Efficacy of Topical versus Oral 5-Aminosalicylate for Treatment of 2,4,6-Trinitrobenzene Sulfonic Acid-induced Ulcerative Colitis in Rats

5-aminosalicylic acid（5-ASA） is drug of choice for the treatment of ulcerative colitis（UC）. In this study, the efficacy of topical versus oral 5-ASA for the treatment of UC was examined as well as the action mechanism of this medication. A flexible tube was inserted into the rat cecum to establish a topical administration model of 2,4,6-trinitrobenzene sulfonic acid（TNBS）-induced UC. A total of 60 rats were divided into sham operation group（receiving an enema of 0.9% saline solution instead of the TNBS solution via the tube）, model group, topical 5-ASA group, oral Etiasa group（a release agent of mesalazine used as positive control） and oral 5-ASA group（n=12 each）. Different treatments were administered 1 day after UC induction. The normal saline（2 mL） was instilled twice a day through the tube in the sham operation group and model group. 5-ASA was given via the tube in the topical 5-ASA group（7.5 g/L, twice per day, 100 mg/kg）, and rats in the oral Etiasa group and oral 5-ASA group intragastrically received Etiasa（7.5 g/L, twice per day, 100 mg/kg） and 5-ASA（7.5 g/L, twice per day, 100 mg/kg）, respectively. The body weight was recorded every day. After 7 days of treatment, blood samples were drawn from the heart to harvest the sera. Colonic tissues were separated and prepared for pathological and related molecular biological examinations. The concentrations of 5-ASA were detected at different time points in the colonic tissues, feces and sera in different groups by using the high pressure liquid chromatography（HPLC）. The results showed that the symptoms of acute UC, including bloody diarrhea and weight loss, were significantly improved in topical 5-ASA-treated rats. The colonic mucosal damage, both macroscopical and histological, was significantly relieved and the myeloperoxidase activity was markedly decreased in rats topically treated with 5-ASA compared with those treated with oral 5-ASA or Etiasa. The mRNA and protein expression of IL-1β, IL-6, and TNF-α was down-regulated in the colonic tissue of rats topically treated with 5-ASA, significantly lower than those from rats treated with oral 5-ASA or Etiasa. The concentrations of 5-ASA in the colonic tissue were significantly higher in the topical 5-ASA group than in the oral 5-ASA and oral Etiasa groups. It was concluded that the topical administration of 5-ASA can effectively increase the concentration of 5-ASA in the colonic tissue, decrease the expression of proinflammatory cytokines, alleviate the colonic pathological damage and improve the symptoms of TNBS-induced acute UC in rats.

Chemical functionalization of chitosan biopolymer and chitosan-magnetite nanocomposite with sulfonic acid for acid-catalyzed reactions

Chemical functionalization of chitosan biopolymer and chitosan-magnetite nanocomposite was performed with sulfonic acid functional groups to achieve new solid acid materials.The sulfonic acid functional groups were created through the ring opening nucleophilic reaction of amine groups of chitosan with 1,4-butane sultone.Fourier transform infrared spectroscopy(FT-IR)and X-ray photoelectron spectroscopies(XPS)verified the successful sulfonic acid functionalization of chitosan.The obtained sulfonic acid functionalized chitosan-magnetite nanocomposite showed superparamagnetic properties according to the vibrating sample magnetometry analysis and exhibited magnetic separation feature from dispersed mixtures.Nitrogen adsorption-desorption analysis indicated the increase in surface area after formation of chitosan-magnetite nanocomposite and functionalization with sulfonic acid.Both of the prepared solid acids exhibited high catalytic activities in the acid-catalyzed acetic acid esterification with n-butanol and benzaldehyde acetalization with ethylene glycol as model reactions.Furthermore,they can be reused several times without considerable loss of their activities.

