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This article discusses the development of a practical method for Fischer indolization, a commonly used synthetic approach in chemistry. The researchers used bench-stable sodium arylhydrazine sulfonates as a substitute for arylhydrazine, which is typically used in Fischer indolization. The sodium arylhydrazine sulfonates were easily obtained from substituted anilines and could be used directly in the reaction without further purification. The method was successful in synthesizing various tetrahydrocarbazoles and tryptamine-based pharmaceutical molecules. The researchers believe that this method has potential applications in the synthesis of indole-based pharmaceutical compounds. [Extracted from the article]

cis-5-Arylpyrrolidine-2-carboxylates, obtained by 1,3-dipolar cycloaddition reactions from glycine aryl aldimines and vinyl sulfones, undergo oxidative aromatization under the action of Mn(IV) oxide to form the corresponding 5-arylpyrrole-2-carboxylates in high yields. Factors responsible for the retention of the sulfonyl substituent in the pyrrole backbone were determined. [ABSTRACT FROM AUTHOR]

In this work, a mineralogical study and thermal decomposition analysis of jarosite residue sample from a zinc plant were carried out. The mineralogical analysis showed that the jarosite residue is mainly composed of four components, including jarosites, sulfates–hydroxides, sulfides and spinel. The distribution of relevant metallic elements in these components was characterized using a sequential extraction process. The X-ray diffraction results showed that AFe3(OH)6(SO4)2 and ZnFe2O4 are the main components of the jarosite residue sample. The thermal decomposition mechanisms of ammoniojarosite and sodium jarosite were studied by TG-DSC (Thermogravimetric analysis–differential scanning calorimetry). The thermal decomposition process and the corresponding mechanism of the jarosite residue were analyzed. The jarosite thermal decomposition process includes the removal of crystal water, dihydroxylation and deammoniation, desulfonation of component jarosite and desulfonation of component zinc sulfate. [ABSTRACT FROM AUTHOR]

We have developed a highly N 2-regioselective method for direct construction of amide bond from N -sulfonyl-1,2,3-triazoles and carboxylic acids in the presence of bases at 60 °C in air. The developed reaction provides the corresponding products with high yields (up to 90 %) and a broad substrate compatibility including aryl acids, heterocyclic acids, and alkyl acids. Mechanistic studies show that the reaction proceeds through a direct nucleophilic attack of N -sulfonyl-1,2,3-triazoles to carboxylate anions via a base- and water-involved synergistic desulfonation process. This work presents an unusual water-involved example for direct synthesis of amides utilizing readily available starting materials under mild conditions. [Display omitted] • Direct construction of amide bonds from N -sulfonyl azoles and carboxylic acids under mild conditions. • The developed reaction provides high yields (up to 90%) of the corresponding products with broad substrate compatibility. • This reaction is facilitated by a synergistic water- and base-involved desulfonation process. [ABSTRACT FROM AUTHOR]

In this work, a mineralogical study and thermal decomposition analysis of jarosite residue sample from a zinc plant were carried out. The mineralogical analysis showed that the jarosite residue is mainly composed of four components, including jarosites, sulfates–hydroxides, sulfides and spinel. The distribution of relevant metallic elements in these components was characterized using a sequential extraction process. The X-ray diffraction results showed that AFe3(OH)6(SO4)2 and ZnFe2O4 are the main components of the jarosite residue sample. The thermal decomposition mechanisms of ammoniojarosite and sodium jarosite were studied by TG-DSC (Thermogravimetric analysis–differential scanning calorimetry). The thermal decomposition process and the corresponding mechanism of the jarosite residue were analyzed. The jarosite thermal decomposition process includes the removal of crystal water, dihydroxylation and deammoniation, desulfonation of component jarosite and desulfonation of component zinc sulfate.

[Display omitted] • The mechanism of flavin MsuD monooxygenase was studied by DFT calculations. • Mechanism A, involving FlN 5 -OO− with O 2 bound at the flavin N 5 atom, is feasible. • It involves electron transfer, N O formation, proton transfer, and O O cleavage. • Mechanism B containing FlC 4 -OO− is ruled out, due to inaccessible hydroxy rebound. • Both FlN 5 -OO− and FlC 4 -OO− intermediates may appear in the MsuD reaction. MsuD, a flavin-dependent monooxygenase, catalyzes the conversion of methanesulfonate (MS−) into formaldehyde and sulfite, playing a crucial role in the organic sulfur cycle. Using density functional calculations, we have demonstrated that the MsuD reaction uses mechanism A involving a FlN 5 -OO− intermediate. It mainly includes electron transfer from the N 5 atom of deprotonated reduced flavin to O 2 , N O bond formation yielding FlN 5 -OO−, deprotonation of MS− methyl by FlN 5 -OO− forming FlN 5 -OOH and MS2− carbanion, and hydroxy rebound from FlN 5 -OOH to MS2− accompanying with immediate C S bond dissociation producing sulfite and formaldehyde. In contrast, mechanism B containing FlC 4 -OO− is ruled out due to the inaccessible hydroxy rebound from FlC 4 -OOH to MS2−, although the FlC 4 -OO− species, a common intermediate in the family of flavin-dependent monooxygenases, may also appear in MsuD. Our research provides insights into the enzymatic C S bond cleavage and confirms the potential of the flavin N 5 site to facilitate various chemical reactions. [ABSTRACT FROM AUTHOR]

