Chemical methods for the determination of reduced ascorbic acid (Zascorbic acid) are based upon its reducing properties. The indophenol method of Bessey (1, 2) and the perinaphthindantrione hydrate method of Moubasher (3) are examples of these methods. Modifications to increase the specificity of the indophenol method have been presented by Robinson and Stotz (4), Lowry, Lopez, and Bessey (5), ...

Financial support: Grants from the Universidad de Buenos Aires (UBA) and from Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) (Argentina). Abbreviations: 2,4 DNPH: 2,4-dinitrophenylhydrazine AEBSF: 4-(2-aminoethyl) benzenesulfonyl fluoride cys: cysteine DAB: diaminobenzidine DNP: dinitrophenyl DTT: dithiothreitol HRP: horseradish peroxidase IAA: iodoacetamide PAGE: polyacry...

Spectrometric analyses of flavonoids in twenty propolis samples, collected from ten different geographic localities in northern Croatia using two complementary methods, are reported. Flavones and flavonols were determined using aluminum chloride and expressed as quercetine equivalent while flavanones were determined using 2,4-dinitrophenylhydrazine and expressed as naringenin. Contents of flavo...

The structural and vibrational properties of 6-(2-(2,4-dinitrophenylhydrazano)-tetrahydro-2thioxopyrimidin-4(1H)-one (3) prepared by condensation of synthesized thiobarbituric acid (1) with 2,4-dinitrophenylhydrazine (2) were studied using experimental FT-IR, FT-Raman, NMR spectra and theoretical calculations based on the density functional method were the simulated spectra coincides with exper...