NaBH4 reduction of alkenones to the corresponding alkenols: a useful tool for their characterisation in natural samples

Rontani, Jean‐François; Marchand, Daphné; Volkman, John K.

doi:10.1016/s0146-6380(01)00091-2

Cited by 40 publications

(28 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Anhydrous tetrahydrofurane (THF), aniline (99.5%), cyclopentylamine (99%), sodium p-toluenesulfinate hy- drate, and 1,4-dioxane (99ϩ%, ACS Reagent) were from Aldrich (Milwaukee, MI). The synthetic standards (E,E,E)-8,15,22-heptatriacontatrien-2-one and (E,E)-15,22-heptatriacontadien-2-one were generously provided by Professor J. R. Maxwell, University of Bristol, UK [15].…”

Section: Materials and Reagentsmentioning

confidence: 99%

See 1 more Smart Citation

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS

López

Grimalt

2004

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

A method for the identification of double bond locations in polyunsaturated long chain alkenones adapted to nanogram amounts as currently analyzed by gas chromatography coupled to mass spectrometry (GC-MS) has been developed. The method is based on interpretation of the electron impact mass spectra of the imino derivatives of the carbonyl groups using either cyclopentyl or phenyl substitutents. Other complementary derivatization methods such as elaidization and hydrogenation have also been used for structural characterization of these compounds. This application has led to the identification of a novel homologous series of di-, tri-, and tetraunsaturated ketones with carbon number chain lengths between 37 and 40 in coastal hypersaline sediments. The novel series identified shows a distribution in which the double bond position between different homologs is established by reference to the distance from the carbonyl group whereas the previously known alkenones were constituted by unsaturated homologs with double bonds located at defined distances of the terminal methyl. This difference points out to a dissimilar, but still unknown, biogenic precursor of these novel alkenones. (J Am Soc Mass Spectrom 2004, 15, 1161-1172

show abstract

Section: Materials and Reagentsmentioning

confidence: 99%

“…The EI mass spectra of the O-methyl and O-ethyl oximes and the TMSiE of the alkenols obtained by NaBH 4 alkenone reduction allowed further differentiation between the ethyl and methyl ketones [13,14]. This derivatization approach was also used for double bond location in a novel series of monounsaturated ketones (C 35 -C 38 ) [15].…”

mentioning

confidence: 99%

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS

López

Grimalt

2004

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…5a shows the concentration profiles of: heptatriacontadien-2-ol and nonatriacontatrien-3-ol, which bear a strong correlation with SST ( Table 2). These alkenols could originate as a consequence of nonselective bacterial reduction of alkenones in anoxic sediments or by biosynthesis of the algae producing the alkenones [48,49]. The concentrations of these alkenones and the previously described compounds in sediments reflect increased marine productivity during higher SST values in site IODP-U1318C (Fig.…”

Section: Neutral Fraction Plsr Resultsmentioning

confidence: 93%

Extraction of climatic signals from fossil organic compounds in marine sediments up to 11.7Ma old (IODP-U1318)

Farrés

Martrat

Mol³

et al. 2015

Analytica Chimica Acta

View full text Add to dashboard Cite

This study focuses on the extraction of climate signals and processes using a combined approach which includes the analysis of a high number of lipid molecules in marine sediments, and the chemometric analysis of the acquired data. Neutral and acidic fractions of marine sediments from site IODP-U1318 (south-west of the UK, Porcupine Seabight) were quantified by GC-MS. The alkenone unsaturation index, U(k')37, was estimated from the composition of C37 alkenones and it was then used for the estimation of sea surface temperatures (SST) for reference. Principal component analysis (PCA), explained 77.45% of the total data variance, and differentiated neutral fraction GC-MS total ion current (TIC) profiles according to SST values of the different sediment sections. GC-MS TIC chromatograms were correlated to sea surface temperatures (SST) by partial least squares regression (PLSR). The compounds more robustly in line with SST values at each sediment section explained 93% of the SST variance and they were identified using the variable importance in projection (VIP) scores method. The proposed approach enables an objective identification of organic compounds sensitive to SST variability throughout complete chromatographic profiles. As a result of this multivariate unbiased approach, lipid composition of sediments was differentiated between compounds of marine (long chain n-alkanes, long chain n-alkan-1-ols) and terrestrial (short chain n-alkan1-ols, alkenols, cholesterol, squalene) origin, whose concentrations were directly and inversely correlated to SST, respectively.

