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Application of liquid chromatography-electrospray-tandem mass spectrometry for the identification and characterisation of linear alkylbenzene sulfonates and sulfophenyl carboxylates in sludge-amended soils.

A novel procedure was developed for the simultaneous determination of linear alkylbenzene sulfonates (LAS) and their major metabolites, sulfophenyl carboxylates (SPC), in sludge-amended soil. After pressurised liquid extraction with methanol/water (90:10) and a clean-up on C18 solid-phase extraction cartridges, final analysis was done by ion-pair liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS/MS). With this method, SPC with 5-13 carbon atoms in the aliphatic side chain were identified for the first time in agricultural soils treated with sewage sludge. Quantification of LAS and SPC in soil from 10 field sites, which differed in the history of sludge application, gave total concentrations of 120-2840 microg kg(-1) for LAS and of 4-220 microg kg(-1) for SPC. The data provided evidence for rapid biodegradation of LAS in the initial phase after sludge amendment with a transitory build-up of high concentrations of, mainly, short-chain SPC. Trace amounts of residual LAS and SPC were detected in soils having received the last sludge treatment 10 days to 4 years prior to sampling.

Carboxylic Acids↗

Synthesis of 9-acridinyl sulfur derivatives: sulfides, sulfoxides and sulfones. Comparison of their activity on tumour cells.

The synthesis of several acridine thioethers is described. These compounds were oxidized to give new sulfoxides and sulfones. Among 23 compounds prepared, 19 were tested in vitro against the human cancer cell lines panel of NCI screening. Activity is increased 5-10 times from sulfides to sulfoxides. Among substituted groups in the side chain, sulfur mustard, epoxy sulfide and sulfoxide displayed the most interesting activity.

Antineoplastic Agents↗

Preliminary screening of perfluorooctane sulfonate (PFOS) and other fluorochemicals in fish, birds and marine mammals from Greenland and the Faroe Islands.

Extensive screening analyses of perfluorooctane sulfonate (PFOS) and related perfluorinated compounds in biota samples from all over the world have identified PFOS as a global pollutant and have shown its bioaccumulation into higher trophic levels in the food chain. Perfluorinated compounds have been found in remote areas as the Arctic. In this study a preliminary screening of PFOS and related compounds has been performed in liver samples of fish, birds and marine mammals from Greenland and the Faroe Islands. PFOS was the predominant fluorochemical in the biota analyzed, followed by perfluorooctane sulfonamide (PFOSA). PFOS was found at concentrations above LOQ (10 ng/g wet weight) in 13 out of 16 samples from Greenland and in all samples from the Faroe Islands. The results from Greenland showed a biomagnification of PFOS along the marine food chain (shorthorn sculpin < ringed seal < polar bear). The greatest concentration of PFOS was found in liver of polar bear from east Greenland (mean: 1285 ng/g wet weight, n = 2). The geographical distribution of perfluorinated compounds in Greenland was similar to that of persistent organohalogenated compounds (OHCs), with the highest concentrations in east Greenland, indicating a similar geographical distribution to that of OHCs, with higher concentrations in east Greenland than in west Greenland.

Alkanesulfonic Acids↗

Anti-HIV-1 activity of pyrryl aryl sulfone (PAS) derivatives: synthesis and SAR studies of novel esters and amides at the position 2 of the pyrrole nucleus.

A SAR study has been performed in order to evaluate how much the ester function could be a determinant for the anti-human immunodeficiency virus type-1 activity of pyrryl aryl sulfones (PASs), a potent family of non-nucleoside reverse transcriptase (RT) inhibitors discovered in the last years. Twenty-three new esters were prepared with the aim to enhance the inhibitory potency of 4a and 4c, two PAS agents endowed with good activity (EC50 = 0.14 microM) and deprived of cytotoxicity up to >200 microM. None of test derivatives was as potent as 4a and 4c and lacked of selectivity due to their higher cytotoxicity (compounds 22-25). Antiviral activity correlate with an ester ramified chain.

Amides↗

Effect of temperature on alpha olefin sulfonate induced softening of gelatin hydrogels.

