The Occurrence of Oleananes in the Beibuwan Basin and Its Application to the Study of Maturity and Oil-Source Rock Correlation

The oleanane parameter, i.e., OP （oleananes/（oleananes＋C30hopanes）） in the two sedimentary columns of the Beibuwan Basin, South China Sea, can be used to delimit the top of oil generation window, with Ro （/%） of 0.53 in Well M1 and 0.55 in Wells H1/Hd1/Hd2, respectively. Comparing with vitrinite reflectance （Ro/%）, the OP features a dynamic range and can indicate the oil generation window more precisely. By using OP and other geochemical indices, the oil-source correlation is also conducted. It suggests that the oils in wells M1 and M2 are derived from the source rocks in situ. The mudstone in Huachang uplift is not the main source rocks for oils in this area, The OP is also a useful oil-source correlation parameter in some Tertiary lacustrine basins.

Oleanane-triterpene Saponins from Clinopodium urticifolium

Four new oleanane triterpene saponins were isolated and purified from the whole plant of Clinopodium urticifolium. They were 3B 16B, 23, 28-tetrahydroxyoleana-9 (11), 12(13)-diene-3-yl-[B-D-glucopyranosyl-(1-2)]-[B-D-glucopyranosyl-(1-3)]- B-D-fucopyranoside 1; 3B, 16B, 21B, 23, 28-pentahydroxyoleana-9(11), 12(13)-diene-3-yl-[B-D-glucopyranosyl-(1-2)]-[B-D-glucopyranosyl-(1-3)]- B-D-fucopyranoside 2; 3B, 16B, 23, 28-tetrahydroxyoleana-9(11), 12(13)-diene-3-yl-[B-D-glucopyranosyl-(1-6)-B-D-glucopyranosyl-(1-3)]-[B-D-glucopyranosyl-(1-2)]-B-D-fucopyranoside 3; 3B, 16B, 23, 28-tetrahydroxyoleana-9(11), 12(13)-diene-3-yl-[B-D-gluco-pyranosyl-(1-4)-B-D-glucopyranosyl-(1-6)-B-D-glucopyranosyl-(1-3)]-[B-D-glucopyranosyl-(1-2)]- B-D-fucopyranoside 4. Their structures were elucidated on the basis of interpretation of NMR and MS data and from chemical evidence.

Two New Oleanane Saponins from Anemone anhuiensis

Two new oleanane triterpene saponins, named as anhuienside C (1) and D (2), were isolated from the rhizomes of Anemone anhuiensis (Ranunculaceae). The structures of the new compounds were elucidated as 3-O-alpha-L-rhamnopyranosyl (1-->2)-beta-D-xylopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl ester (1) and 3-O-beta-D-xylopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl ester (2), respectively.

A Probable Connection between a Bitumen Sample from the Western Niger Delta and Isan Well Sample from the Lower Cretaceous (Neocomian) Shale

An earlier study of GC-MS analysis on bitumen samples from the Agbabu area in Western Niger Delta showed the significant presence of gammacerane and no Oleanane and is suggested to be generated from the Lower Cretaceous (Neocomian) source rock, however, twelve core samples were obtained from the geological survey of Nigeria for both optical geochemical and biomarker analysis, two of the samples from Isan-9 well indicated the presence of Botryococcus braunii a freshwater alga which is characteristic of a lacustrine lake type environment. The extracts from the same core showed m/z = 191 chromatogram with the significant presence of gammacerane which is diagnostic for stratified water columns and characterizes a typical lake environment. However, the m/z = 191 chromatogram also shows the presence of Oleanane which is diagnostic for vascular plant materials, this doesn’t corroborate with that of the Ise-2 well. The Isan-9 well source rock is suggested to have occurred due to the evolving structural geology of the continental shelf after the onset of the rifting, whereby the dominant lake-type environment in the Early Cretaceous was accompanied by a sediment fill of continental runoffs containing vascular plant materials. This implies that an ancient lacustrine lake system was gradually modified as a result of sedimentary infill. And that the bitumen is sourced from the lower Cretaceous Neocomian source rocks.

New triterpenoid saponins from the leaves of Ilex chinensis and their hepatoprotective activity

Seven new triterpenoid saponins,including five ursane-type saponins,ilexchinenosides R–V(1–5),and two oleananetype saponins,ilexchinenosides W–X(6–7),with four known triterpenoid saponins(8–11)were isolated from the leaves of Ilex chinensis.Their structures were elucidated by comprehensive spectroscopic 1 D and 2 D NMR and HR-ESI-MS data.Their sugar moieties were determined by HPLC analysis compared with standards after hydrolysis and derivatization.Compounds 1,2,4,9 and 10 exhibited potential hepatoprotective activity against N-acetyl-p-aminophenol(APAP)-induced Hep G2 cell injury in vitro.

Novel C15 sesquiterpanes and their origin in different crude oils from the Pearl River Mouth Basin of China

In the saturate fractions of crude oils from the Zhu1 and Zhu2 depressions of the Pearl River Mouth Basin,two novel C_(15) sesquiterpanes have been detected except for drimanes and rearranged drimanes.By comparison with spectra and retention times in previous studies,they have been identified as 2,2,4α,7,8-pentamethyl-trans-decalin and 2,2,4α,7,8-pentamethyl-cis-decalin,respectively,which are related to the D/Eringsof18α(H)-and18β(H)-oleanane.ResultsshowthatthenovelC15sesquiterpanesarerelativelyabundantincondensateoilsthathavehighPr/PhratiosandarerichinterrigenoustriterpanessuchasoleananeandbicadinanesfromtheZhu2depression,butevidentlylowinlacustrineoilsthathavelowPr/Phratiosandarerichin4-methylsteranesfromtheZhu1depression.ThissuggeststhatthenovelC15sesquiterpanescouldberelatedtoterrigenousorganicmatterinoriginandcanhelpdistinguishtheoriginandsourceofcrudeoilsinthestudyarea.Inaddition,thereexistcompletelydifferentcorrelationsbetweentherelativeabundancesofdifferentC15sesquiterpanesthathavedifferentsourcesandthePr/Phratio,whichindicatesredoxconditionsinthecrudeoils.Forexample,thenovelC15sesquiterpanesandcadinanethatindicateterrigenousinputarepositivelycorrelatedwiththePr/Phratio,butdrimanesandrearrangeddrimaneshavingmicrobialoriginarenegativelycorrelatedwiththePr/Phratio.ThisimpliesthattheformationofthenovelC15sesquiterpanesrequiresrelativelyoxicconditions.ThenovelC15sesquiterpanesaremuchmoreabundantincarbonaceousmudstone(Pr/Ph=7.39)thanindarkmudstone(Pr/Ph=2.19)fromtheEnpingformation,althoughtheirorganicmatterishumic.However,theyarenotcommoninsapropeliclacustrinesourcerocks(Pr/Ph=2.29)fromtheWenchangFormation.Thissuggeststhatterrigenousorganicmatterisonlyasufficientcondition,butanoxicenvironmentduringdepositionanddiagenesismaybeaprerequisitefortheformationofnovelC15sesquiterpanes.