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Reactive oxygen species (ROS), when in excess, cause damage to biomolecules (DNA, lipids, carbohydrates, and proteins), which are related to several pathologies. There is a growing study of substances that act to inhibit or reduce the action of these ROS. Chalcones are aromatic ketones with a naturally occurring and easily synthesized α,β-unsaturated system. In this work, we investigated the in vitro protective action of a new class of chalcones functionalized by the thiobarbituric acid reactive substances (TBARS) assay. The most promising molecule (Chalcone E) was submitted to the DPPH radical scavenging assay, and the MTT cell viability test evaluated its cytotoxicity. In addition, Chalcone E reduced lipid peroxidation, with maximum inhibition values of 73.05% for the brain, 81.42% for the liver, and 87.23% for the kidney, demonstrating a potential antioxidant effect. Still, the DPPH test did not observe this effect, suggesting further investigation of this molecule.

Mesoionic compounds belonging to the 1,3-oxazol-5-one, 1,3-diazole-4-thione and 1,3-thiazole-5-thione rings have been evaluated by a combination of Density Functional Theory, Quantum Theory of Atoms in Molecules, Electron Localization Function, Natural Bond Orbitals and Geodesic Electrostatic Potential Charge calculations. Atomic, bond, and ring properties have been considered to describe the electronic structure of mesoionic compounds. The results show that not only the ring type, but also the substituent groups have great influence on these properties. In addition, there is a significant and heterogeneous π-bonding contribution throughout the mesoionic rings. Finally, we conclude that some classical conceptions of charge localization and π-bonding contribution in these compounds are misleading or incomplete. © 2015 Wiley Periodicals, Inc.

Alloy clusters of Na x Li y (4 ≤ x + y ≤ 10) are studied by exploring the potential energy surface in the ab initio MP2 level with the support of a quantum genetic algorithm (QGA). In some cases, the structures have been also refined with DFT and coupledcluster methods. The general trends of sodium-lithium structures are in line with previous studies. The ionization potentials and polarizabilities to all structures were calculated with MP2 method and the average error between these two properties compared with experimental data was 6% and 13%, respectively. The topological analysis based on quantum theory of atoms in molecules (QTAIM) showed that by increasing the cluster size of the diatomic system there was a decrease of atomic interaction energies. The degree of degeneracy from D3BIA aromaticity index and the analysis of the atomic charges showed the influence (by charge transfer) of the chemical element in lower quantity in the cluster with respect to the other atoms. Our achievements of comparing our theoretical results with available experimental data have demonstrated that our approach can also predict satisfactorily quantum atomic and alloy clusters properties, at least, for low nuclearities.