This study describes the synthesis of new carboxylated merocyanine dyes by Knoevenagel condensation between 4-carboxybenzaldehyde and indolium/benzoindolium- and benzothiazolium-based coupling compounds. The condensations were performed in the presence of ammonium acetate, and the products were obtained in good yields after simple purification. These merocyanines exhibit UV-A-to-blue absorption and blue-to-green fluorescence emission, characterized by relatively large Stokes shift values (∼5000 cm).
View Article and Find Full Text PDFThe natural products 7-hydroxycoumarin (7HC) and 7-hydroxy-4-methylcoumarin (7H4MC), known as umbelliferone and hymecromone, respectively, are one of the simplest structural examples from coumarin's family, showing several biological activities. Bovine serum albumin (BSA) is the main model protein used in laboratory experiments to characterize the biophysical capacity of potential drugs to be carried until the target in the bloodstream. Thus, the interaction BSA:7HC and BSA:7H4MC was biophysically characterized by circular dichroism (CD), steady-state, and time-resolved fluorescence techniques combined with molecular docking calculations via cross-docking approach to better correlate with the biological medium.
View Article and Find Full Text PDFLapachol (LAP), a natural 1,4-naphthoquinone used in popular medicine in South America, is an antioxidant and antimicrobial compound in teas and infusions and used as a food additive; however, its interactive profile with the main protein carrier of compounds in the human bloodstream (human serum albumin, HSA) was not still characterized. Additionally, the impact of LAP in binding clinically drugs to albumin is still unknown. Thus, the present work describes the interaction HSA:LAP using different biophysical techniques, i.
View Article and Find Full Text PDFPhotodynamic therapy (PDT) combines a light source, oxygen, and a photosensitizer (PS) to generate reactive oxygen species (ROS) for treating diseases. In this study, we evaluated two meso-tetra-pyridyl porphyrins with [Pd(bpy)Cl], namely 3-PdTPyP and 4-PdTPyP, as PS for PDT application. DNA interaction was assessed by spectroscopic measurements (UV-Vis and fluorescence emission), viscosity analysis, and molecular docking simulations.
View Article and Find Full Text PDFKetoprofen (KTF) and ketorolac (KTL) are among the most primarily used non-steroidal anti-inflammatory drugs (NSAIDs) in humans to alleviate moderate pain and to treat inflammation. Their binding affinity with albumin (the main globular protein responsible for the biodistribution of drugs in the bloodstream) was previously determined by spectroscopy without considering some conventional pitfalls. Thus, the present work updates the biophysical characterization of the interactions of HSA:KTF and HSA:KTL by H saturation-transfer difference nuclear magnetic resonance (H STD-NMR), ultraviolet (UV) absorption, circular dichroism (CD), steady-state, and time-resolved fluorescence spectroscopies combined with in silico calculations.
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