Dynamic light scattering (DLS) and oscillatory rheology experiments were performed to study temperature dependence (T=10-25 degrees C) of the interactions in hydrogels of gelatin with AOS (alpha olefin sulfonate, anionic surfactant) for surfactant concentrations in the range 25-100 mM, chosen larger than cmc (approximately 8mM). The network mesh size (xi) values deduced from fastmode diffusivity (D(f)) data obtained from dynamic structure factor measurements, S(q, t) approximately exp(-D(f)q(2)t) (for t<or=1 ms and q being the scattering wave vector), of micelle-bound gelatin gels was analyzed within the framework of Flory-Rhener theory of cross-linking, which revealed a temperature dependence, xi approximately (0.5-chi)(1/5)exp(-DeltaG(Total)/RT) where chi is the Flory-Huggins interaction parameter, the free-energy of the gel-surfactant complex is DeltaG(Total) and R is universal gas constant. The low-frequency isochronal storage, G' and loss, G'' modulii revealed a transition from the rigid to a softened gel state occurring at surfactant concentration close to 55 mM, independent of temperature. The free-energy of interaction between gel and surfactant deduced from Arrhenius plots obtained from temperature dependent rheology, and light scattering data support this observation.

Alkenes↗

Synthesis and characterization of a new cutinase substrate, 4-nitrophenyl (16-methyl sulfone ester) hexadecanoate.

Phytopathogenic fungi penetrate plants by breaking down the cuticular barrier with cutinase. Cutinases are extracellular hydrolytic enzymes that degrade cutin, a polyester composed of hydroxy and epoxy fatty acids. Until now, cutinase has been recognized by its ability to release labeled cutin monomers or by a non-specific esterase assay based on the hydrolysis of p-nitrophenyl esters of short fatty acids. In this work, an insoluble p-nitrophenyl derivative was synthesized and purified, and its structure was determined to be 4-nitrophenyl (16-methyl sulfone ester) hexadecanoate (pNMSEH) by nuclear magnetic resonance (H+ NMR) analysis. pNMSEH was tested as a new cutinase substrate with Pseudomonas mandocino cutinase and porcine liver esterase. While a linear release over time of p-nitrophenol (pNP) was recorded in the presence of cutinase, no response was obtained with the esterase. The calculated kinetic parameters of pNMSEH hydrolysis by cutinase revealed a high specificity (Km=1.8mM), albeit a low catalytic rate (Vmax=10.5 micromol min(-l)l(-1)). This new synthetic substrate may be helpful for detecting and assaying cutinase activity in mixed solutions, such as crude fungal extracellular extracts.

Animals↗

Pseudouridine detection improvement by derivatization with methyl vinyl sulfone and capillary HPLC-mass spectrometry.

A method is presented for improved detection of pseudouridine in nucleoside mixtures based on the specific derivatization with methyl vinyl sulfone followed by analysis by capillary HPLC-mass spectrometry. Reaction conditions were optimized in order to obtain the best yield and specificity. The method was successfully applied to different nucleoside mixtures.

Chromatography, High Pressure Liquid↗

The solubility of ethane, propane, and carbon dioxide in aqueous solutions of sodium cumene sulfonate.

Measurements have been made to determine the solubilities of ethane, C2H6, propane, C3H8, and carbon dioxide, CO2, in aqueous solutions of sodium cumene sulfonate (NaCS) at 25 degrees C. The solubilities measured for each gas satisfy Henry's law at all concentrations of NaCS. The solubilities of C2H6 and C3H8 exhibit quite similar behavior with respect to added NaCS. The solubilities of these two gases are very low in pure water and are found to be nearly independent of NaCS concentration over a concentration range of 0-0.4 mol NaCS/kg H2O. At intermediate concentrations of NaCS, the solubilities of C2H6 and C3H8 exhibit a gradual increase with added NaCS concentrations ranging from 0.4 to 2.0 mol NaCS/kg H2O. At NaCS concentrations greater than 2.0 mol NaCS/kg H2O, the solubilities of these two gases increase with added NaCS in an approximately linear manner, with the solubility of C3H8 increasing more rapidly than that for C2H6 (by a factor of approximately 2.5). CO2 is much more soluble in pure water than the hydrocarbon gases and exhibits markedly different behavior with respect to added NaCS. The solubility of CO2 decreases with added NaCS over a concentration range of 0-0.9 mol NaCS/kg H2O, passes through a minimum at a concentration of approximately 1.0 mol NaCS/kg H2O, and then increases with added NaCS at higher NaCS concentrations in a manner similar to that observed with C2H6 and C3H8. The trends in solubility observed for these three gases dissolved in aqueous solutions of NaCS resemble those found previously with aqueous solutions of ordinary surfactants. The solubility data measured for these three gases can be interpreted surprisingly well in terms of the mass-action model for micellization, in which salting-out effects due to monomer salt ions suppress gas solubility at low NaCS concentrations and gas solubilization by small micelles of NaCS acts to enhance gas solubility at the higher NaCS concentrations.

