Structure determination of nickel(II) deoxophylloerythroetioporphyrin and a C30 homologue from an oil shale: evidence that petroporphyrins are derived from chlorophyll

Abstract

Nuclear Overhauser effect difference spectroscopy has been used to define the structures of two porphyrins isolated from Julia Creek oil shale as nickel(II) 3,4-didehydro-3,9,14-triethyl-4,8,13,18-tetramethylphorbine (DPEP) and its (9-desethyl homologue, thereby providing support for the hypothesis that petroporphyrins originate from chlorophyll.