Biosynthesis of porphyrins and related macrocycles. Part II. Synthesis of δ-amino[5-13C]laevulinic acid and [11-13C] porphobilinogen: incorporation of the latter into protoporphyrin-IX

Abstract
A short synthesis of δ-aminolaevulinic acid is described in which C-5 and the nitrogen atom are introduced as cyanide ion. The sequence is especially well suited to the preparation of material labelled at C-5 and it is used to afford δ-amino[5-13C]laevulinic acid; 13C chemical shifts are reported for the various products. [11-13C]Porphobilinogen is also synthesised from [13C]formaldehyde and this material is incorporated by extracts of Euglena gracilisinto protoporphyrin-IX. The 13C n.m.r. spectrum of the labelled porphyrin proves that the four signals near δ 97 arise from the meso-carbon atoms and that these positions are essentially equally labelled.