Isoprenoid Hydrocarbons Research Articles

Geochemical Fossils of a Possibly Archaebacterial Origin in Ancient Sediments

Summary This article reviews available data on geochemical fossils and their potential precursors in archaebacteria. The evidence compiled during the last 3 years suggests that a large fraction of the isoprenoid hydrocarbons in sedimentary rocks as old as Precambrian is of archaebacterial origin and that archaebacteria have contributed significantly to the sedimentary organic matter through most of earth's history, at least from the late Proterozoic on. It remains to be seen whether geochemical fossils of archaebacterial origin have survived from Archean times.

Accumulation, distribution and depuration in trout of naphthenic and isoprenoid hydrocarbons (dodecylcyclohexane and pristane).

The biological effects in the aquatic environment caused by hydrocarbon pollution have been largely investigated. In order to determine the impact of such complex pollutants on aquatic species, numerous studies have been documented on the uptake and deputation of n-alkanes and aromatic hydrocarbons as reviewed by LEE (1977), but little attention has been given to branched and cyclic paraffins. Nevertheless, these compounds are present in all crude oils in large concentration (POSTHUMA 1977), and it was of interest to assess the accumulation and the distribution of such hydrocarbons in fish tissues and carcass and to determine the rate and conditions of their discharge.

In vitro conversion of humulene to Δ 8(13)−carpenellene. Cyclopropane sliding reaction

Tricyclic epoxide 7 , derived from humulene 6,7-epoxide underwent unusual rearrangement on treatment with TMSOTf to give an apparently methyl group migrated product 8 which was converted to a irregular isoprenoid hydrocarbon Δ 8(13)-capnellene.

Signs of supergenesis in the petroleum of the West Tebuk oil field

Gas-liquid chromatography has been applied to the aromatic, paraffin, and isoprenoid hydrocarbons in oils of various ages from the West Tebuk deposit. The differences in hydrocarbon composition are not genetic but instead indicate the effects of secondary factors, particularly supergene ones. The compositions of the alkanes (normal and isoprenoid) are related to the distance from the source rocks. Selective destruction of the isoprenoid hydrocarbons during abyssal stages of supergenesis is particularly pronounced for the compounds of low molecular weight. These trends in the secondary alteration must be borne in mind in geochemical correlation.

Extractable organic compounds associated with the metamorphosed stratiform Cu-deposit of Tisová (czechoslovakia)

Greenschist facies rocks of the stratiform Cu-deposit of Tisova contain aliphatic hydrocarbons in the n-C13 to n-C22 range and n-fatty acids in the range of n-C8 to n-C22. The amount of n-fatty acids varies from 3.3 to 13.5 μg. g−1. The presence of isoprenoid hydrocarbons, phytane and pristane, and the prevalence of even-numbered fatty acids over the odd ones give evidence of the biogenic origin of isolated substances. The CPI values of hydrocarbons and n-fatty acids and the number of hydrocarbons with a higher molecular weight increase in the deposit in stratigraphically upward direction. The variations in composition of organic matter in different horizons of the ore deposit are suggested to be the result of thermal alteration and/or alteration via the catalytic activity of ore minerals.

Hydrocarbons of Aquatic and Terrestrial Origin in Mountain Streams of the Marmot Basin

AbstractThe abundance of n‐alkanes in stream waters of the Marmot Creek drainage basin was studied to develop an understanding of the source of hydrocarbons in a pristine mountain stream. The n‐alkanes varied in concentration from 0.02 µg/liter to 0.06 µg/liter and exhibited a bimodal distribution with one grouping in the range of C15–C23 and the other between C25–C32. Carbon preference indices (1.2 and 4.0, respectively) suggested that the first group was largely produced by nonphotosynthetic aquatic organisms and second was from soil and terrestrial vegetation. The contributions from stream and soil were roughly equal. Hydrocarbons in pristine mountain streams thus appeared to be derived both from autochthonous and allochthonous sources. Isoprenoid hydrocarbons were present in lesser abundance than alkane hydrocarbons. Abundance of the isoprenoids relative to n‐alkanes indicated that little, if any, degradation of n‐alkanes occurs in the stream waters. Aromatic hydrocarbons were not present above detection limits of 1 ng/liter.

