Lycopane

Last updated
Lycopane
Lycopane structure.png
Names
IUPAC name
2,6,10,14,19,23,27,31-octamethyldotriacontane
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • InChI=1S/C40H82/c1-33(2)19-13-23-37(7)27-17-31-39(9)29-15-25-35(5)21-11-12-22-36(6)26-16-30-40(10)32-18-28-38(8)24-14-20-34(3)4/h33-40H,11-32H2,1-10H3
    Key: VZVGMMPGAFGVOS-UHFFFAOYSA-N
  • CC(C)CCCC(C)CCCC(C)CCCC(C)CCCCC(C)CCCC(C)CCCC(C)CCCC(C)C
Properties
C40H82
Molar mass 563.096 g·mol−1
Related compounds
Related compounds
 Lycopene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Lycopane (C40H82; 2,6,10,14,19,23,27,31-octamethyldotriacontane), a 40 carbon alkane isoprenoid, is a widely present biomarker that is often found in anoxic settings. It has been identified in anoxically deposited lacustrine sediments (such as the Messel formation [1] and the Condor oil shale deposit [2] ). It has been found in sulfidic and anoxic hypersaline environments (such as the Sdom Formation [3] ). It has been widely identified in modern marine sediments, including the Peru upwelling zone, [4] the Black Sea, [5] and the Cariaco Trench. [6] It has been found only rarely in crude oils. [7]

Contents

Biological origins

The pathway for production of lycopane has not been conclusively identified. There are several theories for its origins/production.

Methanogenic archaea

Some of the earliest theories for the biosynthesis of lycopane center around it being anaerobically produced by methanogenic archaea. Lycopane has been observed in recent marine sediments in contexts where methanogenic activity is occurring. In older sediments, methanogenic activity is harder to conclusively determine, as methane can migrate from other layers and not necessarily be a product of that geological time. It is possible that isoprenoid alkanes such as lycopane serve as biomarkers for methanogenesis and methanogenic archaea. [8]

Lycopane has not yet been directly isolated in any biological organism, so its linkage to methanogenic archaea is conjecture. However, the process has been identified in a different isoprenoid alkane: squalane. Squalane was not initially thought to be directly biologically synthesized, but was later determined to be present in archaea. [9]

Some acyclic unsaturated tetraterpenoids (structurally similar to lycopane) have been detected in Thermococcus hydrothermalis , a deep-sea hydrothermal vent archaea. Lycopane has also been found alongside archaeal ethers in certain marine sediments. [10] These findings provide support for a methanogenic origin of lycopane, but it is not conclusive. Furthermore, lycopane has been identified in water columns that contain sulfate, which is potentially an argument against lycopane having a methanogenic origin. Methanogens are generally not widespread in sulfate-rich environments. [11]

Diagenesis of lycopene

Lycopane may be sourced from diagenesis of an unsaturated precursor such as lycopene, a carotenoid that is abundantly present in photosynthetic organisms. In cyanobacteria, lycopene can be an important intermediate in the biosynthesis of other carotenoids. [12] Diagenesis, broadly referring to physical and chemical changes that occur while biological material is undergoing fossilization, may include hydrogenation and transformation of unsaturated precursors to alkane derivatives. Some diagenetic time-dependent reduction of double bonds in carotenoids has been observed in marine sediments. [13]

A direct geochemical diagenetic process for the transformation of lycopene to lycopane during sedimentation has not been determined. However, this process has been identified in other carotenoids (e.g. carotene to carotane). Sulfur has been proposed as a general agent in the diagenesis of isoprenoid alkenes to alkanes. A sulfur polymer (with sulfur binding to unsaturated carbons) could eventually yield isoprenoid alkanes, as carbon-sulfur bonds are weaker than carbon-carbon bonds. Some experimental evidence in support of this theory has been gathered, but it has not been demonstrated in any sediment samples. [14]

Marine photoautotrophs

It has also been theorized that lycopane is directly synthesized by marine photoautotrophs such as cyanobacteria or green algae. Lycopene is abundantly present in marine photosynthetic organisms; possibly it is the precursor in a lycopene-to-lycopane pathway. [15] The detection of lycopa-14(E),18(E)-diene in the green alga Botryococcus braunii strengthens this theory, as the conversion of lycopadiene to lycopane would be simpler and more feasible than that of lycopene to lycopane. [16]

Measurement techniques

Mass spectrum of lycopane. Ms lycopane thic fix.png
Mass spectrum of lycopane.

