No abstract

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. The in vitro antioxidant activities of these fractions and other phenolic standards (catechin, epicatechin, quercetin, and malvidin 3-glucoside) as well as ascorbic acid were verified by DPPH* test. On the other hand, the variation of antioxidant activities during the reaction between epicatechin and malvidin 3-glucoside mediated by acetaldehyde in a model wine solution was also monitored. The results showed that both the phenolic complex fraction and newly formed condensation products between epicatechin and malvidin 3-glucoside maintain antioxidant activities as strong as those of their compositional phenolics. This work provides, for the first time, direct evidence about the in vitro antioxidant activities of red wine phenolic complexes.

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. The solution studies showed that, in comparison with the O,O-analogues, the Mo(VI) complexes with the O,S-ligands present some stabilization, which is even more pronounced for the reduced Mo(IV) species. The crystal structures of the Mo(VI) complexes with the hydroxythiopyrone revealed good flexibility of the coordination modes, with two structural isomers and two polymorphic forms for a mononuclear and a binuclear species, respectively. These results give some support to mechanistic proposals for the XO inhibition involving the interaction of the thione group with the molybdenum cofactor, thus indicating a role of the sulfur atom in the XO inhibition.

No abstract

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. Although pDNA yields > or = 90% were always obtained, ATPS delivered the highest HPLC purity (59%), followed by PP (48%) and TFF (18%). However, the ability of ATPS to concentrate pDNA was very poor when compared with PP or TFF. Processes were also implemented by coupling TFF with ATPS or AS-PP. Process simulations indicate that all options require large amounts of water (100-200 tons/kg pDNA) and that the ATPS process uses large amounts of mass separating agents (65 tons/kg pDNA). Estimates indicate that operating costs of the ATPS process are 2.5-fold larger when compared with the PP and TFF processes. The most significant contributions to the costs in the PP, TFF and ATPS processes came from operators (59%), consumables (75%) and raw materials (84%), respectively. The ATPS process presented the highest environmental impact, whereas the impact of the TFF process was negligible.