Key points are not available for this paper at this time.
Specimens from Prof. C. J. Watson's laboratory have been examined. The uroporphyrin methyl ester I had m.p. 292-293and behaved as uroporphyrin I containing a trace of uroporphyrin III on paper chromatography. The 2080 ester behaved chromatographically as a hexacarboxylic porphyrin.
S V Perry (1953) studied this question.