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Nytoft H.P.,Geological Survey of Denmark | Kildahl-Andersen G.,Chiron AS | Samuel O.J.,Royal Dutch Shell
Organic Geochemistry | Year: 2010

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 resonance (NMR) spectroscopy. The NMR data confirmed the identification of two of them, observed previously in the literature, as 1(10→5)abeo-3β-methyl-24β-nor-18α(H)-oleanane and 5(4→3)abeo-3α(H), 5β(H), 18α(H)-oleanane on the basis of X-ray crystallography and comparison with a synthetic standard. The third compound was a novel rearranged oleanane, 3α,5β-dimethyl-23α,25-dinor-10β(H),18α(H)-oleanane, with one of the methyl groups at C-4 in the oleanane structure shifted to C-3 and another shifted from C-10 to C-5. The distribution of these three rearranged oleananes and other, yet unidentified, rearranged oleanoid C30 triterpanes in 25 Late Cretaceous- or Tertiary-sourced oils from Angola, Canada, Greece, India, Indonesia, Iran, New Zealand, Nigeria and Vietnam was examined by way of reverse phase high pressure liquid chromatography (HPLC), GC-mass spectrometry (GC-MS) and GC-MS-MS. Mass spectra of rearranged oleananes and compounds tentatively assigned as rearranged taraxastanes are presented. Rearranged oleananes and other rearranged triterpanes are probably formed by dehydration and rearrangement of higher plant triterpenoids functionalized at C-3. The distribution of rearranged oleananes and their relative concentration seems to be dependent on the extent of clay catalysis during diagenesis. A diagenetic pathway for formation of the rearranged oleananes is proposed. All 25 oils have almost identical rearranged oleanane/oleanane and diasterane/regular sterane ratio values. Two unidentified early eluting (GC) rearranged oleananes are only abundant in oils with a high proportion of diasteranes. Bicadinanes were found in 20 of the 25 oils. © 2010 Elsevier Ltd.


A test kit for the quantitative determination of narcotic drugs comprising (A) series of sealed vessels, each vessel containing a deuterium free isotopologue of a narcotic drug in exactly defined concentrations and quantities, wherein the isotopologue differs from vessel to vessel andwherein the quantities of the isotopologue differ from vessel to vessel or are the same for all vessels; and/or (B) series of sealed vessels, each vessel containing in exactly defined concentrations and quantities the same isotopologue in quantities which differ from vessel to vessel; wherein the free isotopologues are selected from narcotic drugs; prodrugs, salts, solvates, hydrates and polymorphs and contain at least three stable isotopes selected from the group consisting of


Karlsen M.,Norwegian University of Science and Technology | Karlsen M.,Chiron AS | Liu H.,Chiron AS | Berg T.,Norwegian Institute of Public Health | And 2 more authors.
Journal of Labelled Compounds and Radiopharmaceuticals | Year: 2014

The availability of high-quality 13C-labelled internal standards will improve accurate quantification of narcotics and drugs in biological samples. Thus, the synthesis of 10 [13C6]-labelled phenethylamine derivatives, namely amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxy-N-ethylamphetamine, 4-methoxyamphetamine, 4-methoxymethamphetamine, 3,5-dimethoxyphenethylamine 4-bromo-2,5- dimethoxyphenethylamine and 2,5-dimethoxy-4-iodophenethylamine, have been undertaken. [13C6]-Phenol proved to be an excellent starting material for making 13C-labelled narcotic substances in the phenethylamine class, and a developed Stille-type coupling enabled an efficient synthesis of the 3,4-methylenedioxy and 4-methoxy derivatives. The pros and cons of alternative routes and transformations are also discussed. The [ 13C6]-labelled compounds are intended for use as internal standards in forensic analysis, health sciences and metabolomics studies by gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry. Copyright © 2014 John Wiley & Sons, Ltd.


Kildahl-andersen G.,Chiron AS | Kildahl-andersen G.,University of Oslo | Nytoft H.P.,Geological Survey of Denmark | Johansen J.E.,Chiron AS
Magnetic Resonance in Chemistry | Year: 2010

The full 1H and 13C NMR chemical shift assignment of 2α-methyl-17α(H),21β(H)-hopane is presented. This compound is formed in mature sediments from biogenic sources of 2β-methyl-17β(H), 21β(H)-hopanoids, which include several cyanobacteria. In addition, full 1H and 13C NMR chemical shift data of all four 17,21 isomers of 3β-methylhopane have been assigned. The thermodynamically most stable 3β-configuration corresponds to that found in bacterial sources. The data presented here suggest minor corrections to the 13C chemical assignments reported earlier for 17α(H)-hopanes. Moreover, spectral evidence indicates an unexpected ring-D boat conformation of 17α(H),21α(H)-hopanes, which may serve to explain the steric strain reported for this isomer. © 2010 John Wiley & Sons, Ltd.


Samuel O.J.,Mobil Producing Nigeria Unlimited | Kildahl-Andersen G.,Chiron AS | Kildahl-Andersen G.,University of Oslo | Nytoft H.P.,Geological Survey of Denmark | And 2 more authors.
Organic Geochemistry | Year: 2010

Tricyclic terpanes of the cheilanthane series in crude oils and sediments are routinely used for geochemical correlation. The cheilanthanes are particularly useful to identify crude oils derived from marine-clastic or carbonate source rock as well as input to the source rocks from marine algal or terrigenous organic matter. However, they sometimes have limitations for the correlation of oils expelled from different source rocks that received similar organic matter, (e.g. oils from source rocks dominated by terrigenous organic matter). Novel non-cheilanthane tricyclic terpanes, consisting of C21 and C25 compounds and a C27 tetracyclic terpane were identified in oils from the Assam (India), Beaufort-Mackenzie (Canada), and the Niger (Nigeria), deltas. NMR data reveal that all three compounds have an oleanane-type structure with rings C, D and E intact, while rings A and B have been degraded, leaving a side chain attached to ring C in the case of the tricyclics and only a degraded A ring in the tetracyclic. On the basis of occurrence, NMR structure and co-variance with oleanane abundance, these new tricyclic and tetracyclic compounds are believed to form from A-ring functionalised oleanoid precursors in angiosperm (flowering) plants. The distribution of these compounds in representative oils from the Niger Delta accumulations permits separation of the oils into at least three distinct source rock organofacies. © 2010.

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