The presence of the sulfonic acid group in sulfonated anthraquinones (SAs) resulted in the difficulty in the mineralization of anthraquinone ring. Little information is available on the removal pathway of the sulfonic acid group of SAs under aerobic/anaerobic conditions. Herein, sodium 1-aminoanthraquinone-2-sulfonate (ASA-2) was used as an important intermediate of SAs. A novel Pseudomonas nitroreducens WA capable of ASA-2 desulfonation was isolated from the Reactive Blue 19-degrading consortium WRB. Anaerobic desulfonation efficiency of 0.165 mM ASA-2 by strain WA reached 99% in 36 h at pH 7.5 and 35 ℃ using glucose as an electron donor. Further analysis showed that ASA-2 as an electron acceptor could be anaerobically transformed into 1-aminoanthraquinone and sulfite via the cleavage of C-S bond. Strain WA could also desulfonate sodium 1-amino-4-bromoanthraquinone-2-sulfonate and sodium anthraquinone-2-sulfonate. Under denitrification conditions, the formed sulfite could be oxidized to sulfate by nitrite via a chemical reaction, which was beneficial for nitrite removal. This phenomenon was observed in consortium WRB-amended system. Moreover, the consortium WRB could reduce the formed sulfite to sulfide due to the presence of Desulfovibrio. These results provide a theoretical basis for the anaerobic biodesulfonation of SAs along with nitrate removal and support for the development of sulfite-based biotechnology. [Display omitted] • A novel Pseudomonas nitroreducens WA capable of ASA-2 desulfonation was isolated. • ASA-2 was transformed into AAQ-1 and sulfite via the cleavage of C-S bond. • Strain WA could utilize ASA-2 as an electron acceptor to produce more ATP. • The formed sulfite could be oxidized to sulfate by nitrite via a chemical reaction. • Consortium WRB containing Desulfovibrio reduced sulfite to sulfide. [ABSTRACT FROM AUTHOR]

To utilize the lignin generated by the paper industry and reduce the cost of poly(lactic acid) (PLA), PLA/lignin composites were prepared from PLA and different ratios of lignosulfonate (LS) or desulfonated lignosulfonate (DLS) particles using a casting method. The physicochemical properties of the lignins were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation-high performance liquid chromatography (GPC), and elementary analysis. The results indicate that the sulfur content of the original LS was successfully reduced to half by desulfonation to produce DLS, which was found to have a higher thermal stability and a lower average molecular weight than LS. Additionally, the thermal stability, crystallization, compatibility, mechanical, hydrophobicity, and optical properties of the PLA/lignin composites were also meticulously evaluated. Comparison of the PLA/DLS and PLA/LS composites revealed that the incorporation of DLS into PLA improved compatibility, thermal stability (T5% and Tmax), and hydrophobicity, while the mechanical properties remained almost unchanged. In addition, both PLA/DLS and PLA/LS exhibited UV light absorption capacity. Finally, the low-rate addition of both LS (10%) and DLS (5%) accelerated the crystallization of PLA, but crystallization was delayed with higher lignin content. [ABSTRACT FROM AUTHOR]

The linear low-density polyethylene (LLDPE) fibers were sulfonated in 95 % concentrated sulfuric acid. The structure composition and thermal stability of the polyethylene (PE) fibers sulfonated for various times were determined by Fourier transform infrared spectroscopy (FTIR), resonance Raman spectra, elemental analysis, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). It was confirmed that substitution, oxidation and desulfonation took place in succession during sulfonation. The initial increase of sulfonic acid and hydroxyl groups, as an indication of the substitution reaction, led to a proposal that the reaction was initiated by the abstraction of hydrogen by HSO to give PE radical, which reacted with HSO to give HSO· and HO· radical, and terminated by the formation of PE-SOH and PE-OH. The subsequent decrease of hydroxyl groups and generation of carbonyl groups were attributed to the oxidation reaction. The formation of C=C double bonds and the decrease of sulfur and sulfonic acid groups later on implied that the desulfonation reaction proceeded to induce intermolecular cross-linking. The cross-linked and conjugated polyenes derived from the desulfonation probably attributed to the high char yield for sulfonated LLDPE fibers. [ABSTRACT FROM AUTHOR]

Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160-250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material, most likely via a slight cross-linking by H-substitution. It is well-known that the sulfonate proton plays a major role in the desulfonation reactions, and exchanging the protons with other cations can inhibit both protodesulfonation as well as electrophilic cross-linking reactions of the sulfonate group with other chains. Yet, the implications of such ion-exchange for the thermal processing of sulfonated polymer films has not been recognized. Our study demonstrates that the ion exchange stabilizes thin films and bulk SPEEK up to temperatures exceeding 200 °C, opening up ways for the thermal processing of SPEEK in the temperature range of 160-220 °C without adverse effects. [ABSTRACT FROM AUTHOR]

Abstract: Background: Total (i.e. free+sulfated) metanephrines in plasma is a biomarker for the diagnosis of pheochromocytoma/paraganglioma. Sulfated metanephrines must be completely deconjugated by perchloric acid hydrolysis or sulfatase treatment prior to analytical measurement to enable quantification by current techniques. In this report, we compare the yield and efficiency of both methods. Methods: The deconjugation rate of synthetic sulfated metanephrines (normetanephrine (S-NMN), metanephrine (S-MN) and methoxytyramine (S-MT)) spiked in charcoal-stripped plasma was determined by boiling perchloric acid and compared to sulfatase treatment. Total plasma metanephrines (MN, NMN and MT) were also determined in patient samples by both methods. Results: The complete deconjugation of sulfated metanephrines is achieved after 30min incubation with 0.1M boiling perchloric acid or upon sulfatase treatment. Ten minutes of acid hydrolysis (gold-standard) leads to a 30% underestimation of metanephrine concentrations. The enzyme hydrolysis is time and amount of sulfatase dependent. The rate of hydrolysis is analyte-dependent (MT>>NMN>MN), although it must contain at least 0.8 U/ml of sample. The Deming regression curves comparing acid versus enzyme hydrolysis on patient samples assessed that both methods gave similar unbiased concentrations. Conclusion: Enzyme and acid treatments are equivalent and efficient for removing sulfate from metanephrines as long as the optimal protocol is used for each method. However, the gold standard method for acid hydrolysis at 10min established more than 20 years ago was not satisfactory regarding the hydrolysis of metanephrines in plasma. [Copyright &y& Elsevier]

Abstract: We report a method which protects sulfonated hydrocarbon based proton exchange membranes at the interface between active and non-active area and in the gas inlet/outlet areas, where stresses are maximal during fuel cell operation. The sensitive membrane regions are subjected to a locally confined heat treatment using a stainless steel frame, under which desulfonation and/or crosslinking reactions occur. While modifications in air limit the reaction temperature to 180°C, inert atmosphere allows to raise the temperature and thus to shorten the necessary reaction time from 24h to less than 30min. Membranes are prepared from a commercially available copolymer (SES0005, AquafoneTM), which has a high IEC (2.08meqg−1) and a water uptake of 64%. As expected, modified membranes show reduced IEC values, reduced water uptake, and increased dimensional stability. Catalyst coated membranes (CCMs) are assembled into single cells for fuel cell testing. A membrane modified on all edges shows a stable performance in H2/air fuel cell operation and an H2 crossover current density of 0.52mAcm−2, while a membrane modified only on two edges fails within 50h. Tensile and fuel cell tests show that the interface between modified and pristine area is not the preferred breaking point. [Copyright &y& Elsevier]

Abstract: Sulphonates are often the major form of sulphur in soils where sulphate usually represents less than 5% of the total sulphur. The use of sulphonates as a S source is limited to a functional bacterial guild. However, fungi may assist bacteria in sulphonate desulphurization. In this study, grassland turfs were watered periodically with a modified Hoagland's solution that was i) sulphur free, ii) contained low molecular weight sulphonate iii) or high molecular weight sulphonate. DNA fingerprint analyses of fungal and bacterial communities revealed significant differences between the rhizosphere soil and the bulk soil. Sulphonate treatments had only significant effects on the bacterial and desulphonating bacterial communities and no significant effects on the fungal communities. However, sequencing of the fungal ITS region identified the presence of potentially endophytic fungi in sulphonate amended turfs. Analysis of the sulphur species in soil suggested that the added toluenesulphonate–sulphur was transformed despite the fact that the number of the desulphonating bacteria remained unchanged indicating no sulphonate limitation. The results showcase a robust fungal community in grassland turfs where only the bacterial community with its desulphonating bacterial guild is predominantly responding to the sulphonate amendment. [Copyright &y& Elsevier]

The preparation of 5-bromo-2-naphthol (4) in three steps from 5-amino-2-naphthol (1) is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in 20% aq. sulfuric acid.

