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{{Short description|Class of tetracyclic compounds derived from steroids}} |
{{Short description|Class of tetracyclic compounds derived from steroids}} |
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{{for |
{{for|the drug with trade name Sterane|Prednisolone}} |
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[[File:Steran num ABCD.svg|thumb|Numbering of the C atoms. In steranes the side chain at C-17 varies.]] |
[[File:Steran num ABCD.svg|thumb|Numbering of the C atoms. In steranes the side chain at C-17 varies.]] |
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| ⚫ | '''Sterane''' ('''cyclopentanoperhydrophenanthrenes''') compounds are a class of [[tetracyclic]] [[Triterpene|triterpanes]] derived from [[steroid]]s or [[sterol]]s via [[diagenesis|diagenetic]] and [[catagenesis (geology)|catagenetic]] degradation, such as [[hydrogenation]]. Steranes are detected in sediments and sedimentary rocks in nature.<ref name=":0">{{Cite book |last=Peters |first=K. E. |url=https://www.cambridge.org/core/books/biomarker-guide/38F1AC02B49B61216C2252A9B4D940D0 |title=The Biomarker Guide: Volume 1: Biomarkers and Isotopes in the Environment and Human History |last2=Walters |first2=C. C. |last3=Moldowan |first3=J. M. |date=2004 |publisher=Cambridge University Press |isbn=978-0-521-78697-3 |edition=2 |volume=1 |location=Cambridge |doi=10.1017/cbo9780511524868}}</ref> Steranes have an [[androstane]] skeleton with a side chain at carbon C-17. The sterane structure constitutes the scaffold of all sterols. Steranes are widely used as [[Biomarker (petroleum)|biomarkers]] for the presence of [[Eukaryote|eukaryotes]] in past ecosystems because steroids are nearly exclusively produced by eukaryotes.<ref>{{Cite web|date=November 2006|title=About biomarkers|publisher=The Summons Lab, Massachusetts Institute of Technology (MIT)|url=http://www-eaps.mit.edu/geobiology/biomarkers/steroids.html|access-date=8 October 2009|url-status=dead|archive-url=https://web.archive.org/web/20200424223411/http://www-eaps.mit.edu/geobiology/biomarkers/steroids.html|archive-date=24 April 2020}}</ref> In particular, [[Cholestane|cholestanes]] are diagenetic products of cholesterol in [[Animal|animals]], while stigmastanes are diagenetic products of [[Stigmasterol|stigmasterols]] in [[algae]] and [[Embryophyte|land plants]].<ref name=":0" /> However, some bacteria are now known to produce sterols and it is inferred that the ultimate origin of sterol biosynthesis is in bacteria.<ref name=":1">{{Cite journal |last=Hoshino |first=Yosuke |last2=Gaucher |first2=Eric A. |date=2021-06-22 |title=Evolution of bacterial steroid biosynthesis and its impact on eukaryogenesis |url=https://pnas.org/doi/full/10.1073/pnas.2101276118 |journal=Proceedings of the National Academy of Sciences |language=en |volume=118 |issue=25 |doi=10.1073/pnas.2101276118 |issn=0027-8424 |pmc=PMC8237579 |pmid=34131078}}</ref> Sterols are produced via protosterols that are direct cyclization compounds of [[squalene]] by the catalysis of [[oxidosqualene cyclase]].<ref name=":1" /> All known sterols in eukaryotes are enzymatically extensively modified from protosterols, while organisms that only produce protosterols are not known. The oldest record of modified steranes are in sedimentary rocks deposited ca. 720–820 million years ago.<ref>{{Cite journal |last=Brocks |first=Jochen J. |last2=Jarrett |first2=Amber J. M. |last3=Sirantoine |first3=Eva |last4=Hallmann |first4=Christian |last5=Hoshino |first5=Yosuke |last6=Liyanage |first6=Tharika |date=2017-08-31 |title=The rise of algae in Cryogenian oceans and the emergence of animals |journal=Nature |volume=548 |issue=7669 |pages=578–581 |doi=10.1038/nature23457 |issn=0028-0836}}</ref> In contrast, diagenetic products of protosterols (called protostanes and cyclosteranes) are widely distributed in older [[Proterozoic]] rocks and imply the presence of extinct proto-eukaryotes and/or sterol-producing bacteria before the evolution of crown-group eukaryotes.<ref>{{Cite journal |last=Brocks |first=Jochen J. |last2=Nettersheim |first2=Benjamin J. |last3=Adam |first3=Pierre |last4=Schaeffer |first4=Philippe |last5=Jarrett |first5=Amber J. M. |last6=Güneli |first6=Nur |last7=Liyanage |first7=Tharika |last8=van Maldegem |first8=Lennart M. |last9=Hallmann |first9=Christian |last10=Hope |first10=Janet M. |date=2023-06 |title=Lost world of complex life and the late rise of the eukaryotic crown |url=https://www.nature.com/articles/s41586-023-06170-w |journal=Nature |language=en |volume=618 |issue=7966 |pages=767–773 |doi=10.1038/s41586-023-06170-w |issn=1476-4687}}</ref> |