THERMODYNAMIC STUDY ON ADSORPTION OF AROMATIC SULFONIC ACIDS ONTO MACROPOROUS WEAK BASE ANION EXCHANGER FROM AQUEOUS SOLUTIONS

The adsorption equilibrium isotherms of three aromatic sulfonic acid compounds, 2-naphthalenesulfonic acid, p-toluenesulfonic acid and p-chlorobenzenesulfonic acid, from aqueous solutions by macroporous weak base anion exchanger within the temperature range of 293 K-313 K were obtained. Several isotherm equations were correlated with the equilibrium data, and the experimental data was found to fit the three-parameter Redlich-Peterson equation best within the entire range of concentrations. The study showed that the hydrophobicity of solute has distinct influence on adsorption capacity of the anion exchanger for the aromatic sulfonic acid. Moreover, estimations of the isosteric enthalpy, free energy, and entropy change of adsorption were also reported. The positive isosteric enthalpy and entropy change for adsorption indicate an endothermic and entropy driven process in the present study.

Sterically Stabilized Poly(3, 4-ethylenedioxythiophene) Colloidal Dispersions Doped with Different Sulfonic Acids

The preparation of sterically stabilized poly（3, 4-ethylenedioxythiophene）（PEDOT） colloidal dispersions doped with different sulfonic acids is described. Three different sulfonic acids, i.e., p-toluenesulfonic acid, β-naphthalenesulfonic acid and D-camphor-10-sulfonic acid are used, facilitating the preparation of sterically stable PEDOT colloidal particles. The influences of the dopants and concentration of polymeric stabilizer on the yields, morphologies and electrical properties of the resultant colloidal particles were investigated. The colloidal particles with the size ranging from 172 to 334 nm have been obtained in good yields. The compressed pellet conductivity was as high as 4.5 Scm^-1

A STUDY ON THE DEGRADATION MECHANISM OF PHOTOCROSSLINKING PRODUCTS FORMED BY CYCLIZED POLYISOPRENE-DIAZIDE SYSTEM UNDER THE INFLUENCE OF ALKYL BENZENE SULFONIC ACIDS

The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed.

Selective Detection of Dopamine in the Presence of Ascorbic Acid at Poly (m-Aminobenzene Sulfonic Acid)

Poly (m-aminobenzene sulfonic acid, m-ABSA) films were electrochemically prepared by cyclic voltammetry (CV) in 0.1 mol L–1 KCl solution. The dopamine (DA) selectivity of polymeric electrodes prepared at the different thicknesses was examined in the presence of ascorbic acid (AA). The results showed that the modified electrode showed an excellent electrocatalytical effect towards oxidation of dopamine (DA) and ascorbic acid (AA). Electrostatic interaction between the negatively charged poly(m-ABSA) film and either cationic DA species or anionic AA species favorably contributed to the redox response of DA and AA. Moreover, the regular and repetitive responses for dopamine were obtained even in the presence of the some interfering substances such as ascorbic acid, NaCl, NaClO4, Na2SO4 ,NaNO3 and KCl.

SYNTHESIS, STRUCTURE AND PROPERTIES OF INTERPENETRATING SULFONIC ACID RESINS WITH HIGH CAPACITY

Two series of interpenetrating sulfonic acid resins (ISAR), 10×n and n×10, were prepared by means of the wet method, and the physicochemical, thermodynamic and kinetic properties of the ISAR were measured. The results show: 10×n resins exhibit better properties than n×10 ones, mainly in higher apparent degree of crosslinking and larger conformational entropy effect, among which, 10×1 resin exhibits the best thermodynamic and kinetic properties. In the DTA graphs of n×10 resins, there are two T_g and two T_(ox), but in those of 10×n, only one T_g and one T_(ox). This result well supports the conclusion that 10×n resins have much better interpenetrating structural aspects.

