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
A concise approach to 1,11-didechloro-6-methyl-4′-O-demethyl rebeccamycin and its binding to human serum albumin: Fluorescence spectroscopy and molecular modeling method
TL;DR: The interaction between JDC-108 and human serum albumin (HSA) was studied by spectroscopic methods including fluorescence spectroscopy, UV-vis absorption spectrum, and molecular modeling and the results indicated the binding reaction was mainly entropy-driven and hydrophobic forces played major role in the reaction.
Journal ArticleDOI
Spectroscopic Investigation on the Interaction of a Cyanine Dye with Serum Albumins
TL;DR: In this article, the interactions of a cyanine dye with human serum albumin (HSA) and bovine serum albumins (BSA) have been investigated by using absorption and fluorescence spectra.
Book ChapterDOI
Flavonoids and Cardiovascular Health
TL;DR: The role of flavonoids in cardiovascular health and its potential health promoting properties is discussed and the effectiveness for cardiovascular disease prevention and treatment is discussed.
Journal ArticleDOI
Carbon Nano-Onions and Biocompatible Polymers for Flavonoid Incorporation
TL;DR: Small carbon nano-onions are potentially better systems for some of these applications, because they show higher reactivity and solubility in many solvents, and the good biocompatibility and low cytotoxicity of CNOs are also very promising.
Journal ArticleDOI
Effect of pH on the fluorescence characteristics of some flavones probes.
TL;DR: The photophysical properties such as electronic absorption, molar extinction coefficient, emission spectra, fluorescence quantum yield and lifetime of three different hydroxyflavones (a typical model of flavonols) and the effect of pH on the intramolecular excited state proton transfer process (ESIPT) have been discussed.
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.