Formation of hydrocarbons by bacteria and algae.

The chemical investigation of biologically synthesized hydrocarbons did not begin early in the history of the systematic study of fats. All the neutral or highly non-polar lipids were included in a category of compounds designated as waxes. The waxes were monoesters of fatty acids and long chain alcohols, hydrocarbons, long chain alcohols, and high molecular weight compounds. Systematic investigations into the derivation and chemical nature of the constituents of waxes was started in 1942 by the American Petroleum Institute Project 43 which was designed to determine a) the part played by microorganisms in the formation of petroleum, b) the type hydrocarbons synthesized as animal and plant products to the extent and variety necessary to be able to form crude oil and c) whether radioactive and thermal sources of energy can transform organic matter into petroleum. The rationale for this project was apparently based on a number of factors. In 18 99 it was proposed that complex organisms, such as trees, fish and animal fats could be a direct source of the hydrocarbons in petroleum (1). In 1906, the isoprenoid hydrocarbon squalene was isolated as the major constituent of shark liver oil (2–4). Diatom nobs in tertiary opal shales were reported in 1926 (5).

Characterization of organic compounds associated with weathered, surface‐retorted oil shale

Abstract A sample of weathered, surface‐retorted oil shale was analyzed for organic compounds using capillary gas chromatography/mass spectrometry/computer techniques. Various biological markers were identified including isoprenoid hydrocarbons, stearanes and terpanes, along with other classes of organic compounds including alkanes, fatty acids, alkylbenzenes, and polycyclic aromatic hydrocarbons. The origin and environmental significance of these compounds are discussed.

Pyrolysis and gas chromatographic examination of phytol and isoprenoid hydrocarbons: Pre-calculation of retention indices by computer

For the identification of isoprenoid-type compounds and other degradation products derived from the pyrolysis of phytol and plant pigments, a calculation method was developed to the evaluate the chromatograms, determining the retention indices or net retention volumes of different compounds. Calculations were made by means of computer for different stationary phases and temperatures. Gas chromatographic and derivatographic measurements were made with natural plant pigments and phytol, including the thermal degradation of the compounds mentioned above. Close agreement was found between the measured and calculated data and with literature data.

Molecular fossils of Archaebacteria as selective degradation products of kerogen

A mixture of alkanes is obtained by treatment of the kerogen from the lacustrine Messel oil shale (Eocene) with boron tribromide, followed by the reduction of the released bromides with lithium aluminum hydride (or deuteride). The n-alkanes (C28C34) show a high even predominance. They correspond to long-chain diols from higher plants, which are linked to the kerogen as diethers or diesters. The branched and cyclic alkanes show a relatively simple pattern, between C15 and C40, corresponding to long-chain, slightly branched and isoprenoid hydrocarbons. Anteisopentadecane, C15H32, 8, isopentadecane, C15H32, 7, and its dimer, 13,16-dimethyloctacosane, C30H62, 9, as well as phytane, C20H42, 5, its dimer bis-phytanyl, C40H82, 2 and another isoprenoid compound, C40H80, 3, with 1 5-membered ring, have been idenified as major components by comparison with standards. The C15 and C30 compounds are attached to the kerogen as alcohols and diols implied in ether or ester linkages. The structural identity of the C20 and C40 compounds with those obtained recently by a similar sequence from Archaebacteria, clearly suggests that molecular entities of these micro-organisms, especially of methanogens, are incorporated in the kerogen as mono- and α,ω-diethers. It could also mean that the cell membranes of these bacteria are an integral part of the kerogen.

