Novel saturated hexacyclic C34 and C35 hopanes in lacustrine oils and source rocks

Hans Peter Nytoft; Henrik Ingermann Petersen; Michael Bryld Wessel Fyhn; Lars Henrik Nielsen; Jussi Hovikoski; Ioannis Abatzis

doi:10.1016/j.orggeochem.2015.07.013

Novel saturated hexacyclic C₃₄ and C₃₅ hopanes in lacustrine oils and source rocks

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10 Citations (Scopus)

Abstract

Novel C₃₄ and C₃₅ hexacyclic hopanes having side chains with a pentacyclic or hexacyclic ring at C-22 are abundant in lacustrine oils and source rocks but almost absent from marine oils. The corresponding C₃₄ and C₃₅ hexacyclic hop-17(21)-enes were identified in thermally immature mudstones from Vietnam cored in the 500m deep ENRECA-3 well. All the novel hexacyclic compounds were unambiguously identified by comparison with synthetic standards. Traces of heptacyclic hopanes were detected in a lacustrine oil from Thailand. The C₃₄ and C ₃₅ hexacyclic hopanes have much longer gas chromatography (GC) retention times than the corresponding pentacyclic hopanes. They are isomerized faster at C-22 than the pentacyclic hopanes and their 22S/(22S+22R) ratio values at equilibrium are much higher (0.8 for C₃₄). Precursors could be penta- and hexafunctionalised hopanoids in cyanobacteria and methanotrophs.

Original language	English
Pages (from-to)	107-118
Number of pages	12
Journal	Organic Geochemistry
Volume	87
DOIs	https://doi.org/10.1016/j.orggeochem.2015.07.013
Publication status	Published - 1 Oct 2015

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 14 Life Below Water

Keywords

Biomarkers
Cyanobacteria
GC-MS
Hexacyclic hopanes
Hopanes
HPLC
Lacustrine oils
Methanotrophs

Programme Area

Programme Area 3: Energy Resources

Access to Document

10.1016/j.orggeochem.2015.07.013

Cite this

@article{425632a2c3f84749b14fc0074275726f,

title = "Novel saturated hexacyclic C34 and C35 hopanes in lacustrine oils and source rocks",

abstract = "Novel C34 and C35 hexacyclic hopanes having side chains with a pentacyclic or hexacyclic ring at C-22 are abundant in lacustrine oils and source rocks but almost absent from marine oils. The corresponding C34 and C35 hexacyclic hop-17(21)-enes were identified in thermally immature mudstones from Vietnam cored in the 500m deep ENRECA-3 well. All the novel hexacyclic compounds were unambiguously identified by comparison with synthetic standards. Traces of heptacyclic hopanes were detected in a lacustrine oil from Thailand. The C34 and C 35 hexacyclic hopanes have much longer gas chromatography (GC) retention times than the corresponding pentacyclic hopanes. They are isomerized faster at C-22 than the pentacyclic hopanes and their 22S/(22S+22R) ratio values at equilibrium are much higher (0.8 for C34). Precursors could be penta- and hexafunctionalised hopanoids in cyanobacteria and methanotrophs. ",

keywords = "Biomarkers, Cyanobacteria, GC-MS, Hexacyclic hopanes, Hopanes, HPLC, Lacustrine oils, Methanotrophs",

author = "Nytoft, \{Hans Peter\} and Petersen, \{Henrik Ingermann\} and Fyhn, \{Michael Bryld Wessel\} and Nielsen, \{Lars Henrik\} and Jussi Hovikoski and Ioannis Abatzis",

note = "Publisher Copyright: {\textcopyright} 2015 Elsevier Ltd.",

year = "2015",

month = oct,

day = "1",

doi = "10.1016/j.orggeochem.2015.07.013",

language = "English",

volume = "87",

pages = "107--118",

journal = "Organic Geochemistry",

issn = "0146-6380",

publisher = "Elsevier",

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TY - JOUR

T1 - Novel saturated hexacyclic C34 and C35 hopanes in lacustrine oils and source rocks

AU - Nytoft, Hans Peter

AU - Petersen, Henrik Ingermann

AU - Fyhn, Michael Bryld Wessel

AU - Nielsen, Lars Henrik

AU - Hovikoski, Jussi

AU - Abatzis, Ioannis

PY - 2015/10/1

Y1 - 2015/10/1

N2 - Novel C34 and C35 hexacyclic hopanes having side chains with a pentacyclic or hexacyclic ring at C-22 are abundant in lacustrine oils and source rocks but almost absent from marine oils. The corresponding C34 and C35 hexacyclic hop-17(21)-enes were identified in thermally immature mudstones from Vietnam cored in the 500m deep ENRECA-3 well. All the novel hexacyclic compounds were unambiguously identified by comparison with synthetic standards. Traces of heptacyclic hopanes were detected in a lacustrine oil from Thailand. The C34 and C 35 hexacyclic hopanes have much longer gas chromatography (GC) retention times than the corresponding pentacyclic hopanes. They are isomerized faster at C-22 than the pentacyclic hopanes and their 22S/(22S+22R) ratio values at equilibrium are much higher (0.8 for C34). Precursors could be penta- and hexafunctionalised hopanoids in cyanobacteria and methanotrophs.

AB - Novel C34 and C35 hexacyclic hopanes having side chains with a pentacyclic or hexacyclic ring at C-22 are abundant in lacustrine oils and source rocks but almost absent from marine oils. The corresponding C34 and C35 hexacyclic hop-17(21)-enes were identified in thermally immature mudstones from Vietnam cored in the 500m deep ENRECA-3 well. All the novel hexacyclic compounds were unambiguously identified by comparison with synthetic standards. Traces of heptacyclic hopanes were detected in a lacustrine oil from Thailand. The C34 and C 35 hexacyclic hopanes have much longer gas chromatography (GC) retention times than the corresponding pentacyclic hopanes. They are isomerized faster at C-22 than the pentacyclic hopanes and their 22S/(22S+22R) ratio values at equilibrium are much higher (0.8 for C34). Precursors could be penta- and hexafunctionalised hopanoids in cyanobacteria and methanotrophs.

KW - Biomarkers

KW - Cyanobacteria

KW - GC-MS

KW - Hexacyclic hopanes

KW - Hopanes

KW - HPLC

KW - Lacustrine oils

KW - Methanotrophs

UR - https://www.scopus.com/pages/publications/84952639297

U2 - 10.1016/j.orggeochem.2015.07.013

DO - 10.1016/j.orggeochem.2015.07.013

M3 - Article

SN - 0146-6380

VL - 87

SP - 107

EP - 118

JO - Organic Geochemistry

JF - Organic Geochemistry

ER -