| 摘要 |
<p>1,196,853. Polyoxins J, K and L. RIKAGAKU KENKYUSHO. 28 June, 1968 [30 June, 1967], No. 31140/68. Heading C2A. The invention comprises antifungal antibiotics polyoxins J, K and L which have the formulµ respectively. The polyoxins are produced by the aerobic cultivation in an aqueous nutrient medium of streptomyces cacaoi var. asoensis ATCC 19093 or 19094 or a polyoxin-producing mutant thereof (see also Specification 1,097,189). The polyoxin complex is isolated from the broth by adjusting to pH 2-0, heating to 70‹ C. and filtering. The filtrate is treated with activated C and is eluted therefrom with 60% aqueous acetone. A crude is obtained by adding acetone to the cone. eluate. Purification is by treatment with (a) "Dowex" 50 WX8 and elution with aqueous NaCl, (b) carbon, (c) "Dowex" 50 WX8 and elution with 0À1 M phosphate pH 2.0, (d) chromatography on sulphoethyl "Sephadex" and elution with 0À01M phosphate buffer increasing to 0À1M. The complex is dissolved in water and passed through "Amberlite" IR-4B (Cl type) to remove polyoxins D, E and F (see Specification 1,156,390). Distribution chromatography on a cellulose column using (a) butanol/acetic acid/ water (4 :1: 2) and then (b) 75% aqueous phenol results in a separation of polyoxins J, K and L and also polyoxins A and B (Specification 1,097,189). The antibiotics may be recrystallized from aqueous alcohol, e.g. aqueous ethanol. The polyoxins are amphoteric and can be adsorbed on either cation or anion exchange resins and may be eluted by acid, alkali or salt solutions. Polyoxins J, K and L may be used as agricultural fungicides.</p> |
