Journal ArticleDOI
Protein-flavonol interaction: fluorescence spectroscopic study.
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TLDR
Analysis of relevant spectroscopic data leads to the conclusions that two binding sites are involved in BSA–3HF interaction, and the interaction is slightly positively cooperative in nature with a similar binding constant.Abstract:
Recent studies have shown that various synthetic as well as therapeutically active naturally occurring flavonols possess novel luminescence properties that can potentially serve as highly sensitive monitors of their microenvironments in biologically relevant systems. We report a study on the interactions of bovine serum albumin (BSA) with the model flavonol 3-hydroxyflavone (3HF), using the excited-state proton-transfer (ESPT) luminescence of 3HF as a probe. Upon addition of BSA to the flavonoid solutions, we observe remarkable changes in the absorption, ESPT fluorescence emission and excitation profiles as well as anisotropy (r) values. Complexation of 3HF with protein results in a pronounced shift (20 nm) of the ESPT emission maximum of the probe (from lambda(max)(em) = 513 nm to lambda(max)(em) = 533 nm) accompanied by a significant increase in fluorescence intensity. The spectral data also suggest that, in addition to ESPT, the protein environment induces proton abstraction from 3HF leading to formation of anionic species in the ground state. Fairly high values of anisotropy are observed in the presence of BSA for the tautomer (r = 0.25) as well as anion (r = 0.35) species of 3HF, implying that both the species are located in motion-restricted environments of BSA molecules. Analysis of relevant spectroscopic data leads to the conclusions that two binding sites are involved in BSA-3HF interaction, and the interaction is slightly positively cooperative in nature with a similar binding constant of 1.1 - 1.3 x 10(5) M(-1) for both these sites. Proteins 2001;43:75-81.read more
Citations
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Journal ArticleDOI
Perturbation of planarity as the possible mechanism of solvent-dependent variations of fluorescence quantum yield in 2-aryl-3-hydroxychromones.
TL;DR: The results suggest that the formation of intermolecular hydrogen bond of 3-hydroxy group with the solvent favors non-planar conformations of phenyl group with respect to chromone system.
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Excited State and Ground State Proton Transfer Rates of 3-Hydroxyflavone and Its Derivatives Studied by Shpol'skii Spectroscopy: The Influence of Redistribution of Electron Density†
TL;DR: In this article, the authors studied the mechanisms of excited-state intramolecular proton transfer (ESIPT) and ground-state back propton transfer (BPT) in 3-hydroxyflavone (3HF) at cryogenic temperatures.
Journal ArticleDOI
Analysis of binding interaction between bovine serum albumin and the cobalt(II) complex with salicylaldehyde-2-phenylquinoline-4-carboylhydrazone.
TL;DR: The interaction between bovine serum albumin and the cobalt(II) complex with salicylaldehyde-2-phenylquinoline-4-carboylhydrazone (Co-SPC) was investigated using fluorescence spectroscopy, UV absorption, and circular dichroism under simulated physiologic conditions for the first time.
Journal ArticleDOI
Hydrogen bonding properties of DMSO in ground-state formation and optical spectra of 3-hydroxyflavone anion
TL;DR: In this paper, the ground-state formation of 3-hydroxyflavone (3HF) anion in DMSO has been investigated and a possible new mechanism is proposed.
Journal ArticleDOI
Biomimetic synthesis of HgS nanoparticles in the bovine serum albumin solution
TL;DR: In this article, HgS nanocrystals conjugated with protein were synthesized in aqueous solution of Bovine Serum Albumin (BSA) at room temperature.
References
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Book
Principles of fluorescence spectroscopy
TL;DR: This book describes the fundamental aspects of fluorescence, the biochemical applications of this methodology, and the instrumentation used in fluorescence spectroscopy.
Book
Chemistry and biochemistry of plant pigments
TL;DR: This book will help you to understand the chemistry and biochemistry of plant pigments book much better and the system of this book of course will be much easier.
Journal ArticleDOI
Flavonoids, a class of natural products of high pharmacological potency
TL;DR: The few existing reports on the careful pharmacodynamic, pharmacokinetic and clinical studies which have been made have been summarized to provide a basis for a full-scale investigation of the therapeutic potential of flavonoids.
Journal ArticleDOI
Excited state proton-transfer spectroscopy of 3-hydroxyflavone and quercetin
TL;DR: In this article, the double minimum hydrogen-bonding potential of 3-hydroxyflavone and quercetin at room temperature in solution has been used to explain the luminescence of these molecules at 77 K in 2-methylbutane rigid matrix.