Isoprenoid Fatty Acids Isolated from the Kerogen Matrix of the Green River Formation (Eocene)

Abstract

Demineralized oil shale was oxidized with chromic acid, and C(14) to C(22) isoprenoid fatty acids were isolated and identified. The major components of the branched-chain acid fraction after successive 3-, 6-, and 15-hour oxidations are C(15) and C(16) branched-chain acids; C(17), C(19) (norphytanic acid), and C(20) (phytanic acid) were obtained in lower concentration; no C(18) product was obtained. Separations were effected by column and gas-liquid chromatography, and the structures of individual components were determined by high- and low-resolution mass spectrometry.

Microbial Metabolism of the Isoprenoid Alkane Pristane

“…Sheep perinephric fat contains traces of TMTD, which are postulated to have arisen by the action of rumen bacteria on phytol (14). Presumably, the TMTD found in marine life (fishes and mammals) (11,17,18), recent marine sediments (15), and the shale (23) and kerogen matrix (20) of the Green River formation also has its origin in the phytol moiety of chlorophyll. a-Methylglutaric acid could be formed via cw-oxidation of a long-chain monocarboxylic acid, first reported in bacteria by Kester and Foster (24).…”

Distribution of Acyclic Isoprenoids in Fractions from Stepwise Oxidation of Green River Kerogen

“…In subsequent stepwise (Burlingame and Simoneit 1968;Burlingame and Simoneit 1968) oxidation of Green River kerogen, Burlingame and Simoneit used 3 M chromic acid in sulfuric acid at reflux temperature, and identified by gas chromatography and high and low resolution mass spectroscopy isoprenoid acids ranging from C,, to C,, (except C,,) with major amounts of C, , and C,, acids. Isoprenoid acids were found to decrease drastically from 60% abundance (compared with normal, dicarboxylic, and ketoacids) in the first 3 h of the oxidation period to 5% abundance in the final oxidation period.…”

Physics and Chemistry of Lakes

“…Some biomarker compounds that have been isolated include porphyrins and isoprenoid fatty acids (Burlingame and Simoneit 1968), steranes (Gallegos 1975), and bicyclic carotenoid components (Machihara and Ishiwatari 1987). Recombination and condensation of biological precursor molecules is believed to contribute to construction of the kerogen macromolecular matrix.…”