Sulphonyl Chloride Research Articles

Pyrene sulphonyl chloride as a reagent for quantitation of oestrogens in human serum using HPLC with conventional and laser-induced fluorescence detection.

A highly sensitive HPLC method with conventional and laser-induced fluorescence detection for the analyses of oestrogens is described. beta-oestradiol (beta-ES) was chosen as a model and derivatized with pyrenesulphonyl chloride (PSCL), a novel derivatizing reagent, using a two-phase system with tetrapentylammonium bromide (TPABR) as a phase transfer catalyst. Derivatization was complete in 30 s at room temperature and concentrations as low as 5 x 10(-10) M could be derivatized and detected. The concentration detection limit PSCL derivatized beta-ES was 2 x 10(-11) M which corresponds to an on-column detection limit of one femtomole using conventional chromatography and detection. The relative standard deviation (n = 6) of the derivatization carried out at 2.5 x 10(-9) M was 4%. No significant loss of peak-height of the derivative was observed at room temperature over 24 h period. Baseline resolution of PSCL derivatized oestrone, equilin and beta-oestradiol was achieved with ACN:H2O (75:25 v/v) using a Bondclone C-18 column. The method described here is sufficiently sensitive for analyses of beta-oestradiol at low pg/mL concentrations in 1 mL of human serum. The PSCL derivatives of oestrogens demonstrate excellent potential for excitation by laser-induced fluorescence using the 351 nm line of an Ar ion laser or the 325 nm line of He-Cd laser. A concentration limit of detection of 4 x 10(-12) M for beta-oestradiol was achieved using the 325 nm line of an He-Cd laser. This corresponds to 0.2 fmol of derivatized beta-oestradiol on-column.

Derivatization of Amines with Phthalimidyl Benzene Sulphonyl Chloride

Derivatization of Amines with Phthalimidyl Benzene Sulphonyl Chloride

Derivatization of Amines with Phthalimidyl Benzene Sulphonyl Chloride

Derivatization of Amines with Phthalimidyl Benzene Sulphonyl Chloride

A POSTMORTEM STUDY OF GLYCINE AND ITS POTENTIAL PRECURSORS IN CHRONIC SCHIZOPHRENICS

We have measured the concentrations of glycine and its potential precursors, serine and threonine, in 20 areas of the postmortem brains of chronic schizophrenics and controls using high-performance liquid chromatography by pre-column derivatization with dimethyl-amino-azobenzene sulphonyl chloride. The regional distribution pattern of glycine in the postmortem brains with and without the disease was more similar to that of serine ( r = 0.874, P < 0.0001) than to that of threonine ( r = 0.476, P < 0.01). A multiple regression analysis with regressor variables including diagnosis, age at death and interval between death and freezing revealed that there is a significant difference between schizophrenics and controls in the contents of these amino acids in a number of brain areas. The level of glycine in the orbitofrontal cortex of schizophrenics was found to be significantly increased in schizophrenics, with a tendency to an increase in that of serine. The increase in glycine was also significantly high in the off-drug group of schizophrenics who had not taken antipsychotics more than 40 days before death. Prominent decreases in both glycine and serine were observed in the somesthetic cortex of the on-drug schizophrenics. Serine was found to be significantly decreased in the putamen of the off-drug schizophrenics. A marked decrease in threonine was also observed in the supramarginal cortex and posterior portion of the lateral occipitotemporal cortex of the off-drug group of schizophrenics and in the putamen of all schizophrenics. The highly similar distribution pattern of glycine and serine in the postmortem brains supports the close coupling of synthesis and metabolism between these chemicals in human brains. The increased content of glycine in the orbitofrontal cortex, the reduced level of serine in the putamen and the decrease in threonine in the cerebral cortices, which were prominent in the off-drug schizophrenics, may be involved in the pathophysiology of schizophrenia. Copyright © 1996 Elsevier Science Ltd.

