ABSTRACT
Compounds related in structure to chlorophyll, especially deoxophy11oerythro-etioporphyrin (DPEP) and etioporphyrin, have long been used by the petroleum industry as indicators of thermal maturity. Earlier chlorophyll diagenetic products, especially 7-ethyl-7-despropio deoxomesopyropheophorbide, have been shown to form DPEP by an aromatization reaction that is time and temperature dependent (4). Sedimentary analyses suggest that this reaction takes place between the free base forms of the chlorophyll derivatives, followed by a metalation reaction with nickel to form nickel(II) DPEP.
