Verfahren zur Herstellung eines neuen Antibiotikums

摘要

1,163,270. Antibiotic enduracidin. TAKEDA CHEMICAL INDUSTRIES Ltd. 13 Oct., 1966 [13 Oct., 1965; 26 Oct., 1965], No. 45843/66. Heading C2A. An antibacterial antibiotic Enduracidin is obtained by culturing an enduracidin-producing strain of Streptomyces fungicidicus, e.g. strain B-5477 (ATCC 21013) or its mutant (ATCC- 21014), in a medium containing assimilatable carbon sources, digestible nitrogen sources and other nutrients necessary for the growth of the micro-organism under aerobic conditions of surface or submerged culture. The antibiotic is present in mycelium and clarified broth and may be isolated from both, preferably separately. The washed mycelium is extracted preferably with aqueous acetone or aqueous methanol under neutral or acid conditions, the pH of the extract adjusted to 5 to 6, the organic solvent removed therefrom, the pH adjusted to 3.0 and the extract then further extracted with ethyl acetate. The aqueous layer is separated, adjusted to pH 8.0 and then extracted with nbutanol. The n-butanol extract is treated with aqueous acid of pH 2À0 and the aqueous acid re-extracted with n-butanol at pH 8.0. After concentration, the antibiotic is precipitated by the addition of ether. Purification is by adsorption on activated charcoal followed by treatment with a weakly basic ion-exchange resin to remove the acid. The hydrochloride is formed by treating a methanol solution of the antibiotic with hydrochloric acid. Enduracidin (free base) is a colourless polypeptide antibiotic which on hydrolysis with hydrochloric acid gives threonine, serine, glycine, alanine and aspartic acid; melting point 205-225‹ C., decomposing 225- 240‹ C.; sparingly soluble in water and anhydrous solvents, soluble in aqueous acetone, aqueous methanol, aqueous butanol, aqueous acids and aqueous alkalies; elementary analysis 0=53À2%, H=6.54%, N=14.45%, Cl= 3.36%; specific rotation [α]23 D =+85‹Œ10‹ (C=0À5 in dimethylformamide); R f value acetic acid-n-butanol-water (1: 4: 5) 0À45Œ0À1: ultra-violet absorption spectrum (Fig. 1) maxima 230 mÁ E1% 1cm. =220Œ15, 263 mÁ E1% 1cm. = 150Œ10 (95% aqueous methanol); infra-red absorption spectrum as in Fig. 2 (free form), Fig. 5 (not shown, hydrochloride form).