米国産NTU頁岩油成分の研究(第9報)コロラド産頁岩油の灯油留分より非環式イソプレノイド炭化水素の検出

From cut 2 fraction (bp 215-250°) of Colorado shale oil seven isoprenoid hydrocarbons were isolated and their structures determined by mass and 13C-NMR spectral analyses were as follows : 2, 6-dimethylundecane, 2, 6, 10-trimethylundecane, 2, 6, 10-trimethyldodecane, 2, 6, 10-trimethyltridecane, 2, 6, 10-trimethyl-1-undecene, 3, 7, 11-trimethyl-1-dodecene, and 4, 8, 12-trimethyl-1-tridecent. These isoprenoid components were isolated from the distillate by successive fractional distillation, chromatography on silica gel impregnated with silver nitrate and preparative gas chromatography.

Origin of unsaturated isoprenoid hydrocarbons in pyrolysates of suspended matter and surface sediments

Abstract Curie-point pyrolysis-gas chromatography-mass spectrometry has been used to analyse suspended and sedimentary organic matter from the River Rhine delta. Differences in the relative intensities of phytadienes and prist-1-ene in the pyrograms are interpreted as a reflection of the short-term transformation of the phytyl moiety of chlorophyll into ester bound phytanic acid.

Identification and geochemical significance of long chain acyclic isoprenoid hydrocarbons in crude oils

A series of acyclic isoprenoid hydrocarbons with head-to-tail, tail-to-tail and head-to-head linkages are present as important components in petroleum. This paper presents some evidence for the occurrence of the extended series beyond the C 40 isomers described to date. Thus, the regular head-to-tail homologs up to C 45 have been identified, as well as a new C 21 C 39 series, exhibiting methyl branches in the positions 3, 7, 11, 15,… of the molecule, which could derive from homologue members of the head-to-head series higher than C 40 . To reinforce the mass spectrometric identification of these compounds their gas chromatographic behaviour has been examined and retention indices of individual members compared with those predicted by retention increments. The relative abundance of the above series and the internal distribution of structural isomers in oils and rock extracts are considered as valuable parameters in correlation studies. Such distributions are geochemically significant from the standpoint of the origin and maturation of the sedimentary organic matter. Recent progress in the knowledge of the lipid composition of archaebacteria provides a definite argument for a substantial contribution of bacterial cell-wall lipids to petrogenesis.

Head-to-Head Linked Isoprenoid Hydrocarbons in Petroleum

A series of petroleum isoprenoid hydrocarbons possessing an unusual head-to-head linkage is present as an important component in petroleum. The entire series appears to be produced by diagenesis or catagenesis from precursors containing 40 carbon atoms. A suitable precursor compound has been reported in one type of living organism, thermoacidophile bacteria.

Pristane-phytane ratios in relation to source and diagenesis of ancient sediments from the Labrador Shelf

The pristane-phytane ratios of organic matter associated with the ancient sediments of the Laborador Shelf were determined in relation to the source of organic matter, depth of burial and diagenetic transformations. The results suggest that the ratios of these isoprenoid hydrocarbons generally tend to increase with an increased terrestrial contribution. A correlation was also found between the ratios of pristane to phytane and the diagenetic history of these ancient sediments; the ratios being generally higher in deeply buried and geochemically altered organic facies.

Squalenes, phytanes and other isoprenoids as major neutral lipids of methanogenic and thermoacidophilic “archaebacteria”

The neutral lipids of nine species of methanogenic bacteria including five methanobacilli, two methanococci, a methanospirillum, one methanosarcina as well as two thermoacidophilic bacteria, Thermoplasma and Sulfolobus, were analyzed. The major components were C30, C25 and/or C20 acylic isoprenoid hydrocarbons with a continuous range of hydroisoprenoid homologues. The range of acyclic isoprenoids detected were from C14 to C30. Apart from Methanosarcina barkeri, squalene and/or hydrosqualene derivetives were the predominant components in all species studied. The components of Methanosarcina barkeri were a family of C25 homologues. The distribution of the neutral lipid components and their specific variations in relative intensities emphasized the differences between the test organisms while the generic nature of the isoprenoid hydrocarbons demonstrated similarities between the diverse bacteria. The neutral lipid compositions from these bacteria, many of which exist in environmental conditions like those described for the various evolutionary stages of the archean ecology, resemble the isoprenoid distribution isolated from ancient sediments and petroleum. Therefore, these finding may have major implications to biological and biogeochemical evolution.

