scholarly journals Micro-level Estimation of Methionine Using Inhibitory Kinetic Spectrophotometric Method

2020 ◽  
Vol 11 (3) ◽  
pp. 10654-10663
Keyword(s):  
Quantitative Estimation ◽  
Bioactive Molecules ◽  
Stable Complex ◽  
Kinetic Measurements ◽  
Kinetic Determination ◽  
Mechanism Of Inhibition ◽  
Optimum Reaction ◽  
Amino Acid Methionine ◽  
Micro Level ◽  
Kinetic Spectrophotometric

A large number of bioactive molecules and drugs contain sulfur as an important constituent. Organo-sulfur compounds form a stable complex with Hg2+, thereby inhibiting its catalytic activity. The Hg2+ catalyzed the exchange rate of cyanide with nitroso-R-salt [N-R-salt] from [Ru(CN)6]4- will be reduced by the addition of sulfur-containing amino acid, methionine (MET). This inhibitory property of MET can be employed for its micro-level kinetic determination. Optimum reaction condition viz. I=0.05 M (KNO3), pH = 7.0 ± 0.02, [Ru(CN)64] = 5.25 × 10-5 M, [N-R-salt] = 6.5 × 10-4 M, [Hg+2] = 5.5 × 10-5 M, and Temperature = 45.0 ± 0.1 o C were utilized to investigate the kinetic measurements at 525 nm (λmax of [Ru(CN)5 N-R-salt]3- complex). To explain the mechanism of inhibition caused by methionine on Hg2+ catalyzed exchange of cyanide with N-R-salt from [Ru(CN)6]4-, a modified mechanistic scheme has been proposed. MET can be quantitatively determined up to 2.5 × 10-6 M level by the proposed analytical method. The methodology can be economically and effectively employed for the quantitative estimation of MET in distinct samples.

scholarly journals Quantitative Estimation of D-Penicillamine in Pure and Pharmaceutical Samples Using Inhibitory Kinetic Spectrophotometric Method

2020 ◽  
Vol 11 (4) ◽  
pp. 11404-11417
Keyword(s):  
Quantitative Estimation ◽  
Catalytic Efficiency ◽  
Bioactive Molecules ◽  
Stable Complex ◽  
Kinetic Measurements ◽  
Kinetic Determination ◽  
Pharmaceutical Samples ◽  
Optimum Reaction ◽  
Kinetic Spectrophotometric

Sulfur is the key element in a large number of drugs and bioactive molecules. Organo-sulfur compounds inhibit the catalytic efficiency of Hg2+ by forming a stable complex with it. The Hg2+ catalyzed exchange rate of cyanide with pyrazine from [Ru(CN)6]4- will be reduced by the addition of the sulfur-containing drug, D-penicillamine (D-PCN). This inhibitory property of D-PCN can be employed for its micro-level kinetic determination. Optimum reaction condition viz. Temperature = 45.0 ± 0.1 o C, I = 0.1 M (KCl), [Hg+2] = 1.5 × 10-4 M, [pyrazine] = 7.5 × 10-4 M, pH = 4.0 ± 0.02, and [Ru(CN)64-] = 5.25 × 10-5 M were utilized to investigate the kinetic measurements at 370 nm (λmax of [Ru(CN)5 Pz]3- complex). To acknowledge the inhibition induced by D-PCN on Hg2+ catalyzed substitution of cyanide with pyrazine from [Ru(CN)6]4-, a modified mechanistic scheme has been proposed. D-PCN can be quantitatively determined up to 1.0 × 10-6 M level by the proposed analytical method. The methodology can be economically and effectively employed for the quantitative determination of D-PCN in different samples. This methodology can also be convincingly adopted for the quick determination of D-PCN in the pharmaceutical samples with good accuracy and reproducibility. The addition of common excipients in pharmaceuticals even up to 1000 times with [D-PCN] does not interfere significantly in the estimation of D-PCN.

scholarly journals Micro-level Estimation of Mercaptoacetic Acid Using its Inhibitory Effect to Mercury Catalyzed Ligand Exchange Reaction of Hexacyanoruthenate(II)

