Hydroxy(thio)pyrone and hydroxy(thio)pyridinone iron chelators: physico-chemical properties and anti-oxidant activity.

The O,S-donor analogues of maltol and deferiprone (DMHP), respectively, thiomaltol and DMHTP, have been investigated in solution for their iron-complexation ability, as well as their electrochemical behaviors, in the presence and absence of iron, aimed at the rationalization of their anti-oxidant activity, particularly, as hydroxyl radical scavengers and inhibitors of lipid peroxidation. The results were compared with those of the O,O-donor compounds and revealed that all the compounds are good iron chelators (pFe=14.1-20.

Red wine phenolic complexes and their in vitro antioxidant activity.

Phenolic complexes are a major group of polyphenols in aged red wine. The objective of this work was to evaluate the in vitro antioxidant activity of the phenolic complexes. Thus, red wine polyphenols were fractionated into various fractions including monomers, oligomers, polymers, anthocyanins, and complexes.

Alternatives for the intermediate recovery of plasmid DNA: performance, economic viability and environmental impact.

Robust cGMP manufacturing is required to produce high-quality plasmid DNA (pDNA). Three established techniques, isopropanol and ammonium sulfate (AS) precipitation (PP), tangential flow filtration (TFF) and aqueous two-phase systems (ATPS) with PEG600/AS, were tested as alternatives to recover pDNA from alkaline lysates. Yield and purity data were used to evaluate the economic and environmental impact of each option.

Biologically relevant O,S-donor compounds. Synthesis, molybdenum complexation and xanthine oxidase inhibition.

Two O,S-donor ligands, hydroxythiopyrone and hydroxythiopyridinone derivatives, were developed and studied, as well as the corresponding O,O-derivatives, with a view to their potential pharmacological applications as xanthine oxidase (XO) inhibitors. The biological assays revealed that the O,S-ligands present high inhibitory activity towards XO (nanomolar order, close to that of the pharmaceutical drug allopurinol), in contrast to the corresponding O,O-analogues. Due to the biomedical relevance of this molybdenum-containing enzyme, the corresponding Mo(VI) complexes were studied both in solution and in the solid state, aimed at identifying the source of the biological properties.

Plasma quercetin metabolites: structure-antioxidant activity relationships.

We studied quercetin metabolism in rats to determine the nature and conjugation positions on the resulting metabolites and to evaluate their contribution to the antioxidant activity of plasma. HPLC analysis showed that quercetin is primarily metabolized to glucuronides and sulfoglucuronides and, to a minor extent, to sulfates. ESI-MS/MS studies confirmed these results and indicate that the most plausible positions for glucuronidation and sulfation are the hydroxyl groups located at positions 5 and 7, excluding the 3'-OH and 4'-OH groups.