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| ⚫ | ''' |
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Steranes may be rearranged to diasteranes during [[diagenesis]] (C-27 to C-30, rearrangement at C-18 and C-19, no R at C-24). [[Oil]]s from [[Clastic rock|clastic source rocks]] tend to be rich in diasteranes. |
Steranes may be rearranged to diasteranes during [[diagenesis]] (C-27 to C-30, rearrangement at C-18 and C-19, no R at C-24). [[Oil]]s from [[Clastic rock|clastic source rocks]] tend to be rich in diasteranes. |
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[[Cholesterol]] and its derivatives (such as [[progesterone]], [[aldosterone]], [[cortisol]], and [[testosterone]]), are common examples of compounds with the |
[[Cholesterol]] and its derivatives (such as [[progesterone]], [[aldosterone]], [[cortisol]], and [[testosterone]]), are common examples of compounds with the Sterane |
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==See also== |
==See also== |
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Revision as of 07:50, 25 July 2024
Sterane (cyclopentanoperhydrophenanthrenes) compounds are a class of tetracyclic triterpanes derived from steroids or sterols via diagenetic and catagenetic degradation, such as hydrogenation. Steranes are detected in sediments and sedimentary rocks in nature.[1] Steranes have an androstane skeleton with a side chain at carbon C-17. The sterane structure constitutes the scaffold of all sterols. Steranes are widely used as biomarkers for the presence of eukaryotes in past ecosystems because steroids are nearly exclusively produced by eukaryotes.[2] In particular, cholestanes are diagenetic products of cholesterol in animals, while stigmastanes are diagenetic products of stigmasterols in algae and land plants.[1] However, some bacteria are now known to produce sterols and it is inferred that the ultimate origin of sterol biosynthesis is in bacteria.[3] Sterols are produced via protosterols that are direct cyclization compounds of squalene by the catalysis of oxidosqualene cyclase.[3] All known sterols in eukaryotes are enzymatically extensively modified from protosterols, while organisms that only produce protosterols are not known. The oldest record of modified steranes are in sedimentary rocks deposited ca. 720–820 million years ago.[4] In contrast, diagenetic products of protosterols (called protostanes and cyclosteranes) are widely distributed in older Proterozoic rocks and imply the presence of extinct proto-eukaryotes and/or sterol-producing bacteria before the evolution of crown-group eukaryotes.[5]
Steranes may be rearranged to diasteranes during diagenesis (C-27 to C-30, rearrangement at C-18 and C-19, no R at C-24). Oils from clastic source rocks tend to be rich in diasteranes.
Cholesterol and its derivatives (such as progesterone, aldosterone, cortisol, and testosterone), are common examples of compounds with the Sterane
See also
References
- ^ a b Peters, K. E.; Walters, C. C.; Moldowan, J. M. (2004). The Biomarker Guide: Volume 1: Biomarkers and Isotopes in the Environment and Human History. Vol. 1 (2 ed.). Cambridge: Cambridge University Press. doi:10.1017/cbo9780511524868. ISBN 978-0-521-78697-3.
- ^ "About biomarkers". The Summons Lab, Massachusetts Institute of Technology (MIT). November 2006. Archived from the original on 24 April 2020. Retrieved 8 October 2009.
- ^ a b Hoshino, Yosuke; Gaucher, Eric A. (2021-06-22). "Evolution of bacterial steroid biosynthesis and its impact on eukaryogenesis". Proceedings of the National Academy of Sciences. 118 (25). doi:10.1073/pnas.2101276118. ISSN 0027-8424. PMC 8237579. PMID 34131078.
{{cite journal}}: CS1 maint: PMC format (link) - ^ Brocks, Jochen J.; Jarrett, Amber J. M.; Sirantoine, Eva; Hallmann, Christian; Hoshino, Yosuke; Liyanage, Tharika (2017-08-31). "The rise of algae in Cryogenian oceans and the emergence of animals". Nature. 548 (7669): 578–581. doi:10.1038/nature23457. ISSN 0028-0836.
- ^ Brocks, Jochen J.; Nettersheim, Benjamin J.; Adam, Pierre; Schaeffer, Philippe; Jarrett, Amber J. M.; Güneli, Nur; Liyanage, Tharika; van Maldegem, Lennart M.; Hallmann, Christian; Hope, Janet M. (2023-06). "Lost world of complex life and the late rise of the eukaryotic crown". Nature. 618 (7966): 767–773. doi:10.1038/s41586-023-06170-w. ISSN 1476-4687.
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