benzofurans and acetonitrile

The present work aimed to synthesise promising antioxidant compounds as a valuable alternative to the currently expensive and easily degradable molecules that are employed as stabilizers in industrial preparation. Taking into account our experience concerning domino Friedel-Crafts/lactonization reactions, we successfully improved and extended the previously reported methodology toward the synthesis of 3,3-disubstituted-3

Topics: Acetonitriles; Alkylation; Antioxidants; Benzofurans; Biphenyl Compounds; Electrochemistry; Kinetics; Methanol; Oxidation-Reduction; Phenols; Picrates; Regression Analysis; Solvents

The current environmental legislations recommend monitoring chemical contaminants such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans before the use of sewage sludge on the agricultural land. In this study, a solid-liquid extraction with low-temperature purification (SLE-LTP) was optimized and validated to determine 2,3,7,8-tetrachlorodibenzo-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in sewage sludge and soil samples. The analyses were performed by gas chromatography-mass spectrometry operating in the selective ion mode (GC-MS-SIM). Acetonitrile:ethyl acetate 6.5:1.5 (v/v) was the best extraction phase, and the recoveries percentages were close to 100%. The linearity was demonstrated in the range of 1.25-25 µg L

Topics: Acetonitriles; Agriculture; Benzofurans; Brazil; Chemical Fractionation; Cities; Dibenzofurans, Polychlorinated; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Limit of Detection; Polychlorinated Dibenzodioxins; Sewage; Soil Pollutants

A quantitative analysis method of multi-components with a single marker (QAMS) for simultaneous determination of six marker compounds (one from phenolic acids and five from phthalides) in Chuanxiong Rhizoma was established by applying HPLC and using butylidenephthalide as the internal reference substance. And also the feasibility and accuracy of the established method for quality evaluation and application of Chuanxiong Rhizoma were investigated and validated. The analysis was performed with the mobile phase consisting of acetonitrile - 0.2% aqueous formic acid. The flow rate was 1.0 mL . min-1 and the column temperature was maintained at 30 °C. The detection wavelengths were set at 252 nm (for ferulic acid, Z-ligustilide, and butylidenephthalide) and 266 nm (for senkyunolide I, senkyunolide A, and coniferyl ferulate), separately, and 20 µL was injected for analysis with gradient elution. The results showed that there were no significant differences observed between the HPLC-QAMS method and the external standard method (RSD <5%). The relative correction factors were credible (RSD < 5%) in changed chromatographic conditions. The established HPLC-QAMS method can be accurately used for simultaneously evaluating and controlling the quality of Chuanxiong Rhizoma with multi-components.

Topics: 4-Butyrolactone; Acetonitriles; Benzofurans; Chromatography, High Pressure Liquid; Coumaric Acids; Drugs, Chinese Herbal; Hydroxybenzoates; Quality Control; Rhizome

The first example of the palladium-catalyzed one-pot synthesis of 2-arylbenzofurans in moderate to excellent yields via a tandem reaction of 2-hydroxyarylacetonitriles with sodium sulfinates is reported. A plausible mechanism for the formation of 2-arylbenzofurans involving desulfinative addition and intramolecular annulation reactions is proposed. Moreover, the present synthetic route to benzofurans could be readily scaled up to the gram quantity without any difficulty. Thus, the method represents a convenient and practical strategy for synthesis of benzofuran derivatives.

Topics: Acetonitriles; Benzofurans; Catalysis; Chemistry, Organic; Palladium; Sulfinic Acids

The illicit drug market of psychoactive substances for human abuse is continuously expanding and developing. Besides already known substance classes like cathinones, amphetamines or synthetic cannabinoids, further derivatives such as benzofurys, thiophenes, and structural analogues of methylphenidate entered the global market recently. As many of these new compounds contain a stereogenic centre it is supposed that their isomers may differ in their pharmacological effects as it is the case with amphetamines or several chiral active pharmaceutical ingredients, for instance. In the course of this study, a method for the chiral separation of a set of 16 recreational drugs by CE was developed. The aim was to separate the analytes into their enantiomers at equal conditions within short time. Sulfobutylether β-cyclodextrin served as chiral selector in an aqueous ammonium acetate solution containing ACN. For method optimization, methedrone and ethylphenidate were used as model compounds to find the appropriate concentration of chiral selector. Moreover, the influence of the pH value on enantioseparation was tested. Fourteen or 16 mM sulfobutylether β-cyclodextrin, 50 mM ammonium acetate solution (pH 4.5) with 10% ACN were found to be optimal for enantioseparation of seven benzofurys, four cathinones, two diphenidines, ethylphenidate, methiopropamine, and thiothinone. Most of them were baseline resolved at migration times below 25 min.

