| 摘要 |
PURPOSE:To prepare a novel antibiotic substance PS-3 containing a heptemic acid skeleton and having strong antibacterial activity, in high efficiency, by aerobically culturing Streptomyces sp. A271 strain in a nutrient medium. CONSTITUTION:Spores or mycelia of novel bacterium, Streptomyces sp. A271 strain, are inoculated in a nutrient medium, e.g. sucrose-nitrate-agar medium, and cultured at pH 4-9, and 20-40 deg.C, for 30-90 hours. The antibiotic substance PS-3 of the formula I is accumulated in the medium. Since the substance is soluble in water, and accumulated mainly outside of the bacterial cells, it s preferable to carry out the separation by removing the cells by filtration or centrifugation, and recovering the substance from the filtrate, supernatant liquid, extract, etc. Esterification of the antibiotic substance PS-3 affords the trityl ester II which is a synthetic intermediate of other useful medicines. |