The title compound (2-ammonio-4-chloro-5-methylbenzenesulfonate), C 7H 8ClNO 3S, 1, is an intermediate in the synthesis of laked red and yellow azo pigments. Heating 1 in 2-picoline, quinoline and N,N′-dimethylacetamide (DMAc) [or N-methyl-2-pyrrolidone (NMP)] resulted in the formation of three different compounds: a 2-picolinium hydrate ( 2), a quinolinium quinoline solvate ( 3), and a sulfate of the desulfonated title compound ( 4). The three new compounds were structurally characterised using single-crystal diffraction data and chemically using thermal analysis (DTA/TGA), elemental analysis and spectroscopic methods (IR and NMR). By heating 2, 3 and 4 in the solid state, compound 1 is obtained again. In the case of 4, this corresponds to a desulfonation-resulfonation reaction in subsequent steps, which is rarely observed as such. Graphical Abstract: The title compound 2-ammonio-4-chloro-5-methylbenzenesulfonate was heated in 2-picoline, quinoline and N,N′-dimethylacetamide (DMAc) resulting in the formation of three different compounds: a 2-picolinium hydrate ( 2), a quinolinium quinoline solvate ( 3), and a sulfate of the desulfonated title compound ( 4 see Figure). Heating 2, 3 and 4 in the solid state, compound 1 is obtained again. In the case of 4, this corresponds to a desulfonation-resulfonation reaction in subsequent steps, which is rarely observed as such.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

This paper describes preliminary tests carried out in treatment plants serving two different pig farms in Northern Italy, in order to assess the feasibility of implementing biological sulphur removal from biogas produced by anaerobic digestion processes. This normally consists of mixture of CH4, CO2, and other gases; in the presence of sulphur, H2S is also formed, which must be removed prior to the gas use in thermal engines, to avoid corrosion phenomena. Sulphur removal in the plants considered is currently achieved by means of chemical filtration, however this adds costs to the process and generates a waste to be disposed of. As a process alternative, biological sulphur removal by means of Thiobacillus sp. bacteria can also be obtained. The process, however, requires specific conditions in the gas stream in order to achieve high process efficiency. Biological desulfonation was applied on a trial basis in two biogas production plants, with different layouts, and encouraging results. These confirms the validity of the process, although the maximum foreseen removal efficiencies were not achieved due to structural drawbacks of the tested facilities, that will have to be revamped in order to apply this process with full satisfaction and effectiveness. [ABSTRACT FROM AUTHOR]

Abstract: Poly(ether ether ketone) (PEEK) was dissolved in conc. H2SO4 and its chloromethylation was achieved in presence of paraformaldehyde, trimethylchlorosilane and Lewis acid catalyst, obtained about 35–75% degree of chloromethylation (DCM). This idea is based on partial sulfonation of PEEK to make it soluble and further complete replacement of –SO3H with –CH2Cl groups. Alkaline membranes (AMs) were prepared by quaternization of chloromethylated PEEK (CMPEEK). The reported method is a “green” alternative for the production of AEM without the use of hazardous chemicals (such as chloromethyl methyl ether, chloromethyloctylether, bis(chloromethyl) ether etc.). Chronopotentiometry study of prepared membranes confirmed their homogeneous and alkaline nature suitable for methanol fuel cells. The AMs exhibit a splendid chemical stability at 10M KOH. Alkaline conductivity of quaternized poly(ether ether ketone) membrane with 75% DCM (QPEEK-75) (14.63mScm−1) in equilibration with deionized water was relatively high in compare with other AMs reported in the literature. For the H2/air single fuel cell at 50°C with QPEEK-75 membrane, about 1.02V OCV and 48.09mWcm−2 power density at 109.3mAcm−2 current density were obtained. [Copyright &y& Elsevier]

Three commercial ion-exchange resin based catalysts were compared under different temperature and liquid-volume hourly space velocity (LHSV) in the isobutene (IB, C4) dimerization reaction using a plug flow reactor in the absence of any selectivity enhancing component. High IB conversion for all catalysts was obtained at or higher than 50°C. But, diisobutene (DIB, C8) selectivity decreased with the increase of temperature. High C8 selectivity was observed with LHSV higher than 1.5 at 50°C. The best catalytic performance of the three resins did not show obvious differences. The effect of the selectivity enhancers on the stability of the resins was also studied. Desulfonation was observed in the C4 dimerization reaction when water or the commonly used enhancer tert-butyl alcohol (TBA) was added to the feed. The deactivation of catalyst resulted in decrease of both IB conversion and C8 selectivity. Fourier Transform Infrared spectroscopy showed that desulfonation happened in both para and ortho positions of the sulfonated benzene rings. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Abstract: Background: The quantification of total (free+sulfated) metanephrines in urine is recommended to diagnose pheochromocytoma. Urinary metanephrines include metanephrine itself, normetanephrine and methoxytyramine, mainly in the form of sulfate conjugates (60–80%). Their determination requires the hydrolysis of the sulfate ester moiety to allow electrochemical oxidation of the phenolic group. Commercially available urine calibrators and controls contain essentially free, unhydrolysable metanephrines which are not representative of native urines. The lack of appropriate calibrators may lead to uncertainty regarding the completion of the hydrolysis of sulfated metanephrines, resulting in incorrect quantification. Methods: We used chemically synthesized sulfated metanephrines to establish whether the procedure most frequently recommended for commercial kits (pH 1.0 for 30min over a boiling water bath) ensures their complete hydrolysis. Results: We found that sulfated metanephrines differ in their optimum pH to obtain complete hydrolysis. Highest yields and minimal variance were established for incubation at pH 0.7–0.9 during 20min. Conclusion: Urinary pH should be carefully controlled to ensure an efficient and reproducible hydrolysis of sulfated metanephrines. Synthetic sulfated metanephrines represent the optimal material for calibrators and proficiency testing to improve inter-laboratory accuracy. [Copyright &y& Elsevier]