MICELLIZATION STUDIES OF DODECYL BENZENESULFONIC ACID AND ITS INTERACTION WITH POLYVINYLPYRROLIDONE

Dodecyl benzenesulfonic acid(DBSA)surfactant was used in the present study to find the effect of concentrationon its electrical conductance in solution from 293-323 K above and below the critical micelle concentration(CMC).Themicellization parameters i.e.degree of counter ion binding(β),aggregation number(n)and number of counter ion micelle(m)were measured.The interaction of DBSA with polyvinylpyrrolidone(PVP)was also studied at 293 K throughconductance and surface tension measure ments.A number of important parameters i.e.critical aggregation concentration(CAC),Gibb's free energy(△G)and binding ratio(R)were determined and the effect of NaCl on the CAC and polymersaturation point(PSP)was also investigated.

Preconcentration of Rare Earth Elements with 8-Hydroxyquinoline-5-sulfonic Acid Chelated Cellulose Filter Prior to Determination by Inductively Coupled Plasma Atomic Emission Spectrometry

Hydroxyquinoline 5 sulfonic acid, covalently bound to filter cellulose, was used for preconcentrating trace rare earth element(REE) ions from complex matrices and matrix separation, respectively. Multi REE ions were preconcentrated on the column filled with 8 hydroxyquinoline 5 sulfonic acid cellulose filter and analysed by ICP AES after being eluted with dilute HNO 3. In the given pH range, alkali and alkaline earth metal ions can be separated as matrix elements; a high concentration factor is obtained and the eluates can be measured without interference. The usefulness of the method is shown by the control analyses of standard reference materials. [WT5FZ]

Synthesis and Characterization of the Terpolymer of Itaconic Acid with Acrylamide and 2-Acrylamido-2-methylpropanesulfonic Acid

The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.

Spectrofluorimetric Determination of Magnesium (Ⅱ) with 7-(8-Hydroxy-3, 6-Disulfonaphthylazo)-8-Hydroxyquinoline-5-Sulfonic Acid

A new fluorescent reagent, 7 (8 hydroxy 3, 6 disulfonaphthylazo) 8 hydroxyquinoline 5 sulfonic acid (HDNHQ) for the determination of magnesium has been developed. It reacted with magnesium to form a 1∶1 fluorescent complex with λ ex / λ em =356/495 nm immediately at room temperature in ammonia ammonium chloride buffer (pH 10.7). A linear relationship was obtained in the magnesium concentration range of 0 160 ng·mL -1 with the detection limit of 0.04 ng·mL -1 . The proposed method was simple, rapid and sensitive. It has been successfully applied to the determination of trace magnesium in blood serum with recoveries of 103.75% and 98.16%, respectively.

PREPARATION,CHARACTERIZATION AND ELECTROCHEMICAL PROPERTIES OF POLYPYRROLE-POLYSTYRENE SULFONIC ACID COMPOSITE FILM

Polypyrrole-polystyrene sulfonic acid(PPy-PSSA)composite films have been electrosynthesized in an aqueoussolution of PSSA.The electro-active films exhibit cation exchange during the redox process.Infrared,Raman and energy-dispersive spectroscopic results demonstrated that the polyanion of PSS^- is co-deposited into the PPy matrix and couldn't bestripped fiom the film extensively by dedoping.The doping level together with dipolaron content of the PPy-PSSAcomposite film increases during electrochemical polymerization process.SEM images revealed that the composite film hassmooth and compact morphology and AFM pictures suggested that PPy chains are possibly grown perpendicular to theelectrode surface.TGA tests indicated that the composite films has much better thermal stability than that of pure PPy.Furthermore,electrochemical studies showed that the relaxation process at certain holding potential has great effect on theshape of the cyclic voltammetric curves of PPy-PSSA composite film.The composite film exhibits cation and anionexchange during the redox process after undergoing the relaxation step.It is more difficult for divalent anion to enter thepolymer matrix than a univalent ion,and a large cation such as(CH_3CH_2CH_2CH_2)_4N^+ cannot be involved in the ionexchange process.

