排序方式： 共有7条查询结果，搜索用时 15 毫秒
1
1.
S. Derenne C. Largeau E. Casadevall J.S. Sinninghe Damst E.W. Tegelaar J.W. de Leeuw 《Organic Geochemistry》1990,16(4-6)
The kerogen of a sample of Estonian Kukersite (Ordovician) was examined by spectroscopic (solid state 13C NMR, FTIR) and pyrolytic (“off-line”, flash) methods. This revealed an important contribution of long, linear alkyl chains in Kukersite kerogen. The hydrocarbons formed upon pyrolysis are dominated by n-alkanes and n-alk-1-enes and probably reflect a major contribution of selectivity preserved, highly aliphatic, resistant biomacromolecules from the outer cell walls of Gloeocapsomorpha prisca. This is consistent with the abundant presence of this fossilized organism in Kukersite kerogen. In addition high amounts of phenolic compounds were identified in the pyrolysates. Series of non-methylated, mono-, di- and trimethylated 3-n-alkylphenols, 5-n-alkyl-1,3-benzenediols and n-alkylhydroxybenzofurans were identified. All series of phenolic compounds contain long (up to C19), linear alkyl side-chains. Kukersite kerogen is, therefore, an aliphatic type II/I kerogen, despite the abundance of free phenolic moieties. This study shows that phenol-derived moieties are not necessarily associated with higher plant-derived organic matter.The flash pyrolysate of Kukersite kerogen was also compared with that of the kerogen of the Guttenberg Oil Rock (Ordovician) which is also composed of accumulations of fossilized G. prisca. Similarities in the distributions of hydrocarbons and sulphur compounds were noted, especially for the C1–C6 alkylbenzene and alkylthiophene distributions. However, no phenolic compounds were detected in the flash pyrolysate of the Guttenberg kerogen. Possible explanations for the observed similarities and differences are discussed. 相似文献
2.
在青海湖不同盐度的四孔近代沉积物岩芯（Ｑ－１６Ａ，ＱＨ，ＱＥ和ＱＧ）（图１）抽提物支链和环烷烃组分中检出了非常丰富的Ｃ20，Ｃ25和Ｃ30高度支链类异戊二烯烯烃（ｈｉｇｈｌｙｂｒａｎｃｈｅｄｉｓｏｐｒｅｎｏｉｄａｌｋｅｎｅｓ），简称ＨＢＩ烯烃。这是在我国近代湖泊沉积物发现这类化合物的首次详细报导。由于Ｃ20，Ｃ25和Ｃ30ＨＢＩ烯烃比正构烷烃具有较强的抵抗生物降解的能力（ＲｏｂｓｏｎａｎｄＲｏｗｌａｎｄ，１９８８ｂ），因此，它们广泛分布于各种近代环境中，如湖泊、海洋和高盐环境的近代沉积物中（ＲｏｗｌａｎｄａｎｄＲｏｂｓｏｎ，１９９０）。并且，具有１～６个双键的Ｃ20，Ｃ25和Ｃ30烯烃经常是现代沉积物中丰富的烃类。最近在印度洋现代沉积物中又发现了一个新的具有７个双键的Ｃ35ＨＢＩ烯烃（Ｈｏｅｆｓｅｔａｌ，１９９５）。全饱和的Ｃ20（Ｉ，附图）、Ｃ25（Ⅱ，附图）和Ｃ30（Ⅲ，附图）ＨＢＩ烷烃已通过标样的合成确切地确定了它们的结构。在青海湖ＱＧ孔（尕海，咸水）和ＱＥ孔（耳海，淡水）抽提物中发现了Ｃ20单烯（１号峰，图２ａ）。Ｃ25烯烃（２号峰，图２ａ、２ｂ）和Ｃ30烯烃（主要是３号和８号峰，图２ａ、２ｂ）存在于所有四孔沉积物中。 相似文献
3.
Distributions of alkylated chromans and C20 isoprenoid thiophenes were investigated in four organic-matter- and sulfur-rich black shales of Miocene age deposited in the ancient crater lake of the Nördlinger Ries (southern Germany), a meteorite impact crater. Paleosalinity parameters based on these compound classes generally confirm sedimentological evidence of increased salinity over certain periods of the lake's history, but the data from both groups of compounds are not consistent. Diagenetically related molecular constituents were therefore studied to estimate the sensitivity of these parameters. The influence of thiolanes on the isoprenoid thiophene parameter was found to be low, whereas too little is known at present about the origin and diagenetic fate of alkylated chromans to conclude definitely that an alkylated chroman paleosalinity parameter can reliably be applied to a wide range of depositional settings. 相似文献
4.