Abstract: This paper deals with the desulfonation properties of some strong acid cation-exchange resins. The sulfate concentration in solution is continuously increased when a strong acid cation-exchange resin is mixed with water. The leaching of sulfate results from the desulfonation of the fixed group, and the amount of leached sulfate depends on the counter ion charge, the crosslinking degree and the exchanger matrix. The effects of the counter ion charge on the desulfonation rate suggested that the counter ion induces the nucleophilic attack of a water molecule on the sulfo group. This interpretation was supported by semiempirical molecular orbital calculations for the C6H5SO3 −M m+ (M m+ = Na+, Mg2+ and Al3+) systems, and the transition state of the Na+ system was successfully predicted by DFT calculations. The crosslinking degree influenced the desulfonation rate, which can be related to the decreasing hydration number of each counter ion in the resin phase with the increasing crosslinking degree. Furthermore, different exchanger matrices produced the differences in the rates, which may be derived from the electron-density donation from the exchanger matrix to the sulfo group. The desulfonation is governed by the electron-density of the sulfur atom and the water activity in the solid phase. [Copyright &y& Elsevier]

Abstract: Sulfonates are major soil sulfur components that can be desulfurized by certain soil-borne bacteria as a sulfur source, but application of sulfate through fertilization could affect this natural sulfur mobilizing process. This study investigates the effects of sulfate treatments on bacterial communities in semi-natural grasslands. Agrostis stolonifera-dominated turfs with their autochthonous bacteria from Woburn Experimental Farm, UK, were incubated with and without additional sulfate over a period of eight weeks and compared to soil and rhizosphere samples taken from the field directly. Cultivable rhizobacteria able to desulfurize toluenesulfonate were dominated by strains affiliated to the Variovorax, Polaromonas and Rhodococcus genera. The betaproteobacteria communities (16S rRNA gene-based denaturing gradient gel electrophoresis) and the desulfonating bacterial communities (asfA based terminal restriction fragment length polymorphism) revealed clear differences between field rhizospheres and bulk soil and the two types of incubated rhizospheres. Clone libraries of asfA from the sulfate-limited treatment were dominated by a new AsfA type, affiliated to Polaromonas. The results from this study suggest that the community of desulfonating bacteria in the Agrostis rhizosphere adapts quickly to changing levels of inorganic sulfate. [Copyright &y& Elsevier]

5-Hydroxyisophthalic acid-producing microorganisms were isolated from enrichment cultures using 5-sulfoisophthalic acid as a sulfur source. One bacterium, Ochrobactrum anthropi S9, had the highest 5-sulfoisophthalic acid-degrading activity, and stoichiometrically formed 5-hydroxyisophthalic acid, a raw material for polymer synthesis. Under optimum culture conditions, 1.3 mM 5-hydroxyisophthalic acid accumulated in the medium by 60 h. The addition of Na2SO4, l-methionine or l-cysteine at 2 mM inhibited the conversion of 5-sulfoisophthalic acid. O. anthropi S9 cells converted 5-sulfoisophthalic acid, benzenesulfonic acid, 3-sulfobenzoic acid, 4-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid and naphthalene-2-sulfonic acid into the corresponding hydroxylated compounds. [ABSTRACT FROM AUTHOR]

The preparation of 5-bromo-2-naphthol (4) in three steps from 5-amino-2- naphthol (1) is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in 20% aq. sulfuric acid. [ABSTRACT FROM AUTHOR]