2020 ◽  
Vol 10 (6) ◽  
pp. 7152-7161
Keyword(s):  
Kinetic Method ◽  
Inhibitory Effect ◽  
Bioactive Molecules ◽  
Mercaptoacetic Acid ◽  
Ligand Exchange Reaction ◽  
Donor Ligand ◽  
Cyanide Ligand ◽  
Quality Check ◽  
Micro Level ◽  
Kinetic Spectrophotometric

The sulfur-containing bioactive molecules (soft base) tends to bind strongly with Hg(II) (soft acid), thereby inhibiting the mercury (II) catalyzed exchange rate of cyanide ligand from [Ru(CN)6]4- by pyrazine. This inhibitory effect of Mercaptoacetic acid (MAA) encourages us to establish a new kinetic method for its micro-level estimation. Optimized reaction condition viz. 6.25×10-5 M [Ru(CN)64-], pH = 4.0, 7.5×10-4 M [Pyrazine], 0.05 M KCl, 8.5 ×10-5 M [Hg+2] and 45 (±0.1) oC temperature were utilized for the kinetic spectrophotometric investigation at 370nm (λmax of [Ru(CN)5 Pz]3- complex). The modified mechanistic scheme for inhibition caused by sulfur donor ligand, MAA has been proposed. The proposed analytical method provides the detection of MAA up to 2.0 × 10-6 M, indicates that the methodology can be effectively and economically employed to analyze the biological samples having MAA. This method can also be convincingly adopted for the quality check of MAA containing industrial products.

scholarly journals A Simple and Sensitive Inhibitory Kinetic Method for the Carbocisteine Determination

2021 ◽  
Vol 66 (1) ◽  
Author(s):  
Abhishek Srivastava ◽  
Vivek Sharma ◽  
Vinay Kumar Singh ◽  
Krishna Srivastava
Keyword(s):  
Good Accuracy ◽  
Quantitative Estimation ◽  
Kinetic Method ◽  
Fixed Time ◽  
Disodium Salt ◽  
Disulfonic Acid ◽  
Stable Complex ◽  
Reaction Conditions ◽  
Kinetic Determination

Abstract. A fast, reproducible, and sensitive method is proposed for the kinetic determination of carbocisteine (CCys). The method depends on the inhibitory property of carbocisteine, which reduces the Hg2+ catalyzed substitution rate of cyanide from [Ru(CN)6]4- with N-R-salt (1-Nitroso-2-naphthol-3,6-disulfonic acid disodium salt) via forming a stable complex with Hg2+. Spectrophotometric measurements were carried out by recording the absorbance at 525 nm (λmax of [Ru(CN)5 Nitroso-R-Salt]3- complex) at a fixed time of 10 and 15 min under the optimized reaction conditions with [N-R-salt] = 4.5 × 10-4 M, I = 0.05 M (KNO3), Temp = 45.0 ± 0.2 o C, pH = 7.0 ± 0.03, [Hg2+] = 8.0 × 10-5 M and [Ru(CN)64-] = 4.25 × 10-5  M. With the proposed method, CCys can be determined quantitatively down to 3.0 × 10-6 M. This methodology can be effectively used for the rapid quantitative estimation of CCys in the pharmaceutical samples with good accuracy and reproducibility. The addition of common excipients in pharmaceuticals even up to 1000 times with [CCys] does not interfere significantly in the estimation of CCys.   Resumen. Se propone un método rápido, reproducibley sensible para la determinación cinética de la carbocisteina (CCys). El método depende de la propiedad inhibitoria de la carbocisteina que reduce la tasa de sustitución catalizada por Hg2+ del cianuro de [Ru(CN)6]4- con la sal N-R (sal disódica del ácido 1-Nitroso-2-naftol-3,6-disulfónico) mediante la formación de un complejo estable con Hg2+. Las mediciones espectrofotométricas se llevaron a cabo registrando la absorbancia a 525 nm (λmax del complejo [Ru(CN)5 Sal-Nitroso-R]3-) en un tiempo fijo de 10 y 15 min en las condiciones de reacción optimizadas con [sal-NR] = 4.5 × 10-4 M, I = 0.05 M (KNO3), Temp = 45.0 ± 0.2 o C, pH = 7.0 ± 0.03, [Hg2+] = 8.0 × 10-5 M y [Ru(CN)64-] = 4.25 × 10-5 M. Con el método propuesto, CCys se puede determinar cuantitativamente hasta 3,0 × 10-6 M. Esta metodología se puede utilizar eficazmente para la estimación cuantitativa rápida de CCys en las muestras farmacéuticas con buena precisión y reproducibilidad. La adición de excipientes comunes en productos farmacéuticos incluso hasta 1000 veces con [CCys] no interfiere significativamente en la estimación de CCys.

