672-73-1

Usage

Uses

Epinephrine o-Quinone is used in the electrochemical oxidation studies of catechol amines.

Upstream product

• 51-43-4 L-epinephrine 
• 115780-42-2 C₉H₁₂NO₃ 
• 329-65-7 Epinephrine 
• 50-53-3 chloropromazine cation radical 

Downstream Products

• 54-06-8 adrenochrome 

Relevant academic research and scientific papers

Voltammetric determination of epinephrine and xanthine based on sodium dodecyl sulphate assisted tungsten trioxide nanoparticles

This work reports the voltammetric determination of epinephrine (EP) and xanthine (XA) using gamma irradiated tungsten trioxide (WO3) nanoparticles. WO3 NPs synthesized by anionic surfactant sodium dodecyl sulphate (SDS) assisted template method was subjected to gamma rays under different doses (0-150 kGy). The experimental results revealed that the 50 kGy irradiation on SDS-WO3 NPs led to significant changes in crystallite size and morphology which enriched its electrocatalytic activity greatly. The electrochemical behaviors of EP and XA at 50 kGy gamma irradiated SDS-WO3 modified glassy carbon electrodes (GCE) were studied by cyclic voltammetry and differential pulse voltammetry. The outcomes confirmed that the proposed electrode demonstrate excellent electrocatalytic activity towardsthe oxidation of EP and XA in phosphate buffer solution (PBS, pH 7.0). The fabricated electrode possess lowest detection limit of 1.8?nM and 2.2?nM for EP and XA respectively with the very wide dynamic linear range of 9?nM to 1?mM. Finally, the modified sensor was successfully implemented to detect EP and XA in the human serum samples with excellent selectivity, good stability and reproducibility.

Electrochemical determination of adrenaline at Ru(III) schiff base complex modified carbon electrodes

The anodic oxidation of adrenaline on ruthenium(III) Schiff base complex modified carbon electrodes was used for determination of adrenaline by flow-injection analysis, cyclic voltammetry, differential pulse voltammetry and hydrodynamic amperometry. The e

Reactivity of adrenaline toward alkoxyl radicals and carbonyl triplet states

The reactivities of adrenaline toward hydrogen abstraction by the tert-butoxyl radical and the excited triplet state of benzophenone have been examined in solution using laser flash photolysis techniques. The rate constants obtained in acetonitrile-rich solvents are 13 and 1.5 × 108 M-1 s-1 for benzophenone triplet and the tert-butoxyl radical, respectively. Adrenaline is a better hydrogen donor than phenol, but not as efficient as α-tocopherol.

Stereospecificity of mushroom tyrosinase immobilized on a chiral and a nonchiral support

Mushroom tyrosinase was immobilized from an extract onto glass beads covered with the cross-linked totally cinnamoylated derivates of D-sorbitol (sorbitol cinnamate) and glycerine (glycerine cinnamate). The enzyme was immobilized onto the support by direct adsorption, and the quantity of immobilized tyrosinase was higher for sorbitol cinnamate, the support with the higher number of esterified hydroxyls per unit of monosacharide, than for glycerine cinnamate. The results obtained from the stereospecificity study of the monophenolase and diphenolase activity of immobilized mushroom tyrosinase are reported. The enantiomers L-tyrosine, DL-tyrosine, D-tyrosine, L-dopa, DL-dopa, D-dopa, L-α-methyldopa, DL-α-methyldopa, L-isoprenaline, DL-isoprenaline, L-adrenaline, DL-adrenaline, L-noradrenaline, and D-noradrenaline were assayed with tyrosinase immobilized on a chiral support (sorbitol cinnamate), whereas L-tyrosine, DL-tyrosine, D-tyrosine, L-dopa, DL-dopa, D-dopa, L-α-methyldopa, and DL-α-methyldopa were assayed with tyrosinase immobilized on a nonchiral support (glycerine cinnamate). The same Vmaxapp values for each series of enantiomers were obtained. However, the Kmapp values were different, the L isomers showing lower values than the DL isomers, whereas the highest K mapp value was obtained with D isomers. No difference was observed in the stereospecificity of tyrosinase immobilized on a chiral (sorbitol cinnamate) or nonchiral (glycerine cinnamate) support.

Metallo-ROS in Alzheimer's disease: Oxidation of neurotransmitters by CuII-β-amyloid and neuropathology of the disease

A clear mind: The CuII-β-amyloid (Aβ) complex has been shown to exhibit enzyme-like metal-centered oxidative and hydroxylation catalyses. Metal-centered oxidation of various neurotransmitters by CuAβ under biomimetic conditions has verified the bio-relevance of the metal-centered catalyses and is expected to provide a chemical basis for the better understanding of the etiology of Alzheimer's disease. ROS = reactive oxygen species. (Figure Presented).

