| 摘要 |
<p><PICT:0981278/C2/1> The invention relates to the production of antimicrobial agent M-259 by cultivating an antimicrobial agent M-259-producing strain of the organism streptomyces nigellus, e.g. S. nigellus NRRL 2920, under submerged aerobic conditions in a culture medium containing assimilable sources of carbon, organic nitrogen and inorganic salts until substantial antimicrobial activity is produced by said organism in said culture medium. The culture medium may also contain an insoluble buffering agent and a non-toxic defoaming agent and may be maintained at a temperature from 24-32 DEG C. for 3 to 6 days. The antimicrobial agent M-259 is recovered from the whole broth or the culture filtrate by extraction with a water-immiscible polar organic solvent, e.g. butanol or chloroform, evaporation of the extract to small volume, addition of an inert, non-polar organic solvent, e.g. pentane or hexane, to precipitate impurities and evaporation of the clarified solution obtained. The crude product may be purified by chromatography on activated magnesium silicate or silica gel and elution with a mixture of a hydrocarbon and a more polar solvent, e.g. methanol, ethanol or acetone, and recrystallization. Antimicrobial agent M-259, which in its free base form crystallizes as yellow triangular prisms which melt at 155-157 DEG C., has the following properties:-it is substantially insoluble in water; somewhat soluble in acetone, saturated hydrocarbons, benzene, ethyl acetate, butanol, ethanol and methanol, but readily soluble in dimethyl formamide, chloroform, dimethyl sulphoxide and acidified absolute ethanol; has a U.V. absorption spectrum in methanol exhibiting maxima at 235 mm (E1%1 cm. = 480) and 335 mm (E1%1 cm. = 960); an I.R. spectrum as shown in the Figure; X-ray diffraction d-spacings in </>rA of 10.2, 6.5, 5.7, 5.15, 4.72, 4.50, 4.20, 3.88, 3.37, 3.25, 3.04, 2.95, 2.85, 2.63, 2.56, 2.47, 2.23, 2.12, 1.97, 1.90 and 1.78; elemental analysis C = 63.00%, H = 6.43%, O = 18.42% and N = 11.95%; M. wt. = 795/sB60; and an <FORM:0981278/C2/1> (1 mg. in 1 ml. of ethanol) and is non-dialysable and gives negative results in the acrolein, ninhydrin, phosphate and biuret tests. The antimicrobial agent M-259 may also be used as a herbicide (see Division A5).ALSO:Bactericidal and herbicidal compositions comprise Antimicrobial Agent M-259 (see Division C2) in the form of a dust, an aqueous dispersion or an emulsion.</p> |
