Fluorescent analogues of the natural DNA bases are useful in the study of nucleic acids' structure and dynamics. 2-Aminopurine (2AP) is a widely used analogue with environmentally sensitive fluorescence behavior. The quantum yield of 2AP has been found to be significantly decreased when engaged in π-stacking interactions with the native bases. We present a theoretical study on fluorescence quenching mechanisms in dimers of 2AP π-stacked with adenine or guanine as in natural DNA. Relaxation pathways on the potential energy surfaces of the first excited states have been computed and reveal the importance of exciplexes and conical intersections in the fluorescence quenching process.
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http://dx.doi.org/10.1039/c3pp25449f | DOI Listing |
Chem Biodivers
January 2025
Zhengzhou University, College of Chemistry, Kexue Road 100, 450001, Zhengzhou, CHINA.
The main protease (Mpro) is a cysteine enzyme and represents a vital target for antiviral drug screening. In this work, Twenty-five pyrrole derivatives were synthesized and screened by enzyme activity experiments. Results indicate that six pyrrole derivatives can bind to Mpro and have inhibitory effect on Mpro.
View Article and Find Full Text PDFJ Biomol Struct Dyn
January 2025
Department of Chemistry, National Institute of Technology Silchar, Silchar, Assam, India.
A series of 2,6-di(pyrazine-2-yl)pyridine (dppy) ligands - of varying substituents of different electronic nature (-NMe, -OMe,-Me, and -Cl) in the 4-position of the pyridine moiety has been designed and synthesized to study the binding behavior of the dppy ligands towards Bovine Serum Albumin (BSA), a low-cost serum albumin protein. The interaction between ligands and BSA has been studied using UV-Visible and fluorescence spectroscopy and molecular docking studies. The fluorescence of BSA was found to be quenched in the presence of all the ligands , in which ligand , having the most electron donating group NMe exhibits the maximum binding affinity towards BSA.
View Article and Find Full Text PDFJ Sci Food Agric
January 2025
Laboratorio de Investigación, Desarrollo y Evaluación de Alimentos (LIDEA), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), Santa Fe, Argentina.
Background: The antioxidant capacity of anthocyanins (AC) rapidly degrades during storage, highlighting the need for their stabilization. The conformational properties and high proline content of sodium caseinate (NaCAS), combined with the formation of NaCAS microgels in the presence of tara gum (TG) and acid gelation, suggest its potential as an effective stabilizing or encapsulating agent of AC.
Results: Spectrofluorimetric results suggest the formation of a complex between NaCAS and AC.
Environ Pollut
January 2025
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Extracellular polymeric substances (EPS) can effectively attenuate heavy metal mobility in aquatic ecosystems and reduce metal toxicity to cells. However, a systematic study of microalgae EPS responses and their adsorption behaviors, characteristics, and mechanisms under different heavy metal exposures has not been performed. In this study, EPS extracted from Chlamydomonas reinhardtii CC-125 was analyzed for compositional changes (monosaccharides and proteins) under Cd, Cu, Pb, and Zn treatments.
View Article and Find Full Text PDFTalanta
January 2025
Key Laboratory of Photovoltaic and Energy Conservation Materials, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, China. Electronic address:
Creatinine is an essential biomarker for the clinical diagnosis and treatment of renal insufficiency. Although fluorescent methods are powerful tools for creatinine detection, almost all reported fluorescent probes rely on short-wavelength excitation and a single fluorescent signal, making them susceptible to environmental and operational conditions. In this study, a near-infrared excited, highly sensitive, and multi-output signal sensing system was established using upconversion nanoparticles and 3,5-dinitrobenzoic acid (DNBA) for synergistic luminescent and colorimetric assay for strong visual detection of creatinine.
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