Electrochemical deposition of a copper carboxylate layer on copper as potential corrosion inhibitor

Carboxylic acids and sodium carboxylates are used to protect metals against aqueous and atmospheric corrosion. In this paper we describe the application of a layer of copper carboxylate on the surface of a copper electrode by means of cyclic voltammetry technique, and tests which measure the corresponding resistance to aqueous corrosion. Unlike the soaking process, which also forms a film on the surface, the use of cyclic voltammetry allows one to follow the deposition process of the copper carboxylates onto the electrode. The modified electrodes have been characterized with infrared spectroscopy. In addition the corrosion resistance of the film has been investigated using polarization resistance and Tafel plot measurements

Application of electrochemical methods for the study and protection of heritage copper alloys

The research carried out and presented in this work has focused on different aspects concerning the corrosion of copper and copper alloys by means of electrochemical methods and complementary spectroscopic methods. The aim was to contribute to improvement strategies of preserving our cultural heritage. Three main applications were addressed: the corrosion study of copper-tin alloys, the application of voltammetry of microparticles (VMP) for the characterization of copper alloys and their corrosion products, and the synthesis and characterization of protective coatings for copper surfaces. The corrosion of copper-tin alloys part aimed at studying the influence of the tin content in various environments upon the corrosion behaviour of the alloys. LSV, together with SEM, XRF and XRD, allowed the characterization of the corrosion layers formed. Results showed that the tin content does not affect the type of corrosion products formed on the surface, however, a reduction of the corrosion rate was observed for alloys with a higher tin percentage. VMP was used as a non-destructive technique to characterize copper-based archaeological artefacts from three excavated sites in Flanders. The analyses carried out allowed the qualitative identification of the alloy composition and of the copper corrosion products present on archaeological artefacts. Complementary analyses, performed by means of XRF and XRD, confirmed the results obtained from the VMP analyses

Identification of novel 2-benzoxazolinone derivatives with specific inhibitory activity against the HIV-1 nucleocapsid protein

In this report, we present a new benzoxazole derivative endowed with inhibitory activity against the HIV-1 nucleocapsid protein (NC). NC is a 55-residue basic protein with nucleic acid chaperone properties, which has emerged as a novel and potential pharmacological target against HIV-1. In the pursuit of novel NC-inhibitor chemotypes, we performed virtual screening and in vitro biological evaluation of a large library of chemical entities. We found that compounds sharing a benzoxazolinone moiety displayed putative inhibitory properties, which we further investigated by considering a series of chemical analogues. This approach provided valuable information on the structure-activity relationships of these compounds and, in the process, demonstrated that their anti-NC activity could be finely tuned by the addition of specific substituents to the initial benzoxazolinone scaffold. This study represents the starting point for the possible development of a new class of antiretroviral agents targeting the HIV-1 NC protein

Time course of biochemical, physiological, and molecular responses to field-mimicked conditions of drought, salinity, and recovery in two maize lines

Drought and salinity stresses will have a high impact on future crop productivity, due to climate change and the increased competition for land, water, and energy. The response to drought (WS), salinity (SS), and the combined stresses (WS+SS) was monitored in two maize lines: the inbred B73 and an F1 commercial stress-tolerant hybrid. A protocol mimicking field progressive stress conditions was developed and its effect on plant growth analyzed at different time points. The results indicated that the stresses limited growth in the hybrid and arrested it in the inbred line. In SS, the two genotypes had different ion accumulation and translocation capacity, particularly for Na+ and Cl 12. Moreover, the hybrid perceived the stress, reduced all the analyzed physiological parameters, and kept them reduced until the recovery. B73 decreased all physiological parameters more gradually, being affected mainly by SS. Both lines recovered better from WS than the other stresses. Molecular analysis revealed a diverse modulation of some stress markers in the two genotypes, reflecting their different response to stresses. Combining biochemical and physiological data with expression analyses yielded insight into the mechanisms regulating the different stress tolerance of the two lines

Non-Natural Linker Configuration in 2,6-Dipeptidyl-Anthraquinones Enhances the Inhibition of TAR RNA Binding/Annealing Activities by HIV-1 NC and Tat Proteins

