Molecular Fossils of Chlorophyll c of the 17-nor-DPEP Series. Structure Determination, Synthesis, Geochemical Significance.

Article abstract of DOI:10.1016/S0040-4039(00)80099-4

Two porphyrins 1 and 2, having totally (1) or partially (2) lost the C-17 substituent, have been isolated from two Moroccan oil shales of Cretaceous age.An origin from chlorophyll c, which possesses a 17-acrylic side-chain, can explain this transformation.A synthesis of 1 from chlorophyll (a+b) is described.Porphyrin 1 is widely distributed in sediments and its relative abundance with regard to other molecular fossils of chlorophyll c is discussed briefly.