GB524132A - Preparation of uscharidine - Google Patents

Abstract

524,132. Uscharidine. BOEHRINGER, E., BOEHRINGER, A., LIEBRECHT, J., and LIEBRECHT, [geb. BOEHRINGER], I. Jan. 23, 1939, No. 2323. Convention date, Jan 22, 1938. [Class 2 (iii)] Uscharidine is-prepared by the hydrolysis in acid media at ordinary or increased temperature of the glucoside uscharin, obtained from the milky juices of Calotropis species, after previous isolation as a crystallized substance or an amorphous crude product or as contained in the mother-liquor of the extraction process. The acid medium may be sulphuric acid, hydrochloric acid, fluoboric acid, perchloric acid or organic sulphonic acids such as benzenesulphonic acid, toluenesulphonic acid and alkyl sulphonic acids or potassium bisulphate, preferably in alcoholic or aqueous alcoholic solution. The uscharidine is extracted from the acid aqueous-alcoholic solution with chloroform, carbon tetrachloride or ethyl acetate and crystallized, if necessary after purification by chromatographic adsorption over aluminium oxide or active carbon. During the process the temperature should be kept below 40‹C. Uscharin may be isolated as follows :-ethyl alcohol is added to the milky juices and a preservative such as toluene or thymol or neutral salts such as ammonium sulphate added; impurities such as tannins, albumins and saponins are precipitated by alcoholic lead acetate and filtered; the mother-liquor is concentrated, extracted with chloroform, deacidified with sodium carbonate and evaporated. By dissolving the concentrate in solvents which do not dissolve uscharin in the cold, e.g., chloroform, ethyl acetate or dioxane, a brownish crystallized product is obtained which is recrystallized from chloroform after filtering through aluminium oxide. In the examples uscharidine is obtained by the hydrolysis of uscharin and a crude concentrate containing uscharin by means of sulphuric acid, followed by extraction with chloroform and subsequent working up. The Specification as open to inspection under Sect. 91 also specifies sodium bisulphate and bisulphite as acid media for the hydrolysis and mentions amyl alcohol, and butyl acetate as suitable for extracting uscharine during its working up. Uscharidine may be administered as a complete compound with desoxycholic acid. This subject-matter does not appear in the Specification as accepted.