Isolation of Uroporphyrin from the Feces in Idiopathic Porphyria. ∗

Abstract

Since the first description of uroporphyrin by H. Fischer 1 this substance has been believed to be excreted only in the urine. Numerous publications concerning the excretion of porphyrins under normal or pathological conditions have failed to mention the occurrence of uroporphyrin in the feces. We have found it in the form of the zinc complex in the feces of four out of five cases of idiopathic porphyria.† Its presence was questionable in the fifth. Although uroporphyrin was readily identified in the feces of cases 1 and 3, the method of purification available at the time these were studied was inadequate to permit crystallization. By means of an improved method entailing chromatographic analysis, crystalline uroporphyrin has been isolated from cases 4 and 5. The method employed was as follows: The untreated feces was ground in a mortar with methyl alcohol saturated in the cold with hydrochloric acid gas. The methyl alcohol extract was filtered from the fecal residue on a Buchner funnel, and the residue was then extracted twice more by grinding in a mortar with an additional amount of methyl alcohol HCl. The combined methyl alcohol extract was allowed to stand overnight. It was then mixed with chloroform and several volumes of water and shaken in a separatory funnel. The chloroform fraction was washed twice with water and once with 10% NH₄OH. Shaking with an equal volume of 7% NaCl quickly breaks any emulsion. The chloroform was washed twice more with NaCl solution. It was next filtered through chloroform moistened paper and mixed with 10 volumes of petroleum ether. The filtrate was then passed through a column of Brockmann's Al₂O₃ (Merck) 1.5 × 12 cm in dimensions.