Isorenieratene

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Isorenieratene
Skeletal formula
Space-filling model
Identifiers
CAS number 524-01-6 YesY
PubChem 9984420
ChemSpider 8160010 N
KEGG C15943 N
Jmol-3D images Image 1
Properties
Molecular formula C40H48
Molar mass 528.81 g mol−1
Appearance purple-red crystalline solid[1]
Melting point 199 to 200 °C (390 to 392 °F; 472 to 473 K)[1]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Isorenieratene /ˌsrəˈnɪərətn/ is a carotenoid light harvesting pigment with the chemical formula C40H48.[2] Isorenieratene and its derivatives are useful to marine chemists studying the carbon cycle as biomarkers that indicate photic zone anoxia.[3]

Isorenieratene is produced by green sulfur bacteria (Chlorobium) which perform photosynthesis using hydrogen sulfide rather than water:

H2S + CO2 → SO42− + organic compounds

Such anoxygenic photosynthesis requires reduced sulfur (and therefore strictly anaerobic conditions) and light (). This combination of conditions is very unusual nowadays, since it requires very stratified water columns to achieve a sharp density gradient, i.e. a constrained basin with fresh water flowing, or warm water on top of cooler water. Green sulfur bacteria are commonly found in meromictic lakes and ponds, sediments, and some sinkholes. Some marine environments, such as certain fjords and the Black sea also fulfill these criteria. In the early history of the Earth, however, these conditions were present in all oceans at depths of about 100 m. At such depths, sunlight has a very different wavelength profile than at the surface, so isorenieratene is used instead of chlorophyll to harvest light for photosynthesis.[4]

See also[edit]

References[edit]

  1. ^ a b Yamaguchi, Masaru (1959). "Total Synthesis of Isorenieratene". Bull. Chem. Soc. Jpn. 32 (11): 1171–1173. doi:10.1246/bcsj.32.1171. 
  2. ^ Sinninghe Damsté, J. S.; Schouten, Stefan; van Duin, A. C. T. (2001). "Isorenieratene derivatives in sediments: possible controls on their distribution". Geochim. Cosmochim. Acta 61: 1557–1571. Bibcode:2001GeCoA..65.1557S. doi:10.1016/S0016-7037(01)00549-X. 
  3. ^ Brocks, J. J.; Love, G. D.; Summons, R. E.; Knoll, A. H.; Logan, G. A.; Bowden, S. A. "Biomarker evidence for green and purple sulphur bacteria in a stratified Palaeoproterozoic sea". Nature 437 (7060): 866–870. Bibcode:2005Natur.437..866B. doi:10.1038/nature04068. 
  4. ^ Maresca, J. A.; Romberger, S. P.; Bryant, D. A. (2008). "Isorenieratene Biosynthesis in Green Sulfur Bacteria Requires the Cooperative Actions of Two Carotenoid Cyclases". Journal of Bacteriology 190 (19): 6384–6391. doi:10.1128/JB.00758-08.