Studies on the biosynthesis of blood pigments. 4. The nature of the porphyrins formed on incubation of chicken erythrocyte preparations with glycine, δ-aminolaevulic acid or porphobilinogen

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Abstract
The constitution of a number of porphyrin fractions obtained in in vitro experiments with chicken red-cell preparations was studied. An improved paper -chromatographic method, which allows distinction between coproporphyrin isomers I, II and (II and IV) is described; use of this method reveals that, in the "coproporphyrin" fraction, coproporphyrin HI (or IV) preponderates, but is accompanied by relatively very small amounts of materials which may be hepta-, hexa-, penta- and tri-carboxylic porphyrins possibly a trace of coproporphyrin I is also present. By paper chromatography, it was also found that the "uroporphyrin" fraction consisted, in some instances, of about equal amounts of uroporphyrin in (or IV) and a material which was called pseudouroporphyrin. This porphyrin resembles in some of its properties a uroporphyrin, but it is not one of the isomers I, II, III or IV; it is suggested that it may be of significance in the biosynthesis of protoporphyrin. The "protoporphyrin" fraction sometimes contained traces of a "tricarboxylic" porphyrin, but by all available criteria, including countercurrent distribution, it appears to consist mainly of protoporphyrin. The countercurrent-distribution technique has also been used for studies of the action of aqueous HC1 on protoporphyrin and its methyl ester.