GC/MS

Gas chromatography-mass spectrometry is a common tool for detecting and analyzing biomarkers. Depending on the stationary phase used in the column, lycopane tends to co-elute with the n-C35 alkane. [17] Its tail-to-tail linkage yields diagnostic mass fragments. [18] The mass spectrum has a periodic fragmentation pattern. [19]

Raman spectroscopy

Raman spectroscopy, a non-destructive analytical technique with no sample preparation, is a powerful tool for analyzing biomarkers. [20] Lycopene, the unsaturated carotenoid that lycopane may be derived from, has a very characteristic Raman spectrum that is easily distinguishable. The spectrum of lycopane differs by a strong band at 1455 cm−1 (CH2 scissoring), a series of bands from 1390–1000 cm−1 (C-C stretching), and some bands from 1000–800 cm−1 (methyl in-plane rocking and C-H out-of-plane bending). [21]

Stable isotope analysis

The amount of carbon-13 present in lycopane found in sediment can give indications of its producer, particularly differentiating between methanogenic and algal origin. Lower levels of 13C suggest that the compound originated in methanogens, while higher levels support an algal origin. The high level of 13C found in the Messel shale lycopane (-20.8‰) suggests an algal producer. [22]

Use as a biomarker (case study: Arabian Sea/Peru Upwelling region)

Recent work has proposed elevated levels of lycopane as a proxy for anoxicity. When the C35/C31 n-alkane ratio was calculated both within and outside of the Oxygen Minimum Zone (OMZ) in the Arabian Sea, ratios inside of the OMZ were approximately two to three times higher than they were outside of this zone. This increased ratio was determined to be due to the presence of lycopane, which coelutes with C35n-alkane. Thus, it was determined that the lycopane/C31 ratio is correlated with degree of anoxicity. Similar trends were observed in the Peru Upwelling region. This further solidifies the viability of lycopane abundance as an indicator of oxicitiy/anoxicity and provides additional support for a methanogenic origin of lycopane. [23]

Astrobiological potential

One of the challenges involved in searching for life on other planets is the practical limitations of instrumentation. While GC/MS or NMR may give unequivocal evidence of the existence of biomarkers, it is not practical to include these instruments on highly optimized spacecraft. Raman spectroscopy has emerged as a leading technique due to its sensitivity, miniaturizability, and lack of sample preparation. [24]

Carotenoids have long generated astrobiological interest given their diagnostic Raman spectra, their unlikelihood of being abiotically synthesized, and their high preservation potential. [25] [26] Recent work has indicated that the Raman spectrum of lycopane is sufficiently different from that of lycopene. The two molecules are distinguishable. While functionalized carotenoids in themselves are an attractive astrobiological biomarker, detecting their diagenetic products may be equally characteristic of extraterrestrial life. Detection of diagenetically reduced lycopane on other planetary bodies may be an unambiguous indication of life, as diagenesis occurs during biological fossilization. [27]

Related Research Articles

Pristane is a natural saturated terpenoid alkane obtained primarily from shark liver oil, from which its name is derived. It is also found in the stomach oil of birds in the order Procellariiformes and in mineral oil and some foods. Pristane and phytane are used in the fields of geology and environmental science as biomarkers to characterize origins and evolution of petroleum hydrocarbons and coal.

<span class="mw-page-title-main">Cholestane</span> Chemical compound

Cholestane is a saturated tetracyclic triterpene. This 27-carbon biomarker is produced by diagenesis of cholesterol and is one of the most abundant biomarkers in the rock record. Presence of cholestane, its derivatives and related chemical compounds in environmental samples is commonly interpreted as an indicator of animal life and/or traces of O2, as animals are known for exclusively producing cholesterol, and thus has been used to draw evolutionary relationships between ancient organisms of unknown phylogenetic origin and modern metazoan taxa. Cholesterol is made in low abundance by other organisms (e.g., rhodophytes, land plants), but because these other organisms produce a variety of sterols it cannot be used as a conclusive indicator of any one taxon. It is often found in analysis of organic compounds in petroleum.

<span class="mw-page-title-main">Carbon-to-nitrogen ratio</span>

A carbon-to-nitrogen ratio is a ratio of the mass of carbon to the mass of nitrogen in organic residues. It can, amongst other things, be used in analysing sediments and soil including soil organic matter and soil amendments such as compost.

Phytane is the isoprenoid alkane formed when phytol, a constituent of chlorophyll, loses its hydroxyl group. When phytol loses one carbon atom, it yields pristane. Other sources of phytane and pristane have also been proposed than phytol.

