GB1003383A - - Google Patents

Abstract

1,003,383. Antibiotic F.I. 1762 (Daunomycin). SOC. FARMACEUTICI ITALIA. Nov. 11, 1963 [Nov. 16, 1962], No. 41392/61. Heading C2A. The invention relates to the antibiotic F.I. 1762 (daunomycin), which is effective against tumours; forms red crystals of melting point 208-209‹ C.; is soluble in alcohols, ketones, halogenated hydrocarbons and aqueous acids; and is slightly soluble in water and insoluble in ethers and saturated hydrocarbons. It forms a red crystalline hydrochloride which is soluble in water and insoluble in chloroform; contains C = 55À01%, H = 6À31%, N = 2À46% and Cl = 6À20%; its adsorption spectrum in the U.V. and in the visible ranges shows bands at 234mÁ, 251 mÁ, 290 mÁ, 480 mÁ, 495 mÁ and 532 mÁ in methanol; the I.R. spectrum is shown in Fig. 1. The yellow-red aqueous solutions turn to violet on alkalinisation. On hydrolysis with dilute mineral acids, the antibiotic decomposes into two reducing sugars and a neutral red crystalline aglycone containing C = 61À75%, H = 4À94% and O = 33À31%; melting point 211-213‹ C., soluble in alcohols; insoluble in water; and having I.R. spectrum as shown in Fig. 2; Rf = 0À85 (n-butanol saturated with aqueous phosphate buffer at pH 5À2). The antibiotic has Rf = 0À21 and forms acid addition salts, e.g. hydrochloride, sulphate, acetate, propionate, valerianate, palmitate, oleate, citrate, succinate, mandelate, glutamate, pantothenate and picrate. Antibiotic F.I. 1762 is produced by cultivating Streptomyces peucetius NCIB 9475, or a mutant thereof, under aerobic conditions in a liquid nutrient medium containing assimilable carbon and nitrogen at 25‹ to 37‹ C. for 3 to 7 days, the pH of the medium being initially 6À5 to 7À5 and finally 7À5 to 8À0. A typical medium contains glucose, dry yeast, sodium chloride, potassium hydrogen phosphate, calcium carbonate, magnesium sulphate, iron sulphate, zinc sulphate and copper sulphate in water. The antibiotic is extracted from the mycelium, which is separated from the fermentation broth with the assistance of a siliceous earth filter aid. The initial extraction may be by (a) a solvent such as n-butanol or (b) a mixture of a water-miscible organic solvent such as acetone and aqueous acid e.g. sulphuric acid. In the case of (b), the solvent is removed from the neutralised extract, the aqueous residue is filtered, adjusted to pH 8 to 9 and extracted with a water-immiscible solvent e.g. n-butanol or chloroform. The antibiotic is precipitated from the organic extract by the addition of a non-solvent e.g. diethyl ether. Purification is obtained by extracting an organic solution of the crude antibiotic with aqueous acid of pH 2 to 5, adjusting the aqueous phase to pH 8 to 9, extracting with a waterimmiscible solvent and adding an acid in alcohol to precipitate a salt of the antibiotic. Further purification is by (a) countercurrent distribution using e.g. n-butanol and a phosphate buffer of pH 5À2, (b) chromatography. The antibiotic F.I. 1762, its salts and aglycone have bacteriostatic and antitumoral properties and, alone or in admixture, they may be administered orally, parenterally or topically in the form of e.g. tablets, dragees, powders, salves, creams, suppositories, solutions, suspensions or emulsions.