Electrochemical reduction of the final product of vitamin B-6 catabolism: a spectroscopic characterization of the reduced products of 4-pyridoxic acid

Pineda, Teresa; Lopez-Cozar, M.I.; Sevilla, José Manuel; Blázquez, Manuel

doi:10.1016/0022-0728(95)04217-2

Cited by 9 publications

(7 citation statements)

References 8 publications

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“…The electrochemical behavior of 4-pyridoxic acid was different. The cyclic voltammetry and DPV showed only one peak at )1.3 V. This is in agreement with that reported by Pineda et al (49), and was assigned to the reduction of the carboxylic group at the 4-position of the pyridine ring. The electro-oxidation potential for pyridoxamine also was measured at pH 7 employing DPV.…”

Section: Singlet Quenching By Amino Acidssupporting

confidence: 92%

Photophysics and Photochemical Studies of the Vitamin B6 Group and Related Derivatives

Bueno

Pavez

Salazar

et al. 2010

Photochem & Photobiology

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The photophysics and photochemical properties of vitamin B6 constituents and analogs were studied as function of pH and solvent. The pK of the phenolic oxygen and the pyridine ring nitrogen depends on the electron donor-acceptor ability of the 4-substituent, and agrees with the calculated proton affinity. For all studied compounds, the fluorescence properties showed that the phenolic oxygen is 8 units more acidic in the lowest singlet excited state than in the ground state. The pyridine N-atom is slightly more basic in the excited state. At pH of biological significance, pH 6-8, pyridoxamine and 4-pyridoxic acid are the more efficient chromophores with higher fluorescence yield and longer lifetime. Spectroscopic studies showed that the tautomeric equilibrium depends on the nature of the 4-substituent. The quenching of the singlet excited state of pyridoxamine and 4-pyridoxic acid by amino acids, free or in a peptide, and DNA bases at pH 7 was studied by time-resolved fluorescence techniques. The quenching rate constants are well correlated with the redox properties of the pyridoxinic compound and amino acids, and are related to the free energy change in the electron transfer process. Guanosine and pyrimidine bases also are efficient quenchers, involving an electron transfer reaction.

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Section: Singlet Quenching By Amino Acidssupporting

confidence: 92%

Photophysics and Photochemical Studies of the Vitamin B6 Group and Related Derivatives

Bueno

Pavez

Salazar

et al. 2010

Photochem & Photobiology

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“…The oxidation of PN at a carbon paste electrode has been firstly examined. Consequently, modification of the glassy carbon electrodes, flow and sequential injection techniques improved speed and selectivity as compared with electrochemical assays [14,[44][45][46]. The chemical structure of all the particular vitamin B 6 forms enables their measurement by electrochemical detection at nanomolar concentrations in endogenous plasma and serum.…”

Section: Introductionmentioning

confidence: 99%

“…The chemical structure of all the particular vitamin B 6 forms enables their measurement by electrochemical detection at nanomolar concentrations in endogenous plasma and serum. It should be mentioned that use of electrochemical detection has been already reported in literature [44][45][46][47][48]. However, such application was limited to samples other than pharmaceuticals and foods.…”

Section: Introductionmentioning

confidence: 99%

Application of the high-performance liquid chromatography method with coulometric detection for determination of vitamin B6 in human plasma and serum

Marszałł

Lebiedzińska

Czarnowski

et al. 2009

Journal of Chromatography B

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“…The reaction was followed by monitoring absorption spectra at pH 6, the initial band centered at 315 nm changes to 356 nm as the lactone is formed [23].…”

Section: Reagentsmentioning

confidence: 99%

“…The electrode processes are pH-dependent due to the complex distribution of species in solution provided by acid-base properties, tautomeric equilibria and, in aldehyde compounds, hydration equilibrium (17)(18)(19)(20)(21)(22)(23)(24)(25). Electrochemical responses indicate the exchange of two or four electrons as well as a distribution of characteristic potentials depending of electroactive group.…”

Section: Introductionmentioning

confidence: 99%

A comparative study of the electrochemical properties of vitamin B-6 related compounds at physiological pH

et al. 2011

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A comparative study of vitamin B6 group and related compounds in buffered solutions using electrochemical techniques has been performed at neutral pH. Irreversible bi-or tetraelectronic processes are observed for these substances, and the electron transfer coefficient (αn) calculated. It was concluded that either the first or second electron transfer were the rate determining step of the electrode process. The diffusion coefficient of these substances was calculated and the values given follow an inverse tendency to the molecular size. For aldehydes the values obtained were corrected of the hydration reaction.It is important to remark that catalytic waves were reported for the first time for these compounds. Using a model involving the nitrogen of the basic structure the kinetic constants were calculated for most of them.

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Electrochemical reduction of the final product of vitamin B-6 catabolism: a spectroscopic characterization of the reduced products of 4-pyridoxic acid

Cited by 9 publications

References 8 publications

Photophysics and Photochemical Studies of the Vitamin B6 Group and Related Derivatives

Photophysics and Photochemical Studies of the Vitamin B6 Group and Related Derivatives

Application of the high-performance liquid chromatography method with coulometric detection for determination of vitamin B6 in human plasma and serum

A comparative study of the electrochemical properties of vitamin B-6 related compounds at physiological pH

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