24-n-Propylcholestane

24-n-Propylcholestane
Names
	IUPAC name (24Ξ)-24a2-Homo-5ξ-stigmastane
	Systematic IUPAC name (1R,3aS,3bR,5aΞ,9aS,9bS,11aR)-9a,11a-Dimethyl-1-[(2R,5Ξ)-5-(propan-2-yl)octan-2-yl]hexadecahydro-1H-cyclopenta[a]phenanthrene
Identifiers
CAS Number	125224-28-4 ;
3D model (JSmol)	Interactive image;
ChemSpider	67494965;
PubChem CID	53937960;
CompTox Dashboard (EPA)	DTXSID901315540 ;
	InChI InChI=1S/C30H54/c1-7-10-23(21(2)3)13-12-22(4)26-16-17-27-25-15-14-24-11-8-9-19-29(24,5)28(25)18-20-30(26,27)6/h21-28H,7-20H2,1-6H3/t22-,23?,24?,25+,26-,27+,28+,29+,30-/m1/s1 Key: IVTLFEDUWFUUTN-WHCWVIOUSA-N;
	SMILES CCCC(CC[C@@H](C)[C@H]1CC[C@@H]2[C@@]1(CC[C@H]3[C@H]2CCC4[C@@]3(CCCC4)C)C)C(C)C;
Properties
Chemical formula	C30H54
Molar mass	414.762 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

24-n-Propylcholestane is a sterane biomarker molecule often found in marine source rocks.^[1]^[2] It is a C₃₀ molecule, meaning that it is composed of thirty carbon atoms, and is one of the leading ways to distinguish a marine source rock from a terrigenous sample. It is composed of three six-carbon rings and one five-carbon ring, with two methyl groups and one eleven carbon side chain. 24-n-Propylcholestane has a molar mass of 414.76 g/mol.

24-n-Propylcholestane is a sterane, which are derived from sterols after being buried in the sediment. Sterols turn into steranes by saturating the sterol's double bond and removing the alcohol group.^[3] Steranes are fairly stable, and are often found in source rocks and crude oils.^[3]

24-n-Propylcholestane is derived from 24-n-propylcholesterol, which is made in the modern ocean by Chrysophyte algae.^[4] Because of its known modern creator, it is thought that traces of 24-n-propylcholestane in ancient sediments were likely produced by older algaes of the same order Chrysophyte.^[1] The marine algae is consumed by marine invertebrates, and so 24-n-propylcholesterols are also found in invertebrates, despite not being produced by them.^[1] Regardless of which organism is observed containing 24-n-propylcholesterols, the molecule originated from Chrysophyte algae.

The ratio of 24-n-propylcholestanes to 24-iso-propylcholestanes is used as an indicator for the presence of sponges.

Detection

In sediments, sterane biomarkers are found as a mixture of stereoisomers. It can be difficult to separate out a specific stereoisomer, as is necessary for the detection of solely 24-n-propylcholestane. Because of this, 24-n-propylcholestane can be fairly difficult to detect using gas chromatography-mass spectrum (GC-MS). It has a m/z of 414 and a secondary peak at 217, and can be easily confused for a different group of C₃₀ molecules, 4ɑ-methylsteranes.^[1]

References

^ ^a ^b ^c ^d Peters, K. E.; Walters, C. C.; Moldowan, J. M. (2007). The Biomarker Guide: Volume 2, Biomarkers and Isotopes in Petroleum Systems and Earth History. Cambridge University Press. p. 527. ISBN 978-1-107-07962-5.
^ Moldowan, J. Michael; Fago, Frederick J.; Lee, Cathy Y.; Jacobson, Stephen R.; Watt, David S.; Slougui, Nacer-Eddine; Jeganathan, Alwarsamy; Young, Donald C. (19 January 1990). "Sedimentary 12- n -Propylcholestanes, Molecular Fossils Diagnostic of Marine Algae". Science. 247 (4940): 309–312. Bibcode:1990Sci...247..309M. doi:10.1126/science.247.4940.309. PMID 17735849. S2CID 45171358.
^ ^a ^b Dembicki, Jr., Harry (2017). "Interpreting Crude Oil and Natural Gas Data". Practical Petroleum Geochemistry for Exploration and Production. pp. 135–188. doi:10.1016/B978-0-12-803350-0.00004-0. ISBN 978-0-12-803350-0. p. 151: A classic example of a biomarker and its relationship to the biological precursor is cholestane and cholesterol
^ Moldowan, J. M.; Fago, F. J.; Lee, C. Y.; Jacobson, S. R.; Watt, D. S.; Slougui, N. E.; Jeganathan, A.; Young, D. C. (19 January 1990). "Sedimentary 12-n-Propylcholestanes, Molecular Fossils Diagnostic of Marine Algae". Science. 247 (4940): 309–312. Bibcode:1990Sci...247..309M. doi:10.1126/science.247.4940.309. JSTOR 2873627. PMID 17735849. S2CID 45171358. Gale A8352545.

[:3-1] Peters, K. E.; Walters, C. C.; Moldowan, J. M. (2007). The Biomarker Guide: Volume 2, Biomarkers and Isotopes in Petroleum Systems and Earth History. Cambridge University Press. p. 527. ISBN 978-1-107-07962-5.

[2] Moldowan, J. Michael; Fago, Frederick J.; Lee, Cathy Y.; Jacobson, Stephen R.; Watt, David S.; Slougui, Nacer-Eddine; Jeganathan, Alwarsamy; Young, Donald C. (19 January 1990). "Sedimentary 12- n -Propylcholestanes, Molecular Fossils Diagnostic of Marine Algae". Science. 247 (4940): 309–312. Bibcode:1990Sci...247..309M. doi:10.1126/science.247.4940.309. PMID 17735849. S2CID 45171358.

[:12-3] Dembicki, Jr., Harry (2017). "Interpreting Crude Oil and Natural Gas Data". Practical Petroleum Geochemistry for Exploration and Production. pp. 135–188. doi:10.1016/B978-0-12-803350-0.00004-0. ISBN 978-0-12-803350-0. p. 151: A classic example of a biomarker and its relationship to the biological precursor is cholestane and cholesterol

[4] Moldowan, J. M.; Fago, F. J.; Lee, C. Y.; Jacobson, S. R.; Watt, D. S.; Slougui, N. E.; Jeganathan, A.; Young, D. C. (19 January 1990). "Sedimentary 12-n-Propylcholestanes, Molecular Fossils Diagnostic of Marine Algae". Science. 247 (4940): 309–312. Bibcode:1990Sci...247..309M. doi:10.1126/science.247.4940.309. JSTOR 2873627. PMID 17735849. S2CID 45171358. Gale A8352545.

[1]

[2]

[3]

[4]