Investigations on the biogenesis of chlorophyll a: I. Purification and mass spectra of maleimides from the oxidation of chlorophyll and related compounds

The structure of porphyrins in the amounts of 1–2 mg may be inferred from examination of the mass spectra of the free base ester and of the maleimides resulting from its oxidation with chromic acid. Fragmentation patterns of maleimides found in the chlorophyll a biosynthetic pathway are presented, along with the thin-layer chromatographic procedure for their prior purification.