GB828792A - Antifungal antibiotic designated nc 1968 - Google Patents

Abstract

An antifungal antibiotic designated NC 1968, is obtained from the mycelium formed on fermentation of Streptomyces coelicolor var. aminophilus NRRL 2390 nov. spec. in an aqueous nutrient medium under aerobic conditions of submerged or surface growth. The medium contains a source of (a) carbon, e.g. starch, dextrin, glucose, maltose, inulin, ribose, levulose, galastose, glycerol, mannitol and cellobiose, (b) organic nitrogen (inorganic nitrogen is not utilized) e.g. beef extract, yeast extract and peptone, and (e) mineral salts, e.g. sodium chloride, potassium dihydrogen phosphate and potassium monohydrogen phosphate. Temperature of cultivation is 15 DEG to 40 DEG C. and preferably 20 DEG C., duration is 10 days. The <PICT:0828792/IV (b)/1> and <PICT:0828792/IV (b)/2> broth is filtered, the mycelium washed to remove water-solubles and then extracted several times with an alcohol especially methanol, preferably after rupturing the cells of the mycelium. The mycelium may be agitated with the methanol for several hours at room temperature, filtered, filtrate evaporated, the residue taken up in water and lyophilized. Further purification is by chromatographic absorption. The crude antibiotic is placed in a column packed with wood pulp cellulose and is resolved with a mixture of propanol, water, benzene and glacial acetic acid and the active fractions collected. Antibiotic NC1968 is a yellow amorphous substance soluble in pyridine and dimethylformamide; soluble (with the addition of a little water) in methanol, ethanol, propanol, butanol, acetone and dioxan; practically insoluble in water, carbon tetrachloride, ethyl acetate, methyl isobutyl ketone, ether, benzene and hexane; contains 64.70% carbon, 7.93% hydrogen, and 2.46% nitrogen; in 70% aqueous n-propanol system has an Rf value of 0.8 to 0.9, and exhibits an infra-red absorption spectrum as shown in Fig. 1 and an ultra-violet absorption spectrum as shown in Fig. 2. It is distinguished from the antifungal antibiotics ascosin, candicidin and trichomycin.