Micellar oxidative transformation of ciprofloxacin: a kinetic investigation

2017 ◽  
Vol 14 (4) ◽  
pp. 231 ◽  
Author(s):  
Alpa Shrivastava ◽  
Ajaya Kumar Singh ◽  
Neerja Sachdev ◽  
Dilip R. Shrivastava ◽  
Surendra Prasad
Keyword(s):  
Degradation Products ◽  
Degradation Mechanism ◽  
Sodium Dodecyl ◽  
Oxidative Degradation ◽  
Activation Parameters ◽  
Solvent Polarity ◽  
Major Product ◽  
Oxidative Transformation ◽  
Chlorination Process ◽  
Antibiotic Drugs

Environmental contextPollution of the aquatic environment by drugs results not only during their manufacture, but also from the excretion of drug residues and the discharge of expired drugs by households and hospitals. The transformation of ciprofloxacin, one of the leading antibiotic drugs, in the presence of surfactants has been investigated. The results provide a better understanding of how ciprofloxacin degrades in aquatic environments by considering the effect of omnipresent surfactants. AbstractThe kinetics of the oxidative transformation, i.e. oxidative degradation, of ciprofloxacin (CIP) by chloramine-T (CAT) in cationic and anionic micelle media during the water chlorination process was studied spectrophotometrically at 275nm and 298K. The influence of added salts (1–10×10–4moldm–3) and solvent polarity of the medium on the reaction was studied. The orders with respect to substrate CIP and oxidant CAT were found to be first order in each. The variation of acid concentrations showed opposite effects in cationic and anionic micellar aggregates. Liquid chromatography–electrospray ionisation mass spectrometry was used to identify degradation products of CIP, which confirmed the full dealkylation of the piperazine ring in CIP as the major product. The piperazine moiety of CIP is the principal active site for the CAT during oxidation. Activation parameters for the CIP degradation in cationic and anionic micelles were evaluated by studying the reaction at different temperatures, which lent further support to the proposed degradation mechanism for CIP. The rate constants were evaluated to confirm the micellar effect from incorporating sodium dodecyl sulfate and cetyltrimethylammonium bromide in the reaction mixture and the intrinsic reactivity constants were determined in the aqueous as well as in the micellar pseudo-phases as 4.85 and 0.0083.

Kinetics of metribuzin degradation by colloidal manganese dioxide in absence and presence of surfactants

2014 ◽  
Vol 68 (1) ◽  
Author(s):  
Qamruzzaman ◽  
Abu Nasar
Keyword(s):  
Sodium Dodecyl ◽  
Oxidative Degradation ◽  
Activation Parameters ◽  
Water Soluble ◽  
Ionic Surfactant ◽  
Ammonium Bromide ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Colloidal Mno2 ◽  
Kinetics Of

AbstractThe kinetics of the degradation of metribuzin by water-soluble colloidal MnO2 in acidic medium (HClO4) were studied spectrophotometrically in the absence and presence of surfactants. The experiments were performed under pseudo-first-order reaction conditions in respect of MnO2. The degradation was observed to be of the first order in respect of MnO2 while of fractional order for both metribuzin and HClO4. The rate constant for the degradation of metribuzin was observed to decrease as the concentration of MnO2 increased. The anionic surfactant, sodium dodecyl sulphate (SDS), was observed to be ineffective whereas the non-ionic surfactant, Triton X-100 (TX-100), accelerated the reaction rate. However, the cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), caused flocculation with oppositely-charged colloidal MnO2; hence further study was not possible. The catalytic effect of TX-100 was discussed in the light of the available mathematical model. The kinetic data were exploited to generate the various activation parameters for the oxidative degradation of metribuzin by colloidal MnO2 in the absence as well as the presence of the non-ionic surfactant, TX-100.

scholarly journals Kinetics of Micellar Effect of Non-Ionic Surfactant on Oxidative Degradation of Ciprofloxacin