6:2 fluorotelomer sulfonic acid (6:2 FTSA) is one per- and poly-fluoroalkyl substances commonly detected in the environment. While biotransformation of 6:2 FTSA has been reported, factors affecting desulfonation and defluorination of 6:2 FTSA remain poorly understood. This study elucidated the effects of carbon and sulfur sources on the gene expression of Rhodococcus jostii RHA1 which is responsible for the 6:2 FTSA biotransformation. While alkane monooxygenase and cytochrome P450 were highly expressed in ethanol-, 1-butanol-, and n-octane-grown RHA1 in sulfur-rich medium, these cultures only defluorinated 6:2 fluorotelomer alcohol but not 6:2 FTSA, suggesting that the sulfonate group in 6:2 FTSA hinders enzymatic defluorination. In sulfur-free growth media, alkanesulfonate monooxygenase was linked to desulfonation of 6:2 FTSA; while alkane monooxygenase, haloacid dehalogenase, and cytochrome P450 were linked to defluorination of 6:2 FTSA. The desulfonation and defluorination ability of these enzymes toward 6:2 FTSA were validated through heterologous gene expression and in vitro assays. Four degradation metabolites were confirmed and one was identified as a tentative metabolite. The results provide a new understanding of 6:2 FTSA biotransformation by RHA1. The genes encoding these desulfonating- and defluorinating-enzymes are potential markers to be used to assess 6:2 FTSA biotransformation in the environment. [Display omitted] • High expression of alkane monooxygenase gene linked to high 6:2 FTOH defluorination. • Desulfonation of 6:2 FTSA is a necessary prior to its defluorination. • Alkanesulfonate monooxygenase-producing strain RHA1 desulfonated 6:2 FTSA. • Three defluorinating enzymes involved in defluorination of 6:2 FTSA were identified. • PFHpA was a new metabolite of 6:2 FTSA biotransformation by strain RHA1. [ABSTRACT FROM AUTHOR]

Aerobic enrichment cultures with taurocholate or alkanesulfonates as sole sources of carbon and energy for growth were successful and yielded nine bacterial isolates, all of which utilized taurocholate. Growth was complex and involved not only many, usually transient, excretion products but also sorption of taurocholate and cholate to cells. Three metabolic strategies to dissimilate taurocholate were elucidated, all of which involved bile salt hydrolase cleaving taurocholate to cholate and taurine. Comamonas testosteroni KF-1 utilized both the taurine and the cholate moieties for growth. Pseudomonas spp., e.g. strain TAC-K3 and Rhodococcus equi TAC-A1 grew with the cholate moiety and released taurine quantitatively. Delftia acidovorans SPH-1 utilized the taurine moiety and released cholate. [ABSTRACT FROM AUTHOR]

Abstract: Red HE7B (RHE7B, 100mgl−1), a sulfonated azo dye, was decolorized at static condition by Pseudomonas desmolyticum NCIM 2112 in 72h with 71% reduction in chemical oxygen demand (COD). Extracellular lignin peroxidase (LiP) has played a crucial role in breakdown of the dye by asymmetric cleavage and reductases in the initial 24h incubation to break azo bonds of some dye molecules. Dye also induced the activity of aminopyrine N-demethylase, one of the enzymes of mixed function oxidase system. Decolorization and degradation were analyzed by using UV–vis and high-pressure liquid chromatography (HPLC). The Fourier transform infrared spectroscopy (FTIR) analysis revealed that P. desmolyticum preferred C–N and So break down the RHE7B. GC–MS identification of 8-amino-naphthalene-1,3,6,7-tetraol and 2-hydroxyl-6-oxalyl-benzoic acid as final metabolites supports the degradation of RHE7B by desulfonation before and after ring cleavage. Aerobic degradation of amines and reduced phytotoxicity increased the applicability of this microorganism for dye removal. Scientific relevance of the paper: This is the first report on degradation of Red HE7B by oxidative enzymes and on further degradation by desulfonation before and after ring cleavage. [Copyright &y& Elsevier]

The naturally occurring sulfonate N-acetyltaurine was synthesized chemically and its identity was confirmed. Aerobic enrichment cultures for bacteria able to utilize N-acetyltaurine as sole source of fixed nitrogen or as sole source of carbon were successful. One representative isolate, strain NAT, which was identified as a strain of Delftia acidovorans, grew with N-acetyltaurine as carbon source and excreted stoichiometric amounts of sulfate and ammonium. Inducible enzyme activities were measured in crude extracts of this organism to elucidate the degradative pathway. Cleavage of N-acetyltaurine by a highly active amidase yielded acetate and taurine. The latter was oxidatively deaminated by taurine dehydrogenase to ammonium and sulfoacetaldehyde. This key intermediate of sulfonate catabolism was desulfonated by the known reaction of sulfoacetaldehyde acetyltransferase to sulfite and acetyl phosphate, which was further degraded to enter central metabolism. A degradative pathway including transport functions is proposed. [ABSTRACT FROM AUTHOR]

Cysteate and sulfolactate are widespread natural products in the environment, while propanesulfonate, 3-aminopropanesulfonate and propane-1,3-disulfonate are xenobiotics. While some understanding of the bacterial assimilation of cysteate sulfur has been achieved, details of the dissimilation of cysteate and sulfolactate by microbes together with information on the degradation of the xenobiotics have only recently become available. This minireview centres on bacterial catabolism of the carbon moiety in these C3-sulfonates and on the fate of the sulfonate group. Three mechanisms of desulfonation have been established. Firstly, cysteate is converted via sulfopyruvate to sulfolactate, which is desulfonated to pyruvate and sulfite; the latter is oxidized to sulfate by a sulfite dehydrogenase and excreted as sulfate in Paracoccus pantotrophus NKNCYSA. Secondly, sulfolactate can be converted to cysteate, which is cleaved in a pyridoxal 5′-phosphate-coupled reaction to pyruvate, sulfite and ammonium ions; in Silicibacter pomeroyi DSS-3, the sulfite is excreted largely as sulfite. Both desulfonation reactions seem to be widespread. The third desulfonation mechanism is oxygenolysis of, e.g. propanesulfonate(s), about which less is known. [ABSTRACT FROM AUTHOR]

