Synthetic and biosynthetic studies of porphyrins. Part 8. Syntheses of hepta-, hexa-, and penta-carboxylic porphyrins related to uroporphyrin-I
Abstract
The title porphyrins, of interest as abnormal metabolites in porphyrin biosynthesis, have been synthesized by the Fischer, and b-oxobilane routes, and compared with the naturally derived materials. Enzymic experiments have shown that the conversion of uroporphyrinogen-I into coproporphyrinogen-I both in vivo and in vitro is non-specific and occurs by both possible pathways via the two intermediate hexacarboxylic porphyrinogens.