Philippe Schaeffer

Philippe Schaeffer
University of Strasbourg | UNISTRA ·  Institut de Chimie de Strasbourg

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106
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Publications (106)
Chapter
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Tar was found in the potters’workhop of the Roman period of « Quatre Bornes » at Rue-des-Vignes (Nord, France). Molecular analysis shows it to be birch pitch. This pitch was obvioulsy used to smoke pottery in the process of producing black, polished terracotta, referred to as terra nigra and dark regional ceramics. This use has never been described...
Article
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The absence of unambiguous animal body fossils in rocks older than the late Ediacaran has rendered fossil lipids the most promising tracers of early organismic complexity. Yet much debate surrounds the various potential biological sources of putative metazoan steroids found in Precambrian rocks. Here we show that 26-methylated steranes—hydrocarbon...
Article
Les rideaux de culture sont des talus qui se forment involontairement à l’amont d’une haie, par accumulation de colluvions érodés dans les champs. Ils peuvent constituer des parcellaires de très grande extension spatiale, caractérisés par des parcelles étroites, allongées perpendiculairement à la pente. L’histoire de ces parcellaires et leur datati...
Article
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Today, coastal cities worldwide are facing major changes resulting from climate change and anthropogenic forcing, which requires adaptation and mitigation strategies to be established. In this context, sedimentological archives in many Mediterranean cities record a multi-millennial history of environmental dynamics and human adaptation, revealing a...
Article
The widely distributed aromatic di- and triterpenoids from higher plants occurring in sediments are formed by diagenetic microbial processes affecting their precursor plant lipids. These compounds and their stable isotopic composition (δ¹³C and δ²H) have the potential to be used for palaeoenvironmental and palaeoclimatic studies. In the present stu...
Article
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Organic residue analysis has been undertaken on an organic material found on a necklace with a pendant unearthed from a necropolis dated to the Early Iron Age (800–475 BCE) and located in Eckwersheim (NE France). The molecular composition of the substance, which was investigated using gas chromatography coupled to mass spectrometry, points towards...
Article
The biomarker distributions of mid-Neoproterozoic sediments (800–717 million yr, Ma) from various locations are characterized by the occurrence, besides cholestane isomers, of a novel series of C28 steranes, whereas classical C-24 alkylated steranes are absent. These unusual C28 steranes, termed cryostanes, seem to be restricted to pre-Snowball Ear...
Article
Organic substances from three jars found at Abydos in the tombs of Kings from the two first Egyptian dynasties (3100–2700 BCE) were investigated using gas chromatography–mass spectrometry in order to assess their biological origin, use and mode of preparation. The organic material was found to correspond to essential oils from conifers severely alt...
Article
Molecular and isotopic investigation of lipids from soils filling several structures from an archaeological site located at Obernai (Alsace, NE France) has revealed the presence of miliacin, a triterpenoid marker from Panicum miliaceum (broomcorn millet), indicating that this cereal was cultivated at the site. The concentration profiles of miliacin...
Article
In the course of investigation of lipid extracts from archaeological soils from two Merovingian tombs (7th Century, Ichtratzheim, France) in an agricultural area, a series of N-containing hopanoids was detected. They were postulated to correspond to C31–C33 hopanoid nitriles on the basis of mass spectrometry. The C32 homologue was unambiguously ide...
Conference Paper
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Identification of a resin from Styrax officinalis as ingredient of the decorative coating from the ritual skull found in the Neolithic site of Nahal Hemar (Israel) . The earliest evidence of the use of a plant resin in a cultual context by Neolithic people.
Article
The major bacterial triterpenoids of the hopane series are made of a C30 triterpene hopane moiety and an additional non-terpenic C5 side chain derived from D-ribose and linked via its C-5 carbon atom to the hopane side chain. Bacteriohopanetetrol and aminobacteriohopanetriol are the most common representatives of this natural product series, adenos...
Article
Full-text available
Previous studies (Ertlen et al., 2010) have shown that near infrared (NIR) spectroscopy of soil organic matter (SOM) can be used successfully to discriminate between SOM from topsoils under forest vs. grassland following establishment of a referential. We have now extended this referential of topsoils, and the derived model was used to characterize...
Conference Paper
Full-text available
Soil archives, like historical and sedimentary archives, allow past dynamics of ecosystems to be reconstructed and their current functioning to be understood. In this article, we first remind the principal specifics of soil archives, and then present two methodological approaches which were developed in the framework of the GESSOL-APOGEE program: q...
Article
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We report here the development of an analytical protocol for the specific isolation of isoprenoid and branched glycerol dialkyl glycerol tetraethers (i-and br-GDGTs, respectively) of microbial origin from soil samples for radiocarbon dating. This protocol comprises an extraction step followed by several chromatographic steps combining different tec...