We investigated the laser photolysis of tetrasodium 1,3,6,8-pyrene-tetrasulfonate (Na4PS4) and sodium 1-pyrenesulfonate (NaPS) in aqueous and reverse micellar solutions. The photoproducts as well as their yields were found to strongly depend on the reaction parameters such as pH, dissolved gases and the size of water pool. The primary reaction in aqueous solution was commonly presented by laser-induced formation of the cation radicals followed by hydroxylation of them. In the case of PS44−, pyranine was efficiently and highly selectively formed, possibly via desulfonation of the cation radical, P⋅+S44−, followed by the hydroxylation. On the other hand, from PS−, hydroxypyrenesulfonate (PSOH) was initially formed in alkaline solution and desulfonation occurred secondarily, leading to the formation of hydoxypyrene. These photoreactions were markedly suppressed within a small water pool of the reverse micelle. As the size of water pool increased similar photochemical reactions occurred depending on the dissolved gases. The observed micellar effects could be explained based on the pH of water pool and the nature of the cation radicals in it. [Copyright &y& Elsevier]

Novel isolates of Achromobacter xylosoxidans, Tsukamurella wratislaviensis and a Rhodococcus sp. are described. These grew with short-chain alkanesulfonates as their sole source of carbon and energy. T. wratislaviensis strain SB2 grew well with C3–C6 linear alkanesulfonates, isethionate and taurine, Rhodococcus sp. strain CB1 used C3–C10 linear alkanesulfonates, taurine and cysteate, but neither strain grew with ethanesulfonate. In contrast, A. xylosoxidans strain AE4 grew well with ethanesulfonate, making it the first bacterium to be described which can grow with this compound. It also grew with unsubstituted C3–C5 alkanesulfonates and isethionate. Hydrolysis was excluded as a mechanism for alkanesulfonate metabolism in these strains; and evidence is given for a diversity of uptake and desulfonatase systems. We provide evidence for an initial monooxygenase-dependent desulfonation in the metabolism of ethanesulfonate and propanesulfonate by A. xylosoxidans strain AE4. [ABSTRACT FROM AUTHOR]

Aerobic enrichment cultures (11) yielded three cultures able to utilise ethane-1,2-disulfonate as sole source of carbon and energy in salts medium. Two pure cultures were obtained and we worked with strain EDS1, which was assigned to the genus Ralstonia on the basis of its 16S rDNA sequence and simple taxonomic tests. Strain EDS1 utilised at least seven alkane(di)sulfonates, ethane-1,2-disulfonate, taurine, isethionate, sulfoacetate, sulfoacetaldehyde and propane-1,3-disulfonate, as well as methanesulfonate and formate. Growth with ethanedisulfonate was concomitant with substrate disappearance and the formation of 2 mol sulfate per mol substrate. The growth yield, 7 g protein (mol C)–1, indicated quantitative utilisation of the substrate. Ethanedisulfonate-dependent oxygen uptake of whole cells during growth rose to a maximum before the end of growth and then sank rapidly; this was interpreted as evidence for an inducible desulfonative oxygenase that was not active in cell extracts. Inducible sulfoacetaldehyde sulfo-lyase was detected at high activity. Inducible degradation of taurine or isethionate or sulfoacetate via sulfoacetaldehyde sulfo-lyase is interpreted from the data. [ABSTRACT FROM AUTHOR]

Sulfoxidation of fatty methyl esters with SO2, O2, and ultraviolet light of appropriate wavelength has led to a synthesis of sodium methyl ester sulfonates known as Φ-MES. The designation of Φ refers to the random positioning of SO3 in the alkyl chain. This investigation describes for the first time the operating conditions necessary to produce these new anionic surfactants as well as the analytical methods used in their isolation, analysis, identification. Some surface properties are discussed as well. [ABSTRACT FROM AUTHOR]

Thiosulfate (S2O3 2–) is a natural product that is widely utilized in natural ecosystems as an electron sink or as an electron donor. However, the major biological source(s) of this thiosulfate is unknown. We present the first report that taurine (2-aminoethanesulfonate), the major mammalian solute, is subject to fermentation. This bacterial fermentation was found to be catalyzed by a new isolate, strain GKNTAU, a strictly anaerobic, gram-positive, motile rod that formed subterminal spores. Thiosulfate was a quantitative fermentation product. The other fermentation products were ammonia and acetate, and all could be formed by cell-free extracts. [ABSTRACT FROM AUTHOR]

