{"id":41776,"date":"2026-06-04T09:37:55","date_gmt":"2026-06-04T07:37:55","guid":{"rendered":"https:\/\/karmaka.de\/?p=41776"},"modified":"2026-06-04T09:37:56","modified_gmt":"2026-06-04T07:37:56","slug":"racemic-isoprenoids-in-the-murchison-meteorite-derive-from-petroleum-based-aerosol-pollutants","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=41776","title":{"rendered":"Racemic isoprenoids in the Murchison meteorite derive from petroleum-based aerosol pollutants<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"\n<p>Guillaume Leseigneur, Manuel Reinhardt, Fatma Yesil Sahan, Uwe Meierhenrich<\/p>\n\n\n\n<p>Earth and Planetary Science Letters<br>Volume 690, 15 September 2026, 120141<\/p>\n\n\n\n<p><a href=\"https:\/\/arxiv.org\/pdf\/2606.05036\" target=\"_blank\" rel=\"noreferrer noopener\"><strong>LINK + PDF (OPEN ACCESS)<\/strong><\/a><\/p>\n\n\n\n<p>&#8220;Highlights<\/p>\n\n\n\n<ul>\n<li>Isoprenoid alkanes pristane and phytane are racemic in the Murchison meteorite.<\/li>\n\n\n\n<li>The isoprenoids in Murchison come entirely from petroleum contamination.<\/li>\n\n\n\n<li>Direct chiral separation of pristane and phytane is now readily accessible.<\/li>\n\n\n\n<li>Improved diastereomeric data for Green River, Messel and B\u00e4chental oil shales.<\/li>\n\n\n\n<li>Difference in pure mass spectrometric fingerprints for isoprenoid diastereomers.&#8221;<\/li>\n<\/ul>\n\n\n\n<p class=\"justify-text\">&#8220;The isoprenoid alkanes pristane and phytane are widely detected in meteorites. As isoprenoids are considered markers of Earth\u2019s biosphere, their presence in meteorites has led to a prevailing consensus that they represent terrestrial contamination, thereby calling into question the indigeneity of the entire meteoritic hydrocarbon inventory. Indeed, these chiral molecules are ubiquitous in biological systems, where their stereogenic centers are fixed and of the same absolute configuration. In this study we separate, for the first time, the different relevant chiral configurations of pristane and phytane in a meteorite sample, and we show that the isoprenoid alkanes detected in the Murchison meteorite are racemic. On Earth, racemization of these molecules has only been observed in oil shales and crude oils subjected to a certain degree of thermal maturation. In light of previous findings, these results strongly suggest that the Murchison meteorite was contaminated exclusively by petroleum pollutants present in Earth\u2019s atmosphere, and categorically exclude any contribution from the biosphere at the fall site. Consequently, this work establishes a foundation for systematic investigations into the chirality of isoprenoids in other meteorite samples and the different sources of atmospheric petroleum pollution.&#8221;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Guillaume Leseigneur, Manuel Reinhardt, Fatma Yesil Sahan, Uwe Meierhenrich Earth and Planetary Science LettersVolume 690, 15 September 2026, 120141 LINK + PDF (OPEN ACCESS) &#8220;Highlights &#8220;The isoprenoid alkanes pristane and phytane are widely detected in&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,18,64],"tags":[3273,5549,105,7188,107,3913,2624],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41776"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=41776"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41776\/revisions"}],"predecessor-version":[{"id":41777,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/41776\/revisions\/41777"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=41776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=41776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=41776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}