Deciphering Spectroscopic and Structural Insights into the Photophysical Behavior of 2,2'-Dipyridylamine: An Efficient Environment Sensitive Fluorescence Probe.

Excited state deactivation properties and the effects of solvent hydrogen bonding (HB) on the photophysical behavior of 2,2'-dypyridylamine (DPyA) were investigated by steady state and time-resolved fluorescence experiments, molecular docking, and density functional theory (DFT) calculations. In addition to the polarity effect, the contributions of solvent HB donation (HBD) acidity and HB acceptance (HBA) basicity to modulate the solvatochromic spectral properties were estimated from multiparametric linear regression analysis using Kamlet-Taft (KT) and Catalán formalisms. The importance of C-N bond torsion, leading to the → conversion, was manifested by substantial increase in DPyA fluorescence yield in the presence of cyclodextrin (CD) and glycerol.

Exploring the interaction of bioactive kaempferol with serum albumin, lysozyme and hemoglobin: A biophysical investigation using multi-spectroscopic, docking and molecular dynamics simulation studies.

In recent years research based on kaempferol (KMP) has shown its potential therapeutic applications in medicinal chemistry and clinical biology. Therefore, to understand its molecular recognition mechanism, we studied its interactions with the carrier proteins, namely, human serum albumin (HSA), bovine hemoglobin (BHb) and hen egg white lysozyme (HEWL). The ligand, KMP was able to quench the intrinsic fluorescence of these three proteins efficiently through static quenching mode.

Targeting the heme protein hemoglobin by (-)-epigallocatechin gallate and the study of polyphenol-protein association using multi-spectroscopic and computational methods.

In this work, the interaction of a bioactive tea polyphenol (-)-epigallocatechin gallate (EGCG) with bovine hemoglobin (BHb) along with its anti-oxidative behavior and the anti-glycation property have been explored using multi-spectroscopic and computational techniques. The binding affinity for EGCG towards BHb was observed to be moderate in nature with an order of 104 M-1, and the fluorescence quenching mechanism was characterized by an unusual static quenching mechanism. The binding constant (Kb) showed a continuous enhancement with temperature from 3.

Therapeutic potency of substituted chromones as Alzheimer's drug: Elucidation of acetylcholinesterase inhibitory activity through spectroscopic and molecular modelling investigation.

Documentation on the potency of chromones as acetylcholinesterase (AChE) antagonists has paved the way for the design and usage of new chromone analogues as inhibitors of AChE modelled on the hypothesis based on cholinergic pathway of Alzheimer's disease (AD). Here, 2 minimally substituted chromones, namely 3-cyanochromone (CyC) and 7-amino-3- methylchromone (AMC), were checked for their AChE inhibition efficacies and plasma protein modulation. Colorimetric enzymatic assay as well as fluorescence measurements were performed for obtaining the experimental results, which were further corroborated by molecular docking and simulation studies.

Lysozyme-luteolin binding: molecular insights into the complexation process and the inhibitory effects of luteolin towards protein modification.

In the proposed work, the complexation of bioactive flavonoid luteolin with hen egg white lysozyme (HEWL) along with its inhibitory influence on HEWL modification has been explored with the help of multi-spectroscopic and computational methods. The binding affinity has been observed to be moderate in nature (in the order of 10 M) and the static quenching mechanism was found to be involved in the fluorescence quenching process. The binding constant (K) shows a progressive increase with the increase in temperature from (4.

An insight into the binding of 6-hydroxyflavone with hen egg white lysozyme: a combined approach of multi-spectroscopic and computational studies.

The interaction of 6-hydroxyflavone (6HF) with hen egg white lysozyme (HEWL) has been executed using multi-spectroscopic and computational methods. Steady state fluorescence studies indicated that static quenching mechanism is involved in the binding of 6HF with HEWL, which was further supported by excited state lifetime and UV-vis absorption studies. The binding constant () of the HEWL-6HF complex was observed to be 6.

