5771-67-5Relevant academic research and scientific papers
Development of an enzyme-linked immunosorbent assay for the determination of the linear alkylbenzene sulfonates and long-chain sulfophenyl carboxylates using antibodies generated by pseudoheterologous immunization
Ramon-Azcon, Javier,Galve, Roger,Sanchez-Baeza, Francisco,Marco, M.-Pilar
, p. 71 - 81 (2008/02/12)
ELISA methods have been developed for screening contamination of water resources by linear alkyl benzene sulfonates (LAS) or the most immediate degradation products, the long chain sulfophenyl carboxylates, SPCs. The assay uses antibodies raised through pseudoheterologous immunization strategies using an equimolar mixture of two immunogens (SFA-KLH and 13C13-SPC-KLH) prepared by coupling N-(4-alkylpnenyl)sulfonyl-3-aminopropanoic acid (SFA) andp-(1-carboxy-13-tridecyl)-phenylsulfonic acid (13C13-SPC) to keyhole limpet hemocyanin (KLH). The immunizing haptens have been designed to address recognition versus two different epitopes of the molecule. The SFA hapten maximizes recognition of the alkyl moiety while preserving the complexity of the different alkyl chains present in the LAS technical mixture. The 13C13-SPC hapten addresses recognition of the common and highly antigenic phenylsulfonic group. The antisera raised using this strategy have been shown to be superior to those obtained through homologous immunization procedures using a single substance. By using an indirect ELISA format, LAS and long-chain SPCs can be detected down to 1.8 and 0.2 μg L-1, respectively. Coefficients of variation of 6 and 12% within and between assays, respectively, demonstrate immunoassay reproducibility. The assay can be used in media with a wide range of pH and ionic strength values. Preliminary experiments performed to assess matrix effects have demonstrated the potential applicability of the method as a screening tool to assess contamination by these types of surfactants in natural water samples.
Nitroxyl radical reactions with 4-pentenyl- and cyclopropylketenes: New routes to 5-hexenyl- and cyclopropylmethyl radicals
Allen,Fenwick,Henry-Riyad,Tidwell
, p. 5759 - 5765 (2007/10/03)
4-Pentenylketenes 4a and 9 and cyclopropylketenes 3a, 13, 14 (RCH=C=O) are generated by photochemical Wolff rearrangements and observed by IR as relatively long-lived species at room temperature in hydrocarbon solvents. The reactions of these ketenes with the nitroxyl radicals tetramethylpiperidinyloxyl (TEMPO, TO?) and tetramethylisoindoline-2-oxyl (TMIO, IO?) form carboxy substituted 5-hexenyl and cyclopropylmethyl radicals which are either trapped by a second nitroxyl radical or undergo rearrangements followed by trapping. The rate constant of the reaction of 4a with TEMPO was similar to that of n-BuCH=C=O (1b), while 3a was 4.3 times more reactive, indicating cyclopropyl stabilization of the incipient radical.
ATP-citrate lyase as a target for hypolipidemic intervention. Design and synthesis of 2-substituted butanedioic acids as novel, potent inhibitors of the enzyme
Gribble, Andrew D.,Dolle, Roland E.,Shaw, Antony,McNair, David,Novelli, Riccardo,Novelli, Christine E.,Slingsby, Brian P.,Shah, Virendra P.,Tew, David,Saxty, Barbara A.,Allen, Mark,Groot, Pieter H.,Pearce, Nigel,Yates, John
, p. 3569 - 3584 (2007/10/03)
ATP-citrate lyase is the primary enzyme responsible for the synthesis of cytosolic acetyl-CoA in many tissues. Inhibitors of the enzyme represent a potentially novel class of hypolipidemic agent, which are anticipated to have combined hypocholesterolemic and hypotriglyceridemic properties. A series of 2-substituted butanedioic acids have been designed and synthesized as inhibitors of the enzyme. The best compounds, 58, 68, 71, 74 have reversible K(i)'s in the 1-3 μM range against the isolated rat enzyme. As representative of this compound class, 58, has been shown to exert its inhibitory action through a mainly competitive mechanism with respect to citrate and a noncompetitive one with respect to CoA. None of the inhibitors were able to inhibit cholesterol and/or fatty acid synthesis in HepG2 cells. This has been attributed to the adverse physicochemical properties of the molecules leading to a lack of cell penetration. Despite this, a lead structural class of compound has been identified with the potential for modification into potent, cell-penetrant, and efficacious inhibitors of ATP- citrate lyase.
Novel Ring Cleavage Based on Intermolecular Aldol Condensation
Nagumo, Shinji,Matsukuma, Aki,Suemune, Hiroshi,Sakai, Kiyoshi
, p. 10501 - 10510 (2007/10/02)
Ring cleavage and reconstruction via intramolecular aldol condensation followed by Grob fragmentation under acetalization conditions (BF3/ethylene glycol) was developed into a novel ring cleavage based on intermolecular aldol condensation.On the basis of
Acylcobalt Salophen Reagents. Precursors to Acyl Radical Intermediates for Use in Carbon-to-Carbon Bond-forming Reactions to Alkenes
Coveney, Donal J.,Patel, Vinod F.,Pattenden, Gerald,Thompson, David M.
, p. 2721 - 2729 (2007/10/02)
Acylcobalt salophen reagents (6) are conveniently synthesised from carboxylic acid chlorides following treatment with the sodium derivative (5) produced from reduction of cobalt(II) salophen with sodium amalgam in tetrahydrofuran at room temperature.The acylcobalt salophens (6) undergo homolytic cleavage in the presence of light from a conventional 300 W sunlamp to give acyl radicals (24) which then undergo additions to activated carbon-to-carbon double bonds, leading to enones, viz. (26) , or saturated ketones, viz. (34) .Intramolecular cyclisations of the acylcobalt salophens (42a) and (42b) lead to the ylidenecyclopentanones (43) and (45), respectively.
Regiochemistry of Nucleophilic Opening of β-Substituted Styrene Oxides with Thiolate Anions: Model Experiments in the Synthesis of Leukotriene Analogues
Marples, Brian A.,Saint, Christopher G.,Traynor, John R.
, p. 567 - 574 (2007/10/02)
β-Substituted trans-styrene oxides are cleaved with thiolate anions highly regioselectively by attack at the α-carbon whereas the cis-isomers are cleaved by attack at the α- and β-carbons.Cysteine, in a suitably protected form, similarly cleaves β-substituted trans-styrene oxides, thus allowing the synthesis of a simple LTE model.
