Topic
Aromatic hydrocarbon
About: Aromatic hydrocarbon is a research topic. Over the lifetime, 5814 publications have been published within this topic receiving 55499 citations. The topic is also known as: arene & arenes.
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Patent•
08 Mar 1982
TL;DR: A preparation containing an absorption promoter selected from Nacyl amino acid derivatives or N-acyl peptide derivatives represented by the formula: R-CO-A (R is an aliphatic hydrocarbon group, an aromatic hydrocar group or an aryl-substituted lower hydrocarbon groups which may optionally be substituted, and A is an amino acid residue or a peptide residue) is found to promote absorption of the medicine through a gastrointestinal organ such as the colon and rectum, and through the vagina as mentioned in this paper.
Abstract: A preparation containing an absorption promoter selected from N-acyl amino acid derivatives or N-acyl peptide derivatives represented by the formula: R-CO-A (R is an aliphatic hydrocarbon group, an aromatic hydrocarbon group or an aryl-substituted lower hydrocarbon group which may optionally be substituted, and A is an amino acid residue or a peptide residue), preferably in the presence of a salt at a concentation exhibiting higher osmotic pressure than isotonic sodium chloride solution, and a medicine is found to promote absorption of the medicine through a gastrointestinal organ such as the colon and rectum, and through the vagina.
70 citations
TL;DR: Multivariate statistical analysis indicates that there are two significant end members explaining 90% of the total variation among the samples and confirming petrochemical (79.6%), and thermogenic/pyrolytic (10.4%) sources in the PFS model.
Abstract: Particulate fallout samples (PFS) were collected in Alexandria, and their aliphatic and aromatic hydrocarbon compositions were determined both quantitatively and qualitatively to characterize the homologous and biomarker compounds in terms of their original sources. The results show that all samples contain aliphatic hydrocarbons, including n-alkanes, UCM, isoprenoids, tri- and tetracyclic terpanes, hopanes, and steranes/diasteranes. The main source of these compounds is from petrochemical contamination with trace input of terrestrial higher plant wax. In addition, polycyclic aromatic hydrocarbons, which are considered to be combustion products from fossil fuels such as petroleum, are also widely distributed in all samples. Multivariate statistical analysis, including extended Q-mode factor analysis and linear programming technique, was performed in order to reduce the hydrocarbon data set into a meaningful number of end members (sources). This analysis indicates that there are two significant end members explaining 90% of the total variation among the samples and confirming petrochemical (79.6%), and thermogenic/pyrolytic (10.4%) sources in the PFS model. 65 refs., 7 figs., 4 tabs.
70 citations
TL;DR: The mechanism of the RHO reaction by integrating structural information of the NidAB and NidA3B3 enzymes with substrate and product data is examined, giving an understanding of how the model RHO systems of M. vanbaalenii PYR-1 metabolize HMW PAHs.
Abstract: The Rieske nonheme iron aromatic ring-hydroxylating oxygenases (RHOs) NidAB and NidA3B3 from Mycobacterium vanbaalenii PYR-1 have been implicated in the initial oxidation of high-molecular-weight (HMW) polycyclic aromatic hydrocarbons (PAHs), forming cis-dihydrodiols. To clarify how these two RHOs are functionally different with respect to the degradation of HMW PAHs, we investigated their substrate specificities to 13 representative aromatic substrates (toluene, m-xylene, phthalate, biphenyl, naphthalene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, benzo[a]pyrene, carbazole, and dibenzothiophene) by enzyme reconstitution studies of Escherichia coli. Both Nid systems were identified to be compatible with type V electron transport chain (ETC) components, consisting of a [3Fe-4S]-type ferredoxin and a glutathione reductase (GR)-type reductase. Metabolite profiles indicated that the Nid systems oxidize a wide range of aromatic hydrocarbon compounds, producing various isomeric dihydrodiol and phenolic compounds. NidAB and NidA3B3 showed the highest conversion rates for pyrene and fluoranthene, respectively, with high product regiospecificity, whereas other aromatic substrates were converted at relatively low regiospecificity. Structural characteristics of the active sites of the Nid systems were investigated and compared to those of other RHOs. The NidAB and NidA3B3 systems showed the largest substrate-binding pockets in the active sites, which satisfies spatial requirements for accepting HMW PAHs. Spatially conserved aromatic amino acids, Phe-Phe-Phe, in the substrate-binding pockets of the Nid systems appeared to play an important role in keeping aromatic substrates within the reactive distance from the iron atom, which allows each oxygen to attack the neighboring carbons.
70 citations
TL;DR: In this article, a bifunctional Fe/HBeta catalyst was used for catalytic pyrolysis of palm kernel shell waste with a high lignin content of about 50 wt%.
69 citations
Patent•
07 Dec 1982
TL;DR: In this article, a process for alkylating aromatic hydrocarbons with C2 to C4 olefins and for transalkylating alkyls or poly-alkylaromatic compounds with an aromatic hydrocarbon is described.
Abstract: A process for alkylating aromatic hydrocarbons with C2 to C4 olefins and for transalkylating alkyl or poly-alkylaromatic compounds with an aromatic hydrocarbon. A major portion of the aromatic hydrocarbon is recycled to the alkylation zone while the remainder thereof and poly-alkylaromatic hydrocarbons are subjected to transalkylation in a separate transalkylation zone. Mono-alkylaromatics produced in the alkylation zone are separated from the other reaction products prior to transalkylation.
69 citations