Isorenieratene
| |
| |
| Names | |
|---|---|
| IUPAC name
3,3′-((1E,3E,5E,7E,9E,11E,13E,15E,17E)-3,7,12,16-tetramethyloctadeca-1,3,5,7,9,11,13,15,17-nonaene-1,18-diyl)bis(1,2,4-trimethylbenzene)
| |
| Identifiers | |
3D model (JSmol)
|
|
| ChemSpider | |
| KEGG | |
PubChem CID
|
|
CompTox Dashboard (EPA)
|
|
| |
| |
| Properties | |
| C40H48 | |
| Molar mass | 528.824 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 otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Isorenieratene /ˌaɪsoʊrəˈnɪərətiːn/ 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 (hν). 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 (330 ft). 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
References
- ^ a b Yamaguchi, Masaru (1959). "Total Synthesis of Isorenieratene". Bull. Chem. Soc. Jpn. 32 (11): 1171–1173. doi:10.1246/bcsj.32.1171.
- ^ 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.
- ^ 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. PMID 16208367.
- ^ 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. PMC 2565998. PMID 18676669.