Results 161 to 170 of about 1,982 (213)

Pyridoxal 5′-phosphate, pyridoxal, and 4-pyridoxic acid in the paired serum and cerebrospinal fluid of children

Clinica Chimica Acta, 2017
We quantified pyridoxal 5'-phosphate (PLP), pyridoxal (PL), and 4-pyridoxic acid (PA) in paired serum and cerebrospinal fluid (CSF) samples from children and investigated the effect of age on the concentrations and CSF-to-serum ratios of these vitamers.Serum and CSF samples prospectively collected from 49 pediatric patients were analyzed.
Tomoyuki Akiyama, Yumiko Hayashi, Yoshiyuki Hanaoka, Takashi Shibata, Mari Akiyama, Hiroki Tsuchiya, Tokito Yamaguchi, Katsuhiro Kobayashi   +7 more
openaire   +2 more sources

Pyridoxal phosphate-unrelated inhibition of hippocampal glutamic acid decarboxylase by convulsant pyridoxal sulphate

Neurochemical Research, 1985
Previous studies from this laboratory have shown that pyridoxal-5'-sulphate, the synthetic analogue of pyridoxal phosphate, causes epileptic seizures including tonic-clonic convulsions. These seizure activities are prevented or reversed by GABA or muscimol.
M, Ebadi, A, Earle, S, Wilt
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Determination of urinary 4-pyridoxic acid levels as 4-pyridoxic acid lactone using high-performance liquid chromatography

The American Journal of Clinical Nutrition, 1986
A high-performance liquid chromatography method for quantitation of urinary 4-pyridoxic acid excretion is presented. Urine samples were treated with HCl to form 4-pyridoxic acid lactone. Acid-treated urine samples were diluted and analyzed by cation-exchange chromatography involving post-column alkalinization and fluorescence detection.
J B, Ubbink, W J, Serfontein, P J, Becker, L S, De Villiers   +3 more
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Simultaneous and direct determination of pyridoxal, pyridoxal-5′-phosphate, and pyridoxic acid in serum by derivative synchronous fluorescence spectroscopy

Analytical Biochemistry, 1986
Simultaneous and direct assays of pyridoxal, pyridoxal-5'-phosphate, and pyridoxic acid in human serum are described. The method applied is based on the reaction of these compounds with beryllium in an ammoniacal medium to yield highly fluorescent derivatives.
A, Petidier, S, Rubio, A, Gómez-Hens, M, Valcárcel   +3 more
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Chemical transformations of pyridoxal and pyridoxal 5′-phosphate condensation products with amino acids

Russian Journal of General Chemistry, 2008
The mechanism of chemical transformations of pyridoxal and pyridoxal 5′-phosphate condensation products with amino acids is studied by kinetic measurements. The Schiff bases are shown to be fairly stable in neutral media. In acid media, the Schiff bases are hydrolyzed into the initial components. In alkaline media, cleavage of α-hydrogen from the amino
F. V. Pishchugin, I. T. Tuleberdiev
openaire   +1 more source

Stereoselective amino acid synthesis by synergistic photoredox-pyridoxal radical biocatalysis

Science, 2023
Developing synthetically useful enzymatic reactions that are not known in biochemistry and organic chemistry is an important challenge in biocatalysis. Through the synergistic merger of photoredox catalysis and pyridoxal 5′-phosphate (PLP) biocatalysis, we developed a pyridoxal radical biocatalysis approach to prepare valuable noncanonical
Lei Cheng, Dian Li, Binh Khanh Mai, Zhiyu Bo, Lida Cheng, Peng Liu, Yang Yang   +6 more
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Stereochemistry of pyridoxalamino acid model systems

Inorganica Chimica Acta, 1983
Abstract Pyridoxal phosphate is the essential cofactor for most of the enzymic reactions undergone by amino acids during metabolism [1]. All these reactions proceed through the formation of a Schiff base, such as I, followed by cleavage of one of the bonds to the amino acid α-carbon atom.
Luigi Casella, Michelle Gullotti
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Pyridoxal enzymes acting on D-amino acids

Pure and Applied Chemistry, 1994
Abstract
K. Soda, N. Esaki
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Interaction of pyridoxal-5′-phosphate and acetohydroxy acid isomeroreductase

Biochemical and Biophysical Research Communications, 1971
Summary Acetohydroxy acid isomeroreductase is irreversibly inactivated upon binding approximately 8 moles of pyridoxal-5′-phosphate (PLP) followed by reduction with NaBH4. Various analogs of PLP cause little or no inactivation. Inactivation is both more rapid and occurs at lower PLP concentrations in the presence of the specific cofactor NADPH, but ...
E M, Shematek, S M, Arfin
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Identification of 5-pyridoxic acid and 5-pyridoxic acid lactone as metabolites of vitamin B6 in humans

The Journal of Nutritional Biochemistry, 1991
Abstract Plasma and urine from individuals ingesting large amounts of vitamin B 6 contain several unidentified vitamin B 6 metabolites. Based on movement in 6 TLC solvents, elution in HPLC, and ultraviolet and infrared spectra, two of these metabolites have been identified as 5-pyridoxic acid and its lactone.
J. Dennis Mahuren, Thomas A. Pauly, Stephen P. Coburn   +2 more
openaire   +1 more source