Article
Wild-type Streptomyces coelicolor A3(2) produces aminobacteriohopanetriol as the only elongated C35 hopanoid. The hopanoid phenotype of two mutants bearing a deletion of genes from a previously identified hopanoid biosynthesis gene cluster provides clues to the formation of C35 bacteriohopanepolyols. orf14 encodes a putative nucleosidase; its delet...
Article
A tetracyclic compound tentatively assigned as A-nor-friedel-8-en-10-one was recently reported by Bakar et al. (2011) [Bakar, N.A., Tay, K.S., Omar, N.Y.M.J., Abas, M.R.B., Simoneit, B.R.T., 2011. Applied Geochemistry 26, 1433-1445] from a Malaysian lake sediment. It was postulated to derive from friedelin via a sequence of diagenetic transformatio...
Article
The greatest mass extinction on Earth occurred 252 million years ago during the latest Permian. Complete biotic recovery, characterized by a return to pre-extinction diversity levels, took an extraordinarily long time (ca. 5 x 106 yr), probably because harsh conditions developed repeatedly during the Early Triassic. Here, we show the recurrence of...
Article
Terpenoid biomarkers with high chemotaxonomic value which can be used for the identification of an angiosperm input to sedimentary organic matter are desirable for studies devoted to the reconstitution of past environmental change. There is also a need, in the frame of archaeometric investigations, for reliable biomarkers allowing wood species dete...
Article
Full-text available
Two commonly used proxies based on the distribution of glycerol dialkyl glycerol tetraethers (GDGTs) are the TEX86 paleothermometer for sea-surface temperature reconstructions and the BIT index for reconstructing soil organic matter input to the ocean. An initial round-robin study of two sediment extracts, in which fifteen laboratories participated...
Article
Samples of young, outer surfaces of brucite-carbonate deposits from the ultramafic-hosted Lost City hydrothermal field were analyzed for DNA and lipid biomarker distributions and for carbon and hydrogen stable isotope compositions of the lipids. Methane-cycling archaeal communities, notably the Lost City Methanosarcinales (LCMS) phylotype, are spec...
Article
Maleimides (transformation products of chlorophylls and bacteriochlorophylls) were studied in recent sediments from the Swiss lake Rotsee and the Romanian Black Sea Shelf to investigate chlorophyll degradation, the role of oxygen in maleimide formation, and to identify their sources. Naturally occurring maleimides (i.e. "free" maleimides) and malei...
Article
The article entitled "Ozonation of triterpenoids: Implications for early diagenesis of biomarkers in oxic environments" (Tay, K.S., Rahman, N.A., Abas, M.R.B, Simoneit, B.R.T., 2013. Organic Geochemistry 57, 34-40) deals with an investigation of the early diagenetic transformations undergone by higher plant triterpenoids under oxic conditions by me...
Article
A study of the extracts of samples recording a transgressive–regressive succession of the Werra cyclothem, Zechstein (Upper Permian), from the southern margin of the European Permian Basin (the Fore-Sudetic Monocline, Poland) provides an insight into major sources of organic matter and diagenetic processes. The studied cross-section comprises all l...
Article
Several oleanane-related triterpenoids bearing a unique C-2 oxygenated functionality have been identified as the predominant triterpenoids from a 4900 year old oak wood sample buried in a freshwater sediment. They likely represent specific molecular tools that can be used as markers to reconstruct past vegetation assemblages, or to recognise severe...
Article
Full-text available
Chlorophylls and bacteriochlorophylls are the most abundant photosynthetic pigments on Earth. These compounds and their transformation products (chlorins, porphyrins, maleimides) can be preserved in limnic and marine sedimentary deposits and crude oils and serve as valuable proxies for palaeoenvironmental reconstructions. Among these degradation pr...
Article
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The Dur At Talah escarpment is exposed in the Abu Tumayam Trough at the southern part of the Sirt Basin, central Libya. The cliff (�145 m high and �150 km long) is oriented along an E–W axis and faces southward. Only a few field studies have been previously carried out in this area, and these were mainly focused on the succession’s famous vertebrat...
Article
Treatment of bacterial cells from Zymomonas mobilis in the presence of acidic clay minerals in aqueous medium leads to the formation of 32,35-anhydrobacteriohopanetetrols (anhydroBHTs), confirming that these compounds, widespread in the geological record, are likely formed by diagenetic (abiotic) processes. We determined that anhydroBHTs result not...
Article
The total lipid extracts (TLEs) from a series of 13 soil surface samples from sites covered by a stable vegetation for at least 150 years and located in the Vosges Massif (France) have been investigated in order to establish a molecular reference for soil surface horizons. The TLEs are dominated by plant n-alkyl lipids with distributions (homologue...
