GB1317830A — Method for producing antibiotics namely rifamycins b and o

USPTO Abstract

1317830 Antibiotics rifamycins B and O TAKEDA YAKUHIN KOGYO KK 1 June 1970 [30 May 1969] 26301/70 Heading C2A Rifamycin B and rifamycin O are produced by cultivating Streptomyces tolypophorus (I.F.O.-12554-cf. Specification 1,212,741) or its yellow mutant (I.F.O. 13151) in a nutrient medium containing at least one assimilable C source and at least one digestible N source in the presence of 0À005 to 0À5% of an inorganic iron compound under aerobic conditions. The medium is preferably aqueous and the iron may be ferrous or ferric chloride, sulphate, citrate, phosphate, iodide, oxide or hydroxide. Rifamycin O is obtained by extracting the culture broth at pH 7À2 with ethylacetate and adding a 1 : 10 mixture of diethyl ether and petroleum ether to the extract to precipitate a crude which is further purified by chromatography on carbon and then on silica gel. Rifamycin B is obtained from the aqueous layer after ethyl acetate extraction of the broth by adjusting to pH 2À5, extracting with ethyl acetate and precipitating a crude by the addition of petroleum ether. Further purification is by dissolution in ethyl acetate, extraction with aqueous phosphate, adjustment to pH 3À0, re-extraction into ethyl acetate and precipitation by addition of n-hexane, followed by crystallization from 1 : 1 ethyl acetate and acetone.