable carbon and nitrogen sources, at 20-37 deg.C, preferably 24-32 deg.C and a pH of 6.0-8.0. After culturing, the broth is filtered, and the objective substance is adsorbed on an adequate resin, and eluted. The eluted concentrate is extracted with a water-immiscible organic solvent to take out the solvent layer. The solvent is then evaporated, and the residue is redissolved in a polar organic solvent, e.g. ethyl acetate, and then precipitated with a non-polar solvent, to give the antibiotic A40A. |