Article
The hypothesis of a low temperature natural “vulcanization” process as a potential mechanism for the formation of insoluble bitumen and H2S in reservoirs which have not undergone biodegradation, high thermal stress, or thermochemical sulfate reduction (TSR) has been investigated using laboratory simulation experiments. The experiments, involving el...
Article
Three novel series of 3-carboxyalkyl-steranes have been identified by synthesis in sediments from an evaporitic basin. These compounds may derive from precursor steroids bearing a polyfunctionalised side-chain at C-3, yet unknown in living organisms. Geochemical data suggest a microalgal or a bacterial origin.
Article
Four oleanane-related aromatic triterpenoids isolated from an archeological piece of oak wood have been identified by NMR studies. Their structures give clue to a novel diagenetic transformation pathway of 2,3-oxygenated higher plant triterpenoids in the environment.
Article
A sulfide with a bicyclic squalene hydrocarbon skeleton present in sediments from various depositional settings and of different geological age has been identified by synthesis of a reference compound. In contrast to previous expectations [cf. Schouten, S., Sinninghe Damsté, J.S., de Leeuw, J.W., 1995. A novel triterpenoid carbon skeleton in immatu...
Article
In order to confirm the tentative structure of a dithiane sulfide with a bicyclic squalene hydrocarbon skeleton representing the predominant alkyl sulfide in Shell Beach samples from the Monterey Formation (Miocene, CA) and also occurring in various immature sulphur-rich sediments [Schouten, S., Sinninghe Damsté, J.S., de Leeuw, J.W., 1995. A novel...
Article
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Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 10 (2009): Q03012, doi:10.1029/2008GC002221. Recently, two new proxies based on the distribution of glycerol...
Article
Seafloor investigations of slow- and ultraslow-spreading ridges have reported many occurrences of exposed mantle peridotites and gabbroic rocks on the ocean floor. Along the Mid-Atlantic Ridge, these uplifted portions of oceanic crust host high-temperature black smoker-type hydrothermal systems (e.g., Rainbow, Logatchev, Saldanha), and the more dis...
Article
32,35-Anhydrobacteriohopanetetrol (anhydroBHT) is a functionalized hopanoid of unknown origin found recently in a wide range of sediments. Acidic treatment of cells of the bacterium Zymomonas mobilis and of bacteriohopanetetrol (BHT) led to the formation of anhydroBHTs in the form of an epimeric mixture. These laboratory experiments indicate that s...
Article
The carbon geochemistry of serpentinized peridotites and gabbroic rocks recovered at the Lost City Hydrothermal Field (LCHF) and drilled at IODP Hole 1309D at the central dome of the Atlantis Massif (Mid-Atlantic Ridge, 30°N) was examined to characterize carbon sources and speciation in oceanic basement rocks affected by long-lived hydrothermal alt...
Article
In the course of a detailed palaeoenvironmental study based on biomarker distributions in sediments of Rupelian age (Lower Oligocene from the Rhine Rift Valley), an outcrop sample rich in higher plant fossil remains was collected from a quarry near the city of Burnhaupt-le-Haut (South Alsace, France). In agreement with the macrofossil assemblage, m...
Article
Carbonates of the 1640 million years (Ma) old Barney Creek Formation (BCF), McArthur Basin, Australia, contain more than 22 different C40 carotenoid derivatives including lycopane, γ-carotane, β-carotane, chlorobactane, isorenieratane, β-isorenieratane, renieratane, β-renierapurpurane, renierapurpurane and the monoaromatic carotenoid okenane. These...
Article
Full-text available
Highly cracked and isomerized archaeal lipids and bacterial lipids, structurally changed by thermal stress, are present in solvent extracts of 2,707- to 2,685-million-year-old (Ma) metasedimentary rocks from Timmins, ON, Canada. These lipids appear in conventional gas chromatograms as unresolved complex mixtures and include cyclic and acyclic biphy...
Article
Polycyclic polyprenoid hydrocarbons and related demethylated compounds have been identified in severely altered bitumen from oil stained rocks of Upper Jurassic/Lower Cretaceous age. They occur as three series, one homologue of which has been isolated and structurally characterized from nuclear magnetic resonance (NMR) studies. They comprise hydroc...
Article
The transition from the Middle to the Late Jurassic was characterized by significant changes in oceanography and climate and by changes in global carbon cycle as shown in the C-isotope record. A prominent mid-Oxfordian positive excursion in bulk carbonate carbon isotope values ( δ13C carb) with an amplitude of more than 1‰ has been documented from...
Article
Serpentinization of oceanic peridotites results in the production of volatile-rich (methane and hydrogen) fluids and other light hydrocarbons, and is characteristic of the low-temperature (
Article
Whereas molecular fossil evidence indicates that bacteria and eukarya were present by the Late Archean, similar evidence of the domain archaea is lacking. The existence of archaea is instead inferred based on the occurrence of highly 13C depleted carbon that is thought to derive by carbon cycling between methanogens and methanotrophs. We present ar...