scholarly journals Embelin: an HPTLC method for quantitative estimation in five species of genus Embelia Burm. f.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
K. P. Rini Vijayan ◽  
A. V. Raghu
Keyword(s):  
High Performance ◽  
Quantitative Estimation ◽  
Biological Activities ◽  
Bioactive Molecules ◽  
Plant Parts ◽  
Embelia Ribes ◽  
Ich Guidelines ◽  
Medicinal Properties ◽  
Taxonomic Studies ◽  
Hptlc Method

Abstract Background The plants belonging to the genus Embelia, a significant tropical genus with many biological activities, are benefiting because of their robust medicinal properties. Embelin is one of the principal bioactive molecules responsible for the medicinal properties of the genus Embelia. The quantification of the embelin compound among different species in this genus has not yet been investigated, so still uncertain which species and which part should be accepted. The present study was intended to establish a speedy and precise high-performance thin-layer chromatographic (HPTLC) method for quantitative study of embelin in various plant parts of Embelia ribes, Embelia tsjeriam-cottam, Embelia basaal, Embelia adnata, and Embelia gardneriana. Result This research confirmed the method as per the International Conference on Harmonization (ICH) guidelines. We achieved separation on silica gel 60 F254 HPTLC plates using propanol: butanol: ammonia (7:3:7 v/v/v) as a mobile phase. Densitometry scanning performed for detection and quantification at 254 nm and 366 nm. Among the species investigated, the highest amount of embelin was found in E. ribes fruits. Conclusion Embelia ribes fruits are the best source of embelin. Embelin was first described in the endemic species, such as E. adnata and E. gardneriana. The method illustrated in this research may be applied for quantification of embelin and fingerprint analysis of other species within Embelia genus or described genera and chemo taxonomic studies of this genus.

scholarly journals Kinetic spectrophotometric determination of Co(II) ion by the oxidation of ponceau 4R by hydrogen peroxide

2006 ◽  
Vol 71 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Zora Grahovac ◽  
Snezana Mitic ◽  
Emilija Pecev ◽  
Snezana Tosic
Keyword(s):  
Hydrogen Peroxide ◽  
Kinetic Method ◽  
Calibration Graph ◽  
Borate Buffer ◽  
Linear Calibration ◽  
Reaction Conditions ◽  
Ponceau 4R ◽  
Optimum Reaction ◽  
Kinetic Spectrophotometric

Anew, sensitive and simple kinetic method has been developed for the determination of traces of Co(II) ions based on their catalytic effect in the oxidation of trisodium-2-hydroxy-1-(4-sulphonato-1-naphthylazo)naphthalene-6,8-disulphonate (red artificial color Ponceau 4R) by hydrogen peroxide in borate buffer. The reaction was followed spectrophotometrically by tracing the oxidation product at 478.4 nm within 1 min after the initiation of the reaction. The optimum reaction conditions are: borate buffer (pH 10.50), Ponceau 4R (8 x10-6 mol/dm3), H2O2 (3 x10-2 mol/dm3) at 22 ?C. Following this procedure, Co(II) can be determined with a linear calibration graph up to 1.17 ng/cm3 and a detection limit of 0.20, based on the 3??criterion. The relative error ranges between 4.80-3.25 % for the concentration interval of Co(II) ions 1.76-17.61 ng/cm3. The effects of certain foreign ions on the reaction rate were determined for an assessment of the selectivity of the method. The method was applied for the determination of Co(II) in pharmaceutical samples.

