Fecha de publicación: 08/12/1965 Fuente: WIPO "royal jelly" A therapeutically useful proteinaceous material capable of depressing the blood calcium level is obtained by dissolving royal bee jelly in water at pH2 or 8, removing undissolved material, washing the resultant solution with ether and precipitating the active material by adjusting the pH to a value in the range 4.8 to 7.0. The product may be further purified by re-dissolution and reprecipitation by pH adjustment, precipitation in the range 4.8 to 5.6 giving a product showing greater sex gland-stimulating activity than precipitated at pH 5.7 to 7.0. Alternatively, the material may be reprecipated by ammonium sulphate and dialysed. An aqueous solution of the product, preferably containing a water-soluble amino acid containing not more than 5 carbon atoms, e.g. glycine as stabilizer, may be dried, e.g. by byophilisation to give a solid stable product which may be stored in ampoules reconstituted and used for injections.