Benzene Derivatives↗

Adsorption characteristics of aniline and 4-methylaniline onto bifunctional polymeric adsorbent modified by sulfonic groups.

In this paper a new bifunctional polymeric resin (LS-2) was synthesized by introducing sulfonic groups onto the surface of the resin during the post-crossing of chloromethyl low crosslinking macroporous poly-styrene resin, and the comparison of the adsorption properties of LS-2 with Amberlite XAD-4 toward aniline and 4-methylaniline in aqueous solutions was made. The study focuses on the static equilibrium adsorption behaviors, the adsorption thermodynamics, and the column dynamic adsorption and desorption profiles. Freundlich model gives a perfect fitting to the isotherm data. Although the specific surface area of LS-2 is lower than that of Amberlite XAD-4, the adsorbing capacities for these two adsorbates on LS-2 are higher than those on Amberlite XAD-4 within the temperature range 288-318 K, which is contributed to microporous structure and the polar groups on the network of LS-2 resins. The adsorption for aniline or 4-methylaniline on LS-2 was proved to be an endothermic process and increasing temperature was favorable. From the studies on the adsorption thermodynamics, static equilibrium adsorption, and the desorption conditions, an important conclusion can be drawn that the adsorption for aniline or 4-methylaniline on the LS-2 is a coexistence process of physical adsorption and chemical transition.

Adsorption↗

Detoxification-driven recovery of nitrogen removal under high linear alkylbenzene sulfonate stress by immobilized Pseudomonas sp. LM2.

Linear alkylbenzene sulfonate (LAS) is a widely used anionic surfactant that can inhibit microbial activity and destabilize biological wastewater treatment systems under high loading conditions. In this study, a sequencing batch reactor (SBR) was exposed to increasing LAS concentrations (0-100&#x202f;mg/L) to define the collapse trajectory of activated sludge and evaluate recovery following bioaugmentation with immobilized Pseudomonas sp. LM2. The system remained stable at 20&#x202f;mg/L LAS, deteriorated after prolonged exposure to 50&#x202f;mg/L, and developed severe sludge disintegration with near-complete nitrification failure at 100&#x202f;mg/L. In the LM reactor, LAS removal increased from 25.4% to 53.1% after bioaugmentation, together with improved nitrogen-removal performance. Blank carriers did not restore reactor performance. Genome annotation showed that LM2 encoded genes associated with LAS degradation and denitrification but lacked nitrification genes. Thus, the observed nitrification recovery was likely indirect and associated with lower LAS stress and recovery of indigenous nitrifiers. Quantitative PCR and amplicon analyses showed enrichment of Nitrospira and Thauera and a shift toward more deterministic community assembly after bioaugmentation. The carrier-only control showed taxonomic recovery but persistent functional inhibition under high residual LAS exposure. Overall, the results indicate that immobilized bioaugmentation can support partial recovery of nitrogen removal under severe LAS stress.

Bioaugmentation↗

Spectroscopic studies of inclusion complexes of 1-naphthol-4-sulfonate with beta-cyclodextrin in aqueous solution.

The photophysical properties of 1-naphthol-4-sulfonate (1N4S) in some solvents and in aqueous beta-cyclodextrin solution have been investigated. The effect of beta-cyclodextrin on the fluorescence quantum yield and on the proton transfer is examined. Fluorescence measurements show 1:1 inclusion of 1N4S in the beta-cyclodextrin cavity with an association constant of 108M(-1). NMR studies are used to study the inclusion phenomena and to provide information on the geometry of 1N4S inside the cavity of beta-cyclodextrin.