Article
We describe the structural elucidation of four novel series of hopanoid sulfides bearing a thiane or a thiolane ring fused to the pentacyclic hopanoid skeleton and the partial identification of an additional spiro-type hopanoid sulfide series which occurs in various immature sulfur-rich sediments and crude oils. These novel diagenetic hopanoid deri...
Article
Full-text available
Hydrogenation processes leading from biomolecules to fossil biomarkers in anoxic sediments are crucial for the preservation of organic matter. However, these processes are still poorly understood. The present identification of several reduced carotenoids in recent sediments attests that these processes operate at the earliest stages of diagenesis w...
Article
A novel series of sedimentary aromatic lycopane derivatives, cyclolycopatrienes, has been found in an outcrop sample from the Messel oil shale. The predominant monoaromatic compound 4 from this hydrocarbon series has been isolated using reversed phase HPLC and its structure determined using 1D and 2D 1H NMR spectroscopy, as well as from identificat...
Article
The nor-triterpenoid, 24-nor,28-lupanoic acid, methyl ester 1a, present as the acid in an African crude oil, was isolated and identified using NMR. This compound represents a key intermediate in the formation of nor-lupane derivatives which are widespread petroleum markers indicative of terrestrial inputs.
Article
[reaction: see text] The polyaromatic hydrocarbon 4,4'-dimethyldinaphtho[a,d]cycloheptane (1a) has been identified by NMR studies after isolation from an Oligocene sediment. The original symmetrical structure of 1a, which bears a central seven-membered ring, is closely related to higher plant triterpenoid precursor(s) of the serratane series and is...
Article
Biogenic silicates from the Taupo Volcanic Zone (North Island, New Zealand) are shown to contain a number of unusual polyfunctionalised bacteriohopanepolyols. Hopanoid fractions isolated from the Rotokawa hot spring (80–82 °C) contained significant amounts of 32,35-anhydrobacteriohopanetetrol and two isomers of a related trihydroxylated compound. T...
Article
A novel series of sedimentary C35 diol and triol hopanoids is reported in a wide range of sediments ranging in age from Recent to Jurassic. The predominant diol homologue has been isolated from a Jurassic sediment using reversed phase HPLC and the structure of the functionalised side chain has been elucidated by 1D and 2D 1H NMR spectroscopy. It co...
Article
C30 tetracyclic polyprenoids (TPP) are most prominently observed in samples derived from low salinity, i.e. fresh to brackish lacustrine environments, and are generally present in low levels in samples derived from saline, i.e., marine and saline lacustrine, environments. A near-shore facies of the Chonta Formation, Peru, that has no marine palynom...
Article
An immature sulfur-rich marl from the Gessosso-solfifera Formation of the Vena del Gesso Basin (Messinian, Italy) has been subjected to hydrous pyrolysis (160 to 330°C) to simulate maturation under natural conditions. The kerogen of the unheated and heated samples was isolated and the hydrocarbons released by selective chemical degradation (Li/EtNH...
Article
A series of diaromatic 8,14-secohophanoids of microbial origin has been characterized in a petroleum by NMR studies, disclosing novel geochemical transformations.
Article
During the Messinian, 6 m.y. ago, massive sea-level fall and widespread deposition of evaporites occurred in the Mediterranean Sea when it became isolated from the world oceans. Here we present the first hydrogen isotope data from individual sedimentary biomarkers, n-alkanes and isoprenoids, that tracked climatically driven hydrographic changes in...
Article
We report here on the identification of two novel hexacyclic alkanes (C33 and C35) occurring in bitumen. The C35 compound 1 was identified by comparison with a standard obtained by synthesis involving a biomimetic proton-induced extensive cyclisation of an acyclic heptaprenoid. This cascade cyclisation allows the formation of eleven asymmetric cent...
Article
Two novel triterpenoid biomarkers have been isolated from a recent anoxic sulfur-rich sediment (Lake Cadagno, Switzerland) and identified by NMR as 11,15-dihydro-Δ13,10(14)-cyclosqualene 1 and bis-(6,11-cyclofarnesa-2,7(14)-diene) 2. Both compounds have a novel hydrocarbon skeleton not known thus far in living organisms and formed by cyclization of...
Article
Macromolecular fractions, isolated from the solvent extract of sulfur-rich Recent (Siders Pond, USA; Lake Cadagno, Switzerland; Walvis Bay, Namibia) and immature sediments (Gibellina, Messinian of Sicily; Vena del Gesso, Messinian of Italy), were investigated by chemical degradation using sodium ethanethiolate/methyliodide. This mild reagent which...