Thermal degradation of sulphonylated polystyrene

Three sulphonylated polystyrenes, obtained by sulphonylating polystyrene with the corresponding sulphonyl chlorides, have been characterized by IR and NMR spectroscopy. Elemental analysis shows 76.6, 96.5 and 73.9 mol% of sulphone groups in poly 4-(benzene sulphonyl)styrene, poly 4-(4-toluene sulphonyl)styrene and poly 4-(2-naphthalene sulphonyl)styrene, respectively. Their glass transition temperatures, measured by DSC, are much higher than that of PS. Thermogravimetric studies show that the sulphonylated PSs, with single stage degradation, are similar to PS, but their thermal stabilities are somewhat higher than that of PS. Detailed degradation studies have been carried out only on poly 4-(4-toluene sulphonyl)styrene. Gas chromatography-mass spectrometry (GC-MS) has shown that 4-(4-toluene sulphonyl)styrene is present among the volatile products as 36.3% of the total volatiles. From gas chromatographic studies it has been found that styrene, toluene and SO 2 are minor products of the degradation.

Free jet absorption millimeter wave spectrum of benzene sulphonyl chloride

The free jet millimeter wave spectrum of benzene sulphonyl chloride has been investigated in the 60–66 GHz frequency range. The rotational spectra of the 35Cl and 37Cl isotopomers have been assigned, allowing the determination of the equilibrium configuration: the Cl atom is perpendicular to the benzene ring.

An NQR study of thermally activated motions of nitro groups and of the phase transition in 2,6-dinitrochlorobenzene

A study of the temperature dependence of the 35Cl NQR frequency of 2,6-dinitrochlorobenzene is reported. These measurements show the existence of a second-order phase transition at T approximately 255 K. The temperature dependence of the spin-lattice relaxation time and the line width between 80 and 300 K is also reported. The splitting of the resonance line in the low-temperature phase (LTP) was shown to behave as an order parameter of the phase transition. The experimental order parameter and the anomalous behaviour of the line width near the transition point were interpreted satisfactorily in terms of the librational soft-mode theory, which assumes anharmonic coupling between molecular librational modes in the crystal. The results also show that the totality of results in the LTP is consistent with the onset of reorientations of nitro groups. The parameters deduced are compared with those obtained in our studies of the n-nitrobenzene sulphonyl chloride family of compounds.

Analysis of hydroxyproline in urine by high-performance liquid chromatography after dabsyl-chloride derivatization

In order to analyse hydroxyproline (HYP) in urine, a high-performance liquid chromatographic method was modified. The primary amino groups were blocked with o-phthalaldehyde, and then the secondary amino groups were derivatized with 4-dimethylaminoazobenzene-4'-sulphonyl chloride. In addition, the dabsylated samples were treated with ethyl acetate to obtain a simple elution profile in high-performance liquid chromatography. The dabsyl-HYP and -proline were eluted at 4.7 min and 8.0 min, respectively. The chromatographic analysis was completed within 10 min, including the time needed for reequilibration of the column. Using the present method, the concentration of HYP in urine was determined to 260 ± 6µmol/l.

An HPLC assay for detection of elevated urinary S-sulphocysteine, a metabolic marker of sulphite oxidase deficiency.

Sulphite oxidase deficiency occurs in man in two forms, as the isolated deficiency and as a syndrome of combined molybdoenzyme deficiency. This latter pleiotropic condition has as its underlying cause a defect in the synthesis of the molybdenum cofactor required for the activity of all molybdoenzymes in humans. Difficulties in diagnosis of sulphite oxidase deficiency are often encountered. A new method for detection of a key diagnostic metabolite, S-sulphocysteine, is outlined. The procedure is based on precolumn derivatization of urinary amino acids with dimethylaminoazobenzene sulphonyl chloride (Dabsyl-Cl) and resolution of the modified S-sulphocysteine by reversed-phase HPLC. A number of affected patients and control individuals with similar clinical symptoms have been studied, and a clear demarcation between the two groups has been noted.

An NQR study of the thermally activated motion of nitro groups in 3-nitrobenzene sulphonyl chloride

A study of the temperature dependence of the 35Cl NQR frequency and linewidth, and the 35Cl and 37Cl spin-lattice relaxation times, in 3-nitrobenzene sulphonyl chloride (3:NO2- phi -SO2Cl) is reported. The pressure dependence of the 35Cl frequency is also reported. The latter measurements indicate the existence of a first-order phase transition induced by pressure. It is shown that all the results are consistent with the onset of reorientations of NO2 groups. The parameters deduced, including the activation energy, are compared with those obtained from previous studies of 2:NO2- phi -SO2Cl and 4:NO2- phi -SO2Cl.