γ-Carotene (gamma-carotene) is a carotenoid, and is a biosynthetic intermediate for cyclized carotenoid synthesis in plants. It is formed from cyclization of lycopene by lycopene cyclase epsilon. Along with several other carotenoids, γ-Carotene is a vitamer of vitamin A in herbivores and omnivores. Carotenoids with a cyclized, beta-ionone ring can be converted to vitamin A, also known as retinol, by the enzyme Beta-carotene 15,15'-dioxygenase; however, the bioconversion of gamma-carotene to retinol has not been well-characterized. γ-Carotene has tentatively been identified as a biomarker for green and purple sulfur bacteria in a sample from the 1.640 ± 0.003-Gyr-old Barney Creek Formation in Northern Australia which comprises marine sediments. Tentative discovery of γ-Carotene in marine sediments implies a past euxinic environment, where water columns were anoxic and sulfidic. This is significant for reconstructing past oceanic conditions, but so far γ-Carotene has only been potentially identified in the one measured sample.

Archaeol is composed of two phytanyl chains linked to the sn-2 and sn-3 positions of glycerol. As its phosphate ester, it is a common component of the membranes of archaea.

<span class="mw-page-title-main">Desmosterol</span> Chemical compound

Desmosterol (Cholesta-5,24-dien-3β-ol) is a lipid present in the membrane of phytoplankton. Structurally, desmosterol has a similar backbone to cholesterol, with the exception of an additional double bond in the structure of desmosterol.

<span class="mw-page-title-main">Isorenieratene</span> Chemical compound

Isorenieratene /ˌaɪsoʊrəˈnɪərətiːn/ is a carotenoid light harvesting pigment produced exclusively by the genus Chlorobium. Chlorobium are the brown-colored strains of the family of green sulfur bacteria (Chlorobiaceae). Green sulfur bacteria are anaerobic photoautotrophic organisms meaning they perform photosynthesis in the absence of oxygen using hydrogen sulfide in the following reaction:

<span class="mw-page-title-main">Abietane</span> Chemical compound

Abietane is a diterpene that forms the structural basis for a variety of natural chemical compounds such as abietic acid, carnosic acid, and ferruginol which are collectively known as abietanes or abietane diterpenes.

<span class="mw-page-title-main">Dinosterol</span> Chemical compound

Dinosterol (4α,23,24-trimethyl-5α-cholest-22E-en-3β-ol) is a 4α-methyl sterol that is produced by several genera of dinoflagellates and is rarely found in other classes of protists. The steroidal alkane, dinosterane, is the 'molecular fossil' of dinosterol, meaning that dinosterane has the same carbon skeleton as dinosterol, but lacks dinosterol's hydroxyl group and olefin functionality. As such, dinosterane is often used as a biomarker to identify the presence of dinoflagelletes in sediments.

<span class="mw-page-title-main">Taraxerol</span> Chemical compound

Taraxerol is a naturally-occurring pentacyclic triterpenoid. It exists in various higher plants, including Taraxacum officinale (Asteraceae), Alnus glutinosa (Betulaceae), Litsea dealbata (Lauraceae), Skimmia spp. (Rutaceae), Dorstenia spp. (Moraceae), Maytenus spp. (Celastraceae), and Alchornea latifolia (Euphobiaceae). Taraxerol was named "alnulin" when it was first isolated in 1923 from the bark of the grey alder by Zellner and Röglsperger. It also had the name "skimmiol" when Takeda and Yosiki isolated it from Skimmia (Rutaceae). A large number of medicinal plants are known to have this compound in their leaves, roots or seed oil.

Crocetane, or 2,6,11,15-tetramethylhexadecane, is an isoprenoid hydrocarbon compound. Unlike its isomer phytane, crocetane has a tail-to-tail linked isoprenoid skeleton. Crocetane has been detected in modern sediments and geological records as a biomarker, often associated with anaerobic methane oxidation.

<span class="mw-page-title-main">Okenane</span>

Okenane, the diagenetic end product of okenone, is a biomarker for Chromatiaceae, the purple sulfur bacteria. These anoxygenic phototrophs use light for energy and sulfide as their electron donor and sulfur source. Discovery of okenane in marine sediments implies a past euxinic environment, where water columns were anoxic and sulfidic. This is potentially tremendously important for reconstructing past oceanic conditions, but so far okenane has only been identified in one Paleoproterozoic rock sample from Northern Australia.