show abstract

“…Fujine et al (2006) suggested a relationship with low salinity conditions, although a true freshwater origin is unlikely according to Xu et al (2001) since the C 36:2 EK in the Black Sea occurred only after the introduction of marine water. Association with low salinity conditions is also inconsistent with its present-day occurrence in the Ligurian Sea (Rontani et al, 2001). Noralkenones have also been detected in a culture of E. huxleyi (Prahl et al, 2006), but with double bond positions different from the C 36:2 EK detected in the Black Sea Unit II sediments.…”

Section: Introductionmentioning

confidence: 86%

“…Furthermore, the C 36:2 EK was also detected in Black Sea particulate matter, indicating that the source organism still exists today (Rontani and Wakeham, 2008), although the alkenones in Black Sea surface sediments are dominated by those derived from E. huxleyi (Coolen et al, 2006). In addition to the Black Sea, the unusual C 36:2 EK has been recognized, albeit in relatively small amount, in late Pleistocene sediments from the Japan Sea (Fujine et al, 2006) and in particulate matter from the Ligurian Sea (Rontani et al, 2001). Its occurrence in sediments of Aptian age has also been suggested (Brassell and Dumitrescu, 2004), although no information was provided on the double bond positions.…”

Section: Introductionmentioning

confidence: 93%

Unusual C35 to C38 alkenones in mid-Holocene sediments from a restricted estuary (Charlotte Harbor, Florida)

Soelen

Lammers

Eglinton

et al. 2014

Organic Geochemistry

View full text Add to dashboard Cite

Unusual C 35 to C 38 alkenones were identified in mid-Holocene (8-3.5 kyr BP) sediments from a restricted estuary in southwest Florida (Charlotte Harbor). The distribution was dominated by a C 36 diunsaturated (ω15,20) ethyl ketone, identical to the one present in Black Sea Unit 2 sediments. Other unusual alkenones were tentatively assigned as a C 35:2 (ω 15,20) methyl ketone, a C 37:2 (ω 17,22) methyl ketone and a C 38:2 (ω 17,22) ethyl ketone. In late Holocene sediments < 3.5 kyr BP, the common C 37 to C 39 alkenones were found. Compound-specific 14 C, 13 C, and D isotope measurements were used to constrain the possible origin of the alkenones. Conventional radiocarbon ages of alkenones and higher plant-derived long chain n-alcohols indicated no significant difference in age between mid-Holocene alkenones and higher plant n-alcohols. Both alcohols and alkenones were offset vs. calibrated ages of shell fragments in the same sediment core, which suggests they were pre-aged by 500-800 yr, implying resuspension and redistribution of the fine-grained sedimentary particles with which they are associated. The hydrogen isotopic (δD) composition (-190‰ to -200‰) of the C 37 and C 38 alkenones in the late Holocene sediments is in line with values for coastal haptophytes in brackish water. However, the unusual C 36 and C 38 alkenones from the mid Holocene sediments were enriched in D (by ca. 100‰) vs. the late Holocene alkenones. Also, δ 13 C values of mid-Holocene alkenones were consistently offset compared with late Holocene alkenones (-21‰ to -22‰ and -22‰ to -23‰, respectively). We suggest that the alkenones in Charlotte Harbor were produced by unknown alkenone-producing haptophyte.

show abstract

NaBH4 reduction of alkenones to the corresponding alkenols: a useful tool for their characterisation in natural samples

Cited by 40 publications

References 27 publications

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS

Extraction of climatic signals from fossil organic compounds in marine sediments up to 11.7Ma old (IODP-U1318)

Unusual C35 to C38 alkenones in mid-Holocene sediments from a restricted estuary (Charlotte Harbor, Florida)

Contact Info

Product

Resources

About

NaBH4 reduction of alkenones to the corresponding alkenols: a useful tool for their characterisation in natural samples

Cited by 40 publications

References 27 publications

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C37-C40 alkenones by GC-MS

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C37-C40 alkenones by GC-MS

Extraction of climatic signals from fossil organic compounds in marine sediments up to 11.7Ma old (IODP-U1318)

Unusual C35 to C38 alkenones in mid-Holocene sediments from a restricted estuary (Charlotte Harbor, Florida)

Contact Info

Product

Resources

About

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS

Phenyl- and cyclopentylimino derivatization for double bond location in unsaturated C₃₇-C₄₀ alkenones by GC-MS