Unusual reactivity of 4-carboxyamido-2-oxazoline systems: new synthesis of optically active n-sulphonyl derivatives.

Optically active 2-alkyl-2-oxazoline-4-carboxyamides, derived from enantiomeric pure α-amino-β-hydroxy acids, react with aryl- and alkyl sulphonyl chlorides in pyridine affording the corresponding optically active 2-alkyl-2-oxazoline-4-carboxyamido- N-sulphonyl derivatives without appreciable racemization.

Precursors of N-nitroso compounds in some Nigerian medicinal plants

Twenty-seven tropical plants of medicinal importance were analysed for primary and secondary amines by chemiluminescence detection on a Thermal Energy Analyzer (TEA) modified for use on ‘nitrogen mode’ following derivatization with benzene sulphonyl chloride (BSC) and gas chromatographic (GC) separation of their sulphonamides. Nitrite was determined by colorimetry at 540 nm after diazotization with sulphanilamide and coupling with N-(1-naphthyl)ethylenediamine to form an azo dye. Nitrate was determined as nitrite following on-line reduction by granulated cadmium. Dimethylamine in the range of 0.5 ppm to 18.2 ppm was detected in 96% of samples, while pyrrolidine ranged between 0.7 ppm and 12.78 ppm in 14 samples. Isobutylamine, methylamine and ethylamine were the most ubiquitous primary amines. Largest number of secondary amines (four) was found in Azadirachta indica (Neem) while largest number of primary amines (six) was detected in Azadirachta indica and Tamarindus indica (Tsamiya) which also contained the highest amount of total primary amines (148.8 ppm). Nitrate and nitrite were seldom found in plant extracts whose pH were generally below 7.0. These findings suggests that early exposures to precursors of N-nitroso compounds via medicinal plants might contribute to total risk posed by environmental carcinogens in Nigeria.

Successful and Rapid Verification of the Presence of a Phosphate Group in Synthetic Phosphopeptides Using the Conditions of Standard Dabs-Cl Amino Acid Analysis

Abstract The increased importance of phosphopeptides, and the currently used post-assembly phosphorylation protocol in synthetic peptide laboratories, requires a rapid and sensitive method to verify the presence of the phosphate group in synthetic phosphopeptides. A reversed-phase high-performance liquid chromatography protocol has been developed to verify the success of the phosphorylation reaction in synthetic phosphopeptides after hydrolysis and derivatization with 4-dimethylamino-azobenzene-4′-sulphonyl chloride. Phosphoamino acid standards and model phosphopeptides were used to study the optimal elution and hydrolysis conditions of phosphoamino acids. A 1.5-hour, gas-phase acidic hydrolysis condition liberated the phosphoamino acids from the phosphopeptides, and still did not destroy them. After hydrolysis, the dabsylated free phosphoamino acids were baseline separated from the other acidic amino acids and were eluted from the reversed-phase column in the following order: phosphoserine, phosphothreon...

A new fluorescent triphenodioxazine dye derived from 4-aminodiphenylamine

A new substituent triphenodioxazine compound containing the 3,10-di(N-benzoyl-N-phenyl) amino has been synthesized. The benzoyl groups were introduced into the molecule during the cyclization of the dianilide derived from 4-amino-diphenylamine in the presence of benzoyl chloride as ring closure agent. The absorption and fluorescence spectra of the dye were measured in five solvents and it was found that the fluorescence quantum yields, Stokes shifts and molar extinction coefficients varied linearly with E T of the solvents. When using p-toluene sulphonyl chloride as ring closure agent, p-toluene sulphonyl groups were also introduced.

An NQR study of thermally activated molecular motion in 4-nitrobenzene sulphonyl chloride

A study of the temperature dependence of the 35Cl, NQR frequency and spin-lattice relaxation time in 4-nitrobenzene sulphonyl chloride is reported. The data indicate the existence of four crystalline phases. The observed behaviour of T1 in two of the phases is explained in terms of molecular librations, modulation effects due to the reorientation of NO2 groups, and reorientations between unequal potential wells of SO2SI groups. Values of the activation energies of these motions in both phases are estimated and compared with those obtained in 2-nitrobenzene sulphonyl chloride.