An efficient synthesis of triazolium ion based NHC precursors using diaryliodonium salts and their photophysical properties.

Copper-catalysed N-arylation of fused triazoles using diaryliodonium salts as an aryl source is described. This scalable protocol displayed good compatibility towards diverse sensitive functional groups like ester, alkyl and nitro groups and halogens (F, Cl, Br). The synthetic usefulness of the prepared triazolium salts was proved by preparing α-hydroxyketone through benzoin condensation.

Molecular recognition of bio-active flavonoids quercetin and rutin by bovine hemoglobin: an overview of the binding mechanism, thermodynamics and structural aspects through multi-spectroscopic and molecular dynamics simulation studies.

The binding of two bio-active flavonoids, quercetin and rutin, with bovine hemoglobin (BHb) was investigated by multi-spectroscopic and computational (molecular docking and molecular dynamics simulation) studies. The two flavonoids were found to quench the intrinsic fluorescence of BHb through a static quenching mechanism. The binding constants at 288 K were observed to be (14.

Exploring the non-covalent binding behaviours of 7-hydroxyflavone and 3-hydroxyflavone with hen egg white lysozyme: Multi-spectroscopic and molecular docking perspectives.

The interactions of bio-active flavonoids, 7-hydroxyflavone (7HF) and 3-hydroxyflavone (3HF) with hen egg white lysozyme (HEWL) have been established using differential spectroscopic techniques along with the help of molecular docking method. The characteristic dual fluorescence of 3HF due to the excited intramolecular state proton transfer (ESIPT) process is altered markedly upon binding with HEWL. Both the flavonoids quenched the intrinsic fluorescence of HEWL through static quenching mechanism while the binding affinity of 7HF was found to be greater than 3HF under experimental conditions.

Characterization of non-covalent binding of 6-hydroxyflavone and 5,7-dihydroxyflavone with bovine hemoglobin: Multi-spectroscopic and molecular docking analyses.

Flavonoids are biologically imperative compounds used as anti-oxidants, anti-cancer, anti-bacterial agents etc. The current work reports comprehensive binding studies of two important flavonoids, 6-hydroxyflavone and 5,7-dihydroxyflavone (chrysin) with bovine hemoglobin (BHb) at 298K and 308K, in aqueous medium using UV-vis spectroscopy, steady state fluorescence, circular dichroism (CD) measurements, Fourier Transform infrared spectroscopy (FT-IR) and molecular docking studies. Both 6-hydroxyflavone and chrysin can quench the intrinsic fluorescence intensity of BHb via static quenching mechanism.

Correlation of cholinergic drug induced quenching of acetylcholinesterase bound thioflavin-T fluorescence with their inhibition activity.

The development of new acetylcholinesterase inhibitors (AChEIs) and subsequent assay of their inhibition efficiency is considered to be a key step for AD treatment. The fluorescence intensity of thioflavin-T (ThT) bound in the active site of acetylcholinesterase (AChE) quenches substantially in presence of standard AChEI drugs due to the dynamic replacement of the fluorophore from the AChE active site as confirmed from steady state emission as well as time-resolved fluorescence anisotropy measurement and molecular dynamics simulation in conjunction with docking calculation. The parametrized % quenching data for individual system shows excellent correlation with enzyme inhibition activity measured independently by standard Ellman AChE assay method in a high throughput plate reader system.

Lysozyme binding ability toward psychoactive stimulant drugs: Modulatory effect of colloidal metal nanoparticles.

The interaction and binding behavior of the well-known psychoactive stimulant drugs theophylline (THP) and theobromine (THB) with lysozyme (LYS) was monitored by in-vitro fluorescence titration and molecular docking calculations under physiological condition. The quenching of protein fluorescence on addition of the drugs is due to the formation of protein-drug complex in the ground state in both the cases. However, the binding interaction is almost three orders of magnitude stronger in THP, which involves mostly hydrogen bonding interaction in comparison with THB where hydrophobic binding plays the predominant role.