Hepta-, hexa-, and pentacarboxylic porphyrins of porphyria cutanea tarda. II. Preparation of the porphyrins by stepwise decarboxylation ofuroporphyrins.

Hepta-, hexa-, and pentacarboxylic porphyrins have been detected in porphyric as well as normal urine samples. From the former they have been isolated and converted into pure methyl esters (1). For a better understanding of the chemistry of these porphyrins, pure uroporphyrin I and uroporphyrin III were separately subjected to decarboxylation under controlled conditions. The decarboxylation products are described and their relations with those isolated from the porphyric urine are discussed in this report.