Hydrogen-Ion Concentration↗

FT-IR, FT-Raman and SERS spectra of pyridine-3-sulfonic acid.

FT-IR and FT-Raman spectra of pyridine-3-sulfonic acid are recorded and analysed. Surface enhanced Raman scattering (SERS) spectrum is recorded in a silver colloid. The bands due to upsilonCH, upsilonSO are enhanced in the SERS spectrum. A likely 'perpendicular orientation' of the molecule on the silver surface is suggested.

Colloids↗

Spectrofluorimetric study on the inclusion interaction between lomefloxacin and p-sulfonated calix[4]arene and its analytical application.

The characteristics of host-guest complexation between p-sulfonated calix[4]arene (SC4A) and lomefloxacin (LMFX) were investigated by fluorescence spectrometry. A 1:1 stoichiometry for the complexation was established and an association constant of 6.48x10(4) l mol-1 at 25 degrees C was calculated by applying a deduced equation. The interaction mechanism of the inclusion complex was discussed and the various factors affecting the inclusion process were examined in detail. It was found that an appropriate amount of cationic surfactant cetyltrimethylammonium bromide (CTAB) can remarkably enhance the fluorescence intensity of the supramolecular complex system. Based on the obtained results, a novel sensitive spectrofluorimetric method for the determination of lomefloxacin based on supramolecular complex was developed with a linear range of 0.01-3.0 microg ml-1 and a detection limit of 0.008 microg ml-1, for the first time. The method was applied for the determination of lomefloxacin in pharmaceutical preparations successfully.

Calixarenes↗

Study on the fluorescence behavior of p-sulfonated calix[4,6]arene in cationic surfactant cetyltrimethylammonium bromide solution and its analytical application.

The fluorescence properties of p-sulfonated calix[4,6]arene (SCnA, n=4, 6) in cationic surfactant cetyltrimethylammonium bromide (CTAB) solution were investigated. It was found that the fluorescence intensity of SCnA could be enhanced markedly by an appropriate amount of CTAB. The results indicate the formation of complex between CTAB and SCnA at a 1:1 complex stoichiometry and their association constants were calculated by applying a deduced equation. Based on the obtained results, a new fluorimetric method has been developed for rapid determination of SCnA with a good linearity in the concentration range of 2x10(-7) to 7x10(-6)mol L-1.

Buffers↗

Inclusion complex of 2-naphthylamine-6-sulfonate with beta-cyclodextrin: intramolecular charge transfer versus hydrogen bonding effects.

The photophysical characteristics of the ground and excited states of 2-naphthylamine-6-sulfonate (2-NA-6-S) were investigated in different solvents and in beta-cyclodextrin (beta-CD). The spectral shifts are well correlated with Kamlet-Taft relationship. Multiple linear regression analysis indicated that both non-specific dipolar interaction and specific hydrogen bonding interactions play competitive roles in determining the position of the absorption maximum, while the dipolar interaction is the dominating parameter in determining the emission maximum. For the Stokes shift, both the nonspecific interaction and the hydrogen donation property of the solvent are participating equally. The molecular encapsulation of 2-NA-6-S by beta-CD in aqueous solution has been studied by different spectroscopic techniques. Fluorescence measurements show that the dielectric constant of beta-CD experienced by the included 2-NA-6-S is intermediate between water and methanol. The changes observed in the absorption and fluorescence spectra of 2-NA-6-S upon inclusion in beta-CD allowed the association constant to be calculated and found to be 465+/-100 and 495+/-100 M-1, respectively. The changes observed for the chemical shifts of 2-NA-6-S and beta-CD 1H NMR spectra and the corresponding 1H NMR spectra of their mixture confirmed the formation of the inclusion complex and showed that 2-NA-6-S is encapsulated in beta-CD cavity in a tilted equatorial approach.

Deuterium Oxide↗

Synthesis of 7-(2,4-dichlorophenyl)-D-erythro-3-hydroxy-5-heptanolide, 6-(2,4-dichlorophenyl)-D-erythro-2,4-dihydroxyhexane-1-sulfonic acid, and 6-(2,4-dichlorophenyl)-D-erythro-2,4-dihydroxyhexylphosphonic acid.

