Publications by authors named "Alejandro O Viviano-Posadas"
Optical sensing of L-dihydroxy-phenylalanine in water by a high-affinity molecular receptor involving cooperative binding of a metal coordination bond and boronate-diol.
Dalton Trans
October 2024
Article Synopsis
- The text discusses a novel fluorescent synthetic receptor, CuL1, designed to selectively recognize the neurotransmitter levodopa in water, which is significant for biological and analytical chemistry.
- CuL1 is a cationic Cu(II)-terpyridine complex featuring a fluorescent quinolinium and phenylboronic acid that exhibits a high affinity for levodopa while maintaining selectivity over other neurotransmitters like dopamine and epinephrine.
- The detection of levodopa with CuL1 is demonstrated through a visual sensing method using eosin Y dye, showcasing how the receptor effectively displaces the dye and allows for its efficient monitoring.
Article Synopsis
- The study focuses on creating novel receptors using arylboronic acid-based complexes that can selectively recognize fructosyl amino acids like fructosyl valine (FV) and fructosyl glycyl histidine (FGH) in water, important for understanding glycated hemoglobin in humans.
- Three different cationic Zn-terpyridine complexes were synthesized, with one complex (3Zn) showing the highest acidity and a strong affinity for FV, indicated by significant optical changes when these compounds interact.
- The mechanism of interaction involves a cooperative recognition process and fluorescence quenching due to an electron transfer, with FGH also increasing emission intensity but exhibiting a weaker affinity compared to FV.
Selective Luminescent Chemosensing of Chloride Based on a Cyclometalated Platinum(II) Complex in Water: Crystal Structures, Spectroscopic Studies, Extraction, and Bioimaging.
Inorg Chem
May 2023
Article Synopsis
- - The study focuses on a new luminescent chemosensor based on a cationic platinum complex that selectively detects anions, particularly chloride ions, in water, which is significant for analytical and biological chemistry applications.
- - The platinum complex exhibits strong green phosphorescent emission in response to chloride, showing a high affinity for this anion compared to others, making it promising for quantitative sensing and possibly useful for bioimaging of cell nuclei.
- - Structural analysis and various spectroscopic techniques reveal that the sensor's selectivity for chloride arises from a unique three-point recognition mechanism involving a direct bonding interaction and additional non-covalent interactions.
A series of new D-ring ethisterones substituted with 1,4-1,2,3-triazoles were obtained in a facile manner via click chemistry reactions. The new compounds were characterized by multinuclear NMR spectroscopy, mass spectrometry, IR and unequivocally by single crystal X-ray diffraction studies for compound 1. The cytotoxic activity of these derivatives was tested against a series of human cancer cell lines including human glioblastoma (U-251), human prostatic adenocarcinoma (PC-3), human colorectal adenocarcinoma (HCT-15), human mammary adenocarcinoma (MCF-7), human chronic myelogenous leukemia (K562), and human lung adenocarcinoma (SKLU-1).
View Article and Find Full Text PDFEfficient fluorescent recognition of ATP/GTP by a water-soluble bisquinolinium pyridine-2,6-dicarboxamide compound. Crystal structures, spectroscopic studies and interaction mode with DNA.
RSC Adv
September 2022
Article Synopsis
- - A new compound called compound 1, made from pyridine-2,6-dicarboxamide with two -alkylquinolinium units, was synthesized and studied as a fluorescent sensor for nucleotides in water.
- - When nucleotides are added to compound 1, its blue fluorescence decreases, showing a particular preference for ATP and GTP, as opposed to other nucleotides, highlighting its selective binding.
- - The receptor has a strong affinity for ATP due to its structural characteristics and bonding interactions, and it can effectively bind to DNA, indicating its potential applications in biochemical research.
Article Synopsis
- Biological catecholamines like l-DOPA and dopamine are important for brain function and can indicate certain diseases, prompting the development of new sensors to detect them effectively.
- The study introduces fluorescent Zn(ii)-terpyridine complexes that selectively bind catecholamines and nucleosides, demonstrating a strong affinity for l-DOPA and showing significant changes in fluorescence when in the presence of these compounds.
- Advanced spectroscopic methods reveal the binding mechanism involves a unique interaction between the chemosensors and l-DOPA, allowing for a rapid fluorescent response and color change that can be observed without specialized equipment.
Treatment of 3-oxo-5β-steroids with diacetoxyiodobenzene/KOH triggered a fast and regioselective Favorskii rearrangement that exclusively led to 3β-methoxycarbonyl-5β-4-norsteroids in good yields. The outcome of the reaction indicates that although both Cyclopropanone and Semi-benzylic pathways are possible, in the case of 3-oxo-5β-steroids, only the last participates. Unambiguous characterization of the products was achieved by NMR and X-ray Diffraction studies.
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