Topics: Acetonitriles; Benzofurans; beta-Cyclodextrins; Electrophoresis, Capillary; Hydrogen-Ion Concentration; Illicit Drugs; Methylphenidate; Propylamines; Psychotropic Drugs; Reproducibility of Results; Stereoisomerism; Substance Abuse Detection

A simple and quick method is described for the determination of ferulic acid, senkyunolide I, senkyunolide H, senkyunolide A and ligustilide in rhizomes of Ligusticum chuanxiong. The 5 active ingredients in the sample was extracted using 40% ethanol and analyzed by reversed-phase high performance liquid chromatography (HPLC). Chromatography separation was performed using Agilent 1100 series HPLC system with a Symmetry C18 column and gradient elution with a mixture of three solvents : solvent A, acetonitrile, solvent B, methanol and solvent C, 1% aqueous acetic acid, 0 min to 5 min A: B: C 20: 40: 40, 5 min to 30 min A: B: C 60 to 100 : 0 : 40 to 0. The effluent was monitored using a VWD detector set at 321 nm (0-4.3 min) and 275 nm (4.31-30 min). The flow rate was set at 1 mL x min(-1) and the injection volume was 10 microL. The column temperature was maintained at 35 degrees C. The calibration curve was linear (r > or = 0.99) over the tested ranges. The average recovery was 94.44%-103.1% (n = 6). The method has been successfully applied to the analysis in different harvest periods of L. chuanxiong samples. In this paper, single-factor randomized block design to study the 5 components content of L. chuanxiong on ten collecting stages. For the L. chuanxiong collected from April 15th to May 30rd, the content of 5 ingredients increased primarily, and then decreased. Determine the appropriate harvest time has important significance to the promotion of the quality of L. chuanxiong.

Topics: 4-Butyrolactone; Acetic Acid; Acetonitriles; Benzofurans; Chromatography, High Pressure Liquid; Coumaric Acids; Ligusticum; Methanol; Solvents; Time Factors

A new liquid chromatography with tandem mass spectrometry method was developed and validated for the simultaneous determination of trifolirhizin, (-)-maackiain, (-)-sophoranone, and 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran from Sophora tonkinensis in rat plasma using chlorpropamide as an internal standard. Plasma samples (50 μL) were prepared using a simple deproteinization procedure with 150 μL of acetonitrile containing 100 ng/mL of chlorpropamide. Chromatographic separation was carried out on an Acclaim RSLC120 C18 column (2.1 × 100 mm, 2.2 μm) using a gradient elution consisting of 7.5 mM ammonium acetate and acetonitrile containing 0.1% formic acid (0.4 mL/min flow rate, 7.0 min total run time). The detection and quantitation of all analytes were performed in selected reaction monitoring mode under both positive and negative electrospray ionization. This assay was linear over concentration ranges of 50-5000 ng/mL (trifolirhizin), 25-2500 ng/mL ((-)-maackiain), 5-250 ng/mL ((-)-sophoranone), and 1-250 ng/mL 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran) with a lower limit of quantification of 50, 25, 5, and 1 ng/mL for trifolirhizin, (-)-maackiain, (-)-sophoranone, and 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran, respectively. All the validation data, including the specificity, precision, accuracy, recovery, and stability conformed to the acceptance requirements. The results indicated that the developed method is sufficiently reliable for the pharmacokinetic study of the analytes following oral administration of Sophora tonkinensis extract in rats.

