GB758751A - Improved method of preparing gonadotropins as well as acth from pituitary material and gonadotropins so produced - Google Patents

Abstract

The extraction of ACTH and gonadotropins from the same batch of whole pituitary material e.g. hog pituitary material, comprises extracting the ACTH with acidified aqueous acetone, containing 50 to 85 per cent by volume acetone, at a pH below 4, and subjecting the separated insoluble residue to aqueous extraction at a pH from 7,1 to 10,0 to extract the gonadotropins. The gonadotropins may be precipitated by addition of ethanol, or the extract may be adjusted to a pH between 3 and 7 and the gonadotropin-inert proteins precipitated by addition of a water-soluble zinc salt e.g. acetate, chloride or nitrate, to a concentration of 0,01 to 1,0 molar, prior to the precipitation of the gonadotropins as a zinc complex by the addition of an organic precipitating agent e.g. ethanol (10 to 50 per cent by volume), monohydroxyalkanes, or aliphatic ketones having less than 4 carbon atoms. Extraction of the precipitated zinc complex with aqueous phosphate solution e.g. mono- or dibasic alkali metal phosphates, at pH 7 to 9, which may contain an organic precipitating agent (25 to 55 per cent by volume) results in a supernatent liquid, which contains the gonadotropins free from zinc and inert substances, from which the hormone is recovered by precipitation. Alternatively, the zinc can be removed from the gonadotropin preparation by an ion exchange procedure or dialysis in the presence of a sequestering agent. The hormone may be further purified by fractionation with ammonium sulphate at pH 4,5 to 8,0. The process takes place at a temperature of less than 10 DEG C.