کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5162141 1502275 2015 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Novel saturated hexacyclic C34 and C35 hopanes in lacustrine oils and source rocks
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Novel saturated hexacyclic C34 and C35 hopanes in lacustrine oils and source rocks
چکیده انگلیسی
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 500 m 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 C35 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.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Organic Geochemistry - Volume 87, October 2015, Pages 107-118
نویسندگان
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