GB611984A - Improvements in and relating to the extraction and purification of streptomycin - Google Patents

Abstract

Streptomycin is extracted from the metabolism fluid of Actinomyces griseus by adsorption on a suitable charcoal (i.e. one which will adsorb streptomycin and yet permit its elution without destroying its activity) under neutral or slightly alkaline conditions, and elution with an aqueous solution of an acid. Thereafter the eluate is neutralized, the streptomycin is adsorbed again on to charcoal and eluted with acid methanol or ethanol, the eluate is concentrated to one-tenth of its original volume, and a non-solvent for streptomycin salts which is miscible with methanol and ethanol is added to precipitate the salt of streptomycin. Sulphuric or hydrochloric acid may be used for the first elution, but it is preferable to use phosphoric acid, which makes it possible to carry out this part of the process in stainless steel vessels. The concentration of the phosphoric acid is advantageously 1-2 per cent, preferably about 2 per cent, though when employing static beds of charcoal the concentration may be reduced in the later stages of the elution. In an example, the metabolism fluid at pH 8.5 is stirred with activated charcoal (Farnell 14) and filtered with the aid of the material known by the Registered Trade Mark "Supercel," the filter cake is washed with water and agitated with 2 per cent aqueous phosphoric acid, filtered, neutralized to pH 7 and treated with charcoal and filtered as before, the filter cake is washed with water and with methanol and agitated with methanolic or aqueous methanolic hydrochloric acid, the eluate is neutralized to pH 6 and concentrated, and acetone, amyl acetate or monochlorobenzene is added to precipitate streptomycin hydrochloride, which may be further purified by crystallization of the picrate, helianthate or reineckate salts.