A study of activated molecular motion in 2-nitrobenzene sulphonyl chloride by NQR

A comprehensive chlorine nuclear quadrupole resonance study of the temperature and pressure dependences of frequency, line width and spin-lattice relaxation time in 2-nitrobenzene sulphonyl chloride is reported. The results show that each of the two substituted groups on the benzene ring contributes to the spin-lattice relaxation via a different and independent mechanism. In the high-temperature regime, the data are successfully explained assuming reorientation of the SO2Cl group between unequal potential wells and field gradient fluctuations resulting from reorientations of nearby NO2 groups. The activation energy of both motions and the fraction of the electric field gradient influenced by the motion of nitro groups have been estimated, as well as the pressure dependence of the activation enthalpy and the activation volume for these motions.

CHLOROSULFONATION OFN-ARYLMALEIMIDES

Abstract N-phenylmaleimides, o-, m-and p-substituted (1) reacted with excess chlorosulfonic acid to give the corresponding sulphonyl chlorides (2–5). These were condensed with amines and phenols to give derivatives (7–29) which underwent hydrolysis or ammonolysis to give respectively the sulfamoyl maleamic acids (31–34) and sulfamoyl maleamides (35–39).

High-performance liquid chromatographic determination of spectinomycin in swine, calf and chicken plasma

A rapid clean-up procedure based on ion-pair solid-phase extraction (SPE) for the high-performance liquid chromatographic (HPLC) determination of spectinomycin in swine, calf and chicken plasma at a limit of detection of 50 ng/ml is described. After dilution with water and adjustment of the pH to approximately 5.6, the plasma is applied to a high-hydrophobic C 18 SPE column treated with sodium dioctylsulphosuccinate. Spectinomycin is eluted with methanol and derivatized with 2-naphthalene sulphonyl chloride prior to chromatography. The HPLC set-up consists of a dual-column system using two Chromspher silica columns and dichloromethane—acetonitrile—ethyl acetate—acetic acid, in different ratios, as mobile phases. Detection is performed at 250 nm. Quantification is carried out using external standards prepared in blank cleaned plasma. Mean recoveries were 83 ± 3% ( n = 5), 93 ± 6% ( n = 5) and 92 ± 6% ( n = 6) for swine, calf and chicken plasma, respectively, at the 0.1 μg/ml level.

Determination of amino sugars in synthetic glycopeptides during the conditions of amino acid analysis utilizing precolumn derivatization and high-performance liquid chromatographic analysis

The growing number of synthetic glycopeptides required an in-house method for the analysis of the final products. A reversed-phase high-performance liquid chromatographic protocol was developed to verify the presence of N-acetylglucosamine and N-acetylgalactosamine in synthetic glycopeptides after hydrolysis and derivatization with 4-dimethylaminoazobenzene-4′- sulphonyl chloride. Different sugar and glycoamino acid standards were used to separate the two carbohydrate moieties, and the location of the derivatized 2-aminoglucose was established by the use of radiolabeled sugar. The utility of the approach is demonstrated by the amino acid analysis of N- and O-glycosylated synthetic peptides and the method could provide an alternative for sugar analysis of glycoproteins.

Reactivity ratios for new copolymerizations relevant to thermosetting resins

AbstractFree radical copolymerizations of four new systems, namely (1) methyl methacrylate (MMA) with β‐acryloxypropionic acid (AOPA); (2) MMA with p‐styrene sulphonyl chloride (SSC); (3) 2‐[(phenylamino) carbonyl] oxyethyl methacrylate (PCOMA) with 2‐phenoxyethyl methacrylate (PEMA); and (4) PCOMA with 1‐methyl‐2‐phenoxyethyl methacrylate (MPEMA), have been carried out at 60°C for systems 1 and 2 and at 70°C for systems 3 and 4. The copolymer compositions were analysed by acid‐base titration for system 1 and by FTIR for systems 2–4. The monomer reactivity ratios as well as the 95% individual confidence intervals and 95% joint confidence intervals were calculated from the Kelen‐Tüdős method, the Extended Kelen‐Tüdőos method, and from a new iterative linear method by Mao and Huglin. The results show that all these copolymerizations are strictly linear systems describable by the Mayo‐Lewis equation based on the terminal model and that accurate reactivity ratio data can be obtained. The Q‐e values of the monomers AOPA and SSC have been estimated. Some physical properties of AOPA, PEMA and MPEMA are also presented for the first time.