2019 ◽  
Vol 32 (2) ◽  
pp. 359-368
Author(s):  
Ajaya Kumar Singh ◽  
Alpa Shrivastava ◽  
Dilip R. Shrivastava ◽  
Rajmani Patel ◽  
Neerja Sachdev
Keyword(s):  
Degradation Kinetics ◽  
Oxidative Degradation ◽  
Activation Parameters ◽  
Solvent Polarity ◽  
Degradation Process ◽  
Oxidation Products ◽  
Ionic Surfactant ◽  
Reaction Conditions ◽  
Chloramine T ◽  
Kinetics Of

Oxidative degradation kinetics of leading fluoroquinolone family drug ciprofloxacin (CIP) by chloramine-T (CAT) in TX-100 micelle media was studied spectrophotometrically at 275 nm and 298 K. In pseudo-first-order conditions the rate constant (kobs) decreased regularly with increasing [TX-100]. To understand the self-organizing activities of TX-100, CMC values in varying reaction conditions had been evaluated. The role of non-ionic surfactant in the oxidative degradation process of ciprofloxacin by chlorinating agent chloramine-T is explained in terms of mathematical model explained by Menger-Portnoy. The reaction showed first to zero order dependence on [CAT] and fractional order on [CIP]. Increasing [H+] decreased the rate of reaction. The effect of ionic strength and solvent polarity of the medium in reaction conditions were studied. The effects of added salts [HSO4Na], [KCl], [KNO3] and [K2SO4] had also been studied. The stoichiometry of the reaction determined was 1:2 and the oxidation products were identified by LC-EI-MS. The analysis of degradation product of ciprofloxacin evidently reveals that the piperazine moiety is active site for oxidation in the reaction. Activation parameters were studied to propose appropriate mechanism for the reaction.

Chemistry of renieramycins. Part 6: Transformation of renieramycin M into jorumycin and renieramycin J including oxidative degradation products, mimosamycin, renierone, and renierol acetate

Tetrahedron ◽  
2004 ◽  
Vol 60 (17) ◽  
pp. 3873-3881 ◽  
Author(s):  
Naoki Saito ◽  
Chieko Tanaka ◽  
Yu-ichi Koizumi ◽  
Khanit Suwanborirux ◽  
Surattana Amnuoypol ◽  
...  
Keyword(s):  
Degradation Products ◽  
Oxidative Degradation

Structural Elucidation of Unknown Oxidative Degradation Products of Mycophenolate Mofetil Using LC-MSn

2016 ◽  
Vol 79 (13-14) ◽  
pp. 919-926 ◽  
Author(s):  
Ana Protić ◽  
Marina Radišić ◽  
Jelena Golubović ◽  
Biljana Otašević ◽  
Mira Zečević ◽  
...  
Keyword(s):  
Mycophenolate Mofetil ◽  
Degradation Products ◽  
Oxidative Degradation ◽  
Structural Elucidation

LC-MS-(MS) determination of oxidative degradation products of nonylphenol ethoxylates, carboxylates and nonylphenols in water

2004 ◽  
Vol 50 (5) ◽  
pp. 227-234 ◽  
Author(s):  
M. Petrovic ◽  
P. Gehringer ◽  
H. Eschweiler ◽  
D. Barceló
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Oxidative Degradation ◽  
Nonylphenol Ethoxylates ◽  
Beam Irradiation ◽  
Treatment Processes ◽  
By Products

A commercial blend of nonylphenol ethoxylates (NPEOs) was chosen as representative for non-ionic polyethoxylated surfactants to study the oxidative degradation of this class of surfactants in water using ozonation as well as electron beam irradiation with and without the addition of ozone as treatment processes. The electron beam irradiation processes applied represent so-called Advanced Oxidation Processes (AOPs); the combined ozone/electron beam irradiation is, moreover, the most powerful AOP which can be applied in aqueous systems. It was found that both ozonation and the two AOPs applied were able to decompose not only the NPEOs but also the polyethyleneglycoles (PEGs) formed as by-products from NPEO degradation to residual concentrations below the limit of detection. Moreover, the treatment processes were also used to study the oxidative degradation of nonylphenoxy acetic acid (NPEC) and of nonylphenol (NP) which are formed as by-products from biodegradation of NPEOs.

