Human porphyria cutanea tarda isolation and properties of the urinary porphyrins

Porphyrins with 8-, 7-, 6-, 5-, and 4-COOH were isolated from urine of patients with porphyria cutanea tarda and were studied by column and paper chromatographic techniques both qualitatively and quantitatively, and their absorption spectra and melting points were determined. It was found that the relative excretion pattern was uroporphyrin > coproporphyrin > phyriaporphyrin > 5-COOH porphyrin > 6-COOH porphyrin. Studies of the isomeric composition of these different porphyrins showed that: the uroporphyrin was a mixture of isomers I and III in a 4:1 proportion; phyriaporphyrin and 6-COOH porphyrin were only type III; 5-COOH porphyrin and coproporphyrin were a mixture of isomers I and III.