Crenarchaeol is a glycerol biphytanes glycerol tetraether (GDGT) biological membrane lipid. Together with archaeol, crenarcheol comprises a major component of archaeal membranes. Archaeal membranes are distinct from those of bacteria and eukaryotes because they contain isoprenoid GDGTs instead of diacyl lipids, which are found in the other domains. It has been proposed that GDGT membrane lipids are an adaptation to the high temperatures present in the environments that are home to extremophile archaea

<span class="mw-page-title-main">Tetrahymanol</span> Chemical compound

Tetrahymanol is a gammacerane-type membrane lipid first found in the marine ciliate Tetrahymena pyriformis. It was later found in other ciliates, fungi, ferns, and bacteria. After being deposited in sediments that compress into sedimentary rocks over millions of years, tetrahymanol is dehydroxylated into gammacerane. Gammacerane has been interpreted as a proxy for ancient water column stratification.

Arborane is a class of pentacyclic triterpene consisting of organic compounds with four 6-membered rings and one 5-membered ring. Arboranes are thought to be derived from arborinols, a class of natural cyclic triterpenoids typically produced by flowering plants. Thus arboranes are used as a biomarker for angiosperms and cordaites. Arborane is a stereoisomer of a compound called fernane, the diagenetic product of fernene and fernenol. Because aborinol and fernenol have different biological sources, the ratio of arborane/fernane in a sample can be used to reconstruct a record for the relative abundances of different plants.

Highly branched isoprenoids (HBIs) are long-chain alkenes produced by a small number of marine diatoms. There are a variety of highly branched isoprenoid structures, but C25 Highly branched isoprenoids containing 1 to 3 double bonds are the most common in the sedimentary record. Highly branched isoprenoids have been used as environmental proxies for sea ice conditions in the Arctic and Antarctic throughout the Holocene, and more recently, are being used to reconstruct more ancient ice records.

<span class="mw-page-title-main">Hydroxyarchaeol</span> Chemical compound

Hydroxyarchaeol is a core lipid unique to archaea, similar to archaeol, with a hydroxide functional group at the carbon-3 position of one of its ether side chains. It is found exclusively in certain taxa of methanogenic archaea, and is a common biomarker for methanogenesis and methane-oxidation. Isotopic analysis of hydroxyarchaeol can be informative about the environment and substrates for methanogenesis.

<span class="mw-page-title-main">Glycerol dialkyl glycerol tetraether</span>

Glycerol dialkyl glycerol tetraether lipids (GDGTs) are a class of membrane lipids synthesized by archaea and some bacteria, making them useful biomarkers for these organisms in the geological record. Their presence, structure, and relative abundances in natural materials can be useful as proxies for temperature, terrestrial organic matter input, and soil pH for past periods in Earth history. Some structural forms of GDGT form the basis for the TEX86 paleothermometer. Isoprenoid GDGTs, now known to be synthesized by many archaeal classes, were first discovered in extremophilic archaea cultures. Branched GDGTs, likely synthesized by acidobacteriota, were first discovered in a natural Dutch peat sample in 2000.

Biphytane (or bisphytane) is a C40 isoprenoid produced from glycerol dialkyl glycerol tetraether (GDGT) degradation. As a common lipid membrane component, biphytane is widely used as a biomarker for archaea. In particular, given its association with sites of active anaerobic oxidation of methane (AOM), it is considered a biomarker of methanotrophic archaea. It has been found in both marine and terrestrial environments.