scholarly journals Specific identification of fibrin polymers, fibrinogen degradation products, and crosslinked fibrin degradation products in plasma and serum with a new sensitive technique

Blood ◽  
1985 ◽  
Vol 65 (3) ◽  
pp. 589-597
Author(s):  
DG Connaghan ◽  
CW Francis ◽  
DA Lane ◽  
VJ Marder
Keyword(s):  
Degradation Products ◽  
Sodium Dodecyl ◽  
Fibrinolytic Therapy ◽  
Electrophoretic Patterns ◽  
Fibrin Degradation Products ◽  
Low Concentrations ◽  
Combined Action ◽  
Derivatives Of ◽  
Normal Controls ◽  
Immunological Identification

A new method is described for identifying low concentrations of circulating derivatives of fibrinogen and fibrin, even when present in heterogeneous mixtures. This technique is applicable to plasma and serum and uses electrophoresis in 2% agarose in the presence of sodium dodecyl sulfate (SDS) followed by immunological identification of separated derivatives, using radiolabeled antifibrinogen antiserum and autoradiography. Unique electrophoretic patterns distinguish plasmic derivatives of crosslinked fibrin from those of fibrinogen and also identify crosslinked fibrin polymers produced by the combined action of thrombin and factor XIII on fibrinogen. The assay is sensitive to a concentration of 0.1 micrograms/mL of fibrinogen in serum or plasma. Fibrin polymers, plasmic degradation products of fibrinogen, and plasmic degradation products of crosslinked fibrin were detected in the plasma or serum of a patient with disseminated intravascular coagulation. Plasmic derivatives of both fibrinogen and crosslinked fibrin appeared in serum in the course of fibrinolytic therapy for pulmonary embolism, whereas during acute myocardial infarction a marked increase in the proportion of fibrin polymers in plasma was found in comparison with normal controls. Thus, the procedure can distinguish between the simultaneous processes of fibrin polymer formation, fibrinogenolysis, and fibrinolysis, and is sufficiently sensitive to detect relevant quantities of derivatives in pathologic conditions.

Oxidation of Plasmalogens Produces Highly Effective Modulators of Macrophage Function

2000 ◽  
Vol 55 (1-2) ◽  
pp. 115-120 ◽  
Author(s):  
Helmut Heinle ◽  
Nadja Gugeler ◽  
Roswitha Felde ◽  
Dagmar Okech ◽  
Gerhard Spiteller
Keyword(s):  
Degradation Products ◽  
Oxidative Degradation ◽  
Oxidative Modification ◽  
Oxygen Species ◽  
Cytotoxic Effects ◽  
Macrophage Function ◽  
Enhanced Chemiluminescence ◽  
Derivatives Of ◽  
Assay Conditions

Abstract Model derivatives of plasmalogens and chemically synthesized oxidative degradation products as found e.g. during oxidation of low density lipoproteins show strong effects on phagocytosis induced secretion of reactive oxygen species of macrophages which was measured by luminol-enhanced chemiluminescence. Whereas a plasmalogen epoxide showed enhancing effects in submicromolar range, inhibition was found with higher concentrations as well as with a-hydroxyaldehydes. The substances showed only little effects on the non-cellular ROSdependent chemiluminescence of the reaction between hydrogen peroxide and opsonized zymosan and no cytotoxic effects under the assay conditions used. These results show that oxidative modification and degradation of plasmalogens occuring also under pathophysiological situations in vivo produces effective modulators of macrophage function which could be important; e.g. during inflammation or atherogenesis.

scholarly journals RP-HPLC assay method development for Paracetamol and Lornoxicam in combination and characterization of oxidative degradation products of Lornoxicam

