Thomas S. Bianchi and Elizabeth A. Canuel
- Published in print:
- 2011
- Published Online:
- October 2017
- ISBN:
- 9780691134147
- eISBN:
- 9781400839100
- Item type:
- chapter
- Publisher:
- Princeton University Press
- DOI:
- 10.23943/princeton/9780691134147.003.0009
- Subject:
- Biology, Ecology
This chapter discusses several classes of cyclic isoprenoids and their respective derivatives, which have proven to be important biomarkers that can be used to estimate algal and vascular plant ...
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This chapter discusses several classes of cyclic isoprenoids and their respective derivatives, which have proven to be important biomarkers that can be used to estimate algal and vascular plant contributions as well as diagenetic proxies. Sterols are a group of cyclic alcohols (typically between C26 and C30) that vary structurally in the number, stereochemistry, and position of double bonds as well as methyland ethyl-group substitutions on the side chain. Sterols are biosynthesized from isoprene units using the mevalonate pathway and are classified as triterpenes (i.e., consisting of six isoprene units). Marine organisms such as phytoplankton and zooplankton tend to be dominated by C27 and C28 sterols, while vascular plants have been shown to have a relatively high abundance of C29 sterols. The chapter shows that although C29 sterols are considered to be the dominant sterols found in vascular plants, these compounds may be present in certain epibenthic cyanobacteria and phytoplanktonic species, indicating that these compounds represent a very diverse and powerful suite of chemical biomarkers in aquatic ecosystems.Less
This chapter discusses several classes of cyclic isoprenoids and their respective derivatives, which have proven to be important biomarkers that can be used to estimate algal and vascular plant contributions as well as diagenetic proxies. Sterols are a group of cyclic alcohols (typically between C26 and C30) that vary structurally in the number, stereochemistry, and position of double bonds as well as methyland ethyl-group substitutions on the side chain. Sterols are biosynthesized from isoprene units using the mevalonate pathway and are classified as triterpenes (i.e., consisting of six isoprene units). Marine organisms such as phytoplankton and zooplankton tend to be dominated by C27 and C28 sterols, while vascular plants have been shown to have a relatively high abundance of C29 sterols. The chapter shows that although C29 sterols are considered to be the dominant sterols found in vascular plants, these compounds may be present in certain epibenthic cyanobacteria and phytoplanktonic species, indicating that these compounds represent a very diverse and powerful suite of chemical biomarkers in aquatic ecosystems.