References

  1. ↑ Freeman, Katherine H.; Hayes, J. M.; Trendel, Jean-Michel; Albrecht, Pierre (January 1990). "Evidence from carbon isotope measurements for diverse origins of sedimentary hydrocarbons". Nature. 343 (6255): 254–256. Bibcode:1990Natur.343..254F. doi:10.1038/343254a0. ISSN   1476-4687. PMID   11536462. S2CID   4307351.
  2. ↑ Freeman, K. H. (1992). The carbon isotopic compositions of individual compounds from ancient and modern depositional environments (Thesis).
  3. ↑ Grice, Kliti; Schouten, Stefan; Nissenbaum, Arie; Charrach, Josef; Sinninghe Damsté, Jaap S. (1998-04-09). "A remarkable paradox: Sulfurised freshwater algal (Botryococcus braunii) lipids in an ancient hypersaline euxinic ecosystem". Organic Geochemistry. 28 (3–4): 195–216. doi:10.1016/S0146-6380(97)00127-7. ISSN   0146-6380.
  4. ↑ Farrington, John W.; Davis, Alan C.; Sulanowski, Jacek; McCaffrey, Mark A.; McCarthy, Matt; Clifford, C.H.; Dickinson, Peggy; Volkman, John K. (1988-01-01). "Biogeochemistry of lipids in surface sediments of the Peru Upwelling Area at 15°S". Organic Geochemistry. 13 (4–6): 607–617. doi:10.1016/0146-6380(88)90080-0. ISSN   0146-6380.
  5. ↑ Wakeham, Stuart G.; Beier, Joy A.; Clifford, C. Hovey (1991), İzdar, Erol; Murray, James W. (eds.), "Organic Matter Sources in the Black Sea as Inferred from Hydrocarbon Distributions", Black Sea Oceanography, NATO ASI Series, Dordrecht: Springer Netherlands, pp. 319–341, doi:10.1007/978-94-011-2608-3_20, ISBN   978-94-011-2608-3 , retrieved 2021-05-09
  6. ↑ Wakeham, Stuart G. (1990-05-01). "Algal and bacterial hydrocarbons in particulate matter and interfacial sediment of the Cariaco Trench". Geochimica et Cosmochimica Acta. 54 (5): 1325–1336. Bibcode:1990GeCoA..54.1325W. doi:10.1016/0016-7037(90)90157-G. ISSN   0016-7037.
  7. ↑ Walters, C. C.; Moldowan, J. M.; Peters, K. E., eds. (2004), "Source- and age-related biomarker parameters", The Biomarker Guide: Volume 2: Biomarkers and Isotopes in Petroleum Systems and Earth History (2 ed.), Cambridge: Cambridge University Press, vol. 2, pp. 483–607, doi:10.1017/cbo9781107326040.004, ISBN   978-0-521-03998-7 , retrieved 2021-05-08
  8. ↑ Brassell, S. C.; Wardroper, A. M. K.; Thomson, I. D.; Maxwell, J. R.; Eglinton, G. (April 1981). "Specific acyclic isoprenoids as biological markers of methanogenic bacteria in marine sediments". Nature. 290 (5808): 693–696. Bibcode:1981Natur.290..693B. doi:10.1038/290693a0. ISSN   1476-4687. PMID   7219553. S2CID   4338862.
  9. ↑ Tornabene, T. G.; Langworthy, T. A.; Holzer, Günther; Oró, J. (1979-03-01). "Squalenes, phytanes and other isoprenoids as major neutral lipids of methanogenic and thermoacidophilic "archaebacteria"". Journal of Molecular Evolution. 13 (1): 73–83. Bibcode:1979JMolE..13...73T. doi:10.1007/BF01732755. ISSN   1432-1432. PMID   458874. S2CID   24427972.
  10. ↑ Lattuati, Agnès; Guezennec, Jean; Metzger, Pierre; Largeau, Claude (March 1998). "Lipids of Thermococcus hydrothermalis, an archaea isolated from a deep-sea hydrothermal vent". Lipids. 33 (3): 319–326. doi:10.1007/s11745-998-0211-0. ISSN   0024-4201. PMID   9560807. S2CID   11130301.
  11. ↑ Wakeham, Stuart G.; Ertel, John R. (1988-01-01). "Diagenesis of organic matter in suspended particles and sediments in the Cariaco Trench". Organic Geochemistry. 13 (4–6): 815–822. doi:10.1016/0146-6380(88)90105-2. ISSN   0146-6380.
  12. ↑ "Carotenoids | Linus Pauling Institute | Oregon State University". 2017-05-21. Archived from the original on 2017-05-21. Retrieved 2021-05-08.
  13. ↑ Watts, C.D.; Maxwell, J.R. (1977-04-01). "Carotenoid diagenesis in a marine sediment". Geochimica et Cosmochimica Acta. 41 (4): 493–497. Bibcode:1977GeCoA..41..493W. doi:10.1016/0016-7037(77)90287-3. ISSN   0016-7037.
