Fluorometric assay of tiopronin based on inhibition of multienzyme redox system

Xu, Juntian; Cai, Ruxiu; Wang, Jun; Liu, Zhihong; Wu, Xinguo

doi:10.1016/j.jpba.2005.03.004

Cited by 15 publications

(7 citation statements)

References 17 publications

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“…The British Pharmacopoeia recommend redox titration for GSH [7] and MPG, [8] and acidbase titration in non-aqueous media for PEN. [9] Other reported methods for determination of these RSH in pharmaceuticals include spectrophotometry, [10][11][12][13][14] fluorimetry, [15][16][17] chemiluminescence, [18][19][20] electroanalytical [21][22][23] and chromatographic techniques. [24][25][26] Flow injection analysis (FIA) became a versatile instrument tool for the quality control of pharmaceuticals in the 21 st century.…”

Section: Introductionmentioning

confidence: 99%

Flow-injection Determination of Glutathione, Penicillamine and Tiopronin Based on the Reduction of Copper(II)-neocuproine Reagent

2020

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A new flow-injection spectrophotometric method for the determination of glutathione (GSH), penicillamine (PEN) and tiopronin (mercaptopropionyl glycine, MPG) in pharmaceutical formulations is reported. The method is based on the reduction of Cu(II)-neocuproine reagent to Cu(I)-neocuproine by GSH, PEN or MPG in buffered medium (pH = 3) to form a stable coloured complex (λmax = 458 nm). Experimental conditions were optimized by univariate method, resulting with linear calibration curves in concentration range from 2 × 10 −6 to 3 × 10 −5 mol L −1 for GSH, 6 × 10 −7 to 4 × 10 −5 mol L −1 for PEN and 4 × 10 −7 to 4 × 10 −5 mol L −1 for MPG. The achieved analytical frequency was 180 h −1 for GSH and PEN and 120 h −1 for MPG. The proposed method was successfully applied for determination of GSH, PEN and MPG in pharmaceutical formulations, and the usual excipients in pharmaceuticals did not interfere with the analysis.

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Section: Introductionmentioning

confidence: 99%

Flow-injection Determination of Glutathione, Penicillamine and Tiopronin Based on the Reduction of Copper(II)-neocuproine Reagent

2020

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“…Additionally, it can increase intracellular concentration of glutathione and other non‐protein sulfydryl groups and thereby increase intracellular defense against oxygen free radicals (3). Several methods have already been reported for the quantitative determination of tiopronin, including spectrophotometry (4), fluorimetry (5,6), chemiluminescence (7), reversed‐phase high‐performance liquid chromatography (8) and high‐performance liquid chromatography–telectrospray ionization–mass spectrometry (9). Of all these methods, the most commonly used are high‐performance liquid chromatography, fluorimetry and spectrophotometry.…”

Section: Introductionmentioning

confidence: 99%

High‐sensitivity spectrofluorimetric determination of tiopronin based on inhibition of hemoglobin

2010

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A highly sensitive and simple spectrofluorimetric method for the determination of tiopronin based on its inhibitory effect on the hemoglobin-catalyzed reaction of H(2)O(2) and L-tyrosine was developed. The concentration of tiopronin is linear with decreased fluorescence (ΔF) of the system under the optimal experimental conditions. The calibration graph is linear in the range 1.23 × 10(-8) to 3.06 × 10(-5) mol L(-1) with a detection limit of 6.13 × 10(-9) mol L(-1). The relative standard deviation was 4.38% for 11 determinations of 6.13 × 10(-6) mol L(-1). This method can be used for the determination of tiopronin in pharmaceuticals with satisfactory results.

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“…Several methods have been developed for the determination of tiopronin such as chemiluminescent methods (Zhao et al, 1997;Lu et al, 2003), fl uorimetric methods (Ruiz et al, 1996;Xu et al, 2005), gas chromatography-mass spectrometry (GC-MS) method (Matsuura and Takashina, 1993) and electrochemical oxidation by amperometric fl ow injection analysis (Siangproh et al, 2003). Equipment for the chemiluminescent, fl uorimetric and electrochemical methods are not commonly available in laboratories, however, because of the need for specifi c detectors.…”

Section: Introductionmentioning

confidence: 99%

Sensitive LC‐MS‐MS method for the determination of tiopronin in human plasma

Jiang

et al. 2009

Biomedical Chromatography

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A highly selective and sensitive LC-MS-MS method was developed and validated to quantify tiopronin in human plasma, using fudosteine as the internal standard (IS). L-Cysteine and 1,4-dithiothreitol (DTT) were used as the reducer and the stabilizer to release and stabilify tiopronin from a dimmer and mix forms with endogenous thiols in the treatment of plasma samples. After a simple liquid-liquid extraction with ethyl acetate in acidic condition, the post-treatment samples were analyzed on a C(18) column interfaced with a triple-quadruple tandem mass spectrometer using negative electrospray ionization. Methanol and water (40:60, v/v) were used as the isocratic mobile phase, with 0.2% formic acid and 1.0 mM tris (hydroxymethyl) aminomethane (Tris) in water. The method was validated to demonstrate the specificity, lower limit of quantification, accuracy and precision of measurements. The assay was linear over the concentration range 0.078-10 microg/mL. The correlation coefficients for the calibration curves ranged from 0.9980 to 0.9990. The intra- and inter-day precisions, calculated from quality control samples, were not more than 10.49%. The method was employed in a pharmacokinetic study after oral administration of 200 mg tiopronin tablets to 24 healthy volunteers.

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Fluorometric assay of tiopronin based on inhibition of multienzyme redox system

Cited by 15 publications

References 17 publications

Flow-injection Determination of Glutathione, Penicillamine and Tiopronin Based on the Reduction of Copper(II)-neocuproine Reagent

Flow-injection Determination of Glutathione, Penicillamine and Tiopronin Based on the Reduction of Copper(II)-neocuproine Reagent

High‐sensitivity spectrofluorimetric determination of tiopronin based on inhibition of hemoglobin

Sensitive LC‐MS‐MS method for the determination of tiopronin in human plasma

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