Rearranged hopanes in sediments and petroleum

  title={Rearranged hopanes in sediments and petroleum},
  author={J. Michael Moldowan and Frederick J. Fago and Robert M. K. Carlson and Donald Charles Young and Greg an Duvne and Jon Clardy and Martin Schoell and Colin T. Pillinger and David S. Watt},
  journal={Geochimica et Cosmochimica Acta},
Abstract Two new rearranged hopanoid hydrocarbons have been isolated from a Prudhoe Bay crude, Alaska. 17α(H)-15α-methyl-27-norhopane was determined by X-ray crystallography. It is the first identified member of a new series of rearranged hopanes we propose to call “17α(H)-diahopanes.” Analysis by gas chromatography-mass spectrometry—mass spectrometry (GC-MS-MS) of the parents of m/z 191 in several crudes suggests that this compound is a member of a C 29 -C 34 series of 17α(H)-diahopanes common… Expand
Identification of the four rearranged hopane series in geological bodies and their geochemical significances
Abstract Saturated fractions in a total of 23 oil samples and hydrocarbon source rocks from the Songliao, Tarim, and Ordos Basins have been analyzed by GC–MS and GC–MS–MS. According to the relativeExpand
28-Nor-spergulanes, a novel series of rearranged hopanes
Abstract A new series of rearranged hopanes ranging from C 29 to at least C 34 has been identified as 28- nor -spergulanes (or 21-methyl-28- nor -hopanes). The C 29 member of the series wasExpand
Rearranged oleananes: Structural identification and distribution in a worldwide set of Late Cretaceous/Tertiary oils
Abstract The three most abundant rearranged oleanoid triterpanes eluting early in gas chromatography (GC) have been isolated from a Niger Delta oil and characterized using nuclear magnetic resonanceExpand
Four series of rearranged hopanes in the Mesoproterozoic sediments
Abstract Analysis of the Mesoproterozoic molecular markers by gas chromatography–mass spectrometry (GC–MS) and GC–MS metastable reaction monitoring (MRM) revealed four series of rearranged hopanes inExpand
Three series of rearranged hopanes in Toarcian sediments (northern Italy)
Abstract A suite of 36 shales and marls from the Toarcian Oceanic Anoxic Event section at three localities in northern Italy was found to contain variable contents of three series of rearrangedExpand
Spiro-triterpenes from clay-catalysed rearrangement of hopenes: NMR structural elucidation and occurrence in a recent sediment
Acidic K-10 montmorillonite clay-catalysed rearrangement of hop-22(29)-ene 5 and of hop-17(21)-ene 6 leads to the formation of small quantities of various fernenes and of new compounds, theExpand
Identification, distribution and geochemical significance of four rearranged hopane series in crude oil
Abstract Four rearranged hopane series were simultaneously detected in oils from the Muglad Basin, one of several rift basins on the Central African Shear Zone (CASZ). The series are identified asExpand
Jurassic oils in the central Sichuan basin, southwest China: Unusual biomarker distribution and possible origin
Abstract Crude oils in the Jurassic reservoirs of the Shilongchang oilfield in central Sichuan basin are characterized by a high abundance of methylcyclohexane relative to n-heptane in the C7 lightExpand
Distribution and Geochemical Significance of Rearranged Hopanes in Jurassic Source Rocks and Related Oils in the Center of the Sichuan Basin, China
  • Xiaolin Lu, Meijun Li, +6 authors Yuan Liu
  • Medicine
  • ACS omega
  • 2021
The results of this study show that the relatively high abundance of rearranged hopanes in Jurassic source rocks in the study area is associated with their depositional environments and with clay-mediated acidic catalysis rather than, as was previously thought, thermal maturity. Expand
Geochemical characteristics and significances of rearranged hopanes in hydrocarbon source rocks, Songliao Basin, NE China
Abstract On the basis of GC/MS analysis, a suite of 56 core samples from the Songliao Basin in northeastern China was found to contain variable amounts of four series of rearranged hopanes: theExpand


First proof of structure of a C28-pentacyclic triterpane in petroleum
DURING the past decade, C27, C29, C30, and C31 modified pentacyclic triterpane hydrocarbons, mainly hopanes, have been discovered in fossil fuels1–4. Besides their fundamental importance asExpand
Structure proof and significance of stereoisomeric 28,30-bisnorhopanes in petroleum and petroleum source rocks
Abstract Two C28H48-pentacyclic triterpanes were isolated from Monterey shale. X-ray crystallography of a crystal containing both compounds proved their structures asExpand
An unusual hopane biodegradation sequence in tar sands from the Pt Arena (Monterey) Formation
HOPANES are ubiquitous in petroleum source rocks and crude oils. These compounds are thought to be derived mainly from a specific oxygenated precursor, bacteriohopanetetrol, found in the cell wallsExpand
Thermodynamic stability of various alkylated, dealkylated and rearranged 17α- and 17β-hopane isomers using molecular mechanics calculations
Abstract The thermodynamic stability of selected alkylated, dealkylated and rearranged 17α- and 17β-hopane isomers in the C27, C28, C29, C30 and C31 families were calculated using molecular mechanicsExpand
Applications of steranes, terpanes and monoaromatics to the maturation, migration and source of crude oils
Abstract Novel biological marker parameters are applied to problems of geochemical correlation of crude oils in the McKittrick Field, California. An attempt is described to distinguish fourExpand
Simulation of the geochemical transformations of sterols: superacid effect of clay minerals
Abstract The heating of cholestanol 2a with kaolinite (140°C, 16 hr) mainly leads to a mixture of steranes (40%) and sterenes (35%). The major compounds which are formed have been identified asExpand
Sedimentary 12-n-Propylcholestanes, Molecular Fossils Diagnostic of Marine Algae
Screening of a few organic-rich sedimentary rocks and oils from throughout the Phanerozoic suggests that these C30-steranes first appeared and, therefore, their source algae evolved between Early Ordovician and Devonian. Expand
Distinctive hydrocarbon biomarkers from fossiliferous sediment of the Late Proterozoic Walcott Member, Chuar Group, Grand Canyon, Arizona
Abundant extractable hydrocarbons, in association with well preserved kerogen, have been recognised in a dolostone from the Chuar Group (approx. 850 Ma). The biomarkers present include C15-C30,Expand
Lichens and fungi. Part VI. Dehydration rearrangements of 15-hydroxyhopanes
Dehydration of 15α-hydroxyhopane and of the 21αH-epimer gives the corresponding 13(14→15)abeo-hop-14(27)-enes together with alkenes which result from migration of the C-14 methyl group. DehydrationExpand
Effects of source, thermal maturity, and biodegradation on the distribution and isomerization of homohopanes in petroleum
Abstract The distributions of C31–C35 17α,21β(H)-homohopanes in marine petroleums can be used to describe redox conditions in the source rock depositional environment. For example, highExpand