  14. ↑ Organic matter : productivity, accumulation, and preservation in recent and ancient sediments. Jean K. Whelan, John W. Farrington. New York, N.Y.: Columbia University Press. 1992. ISBN   0-585-01922-3. OCLC   44958573.{{cite book}}: CS1 maint: others (link)
  15. ↑ Peters, Kenneth E. (2005). The biomarker guide. C. C. Walters, J. M. Moldowan (2 ed.). Cambridge, UK: Cambridge University Press. ISBN   0-521-78158-2. OCLC   53331751.
  16. ↑ Metzger, P.; Casadevall, E. (1987-01-01). "Lycopadiene, a tetraterpenoid hydrocarbon from new strains of the green alga Botryococcus braunii". Tetrahedron Letters. 28 (34): 3931–3934. doi:10.1016/S0040-4039(00)96423-2. ISSN   0040-4039.
  17. ↑ Sinninghe Damsté, Jaap S.; Kuypers, Marcel M.M.; Schouten, Stefan; Schulte, Sonja; Rullkötter, Jürgen (2003-04-15). "The lycopane/C31 n-alkane ratio as a proxy to assess palaeoxicity during sediment deposition". Earth and Planetary Science Letters. 209 (1–2): 215–226. Bibcode:2003E&PSL.209..215S. doi:10.1016/S0012-821X(03)00066-9. ISSN   0012-821X.
  18. ↑ Peters, Kenneth E. (2005). The biomarker guide. C. C. Walters, J. M. Moldowan (2 ed.). Cambridge, UK: Cambridge University Press. ISBN   0-521-78158-2. OCLC   53331751.
  19. ↑ "2,6,10,14,19,23,27,31-OCTAMETHYLDOTRIACONTANE - MS - Spectrum - SpectraBase". spectrabase.com. Retrieved 2021-05-23.
  20. ↑ Long, D. A. (1977). Raman spectroscopy. New York: McGraw-Hill. ISBN   0-07-038675-7. OCLC   2331511.
  21. ↑ Marshall, Craig P.; Olcott Marshall, Alison (2010-07-13). "The potential of Raman spectroscopy for the analysis of diagenetically transformed carotenoids". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 368 (1922): 3137–3144. Bibcode:2010RSPTA.368.3137M. doi:10.1098/rsta.2010.0016. PMID   20529950. S2CID   10051992.
  22. ↑ Freeman, Katherine H.; Hayes, J. M.; Trendel, Jean-Michel; Albrecht, Pierre (January 1990). "Evidence from carbon isotope measurements for diverse origins of sedimentary hydrocarbons". Nature. 343 (6255): 254–256. Bibcode:1990Natur.343..254F. doi:10.1038/343254a0. ISSN   1476-4687. PMID   11536462. S2CID   4307351.
  23. ↑ Sinninghe Damsté, Jaap S.; Kuypers, Marcel M.M.; Schouten, Stefan; Schulte, Sonja; Rullkötter, Jürgen (April 2003). "The lycopane/C31 n-alkane ratio as a proxy to assess palaeoxicity during sediment deposition". Earth and Planetary Science Letters. 209 (1–2): 215–226. Bibcode:2003E&PSL.209..215S. doi:10.1016/S0012-821X(03)00066-9.
  24. ↑ Jorge Villar, Susana E.; Edwards, Howell G. M. (2006-01-01). "Raman spectroscopy in astrobiology". Analytical and Bioanalytical Chemistry. 384 (1): 100–113. doi:10.1007/s00216-005-0029-2. ISSN   1618-2650. PMID   16456933. S2CID   22753604.
  25. ↑ Baqué, Mickael; Napoli, Alessandro; Fagliarone, Claudia; Moeller, Ralf; de Vera, Jean-Pierre; Billi, Daniela (June 2020). "Carotenoid Raman Signatures Are Better Preserved in Dried Cells of the Desert Cyanobacterium Chroococcidiopsis than in Hydrated Counterparts after High-Dose Gamma Irradiation". Life. 10 (6): 83. doi: 10.3390/life10060083 . PMC   7345886 . PMID   32521820.
  26. ↑ Jehlička, Jan; Edwards, Howell G. M.; Osterrothová, Kateřina; Novotná, Julie; Nedbalová, Linda; Kopecký, Jiří; Němec, Ivan; Oren, Aharon (2014-12-13). "Potential and limits of Raman spectroscopy for carotenoid detection in microorganisms: implications for astrobiology". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 372 (2030): 20140199. Bibcode:2014RSPTA.37240199J. doi:10.1098/rsta.2014.0199. ISSN   1364-503X. PMC   4223861 . PMID   25368348.
  27. ↑ Marshall, Craig P.; Olcott Marshall, Alison (2010-07-13). "The potential of Raman spectroscopy for the analysis of diagenetically transformed carotenoids". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 368 (1922): 3137–3144. Bibcode:2010RSPTA.368.3137M. doi:10.1098/rsta.2010.0016. ISSN   1364-503X. PMID   20529950. S2CID   10051992.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.