Combinatorial Chemistry & High Throughput Screening - Volume 16, Issue 2, 2013

An electrochemical microsensor has been developed for the simultaneous assay of ascorbate (AA) and urate (UA) antioxidants in human blood serum. The electrode surface was modified by means of electropolymerized conductive poly(3,4-ethylenedioxythiophene) PEDOT organic films. Highly selective responses (detection potential difference more than 250 mV) were obtained for both biomarkers by optimizing the PED Read More

The electrochemical oxidation mechanisms of rosmarinic acid (RA) and verbascoside (VB), both caffeic acid esters with two catechol moieties, were investigated. The redox mechanism is associated with the oxidation of the catechol groups, and was studied over a wide pH range by cyclic, differential pulse and square wave voltammetry, using a glassy carbon electrode. The voltammetric study revealed that both molecules, Read More

Vegetal extracts are among the most important source of polyphenols in the diet, highlighting the importance of their characterization and determination. For this reason, analytical methods have gained increasing interest, with many publications devoted to this subject. Among the wide possibilities of analytical methods, electroanalytical techniques can provide valuable information, since the antioxidant activity of polyph Read More

The prevention of oxidative reactions in a biological medium as well as the role of reactive oxygen species (ROS) in chronic degenerative diseases are questions that continue to be investigated. Electrochemical biosensors have shown attractive features to evaluate the oxidative stress condition at a level comparable to chromatographic and spectroscopic techniques. The biosensors developed so far are based on direct analysis o Read More

The present study aims to determine the antioxidant capacity of the ethanolic extracts of husk fiber of four coconut (Cocos nucifera L.) varieties (yellow dwarf, green dwarf, giant and hybrid) and to evaluate the electrochemical behavior of these extracts on a glassy carbon electrode and on a modified glassy carbon electrode. The highest values of total phenolic content were obtained for the hybrid (531 ± 24 mg GAE g-1 dry e Read More

Many compounds can interact with DNA leading to changes of DNA structure as point mutation and bases excision, which could trigger some metabolic failures, which leads to the changes in DNA structure resulting in cancer. Oxidation of nucleic acid bases belongs to the one of the mostly occurred type of DNA damaging leading to the above mentioned phenomena. The investigation of processes of DNA oxidation damage i Read More

A new and simple high-performance liquid chromatography method was developed and validated for the simultaneous determination of retinol, retinyl palmitate, β-carotene, α-tocopherol and vitamin C in rat serum treated with Plantago Major L. and 7,12 dimethylbenz[a]anthracene. High-performance liquid chromatography analysis was performed utilizing an Inertsil ODS3 reversed phase column with methanol-tetrahydro Read More

A convenient one-pot, three-component reaction of aromatic aldehydes, 6-amino-1,3-dimethyluracil and active methylene compounds in the presence of Zr(HSO4)4 as a heterogeneous catalyst, under solvent-free conditions brings a very simple and highly efficient method for the preparation of pyrimido[4,5-b]quinolines, pyrimido[5',4':5,6]pyrido[2,3- d]pyrimidines, indeno[2',1':5,6]pyrido[2,3-d]pyrimidines and a ne Read More

A new linderone A, namely 2-cinnamoyl-3-hydroxy-4, 5-dimethoxycyclopenta-2, 4-dienone (5), together with three known flavonoids (1-3) and one linderone (4), were isolated from the bark of Lindera oxyphylla. Extensive spectroscopic analysis including 1D and 2D-NMR spectra determined their sturctures. In addition, the antioxidant activity of all the compounds has been determined using 2, 2-diphenyl-1-picrylhydrazyl radical sc Read More