We isolated a strictly anaerobic bacterium, strain GRZCYSA, from a sludge digestor for its ability to ferment cysteate (2-amino-3-sulfopropionate). The organism also fermented the organosulfonates isethionate (2-hydroxyethanesulfonate) and aminomethanesulfonate, but taurine (2-aminoethanesulfonate) was not a substrate. Strain GRZCYSA, a gram-negative, oxidase-negative and catalase-positive vibrio that could reduce sulfate and contained desulfoviridin, was tentatively identified as Desulfovibrio sp. Utilization of cysteate as a substrate for fermentative growth led to the formation of four products identified as acetate, ammonia, and equimolar amounts of sulfide and sulfate. The fermentation was in balance. Some reactions involved in this novel process were detected in cell-free extracts in which ammonia and acetate were formed from cysteate. [ABSTRACT FROM AUTHOR]

Organisms able to utilize one of several alkyl- and arylsulfonates as sole source of sulfur under anoxic conditions were enriched. Three fermenting bacteria, all putative Clostridium spp., were isolated in pure culture. All three organisms had wide substrate ranges for alkylsulfonates, taurine and arylsulfonates, presumably due to three different enzyme systems. One organism, strain KNNDS (DSM 10612) was selected for further characterization. The organism was possibly a new Clostridium sp., with Clostidium intestinalis as its nearest neighbor (97.6% similarity of rDNA). Strain KNNDS catalyzed complete sulfonate utilization concomitant with growth. Growth yields of approximtely 3 kg protein/mol sulfur were observed, independent of the sulfur source [e.g. sulfate, sulfide, 4-(phenyl)butyl-1-sulfonate, 2,6-naphthyldisulfonate or 4-nitrocatechol sulfate]. We failed to detect significant amounts of either an arylsulfonatase or an arylsulfatase, and we hypothesize different arylsulfatases [EC 3.1.6.1] in aerobes and in Clostridium spp. [ABSTRACT FROM AUTHOR]

Terminal olefins can be converted into the corresponding sulfonates by sulfonation with SO followed by hydrolysis, the products are used as detergent ingredients. Although internal olefins were also expected to be good feed stocks, it was difficult to convert them into the corresponding sulfonates with as good of a yield as that of terminal olefins under the same synthesis conditions. Our studies have been carried out in order to clarify the reason for poorer conversion of the internal olefins. It was found by a nuclear magnetic resonance spectroscopic study that the major components of the sulfonated intermediate of internal olefins were β-sultones, the amounts of which were usually very small in sulfonated terminal olefins. A portion of these β-sultones was desulfonated, depending on temperature, to the original olefins and the corresponding sulfate salts during alkaline hydrolysis. The prevention of desulfonation of the β-sultones in the hydrolysis process was one of the most important aspects for the production of internal olefin sulfonates. Finally, by keeping the hydrolysis temperature below 35°C, the conversion of internal olefins into sulfonates was achieved with the same yield as that of conventional terminal olefins. [ABSTRACT FROM AUTHOR]

A simple and efficient preparation of biaryl derivatives from arylsulfonyl hydrazides has been developed using Pd(OAc)2 as the catalyst in a mixed solvent of DMA and THF and without the use of any ligand and base. [ABSTRACT FROM AUTHOR]

• nNiFeo-AC particles transformed both L- and Br-PFOS isomers. • PFOS transformation highest at 50 °C at 94 % (40–60 °C investigated). • Fluoride and sulfite generation accounted for nearly all the PFOS decomposed. • Several organic transformation products were identified in particle extracts. Degradation of linear (L) and branched (Br) perfluorooctanesulfonate (PFOS) using nNiFe° particles supported on activated carbon (AC) and heat is demonstrated for the first time and with several lines of evidence. At 60 °C, PFOS degradation plateaued at 50 ± 6%, while at 50 °C, 94 ± 4.1 % PFOS transformed. The accelerated iron corrosion at the higher temperature is attributed to the lower PFOS transformation at 60 °C. However, at both temperatures, ≥ 97 % of the PFOS transformed was accounted for by the moles of fluoride generated. At 60 °C, PFOS degradation rates were estimated at 0.028 ± 0.003 h−1 and fluoride and sulfite generation rates of 0.70 ± 0.165 h−1 and 0.62 ± 0.157 h−1, respectively, with no differences between L-PFOS and total Br-PFOS. Using time-of-flight mass spectrometry, some organic products were identified in the particle extracts from the 60 °C reaction. Products included single-bonded C8 polyfluoroalkyl sulfonates (F 16 to F 7) and alkyl acids (PFCAs, C 4 -C 8) and one perfluorinated C 8 desulfonated product supporting both defluorination and desulfonation pathways. Most of the organic products were gone after the first 25 h. High PFOS mineralization using nNiFe°-AC technology warrants further investigation for its use in permeable reactive barriers. [ABSTRACT FROM AUTHOR]