Oxidation of benzenediols by hexabromoiridate(IV): Kinetics at ambient and elevated pressures

The kinetics of oxidation of several benzenediols by the hexabromoiridate(IV) ion have been studied spectrophotometrically by the stopped-flow method. In 0.010 mol dm-3 HClO4 and an ionic strength of 0.10 mol dm-3 (NaClO4) at 25.0°C the second-order rate constants (the reaction is first order in each reactant concentration), vary from 1.26 × 102 to 9.3 × 104 dm3 mol-1 s-1. The enthalpies of activation range from about 44 kJ mol-1 for the slowest reacting substrate to about 20 kJ mol-1 for the faster reactions. The ΔS? values do not vary over a wide range; the reaction rates are governed more by the enthalpy barrier. Application of pressure (up to 125 MPa) causes significant rate accelerations, giving rise to ΔV? values in the -17 to -26 cm3 mol-1 range, consistent with the large, negative ΔS? values. This indicates that the rate limiting step is largely characterised by an increase in species ordering and electrostriction, and in the present case slightly less than for the corresponding reactions with the less bulky hexachloroiridate(IV) ion.

Screening test for insecticides interfering with cuticular sclerotization

The potential of known and new insecticides to interfere with cuticle sclerotization was investigated using assays for key enzymes such as phenoloxidase, quinone methide isomerase and DOPA decarboxylase. Homogenates from the blowfly Lucilia cuprina and from the epithelial cell line from Chironomus tentans were used to examine the compounds under investigation. Phenoloxidases are known to oxidize DOPA, the substrate for DOPA decarboxylase. Since phenoloxidases were not detectable in C. tentans cell homogenates, inhibitor and kinetic studies were done for comparison with DOPA decarboxylase of this insect cell line. DOPA decarboxylase and phenoloxidase of L. cuprina exerted highest specific activities at early pupal stages (day 7). The apparent K(m) values for the two enzymes were 0.47(±0-21) mM and 0.71(±0.16) mM, respectively, using L-DOPA as substrate. DOPA decarboxylase from C. tentans had a K(m) value of 0.42(±0.18) mM. Quinone methide isomerase was most active in young pupae. In terms of substrate specificity for enzymic (mushroom-tyrosinase) production of different quinones from their corresponding catechols, that with dopamine quinone proved to be the most efficient. Synthesis of derivatives of L-DOPA and L-tyrosine led to a compound which inhibited both phenoloxidase and quinone methide isomerase. DOPA decarboxylase from L. cuprina and from cells of C. tentans was inhibited by carbidopa (IC50 values of 0.021(±0.011) μM and 0.031(±0.019) μM, respectively) and indomethacine (IC50 values of 22.6(±7.1) μM and 18.8(±9.7) μM). Both compounds exerted a competitive type of inhibition and were able to interfere with development of L. cuprina.

Spectroelectrochemical Examination of Charge Transfer between Chlorpromazine Cation Radical and Catecholamines

With chlorpromazine (CPZ) and dopamine (DA) in their reduced forms in solution, the potential of a platinum electrode was stepped to a value where both species were oxidized at diffusion controlled rates.The CPZ+. cation radical so generated then diffused away from the electrode and encountered reduced DA, which it oxidized.The rate of oxidation was determined by monitoring the absorbance due to CPZ+. or dopamine quinone (DPQ) using the glancing incidence reflection spectroelectrochemical technique.The kinetics of the process indicate that the rate law is first order in both CPZ+. and DA, implying that the first encouter of the two molecules is the rate limiting step, rather than some subsequent process.The rate constant for dopamine was compared with those for three other catechols, and the rate constant increased monotonically with driving force, as measured by the difference in redox potentials between catechol and CPZ.The advantages of the technique for studying homogeneous charge transfer reactions are noted, as is the implication of the results on the CPZ+./DA reaction on the biological effects of CPZ.

Glancing Incidence External Reflection Spectroelectrochemistry with a Continuum Source

A previous report demonstrated that light reflected from an electrode at small angles could be used to make optical absorption measurements on electrogenerated chromophores.A large sensitivity enhancement over previous method was realized due to the relatively long effective path length.The present report discussed the extension of the technique to carbon and platinum electrodes and the use of continuum rather than laser light source.For all combinations of source and electrode, the sensitivity of the method is about 100 times that of a comparable experiment using an optically transparent electrode, and the magnitude of the enhancement can be calculated from geometric considerations.In addition, the effect of the beam entering the side of the diffusion layer was cosidered, and it was found that this effect can be neglected if the experiment is designed properly.