Search results for "Estructura química"
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On the Intrinsically Low Quantum Yields of Pyrimidine DNA Photodamages: Evaluating the Reactivity of the Corresponding Minimum Energy Crossing Points
2020
The low quantum yield of photoformation of cyclobutane pyrimidine dimers and pyrimidine-pyrimidone (6-4) adducts in DNA bases is usually associated with the presence of more favorable nonreactive decay paths and with the unlikeliness of exciting the system in a favorable conformation. Here, we prove that the ability of the reactive conical intersection to bring the system either back to the absorbing conformation or to the photoproduct must be considered as a fundamental factor in the low quantum yields of the mentioned photodamage. In support of the proposed model, the one order of magnitude difference in the quantum yield of formation of the cyclobutane thymine dimer with respect to the t…
Elucidating the aryl hydrocarbon receptor antagonism from a chemical-structural perspective.
2020
The aryl hydrocarbon receptor (AhR) plays an important role in several biological processes such as reproduction, immunity and homoeostasis. However, little is known on the chemical-structural and physicochemical features that influence the activity of AhR antagonistic modulators. In the present report, in vitro AhR antagonistic activity evaluations, based on a chemical-activated luciferase gene expression (AhR-CALUX) bioassay, and an extensive literature review were performed with the aim of constructing a structurally diverse database of contaminants and potentially toxic chemicals. Subsequently, QSAR models based on Linear Discriminant Analysis and Logistic Regression, as well as two tox…