Patent GB-914683-A (GB)
Title: The new antibiotic x-5079c and a process for its manufacture
IPC: C12P1/06
Filed: 1961-01-13
Abstract: <PICT:0914683/IV (b)/1> A new antibiotic X-5079C effective against certain fungi is produced by cultivating an antibiotic X-5079C-producing strain or variant strain of Streptomyces saraceticus under submerged aerobic conditions in an aqueous nutrient medium containing inorganic salts and a source of organic carbon and nitrogen until the medium acquires a substantial antifungal activity and recovering said antibiotic therefrom.  Specified nitrogen sources are soyabean flour, cotton seed meal, peanut protein meal, fish meal, wheat germ flour, meat flour, peptones (thiopeptone, thiotone, pork heart digest), dried torula yeast, dried brewers yeast, dried beef blood, distillers dried solubles, corn steep liquor, linseed oil meal, casein hydrolysate, alanine, arginine, glutamic acid, lysine and valine.  Specified carbon sources are glucose, sucrose, brown sugar, starch or dextrin.  A specified inorganic salt is dipotassium hydrogen phosphate.  The cultivation is preferably carried out at a temperature of 23 DEG 34 DEG C. for 2 to 6 days at a pH of 5.8 to 7.5.  The antibiotic is isolated by (a) extracting the filtered broth with a water immiscible alcohol e.g. butanol (b) extracting the wet mycelium with an aliphatic alcohol of 1 to 5 carbon atoms e.g. methanol, ethanol or butanol or (c) acidifying the whole broth, filtering and extracting the mycelium as in (b).  The antibiotic is precipitated by concentrating the solvent extract and then adding a petroleum solvent e.g. a hexane-containing solvent.  The antibiotic may be purified by (a) adsorption in methanol solution on aluminium oxide (b) extracting the antibiotic from butanol solution with aqueous alkali, acidifying the extract and extracting back into butanol or (c) chromatography in methanol solution on aluminium oxide or chromatography on a silica-gel distribution column or a water-containing diatomaceous earth distribution column using butanol saturated with water as mobile phase.  Antibiotic X-5079C is a high molecular-weight acidic polypeptide, having in its sodium salt form the analysis C = 46 to 48%; H = 4 to 5%; N = 14 to 16%; S = 12 to 14% and Na = 1 to 2%, no distinct melting point, a specific optical rotation in water [a ]25D = 40 DEG  to 42 DEG  (c = 1 in water), absorption maxima in the U.V. spectrum in isopropanol at 222 mm , E1%cm. = 510 and at 273 mm , E1%cm. = 245 and absorption peaks in potassium bromide in the infra-red absorption spectrum at 3320, 2980, 1689, 1668, 1610, 1506, 1437, 1379, 1280, 1168 and 1034 cm-1 (see Figure) and in its acid form a fair solubility in methanol and watersaturated butanol, a slight solubility in water and acetone and insolubility in diethyl ether, ethyl acetate, chloroform, benzene and hexane, and at a pH of 7-9 it is soluble in methanol and water, slightly soluble in butanol and insoluble in ether, ethylacetate, chloroform acetone, hexane ethyl acetate and benzene.  On hydrolysis with acid and treatment with hydrogen peroxide of antibiotic X-5079C the following amino acids were identified cysteic acid, aspartic acid, glycine, threonine and proline.  The antibiotic has a neutral equivalent of 1000-3000 determined by electromeric titration.  Salts are prepared by passing an aqueous solution of the sodium salt through a cation exchange resin column containing the appropriate cation e.g. potassium, lithium or ammonium ions. The antibiotic X-5079C is active against fungus infections e.g. histoplarnoris and blastomycoris.