N-Substituted benzoxazolyl ureas and thioureas in Biginelli reaction promoted by trifluoromethane sulfonic acid:An efficient and convenient synthesis of substituted benzoxazolyl 3,4-dihydropyrimidine(1H)-(thio)-ones

An efficient synthesis of 3,4-dihydropyrimidine 2 （1H）-ones and thiones （3,4-DHPMs） core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The classical BigneUi reaction has been extended by the use of N-substituted benzoxazolyl semicarbazides and thiosemicarbazides and this method has the advantage of excellent yields and short reaction times. ？2009 M. Saranga Pard. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

The Modulatory Effect of Dietary Apostichopus japonicus on Mice with Ulcerative Colitis Induced by Trinitrobenzene Sulfonic Acid

Sea cucumber is a food with nutritional benefits distributing mainly in Asia, and Apostichopus japonicus (A. japonicus) is a kind of sea cucumber whose quality is better than any others. However, different processing methods make various effect on its quality. In this study, we evaluated the protection effect of A. japonicus with different processing methods on mice with ulcerative colitis induced by trinitrobenzene sulfonic acid (TNBS), especially on the intestinal microflora. The expression of IFN-γ/IL-4 and IL-1β in gut, and intestinal microbiota were discussed. The results revealed that three different processing methods of A. japonicus could decrease the expression of inflammatory cytokines, except for the expression of IFN-γ/IL-4 treated with enzymatic, and dried A. japonicus was the most efficient. A. japonicus could change the microbiotic imblance relatively back to normal in terms of bacterial diversity and composition, meanwhile increase the abundance of Bifidobacteria, Lactobacillus and Clostridium leptum. The elements of protein, polysaccharide in dried, instant, enzymatic A. japonicus are 73.09%, 65.06%, 57.42% and 6.72%, 5.46%, 5.45% respectively. This study indicated that A. japonicus have a good improving effect on ulcerative colitis, especially on the microbiome, and processing methods had an effect on alleviation of ulcerative colitis, which might be associated with content of protein and polysaccharide.

Indole alkaloid sulfonic acids from an aqueous extract of Isatis indigotica roots and their antiviral activity

Six new indole alkaloid sulfonic acids(1–6), together with two analogues(7 and 8) that were previously reported as synthetic products, were isolated from an aqueous extract of the Isatis indigotica root. Their structures including the absolute configurations were determined by spectroscopic data analysis, combined with enzyme hydrolysis and comparison of experimental circular dichroism and calculated electronic circular dichroism spectra. In the preliminary assay, compounds 2 and 4 showed antiviral activity against Coxsackie virus B3 and influenza virus A/Hanfang/359/95(H3N2), respectively.

Esterification of levulinic acid into n-butyl levulinate catalyzed by sulfonic acid-functionalized lignin-montmorillonite complex

In this study,sulfonic acid-functionalized lignin-montmorillonite complex(LMT-SO_(3)H)was pre-pared and employed as an efficient heterogeneous catalyst for the esterification of levulinic acid(LA)into n-butyl levulinate(BL).An intermediate pseudo-butyl levulinate(p-BL)was determined by distilled water treatment and nuclear magnetic resonance(NMR)analysis,and a possible mech-anism for the esterification of LA is proposed.The effects of various process parameters were studied and the results showed that the LMT-SO_(3)H catalyst had the excellent catalytic perfor-mance for esterification of the LA.Under optimum reaction conditions,the yield of BL was 99.3%and the conversion of LA was 99.8%.The LMT-SO_(3)H catalyst exhibited strong acidic sites and high stability even after seven cycles of usage.Furthermore,esterification of the LA with various alcohols over the LMT-SO_(3)H was further investigated.

