1308843 Antibiotic X-5108 F HOFFMANN-LA ROCHE & CO AG 12 Aug 1971 [14 Aug 1970] 37925/71 Heading C2A The novel antibiotic X-5108, which is a yellow amorphous substance, soluble in alkanols, water-immiscible esters and chloroform, and insoluble in neutral water, forms salts with cations (e.g. Na, K and Ca), and may be identified by the following characteristics: analysis, C = 63??63%, H = 7??81%, N = 3??48% and O (by difference) = 25??08%; optical rotation of the Na salt [α]25 D = -82??8 degrees (ethanol, C = 0??52); I.R. absorption spectrum as shown in Fig. 1, i.e. broad band at 3400 cm.-1, strong band at 1660 cm.-1, and prominent bands at 1580, 1380, 1250, 1100, 1040 and 995 cm.-1; U.V. absorption spectrum as shown in Fig. 3, having maxima as follows: in 0??1 N HCl, # max. 334 m?? (E1% 1 cm. = 403), 233 m?? (E1% 1 cm. = 610), and 206 m?? (E1% 1 cm . = 500); in pH 7??0 buffer (isopropanol/K 2 HPO 4 ), #max 327 m?? (E1% 1 cm . = 423) and 231 m?? (E1% 1 cm. = 660); and in 0??1N KOH, #max 327 m?? (E1% 1 cm . = 416) and 231 m?? (E1% 1 cm. = 647); is prepared by cultivating Streptomyces sp. X-5108 (ATCC. 21386) or an antibiotic X-5108-producing mutant, subculture or variant thereof, under submerged aerobic conditions in an aqueous medium containing assimilable C and N sources and inorganic salts and recovering the antibiotic X-5108 from the culture medium. The antibiotic may be recovered by extraction (batchwise or by counter-current procedures) of the filtered medium with a waterimmiscible solvent therefor, e.g. butyl acetate, and purified by gel-permeation chromatography on crosslinked or polymerized dextran gel. It is isolated by treating an organic solvent solution of the purified antibiotic with diethyl sodium malonate to precipitate the antibiotic sodium salt, from which the free antibiotic may be obtained by treatment with aqueous acid e.g. NaH 2 PO 4 . A composition for enhancing the feed efficiency and stimulating the growth of poultry comprises antibiotic X-5108 or a physiologically acceptable salt thereof together with a non- toxic inert carrier ingredient and/or a nutrient feedstuff for poultry. The antibiotic has activity against Gram-positive and -negative bacteria, especially Streptococci, Pneumococci and other bacteria causing caecal coccidiosis.