6-(2,4-Dichlorophenyl)-D-erythro-1,2,4-hexanetriol, synthesised from D-glucose, was partially silylated, then reacted with 2-methoxypropene to afford 1-O-tert-butyldimethylsilyl-6-(2,4- dichlorophenyl)-2,4-O-isopropylidene-D-erythro-1,2,4-hexanetriol (17). Desilylation of 17 gave 6-(2,4-dichlorophenyl)-2,4-O-isopropylidene-D- erythro-1,2,4-hexanetriol, which was converted into the 1-tosylate 18 and the 1-bromo derivative 19. Reaction of 18 with potassium thiolbenzoate gave, after debenzoylation, oxidation, and deprotection, 6-(2,4-dichlorophenyl)-D-erythro-2,4-dihydroxyhexane-1-sulfonic acid (4). Reaction of 18 or 19 with triethyl phosphite gave, after deprotection, 6-(2,4-dichlorophenyl)-D-erythro-2,4-dihydroxyhexyl-phosphonic acid (5), and reaction of 19 with potassium cyanide gave, after subsequent hydrolysis and deprotection, 7-(2,4-dichlorophenyl)-D-erythro-3-hydroxy-5-heptanolide (3).

Hydroxymethylglutaryl-CoA Reductase Inhibitors↗

Sulfonate protecting groups. Regioselective sulfonylation of myo-inositol orthoesters-improved synthesis of precursors of D- and L-myo-inositol 1,3,4,5-tetrakisphosphate, myo-inositol 1,3,4,5,6-pentakisphosphate and related derivatives.

The regioselectivity of sulfonylation of myo-inositol orthoesters was controlled by the use of different bases to obtain the desired sulfonate. Monosulfonylation of myo-inositol orthoesters in the presence of one equivalent of sodium hydride or triethylamine resulted in the sulfonylation of the 4-hydroxyl group. The use of pyridine as a base for the same reaction resulted in sulfonylation of the 2-hydroxyl group. Disulfonylation of these orthoesters in the presence of excess sodium hydride yielded the 4,6-di-O-sulfonylated orthoesters. However, the use of triethylamine or pyridine instead of sodium hydride yielded the 2,4-di-O-sulfonylated orthoester. Sulfonylated derivatives of myo-inositol orthoesters were stable to conditions of O-alkylation but were cleaved using magnesium/methanol or sodium methoxide in methanol to regenerate the corresponding myo-inositol orthoester derivative. These new methods of protection-deprotection have been used: (i) for the efficient synthesis of enantiomers of 2,4-di-O-benzyl-myo-inositol, which are precursors for the synthesis of D- and L-myo-inositol 1,3,4,5-tetrakisphosphate; (ii) for the preparation of 2-O-benzyl-myo-inositol which is a precursor for the preparation of myo-inositol 1,3,4,5,6-pentakisphosphate.

Crystallography, X-Ray↗

Sulfonated acrylamide copolymers as pseudo-stationary phases in electrokinetic chromatography.

Sulfonated copolymers were synthesized, characterized and used as separation media in electrokinetic chromatography. The polymers used were synthesized from AMPS (2-acrylamido-2-methyl-1-propanesulfonic acid) and LMAm (lauryl methacrylamide) in different mole ratios (from 100:0 to 60:40). Electrophoretic mobilities and methylene selectivities were calculated, which showed the expected correlation with the monomer ratios. The chemical selectivities for the separation of nine solutes by the copolymers were compared with that of sodium lauryl sulfate micelles, showing significant differences. No significant difference in chemical selectivities was observed for copolymers with different monomer ratios. No significant change of hydrophobic microdomain of copolymers was found in background buffers with different ionic strength values, based on the investigation of the retention factors, methylene selectivities and polymer effective mobilities. No change of hydrophobic microdomain of the copolymer solutions was found at copolymer concentrations from 0.17 to 3% (w/v), however, plots of k' versus polymer concentration suggested a different copolymer phase at lower concentrations (from 0 to 0.1%, w/v) from that at higher concentrations (from 0.17 to 3%, w/v). The copolymer with AMPS-LMAm (80:20) could be chosen as optimum copolymer as far as the methylene selectivity, peak symmetry and polymer mobility were concerned.

Acrylamides↗