Study of the Catalytic Effects of Trace Titanium on Oxidation of Pyronin B with Hydrogen Peroxide and its Application

2012 ◽  
Vol 602-604 ◽  
pp. 1233-1237
Author(s):  
Zhi Rong Zhou ◽  
Li Zhen Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Medium ◽  
Reaction Conditions ◽  
Relative Standard ◽  
Extraction Separation ◽  
Optimum Reaction ◽  
Kinetic Spectrophotometric ◽  
Replicate Measurements ◽  
Catalytic Effects

A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts titanium (IV), based on the catalytic effect of Ti (IV) on the oxidation pyronin B with hydrogen peroxide in 0.02 mol/L sulfuric acid, is described. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of pyronin B at 555 nm. The detection limit of the method is 0.017 μg/L, and the linear range is 0.055–1.0 µg/L. The influences of reaction medium and acidity, concentrations of reactants, reactive temperature and foreign ions is also discussed. The optimum reaction conditions were established. The relative standard deviation for 11 replicate measurements of 0.010 and 0.020 μg/25mL of titanium (IV) were 2.8 % and 2.3 %, respectively. In combination with solvent extraction separation, the method has been successfully applied to the determination of trace titanium (IV) in rock samples. The results are in good agreement with the certified volumes with the relative standard deviations (RSD) of 1.6 %–3.6 %.

scholarly journals Simultaneous Kinetic Spectrophotometric Determination Of Ascorbic Acid And Cysteine With An Optical Probe By Mean Centering Of Ratio Kinetic Profiles Method

2019 ◽  
Vol 14 (3) ◽  
pp. 163-170
Author(s):  
A.B. Vishnikin ◽  
Yu.V. Miekh ◽  
Ya.R. Bazel ◽  
M.E.A. Al-Shwaiyat ◽  
G.O. Petrushina
Keyword(s):  
Ascorbic Acid ◽  
Binary Mixture ◽  
Standard Addition ◽  
Optical Probe ◽  
Addition Method ◽  
Kinetic Measurements ◽  
Mean Centering ◽  
The Difference ◽  
Kinetic Spectrophotometric

A procedure for simultaneous kinetic analysis of a binary mixture of ascorbic acid (Asc) and cysteine (Cys) was developed using the method of mean centering of ratio kinetic profiles. The method is based on the difference in the rate of reactions of Asc and Cys with the complex of iron(III) with o-phenanthroline at pH 7.05. The use of an optical probe simplifies the carrying out of kinetic measurements, allows to obtain highly reproducible (Sr=0.01-0.02) results, and significantly reduces the time of analysis. The method of mean centering of ratio kinetic profiles is superior to the H-Point standard addition method, since it does not require such a long measurement time and there is no restriction on the constancy of absorbance of one of the components. Asc and Cys can be determined in the concentration range from 1 to 10 mg/L. The method was successfully used to determine Asc and Cys in dietary supplements.

scholarly journals Kinetic determination of morin nanoamounts

2004 ◽  
Vol 69 (6) ◽  
pp. 477-484 ◽  
Author(s):  
Danijela Kostic ◽  
Snezana Mitic ◽  
Gordana Miletic
Keyword(s):  
Reaction Rate ◽  
Limit Of Detection ◽  
Kinetic Equations ◽  
Calibration Graph ◽  
Linear Calibration ◽  
Kinetic Determination ◽  
Concentration Interval ◽  
Kinetic Spectrophotometric ◽  
The Given

kinetic-spectrophotometric method is proposed for the determination of morin. The method is based on the inhibition effect of morin on the oxidation of C6H5COON aby hydrogen peroxide in the presence of the complex Fe(II)-AA(ascorbic acid),which acts as a catalyst. The concentration range for the determination of morin is one of the lowest achieved so far (a linear calibration graph was obtained for morin from 2.255?22.55 ng cm-3). The limit of detection of the method is 0.28 ng cm-3. The relative error ranges between 1.42 to 5.10% for the given concentration interval. Kinetic equations are proposed for the investigated process. The effects of certain foreign ions upon the reaction rate were determined in order to assess the selectivity of the method. The major advantages of this kinetic-spectrophotometric assay are its sensitivity, selectivity, reproducibility, speed and simplicity.

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