The HIV-1 nucleocapsid (NC) protein represents an excellent molecular target for the development of antiretrovirals by virtue of its well-characterized chaperone activities, which play pivotal roles in essential steps of the viral life cycle. Our ongoing search for candidates able to impair NC binding/annealing activities led to the identification of peptidylanthraquinones as a promising class of nucleic acid ligands. Seeking to elucidate the inhibition determinants and increase the potency of this class of compounds, we have now explored the effects of chirality in the linker connecting the planar nucleus to the basic side chains. We show here that the non-natural linker configuration imparted unexpected TAR RNA targeting properties to the 2,6-peptidyl-anthraquinones and significantly enhanced their potency. Even if the new compounds were able to interact directly with the NC protein, they manifested a consistently higher affinity for the TAR RNA substrate and their TARbinding properties mirrored their ability to interfere with NC-TAR interactions. Based on these findings, we propose that the viral Tat protein, sharing the same RNA substrate but acting in distinct phases of the viral life cycle, constitutes an additional druggable target for this class of peptidyl-anthraquinones. The inhibition of Tat-TAR interaction for the test compounds correlated again with their TAR-binding properties, while simultaneously failing to demonstrate any direct Tat-binding capabilities. These considerations highlighted the importance of TAR RNA in the elucidation of their inhibition mechanism, rather than direct protein inhibition. We have therefore identified anti-TAR compounds with dual in vitro inhibitory activity on different viral proteins, demonstrating that it is possible to develop multitarget compounds capable of interfering with processes mediated by the interactions of this essential RNA domain of HIV-1 genome with NC and Tat proteins

3,4-Dihydroxyphenylethanol and 3,4-dihydroxyphenylacetic acid affect the aggregation process of E46K variant of α-synuclein at different extent: Insights into the interplay between protein dynamics and catechol effect.

peer reviewedParkinson's disease (PD) is a chronic multifactorial disease, whose etiology is not completely understood. The amyloid aggregation of α-synuclein (Syn) is considered a major cause in the development of the disease. The presence of genetic mutations can boost the aggregation of the protein and the likelihood to develop PD. These mutations can lead to early onset (A30P, E46K, and A53T) or late-onset (H50Q) forms of PD. The disease is also linked to an increase in oxidative stress and altered levels of dopamine metabolites. The molecular interaction of these molecules with Syn has been previously studied, while their effect on the pathological mutant structure and function is not completely clarified. By using biochemical and biophysical approaches, here we have studied the interaction of the familial variant E46K with two dopamine-derived catechols, 3,4-dihydroxyphenylacetic acid and 3,4-dihydroxyphenylethanol. We show that the presence of these catechols causes a decrease in the formation of amyloid fibrils in a dose-dependent manner. Native- and Hydrogen/deuterium exchange-mass spectrometry (HDX-MS) provide evidence that this effect is strongly conformation dependent. Indeed, these molecules interact differently with the interconverting conformers of Syn and its familial variant E46K in solution, selecting the most prone-to-aggregation one, confining it into an off-pathway oligomer. These findings suggest that catechols could be a molecular scaffold for the design of compounds potentially useful in the treatment of Parkinson's disease and related conditions

3,4-Dihydroxyphenylethanol and 3,4-dihydroxyphenylacetic acid affect the aggregation process of E46K variant of α-synuclein at different extent: Insights into the interplay between protein dynamics and catechol effect.

peer reviewedParkinson's disease (PD) is a chronic multifactorial disease, whose etiology is not completely understood. The amyloid aggregation of α-synuclein (Syn) is considered a major cause in the development of the disease. The presence of genetic mutations can boost the aggregation of the protein and the likelihood to develop PD. These mutations can lead to early onset (A30P, E46K, and A53T) or late-onset (H50Q) forms of PD. The disease is also linked to an increase in oxidative stress and altered levels of dopamine metabolites. The molecular interaction of these molecules with Syn has been previously studied, while their effect on the pathological mutant structure and function is not completely clarified. By using biochemical and biophysical approaches, here we have studied the interaction of the familial variant E46K with two dopamine-derived catechols, 3,4-dihydroxyphenylacetic acid and 3,4-dihydroxyphenylethanol. We show that the presence of these catechols causes a decrease in the formation of amyloid fibrils in a dose-dependent manner. Native- and Hydrogen/deuterium exchange-mass spectrometry (HDX-MS) provide evidence that this effect is strongly conformation dependent. Indeed, these molecules interact differently with the interconverting conformers of Syn and its familial variant E46K in solution, selecting the most prone-to-aggregation one, confining it into an off-pathway oligomer. These findings suggest that catechols could be a molecular scaffold for the design of compounds potentially useful in the treatment of Parkinson's disease and related conditions

Centerscope

Centerscope, formerly Scope, was published by the Boston University Medical Center "to communicate the concern of the Medical Center for the development and maintenance of improved health care in contemporary society.