13C-NMR evidence for the pathway of chlorophyll biosynthesis in green algae

Abstract

Analysis of the 13C-NMR spectra of chlorophyll enriched by feeding [1- 13C]glutamate or [2- 13C]glycine to a green alga, Scenedesmus obliquus , showed that 13C of the glutamate was incorporated in eight carbon atoms in a tetrapyrrole macrocycle derived from C-5 of 5-aminolevulinic acid (ALA), while 13C of glycine was in the methoxyl group adjacent to the isocyclic ring. A reversion was proposed in assignment of 13C chemical shifts of quaternary carbon in chlorophyll a .