The porphyrin pattern of normal urine

Abstract

1. 1, The porphyrins in 4001. pooled normal urine were studied by talc adsorption with subsequent esterification, hydrolysis of the crude ester and subsequent re-esterification. The purified ester was subjected to TLC on SiO 2, the fractions isolated and eluted, and the sub-uro fractions subjected to re-esterification and re-chromatography. Spectrophotometric reading on the isolated fractions showed 70% coproporphyrin, 15% uroporphyrin, 5% pentacarboxylate, 1–2% hexacarboxylate, 3% heptacarboxylate, 1–2% tricarboxylate below 1% dicarboxylate (proto) porphyrin and about l% sub-uro porphyrin. 2. 2. The total porphyrin was found to vary between 20 and 40 μg per litre, calculated as coproporphyrin by Spectrophotometric readings on 1:25 dilutions with 0.1 mol/1 HCI of the primary H 2SO 4-methanol eluate from the talc, corresponding to a 165 times concentrated urine and fluorescing deeply red in Wood's light. 3. 3. Decarboxylation and subsequent isomer analysis showed that the coproporphyrin consisted of about 70% isomer III, the uroporphyrin of above 90% isomer I while the 5-, 6- and 7-carboxylate porphyrins gave very faint spots pointing to domination of the III isomers. Decarboxylation was performed both by the simple technique at atmospheric pressure and under pressure and the latter more laborious technique did not give better results.