Studien über die Entstehung der roten Harnpigmente (Uroporphyrin und Porphobilin) bei der akuten Porphyrie aus ihrer farblosen Vorstufe (Porphobilinogen)

Abstract

Porphobilinogen ( = chromogen) was isolated by a chro-matographic analysis of the urine and purified by adsorption on Al2O3, elution with NH4OH and following electro-phoresis. Porphobilinogen contained basic and acidic radicals; its isoelectric point wag at pH 4.1; the molecular wt., detd. by Northrop and Anson''s diffusion method, was about 350. Porphobilin (=Waldenstroem''s "red pigment") could not be prepared in crystalline form, due to its complete insolubility in organic solvents. The methyl ester, however, was soluble in chloroform and was obtained as an amorphous mass.[long dash]Porphobilinogen could be changed into porphyrin by alkaline hydrolysis.