Publications by authors named "Antonio Romero Silva"
Radicals in biochemical environments can lead to protein damage. Theoretical studies can help us to understand the observed radical selectivity. In this work, the kinetics and thermodynamics of the hydrogen-transfer (HT) and single-electron transfer (SET) reactions between a cysteine derivative and 17 free radicals of biological significance have been theoretically investigated in aqueous and lipid media.
View Article and Find Full Text PDFTwo empirically fitted parameters have been derived for 74 levels of theory. They allow fast and reliable pKa calculations using only the Gibbs energy difference between an acid and its conjugated base in aqueous solution (ΔGs(BA)). The parameters were obtained by least-squares fits of ΔGs(BA) vs experimental pKa values for phenols, carboxylic acids, and amines using training sets of 20 molecules for each chemical family.
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- A ruthenium complex with a specific ligand was created and its properties were explored through DFT analysis, focusing on oxidation states and reactive sites.
- The complex demonstrates a preference for bonding based on metal oxidation states, with Ru(IV) interacting more readily with hard bases and Ru(II) with soft bases, influenced by the Jahn-Teller effect.
- It effectively oxidizes phenol to benzoquinone using H2O2, with experiments identifying intermediates, while a potential mechanism and rate law for this reaction were also proposed.
Article Synopsis
- Organic nanoparticles (ONPs) made from lipoic acid and its silver (Ag) and gold (Au) doped derivatives were created and analyzed using various techniques like UV-Visible spectroscopy, EDS, and TEM.
- Antibacterial tests showed that ONPs/Ag were particularly effective against bacteria, especially Gram-positive strains like Staphylococcus aureus, outperforming ONPs and ONPs/Au in inhibiting growth.
- Further analysis of the bacteria's cell membranes and bonding characteristics of lipoic acid with Ag or Au was done using scanning electron microscopy (SEM) and computational methods like density functional theory (DFT).