2013 ◽  
Vol 19 (4) ◽  
pp. 471-484
Author(s):  
Pritam Jain ◽  
Miketa Patel ◽  
Amar Chaudhari ◽  
Sanjay Surana
Keyword(s):  
Method Development ◽  
Degradation Products ◽  
Oxidative Degradation ◽  
Assay Method ◽  
Forced Degradation ◽  
Control Analysis ◽  
Reverse Phase ◽  
Solution Form ◽  
Forced Degradation Studies ◽  
Degradation Studies

A simple, specific, accurate and precise reverse phase high pressure liquid chromatographic method has been developed for the simultaneous determination of Paracetamol and Lornoxicam from tablets and to characterize degradation products of Lornoxicam by reverse phase C18 column (Inertsil ODS 3V C-18, 250 x 4.6 mm, 5 ?). The sample was analyzed using Buffer (0.02504 Molar): Methanol in the ratio of 45:55, as a mobile phase at a flow rate of 1.5 mL/min and detection at 290 nm. The retention time for Paracetamol and Lornoxicam was found to be 2.45 and 9.40 min respectively. The method can be used for estimation of combination of these drugs in tablets. The method was validated as per ICH guidelines. The linearity of developed method was achieved in the range of 249.09 - 747.29 ?g/mL (r2=0.9999) for Paracetamol and 4.0125 - 12.0375 ?g/mL (r2=0.9999) for Lornoxicam. Recoveries from tablets were between 98 and 102%. The method was validated with respect to linearity, accuracy, precision, robustness and forced degradation studies which further proved the stability-indicating power. During the forced degradation studies lornoxicam was observed to be labile to alkaline hydrolytic stress and oxidative stress (in the solution form). However, it was stable to the acid hydrolytic, photolytic and thermal stress (in both solid and solution form). The degraded products formed were investigated by electrospray ionization (ESI) time-of-flight mass spectrometry, NMR and IR spectroscopy. A possible degradation pathway was outlined based on the results. The method was found to be sensitive with a detection limit of 0.193 ?g/ml, 2.768 ?g/ml and a quantitation limit of 0.638 ?g/ml, 9.137 ?g/ml for lornoxicam and paracetamol, respectively. Due to these attributes, the proposed method could be used for routine quality control analysis of these drugs in combined dosage forms.

scholarly journals Kinetics, Mechanism, and Toxicity of Amlodipine Degradation by the UV/Chlorine Process

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3150
Author(s):  
Jianye Xu ◽  
Siqi Zhou ◽  
Erdeng Du ◽  
Yongjun Sha ◽  
Lu Zheng ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Advanced Oxidation Process ◽  
High Resolution Mass Spectrometry ◽  
Ph Value ◽  
Degradation Products ◽  
Degradation Mechanism ◽  
Complete Removal ◽  
Ammonia Concentration ◽  
Ammonia Nitrogen ◽  
Toxicity Tests

The UV/chlorine process, as a new type of AOP (Advanced Oxidation Process), was utilized to treat amlodipine (AML)-containing water. The influencing factors, including chlorine dose, UV intensity, solution initial pH value, and ammonia concentration, were investigated. The degradation of AML in real water and the relative contributions of OH• and Cl• were also studied. Finally, high-resolution mass spectrometry (HRMS) and GC-MS were used to identify the possible degradation products. The results demonstrated that the AML degradation process was fitted with apparent first-order kinetics. AML degradation had a positive correlation with UV intensity and chlorine dose, and a negative correlation with ammonia concentration. In the presence of ammonia nitrogen and DOM, the removal of AML from real water was reduced. OH• made a dominant percentage contribution of 55.7% to the degradation of AML. Sixteen intermediates were detected and identified. A possible degradation mechanism was also proposed. Acute toxicity tests and risk prediction both illustrated that the complete removal of AML does not guarantee the reduction of acute toxicity, but a prolonged degradation promoted the detoxification of toxic intermediates. The UV/chlorine process can be regarded to be an effective method to remove AML and reduce ecological risk.

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