View in EDS

Synthesis of 26-methyl cholestane and identification of cryostanes in mid-Neoproterozoic sediments.

Saved in:
Bibliographic Details
Title: Synthesis of 26-methyl cholestane and identification of cryostanes in mid-Neoproterozoic sediments.
Authors: Adam, Pierre1 padam@unistra.fr, Schaeffer, Philippe1, Brocks, Jochen J.2
Source: Organic Geochemistry. Jan2018, Vol. 115, p246-249. 4p.
Subjects: Cholestanes, Marine sediments, Steranes, Gas chromatography, Mass spectrometry, Molecular clock
Abstract: The biomarker distributions of mid-Neoproterozoic sediments (800–717 million yr, Ma) from various locations are characterized by the occurrence, besides cholestane isomers, of a novel series of C 28 steranes, whereas classical C-24 alkylated steranes are absent. These unusual C 28 steranes, termed cryostanes, seem to be restricted to pre-Snowball Earth sediments. We report their conclusive identification as 26-methyl cholestanes based on comparison of gas chromatographic (GC) behavior and mass spectrum of the last eluting cryostane isomer with those of a 26-methyl 5α(H),14α(H),17α(H),20 R -cholestane standard obtained by way of synthesis. Sterols methylated at C-26 seem to be restricted to some demosponges and, based on molecular clock estimates, demosponges may have emerged in the time interval 800–700 Ma. A sponge origin of cryostanes is thereby conceivable, making cryostanes the oldest molecular markers for animals. However, other biological sources need to be explored, including the wide variety of eukaryotic protists. [ABSTRACT FROM AUTHOR]
Copyright of Organic Geochemistry is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
FullText Text:
  Availability: 0
Header DbId: egs
DbLabel: Engineering Source
An: 126994795
AccessLevel: 6
PubType: Academic Journal
PubTypeId: academicJournal
PreciseRelevancyScore: 0
IllustrationInfo
Items – Name: Title
  Label: Title
  Group: Ti
  Data: Synthesis of 26-methyl cholestane and identification of cryostanes in mid-Neoproterozoic sediments.
– Name: Author
  Label: Authors
  Group: Au
  Data: <searchLink fieldCode="AR" term="%22Adam%2C+Pierre%22">Adam, Pierre</searchLink><relatesTo>1</relatesTo><i> padam@unistra.fr</i><br /><searchLink fieldCode="AR" term="%22Schaeffer%2C+Philippe%22">Schaeffer, Philippe</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Brocks%2C+Jochen+J%2E%22">Brocks, Jochen J.</searchLink><relatesTo>2</relatesTo>
– Name: TitleSource
  Label: Source
  Group: Src
  Data: <searchLink fieldCode="JN" term="%22Organic+Geochemistry%22">Organic Geochemistry</searchLink>. Jan2018, Vol. 115, p246-249. 4p.
– Name: Subject
  Label: Subjects
  Group: Su
  Data: <searchLink fieldCode="DE" term="%22Cholestanes%22">Cholestanes</searchLink><br /><searchLink fieldCode="DE" term="%22Marine+sediments%22">Marine sediments</searchLink><br /><searchLink fieldCode="DE" term="%22Steranes%22">Steranes</searchLink><br /><searchLink fieldCode="DE" term="%22Gas+chromatography%22">Gas chromatography</searchLink><br /><searchLink fieldCode="DE" term="%22Mass+spectrometry%22">Mass spectrometry</searchLink><br /><searchLink fieldCode="DE" term="%22Molecular+clock%22">Molecular clock</searchLink>
– Name: Abstract
  Label: Abstract
  Group: Ab
  Data: The biomarker distributions of mid-Neoproterozoic sediments (800–717 million yr, Ma) from various locations are characterized by the occurrence, besides cholestane isomers, of a novel series of C 28 steranes, whereas classical C-24 alkylated steranes are absent. These unusual C 28 steranes, termed cryostanes, seem to be restricted to pre-Snowball Earth sediments. We report their conclusive identification as 26-methyl cholestanes based on comparison of gas chromatographic (GC) behavior and mass spectrum of the last eluting cryostane isomer with those of a 26-methyl 5α(H),14α(H),17α(H),20 R -cholestane standard obtained by way of synthesis. Sterols methylated at C-26 seem to be restricted to some demosponges and, based on molecular clock estimates, demosponges may have emerged in the time interval 800–700 Ma. A sponge origin of cryostanes is thereby conceivable, making cryostanes the oldest molecular markers for animals. However, other biological sources need to be explored, including the wide variety of eukaryotic protists. [ABSTRACT FROM AUTHOR]
– Name: AbstractSuppliedCopyright
  Label:
  Group: Ab
  Data: <i>Copyright of Organic Geochemistry is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.)
PLink https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=126994795
RecordInfo BibRecord:
  BibEntity:
    Identifiers:
      – Type: doi
        Value: 10.1016/j.orggeochem.2017.11.006
    Languages:
      – Code: eng
        Text: English
    PhysicalDescription:
      Pagination:
        PageCount: 4
        StartPage: 246
    Subjects:
      – SubjectFull: Cholestanes
        Type: general
      – SubjectFull: Marine sediments
        Type: general
      – SubjectFull: Steranes
        Type: general
      – SubjectFull: Gas chromatography
        Type: general
      – SubjectFull: Mass spectrometry
        Type: general
      – SubjectFull: Molecular clock
        Type: general
    Titles:
      – TitleFull: Synthesis of 26-methyl cholestane and identification of cryostanes in mid-Neoproterozoic sediments.
        Type: main
  BibRelationships:
    HasContributorRelationships:
      – PersonEntity:
          Name:
            NameFull: Adam, Pierre
      – PersonEntity:
          Name:
            NameFull: Schaeffer, Philippe
      – PersonEntity:
          Name:
            NameFull: Brocks, Jochen J.
    IsPartOfRelationships:
      – BibEntity:
          Dates:
            – D: 01
              M: 01
              Text: Jan2018
              Type: published
              Y: 2018
          Identifiers:
            – Type: issn-print
              Value: 01466380
          Numbering:
            – Type: volume
              Value: 115
          Titles:
            – TitleFull: Organic Geochemistry
              Type: main
ResultId 1