Topics: Acetates; Acetonitriles; Animals; Benzodioxoles; Benzofurans; Blood Chemical Analysis; Calibration; Chromatography, Liquid; Flavonoids; Formates; Glucosides; Heterocyclic Compounds, 4 or More Rings; Limit of Detection; Linear Models; Male; Plant Extracts; Pterocarpans; Quality Control; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Sophora; Tandem Mass Spectrometry

Three sensitive, selective, accurate spectrophotometric and spectrofluorimetric methods have been developed for the determination of ropinirole hydrochloride in tablets. The first method was based on measuring the absorbance of drug solution in methanol at 250 nm. The Beer's law was obeyed in the concentration range 2.5-24 microg ml(-1). The second method was based on the charge transfer reaction of drug, as n-electron donor with 7,7,8,8-tetracyanoquinodimethane (TCNQ), as pi-acceptor in acetonitrile to give radical anions that are measured at 842 nm. The Beer's law was obeyed in the concentration range 0.6-8 microg ml(-1). The third method was based on derivatization reaction with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in borate buffer of pH 8.5 followed by measuring the fluorescence intensity at 525 nm with excitation at 464 nm in chloroform. Beer's law was obeyed in the concentration range 0.01-1.3 microg ml(-1). The derivatization reaction product of drug with NBD-Cl was characterized by IR, 1H NMR and mass spectroscopy. The developed methods were validated. The following analytical parameters were investigated: the molar absorptivity (epsilon), limit of detection (LOD, microg ml(-1)) and limit of quantitation (LOQ, microg ml(-1)), precision, accuracy, recovery, and Sandell's sensitivity. Selectivity was validated by subjecting stock solution of ropinirole to acidic, basic, oxidative, and thermal degradation. No interference was observed from common excipients present in formulations. The proposed methods were successfully applied for determination of drug in tablets. The results of these proposed methods were compared with each other statistically.

Topics: Acetonitriles; Benzofurans; Borates; Buffers; Calibration; Chloroform; Dopamine Agonists; Hydrogen-Ion Concentration; Indoles; Magnetic Resonance Spectroscopy; Mass Spectrometry; Methanol; Molecular Structure; Nitriles; Phosphates; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Fluorescence; Spectrophotometry; Tablets

Usnic acid is unambiguously confirmed by tandem mass spectrometry (MS/MS) in tumbleweed shield lichen, Xanthoparmelia chlorochroa. The lichen contains 2% usnic acid by liquid chromatography with UV quantification at 282 nm. The UV linear range for usnic acid quantification is from its 4 ng limit of detection to 2 microg injected. UV signal saturation is recognized by distortion of the usnic acid UV spectrum. Positive ion electrospray-tandem mass spectrometry offers no similar means to recognize quantification data recorded above the linear range of electrospray. Electrospray ionization capacity and matrix effects limit the reliability of tandem mass spectrometry quantification. The combination of UV quantification and MS confirmation provides a reliable analytical method for measuring usnic acid levels in plant material.

Topics: Acetone; Acetonitriles; Animals; Benzofurans; Chromatography, High Pressure Liquid; Deer; Lichens; Solubility; Spectrometry, Mass, Electrospray Ionization; Wyoming

A precise and reproducible HPLC method has been established and validated for determination of salvianolic acid B (SalB) in rat plasma after oral administration of Radix Salviae Miltiorrhizae extract. Liquid-liquid extraction was adopted for the sample preparation. Separation was accomplished on a C(18) column with a linear gradient elution consisting of acetonitrile and aqueous phosphoric acid. Ultraviolet detection was at 280 nm. The method was validated over the concentration range 10.8-259.4 microg/mL using 1 mL of plasma. The assay was linear over this concentration range with a coefficient of variation less than 7%. The extraction recovery of SalB was within the range 71-83% with RSD 11%. The mean recovery of the internal standard was 84% (n = 6) with RSD of 5.6%. This method is suitable to determine SalB in plasma and to investigate the pharmacokinetics of SalB.

Topics: Acetonitriles; Administration, Oral; Animals; Benzofurans; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Male; Phosphoric Acids; Plant Extracts; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Salvia miltiorrhiza; Sensitivity and Specificity