A saline circuit has been studied as a model of coastal evaporite system. The lipid composition of diverse salt ponds encompassing calcite, gypsum and halite domains has been determined. Most of the lipid materials has been found in the carbonate samples and is related to algal/cyanobacterial debris. Lipids in the gypsum domain are of heterotropic microbialorigin and extreme halophilic bacteria constitute the main lipid contribution in the halite samples. n-Alkane distributions with high predominance of n-docosane constitute a previously described feature of sedimentary evaporitic conditions that is charateristics of the intermediate calcite/gypsum samples. In the calcite domain, the presence of C20 highly branched isoprenid olephines, tetrahymanol and the large amounts of phytol constitute likely precursors of lipids usually found in evaporitic environments (i.e. C20 highly branched isoprenoid alkanes, gammacerane and high phytane/pristane ratios). Their occurence point to dehydration and hydrogenations as two main diagenetic processes leading to the formation of “evaporitic molecular markers”. 相似文献
5.
The theoretical basis for a type of reaction of sulfur-acceptor carbon molecules with donor catenated forms of sulfur is presented. The reactions between conjugated ene carbonyls as sulfur-acceptors and polysulfide as a sulfur donor are described. The scope of this reaction is broadened by demonstrating that the room-temperature action of polysulfide on dienones produces thiophenes. Evidence is given for the structure of 2-benzoyl-5-phenylthiophene, resulting from 1,5-diphenyl-2,4-pentadien-1-one, and 2-acetyl-5-phenylthiophene, resulting from 6-phenyl-3,5-hexadien-2-one. Evidence is also presented for the structure of 2,4-dibenzoyl-3,5-diphenylthiolane, the product resulting from the action of polysulfide on the mixture of benzaldehyde and acetophenone. The same thiolane is shown to result as the minor thiolane component when chalcone reacts with polysulfide in 80% water/20% ethanol. The major component is a known rearranged thiolane identified by its physical properties. The reactiol of chalcone and polysulfide in ethanol at 0 or 25°C results in thiolane formation as evidenced by the isolation of 2,4-dibenzoyl-3,5-diphenylthiolane. However, the reaction of the same two compounds in boiling methanol (65°C) results in a competitive hydrogenation of chalcone giving dihydrochalcone in addition to the formation of thiolane. The demonstration of the low-temperature reaction of polysulfide with conjugated ene carbonyls in the present work adds an additional pathway for possible formation of S-heterocycles in the geosphere. 相似文献
6.
C25 HBI alkenes of the diatom, Haslea ostrearia, have been examined in experiments in which the algae were cultured for up to 10 days at 14–15°C at nine different salinities (15 to 40 per mil). H. ostrearia proved to be an osmotolerant organism and growth was observed at all salinities. After 10 days growth at the lowest and highest salinities of 15 and 40 per mil, the concentrations of 2,10,14-trimethyl-6-methylene-7-(3-methylpent-1-enyl)pentadec-9-ene, which was the only HBI present in any of the samples, averaged 1.2±0.7 and 2.1±0.7 pg cell−1, respectively. These were slightly lower than the HBI concentrations at 25 to 35 per mil (2.8±0.5 pg cell−1). The data indicate that although salinity has an influence on HBI production in H. ostrearia, factors other than salinity are probably more important in controlling the large variations of HBI alkene concentrations and distributions found in sedimentary environments. 相似文献
7.
Series of n-alkyl and isoprenoid thiophenes and thiolanes, most of which have not been previously reported, have been identified in an extract from a Messinian (Upper Miocene) marl layer deposited under hypersaline, euxinic conditions. The identifications were based on mass spectra and Chromatographic data of synthesized reference compounds and on comparison of mass spectra, relative retention times and response on the FPD. Their specific structures and their distribution patterns show similarities with those of the alkanes. Inorganic sulphur is therefore considered to be incorporated into specific lipid moieties from (archae)bacterial and/or algal input during diagenesis. A biosynthetic origin of these compounds is also possible, however. The organic sulphur compounds encountered are thought to be indicators of a hypersaline depositional environment. 相似文献
1