Patent GB-898936-A (GB)
Title: The antibiotic baí¬163, preparation thereof and compounds of and compositions containing said antibiotic
Filed: 1959-08-05
Abstract: A new antibiotic designated BA-163 is produced by cultivating an antibiotic BA-163-producing strain of Streptomyces flocculus, especially S. flocculus ATCC 13535, S. flocculus ATCC 13257 or S. flocculus ATCC 13536 under submerged aerobic conditions in an aqueous nutrient medium containing an assimilable source of carbon nitrogen and mineral salts and preferably at a temperature of 28 DEG C. for 60 to 80 hours.  Specified nitrogen sources are <PICT:0898936/IV (b)/1> <PICT:0898936/IV (b)/2> myriad proteinaceous materials, e.g. hydrolysed casein, soyabean meal, casein, distillers solubles and cornmeal.  Specified carbon sources are dextrose, glycerin, glucose, dextrin, starch or lactose.  Specified minerals are calcium carbonate, sodium chloride and dipotassium phosphate.  The antibiotic is isolated from the clarified broth by solvent extraction with a water-immiscible organic solvent, e.g. butanol, methyl, isobutyl ketone or ethyl acetate, preferably adjusting the broth to pH 3.5-7.2 before clarifying.  When ethyl acetate is used as the extracting solvent the extract is concentrated under reduced pressure extracted with isopropylether and the antibiotic BA-163 is extracted from the organic solvent with an aqueous phosphate buffer pH 7.5.  The buffer extract on acidification, extraction with methylene chloride and evaporation of solvent or precipitation with diethyl ether gives antibiotic BA-163.  The antibiotic BA-163 is a weak monobasic acid forming salts with amines, metal hydroxides and basic metal salts and ethers with alkanols from methanol to butanol by reaction of the antibiotic with the alkanol in the presence of an acid catalyst or with diazomethane in ether.  With concentrated sulphuric acid or sodium bisulphite it gives a bright yellow colouration and with alcoholic ferric chloride it gives a dark greenish-brown colour. It is only slightly soluble in water at neutral and acid pH's; soluble in aqueous sodium bicarbonate, unstable in alkaline solution, slightly soluble in ether benzene and methylene chloride and moderately soluble in ethyl acetate, the alkanols from methanol to butanol and acetone.  The antibiotic BA-163 is dark maroon in colour but orange by transmitted light, melts at 268 DEG C.-270 DEG C., contains 58.3% C, 4.5% H, 10.9% N, 18.0% methoxyl and 26.3% O, shows U.V. maxima at 245 and 390 mm  in methanol and 245 and 365 mm  in pH 6 buffer.  It is active against both gram positive and gram negative bacteria and tumours and its salts and ethers may be used in medicinal preparations (see Group VI).ALSO:A therapeutic composition for oral and parenteral administration to man and animals comprises the antibiotic BA-163, its salts or alkyl ethers (see Group IV (b)) in admixture with a pharmaceutical carrier.  The antibiotic calculated as free BA-163 is present in at least 0.0001% by weight of the final composition. Specified carriers are water, aqueous ethanol, syrup; isotonic saline or glucose, starch lactose, calcium phosphate or an animal feedstuff.  The composition is useful in the therapy of tumours preferably in admixture with one or more other carcinostatic agents e.g. nitrogen mustard type carcinostats, 6 mercaptopurine, 8 azaguanine, 6-diazo - 5 - oxo - 1 - norleucine, azaserine, triethylenemelamine, mitomycin C, triethylenephosphoramide, 1,4 - dimethylsulphonyloxybutane, the carcinostatic folic acid analogues or ethyl carbonate.