Sulfonic acid-functionalized mesoporous silica catalyst with different morphology for biodiesel production

Sulfonic acid functionalized mesoporous silica based solid acid catalysts with different morphology were designed and fabricated.The synthesized materials were characterized by various physicochemical and spectroscopic techniques like scanning electron microscopeenergy dispersive X-ray spectroscopy,Fourier transform infrared spectroscopy,Brunauer–Emmett–Teller surface area,thermogravimetric analysis and n-butylamine acidity.The shape of catalysts particles plays an important role in its activity.The sulfonic acid functionalized mesoporous silica catalysts of spherical shape and the cube shape were assessed for catalytic activity in biodiesel production.The catalytic biodiesel production reaction over the catalysts were studied by esterification of free fatty acid,oleic acid with methanol.The effect of various reaction parameters such as catalyst concentration,acid/alcohol molar ratio,catalyst amount,reaction temperature and reaction time on catalytic activity were investigated to optimize the conditions for maximum conversion.It was sulfonated cubic shape mesoporous silica which exhibited better activity as compared to the spherical shape silica catalysts.Additionally,the catalyst was regenerated and reused up to three cycles without any significant loss in activity.The present catalysts exhibit superior performance in biodiesel production and it can be used for the several biodiesel feedstock’s that are rich in free fatty acids.

One-pot, solvent-free and efficient synthesis of 2,4,6-triarylpyridines catalyzed by nano-titania-supported sulfonic acid as a novel heterogeneous nanocatalyst

Nano titania-supported sulfonic acid（n-TSA） has found to be a highly efficient, eco-friendly and recyclable heterogeneous nanocatalyst for the solvent-free synthesis of 2,4,6-triarylpyridines through one-pot three-component reaction of acetophenones, aryl aldehydes and ammonium acetate. This reported method illustrates several advantages such as environmental friendliness reaction conditions,simplicity, short reaction time, easy work up, reusability of catalyst and high yields of the products. One new compound is reported too. Furthermore, the catalyst could be recycled after a simple work-up, and reused at least six times without substantial reduction in its catalytic activity.

Synthesis and crystal structure of novel samarium coordination polymer derived from sulfonic acid ligand

The self-assembly of HL(L=[5-(ethoxycarbonyl)-4-phenyl-3,4-dihydropyrimidin-2(1H)-one-6-yl]methanesulfonate) with Sm(ClO4)3·6H2O yielded a 2D coordination polymer {[SmL3(H2O)2]·4H2O}n(1).Its crystallographic data indicated that it belonged to a triclinic system,space group P-1,a=1.42233(8),b=1.47155(8),c=1.53868(9) nm,α=8.62710(10),β=6.35250(10),γ=71.5790(10)°,V=2.7241(3) nm3,Z=2,R1=0.0693,wR2=0.1054.X-ray analysis revealed that the local coordination environment around Sm(III) was a slightly distorted dodecahedron in which Sm center was eight-coordinate geometry with eight oxygen atoms from three sulfonic groups,three carbonyl groups and two aqua ligands.Each L-acted as a bidentate spacer to link two Sm centers,resulted in the formation of a 2D hexagonally grid network.The discrete 2D planes in 1 were assembled into a 3D supramolecular network via strong hydrogen bonds among noncoordinated aqua O atoms,coordinated aqua O atoms,and noncoordinated O atoms of sulfonic groups and carbonyl groups.Furthermore,this metal-organic polymer exhibited strong photoluminescence maximized at 379 nm upon 274 nm excitation in the solid state at room temperature.

Imidazolium ionic liquid-supported sulfonic acids:Efficient and recyclable catalysts for esterification of benzoic acid

Several imidazolium ionic liquid（IL）-supported sulfonic acids with different anions,[C_3SO_3Hmim]HSO_4,[C_3SO_3Hmim]BF_4, [C_3SO_3 Hmim]PF_6,and[C_3SO_3Hmim]CF_3SO_3,were synthesized and applied as catalysts for esterification reaction of benzoic acid. The experimental results indicate that imidazolium IL-supported sulfonic acid containing anion of HSO_4^- shows the best catalytic activity.Only when less[C_3SO_3Hmim]HSO_4（0.3 equiv.） applied,was the product obtained with high yield of 97%.Furthermore, the produced esters could be separated by decantation,and the catalyst could be reused after the removal of water.