Distribution of hydrocarbons in bovine tissues

Liver, heart, kidneys, muscle and adipose (perirenal and subcutaneous) tissues were collected from six animals for analysis of their hydrocarbon composition. Qualitative and quantitative determinations were carried out by gas chromatography and combined gas chromatography-mass spectrometry. Although differing in the proportions, a homologous series of n-alkanes ranging from n-C12 to n-C31 was found in all the samples examined. The isoprenoid hydrocarbons phytane and phytene (phy-1-ene and phyt-2-ene) were also identified.

Phytanyl-glycerol ethers and squalenes in the archaebacterium Methanobacterium thermoautotrophicum.

The lipids of a thermophilic chemolithotroph,Metbanobacterium thermoautotropbicum, have been analyzed by chromatographic techniques and identified by infrared spectrometry and combined gas chromatography-mass spectrometry. Of the total chloroform soluble lipids 79% and 21% are polar and non-polar lipids, respectively. The major components of the polar lipids are dialkyl ethers of glycerol or its derivatives. The nature of the glycerol ether alkyl groups was found to be that of the saturated tetraisoprenoid hydrocarbon phytane. The non-polar lipids of the chloroform soluble fraction consist principally of three series of C20, C25 and C30 acyclic isoprenoid hydrocarbons, the major components being squalene and a continuous range of hydrosqualene derivatives, from dihydrosqualene up to and including decahydrosqualene. These data establish thatM. tbermoautotropbicum contains predominantly non-sapo-nifiable lipids as doHalobacterium, Halococcus, Sulfolobus andTbermoplasma. In particular, the composition of the chloroform soluble lipids ofM. tbermoautotropbicum is quite similar to that ofHalobacterium cutirubrum. The results strongly support the recent proposal, based on 16S rRNA sequence homologies, that the extreme halophiles and methanogens share a common ancestor. In addition, it is pointed out that the occurrence of phytane and related polyisoprenoid compounds in ancient sediments can no longer be considered unequivocally as indicative of past photosynthetic activity. Finally, speculations are made concerning the possible role of and evolutionary significance of the presence of squalene and hydrosqualenes in these organisms. To our knowledge this is the first report of squalene and hydrosqualenes in a strictly anaerobic microorganism.

Sterenes in surface sediments from the southwest African shelf and slope

Surface sediment samples collected from the southwest African (Namibian) shelf and slope have been analyzed for their hydrocarbon content. In the surface samples a class of olefinic isoprenoid hydrocarbons, the Sterenes, have been found to represent 20–40% of the total hydrocarbons. To the best of our knowledge Sterenes have not been reported in surface marine sediments in such high concentrations. Cholest-2-ene, cholestadiene, cholestatriene, 24-methylcholest-2-ene, 24-methylcholestadiene, 24-ethylcholest-2-ene and 24-ethylcholestadiene were found in the sediments and identified by high resolution glass capillary gas chromatography-mass spectrometry. The formation of Sterenes from sterols via microbiological processes or chemical auto-oxidation, followed by subsequent dehydration mechanisms and double bond isomerizations. is postulated. It appears that there are highly unique environments in the upwelled area off southwest Africa providing the microbiological and chemical conditions for rapid diagenesis of the sterols within a time scale of 100 yr or less.

Mathematical models for petroleum-forming processes: n-paraffins and isoprenoid hydrocarbons

Mathematical models have been developed which simulate both random and nonrandom thermal cracking of branched and straight-chain hydrocarbons. Application of these models to n-paraffins suggests that thermal cracking alone cannot be the dominant mechanism in formation of the n-paraffin distributions present in crude oils. Application to isoprenoid hydrocarbons indicates that nonrandom cracking could be important in producing the isoprenoid distributions found in oils. Results of the mathematical modeling show that methane formation should, as predicted from energy considerations, be kinetically disfavored. It therefore is likely that substantial quantities of methane are produced from saturated hydrocarbons only under thermal conditions more severe than those under which oil is produced. The mathematical models employed are adaptable for other geochemical applications, such as isotope fractionation.