GB866425A - The antibiotic variotin and the production thereof - Google Patents

Abstract

<PICT:0866425/IV (b)/1> A new antibiotic variotin active against fungi is obtained by cultivating a strain of Paecilomyces varioti Bainier var antibioticus (e.g. ATCC 13435, or a mutant thereof) under aerobic and preferably submerged conditions in an aqueous nutrient medium containing a source of carbon, nitrogen and mineral salts. The temperature is 20 to 40 and preferably 25 DEG C., the pH 6,0 and the duration 2 to 6 days for submerged cultivations. Suitable carbon sources are sucrose, glucose, fructose, mannose, glycerine, starch, mannan, malt sugar, xylose, lactose and molasses. Nitrogen sources are sodium nitrate, ammonium nitrate, calcium nitrate, ammonium sulphate, soybean meal, peanut meal, cottonseed meal, meat extract, peptone, corn steep liquor and yeast extract. Mineral Mineral salts are sodium chloride, potassium dihydrogen phosphate, potassium chloride, magnesium sulphate and ferrous sulphate. Variotin is isolated by the solvent extraction of (a) whole broth (b) the clarified broth and (c) the separated mycelium. In the case of (a) and (b), there is used a water-immiscible organic solvent such as butanol, amyl alcohol, methyl isobutyl ketone, benzene, chloroform, ethyl acetate, butyl acetate and carbon tetrachloride. In the case of (c), the mycelium is extracted with a water-immiscible solvent such as methanol, the solvent removed and the residue extracted with the water-immiscible solvent. Further purification is by means of countercurrent distribution using 70% methanol and carbon tetrachloride (1 : 1). Variotin is a colourless oil with ester-like fragrance, scarcely soluble in water, petroleum ether and ligroin; soluble in methanol, ethanol, butanol, amyl alcohol, ethyl acetate, butyl acetate, acetone, chloroform, glycerol and others; [a ]2D8 = -5,68 DEG (C = 1,0% methanol); contains C=67,35%, H=8,58%, N=4,16% and O=19,91%; in methanol shows maximum absorption in ultraviolet at 318-324 mm (E 1% 1 cm.=1198); in infra red shows maximum absorption at 3460, 3100, 2950, 2880, 1740, 1670, 1600, 1485, 1465, 1430, 1350, 1310, 1260, 1190, 1160, 1125, 1075, 1065, 1025, 1005, 970, 935, 885, 865, 840, 800 and 715 cm-1. Variotin is unstable especially in alkaline solution, more stable at pH 4 to 7,0 and in organic solvents such as butyl acetate, methanol, carbon tetrachloride and 75% aqueous ethanol. Stability is enhanced by the addition of 0,001 to 0,1% of (a) an antioxident such as hydroxyquinone, resorcin, butylhydroxyanisole or butyl hydroxytoluene, and/or(b) a chelating agent such as 8-hydroxyquinoline, 2,3-dimercaptopropanol or ethylene diamine tetraacetic acid or its salts. Variotin may be used medicinally (see Group VI).ALSO:Therapeutic preparations comprise the antifungal antibiotic variotin (see Group IV (b)), in the form of an ointment, solution, suspension, powder or suppository. It is stabilized by (a) dissolving in an organic solvent, e.g. butyl acetate, methanol, carbon tetrachloride or 75% aqueous, (b) the addition of 0.001 to 0.1% of at least one antioxidant selected from hydroxy quinone, 1,3-dihydroxybenzene, 2- or 3-t-butyl-4 - hydroxyanisole or 3,5 - di - tert. - butyl - 4 - hydroxytoluene and/or at least one of the chelating - agents 8 - hydroxyquinoline, 2,3 - dimercaptopropanol, ethylenediamine tetraacetic acid and its salts. Examples are given of ointment bases (e.g. polyethylene glycol and cetanol) containing such stabilizers.