Potential combination therapy using twenty phytochemicals from twenty plants to prevent SARS- CoV-2 infection: An in silico Approach.

Covid 19 caused by novel strain SARS- CoV-2 has become a pandemic due to its contagious nature of infection. It enters by binding with ACE2 receptor present on the outer surface of a cell by cleaving S1/S2 with proteolytic protein Furin. Further viral replication or transcription then takes place with the help of main protease 3CLpro and polymerase RdRp.

Chemical physics behind formation of efficient charge-separated state for complexation between PC70BM and designed diporphyrin in solution.

The present work reports supramolecular interaction of [6,6]-phenyl C71 butyric acid methyl ester (PC70BM) with two designed diporphyrin molecules having dithiophene (1) and carbazole (2) spacer in solvent having varying polarity. Studies on complex formation reveal relatively higher binding constant for PC70BM/2 complex in all the solvent studied. Solvent dependence of charge separation and charge recombination processes in PC70BM/diporphyrin non-covalent complexes has been well established in present work.

FCS study of the structural stability of lysozyme in the presence of morpholinium salts.

Ability of the ionic liquids to alter the structural stability of proteins in aqueous solution is a topic of considerable interest in modern bioscientific research because of possible applications of these substances in protein purification and as refolding agents. A few early studies involving the imidazolium ionic liquids have demonstrated their role as both denaturants and refolding agents. As the influence of an ionic liquid on a given protein depends on the identity of both species, it is necessary to extend the studies to a wider number of ionic liquids and proteins to obtain insight into the mechanism of interaction between the two and to arrive at a comprehensive picture.

Potential charge transfer probe induced conformational changes of model plasma protein human serum albumin: Spectroscopic, molecular docking, and molecular dynamics simulation study.

The nature of binding of specially designed charge transfer (CT) fluorophore at the hydrophobic protein interior of human serum albumin (HSA) has been explored by massive blue-shift (82 nm) of the polarity sensitive probe emission accompanying increase in emission intensity, fluorescence anisotropy, red edge excitation shift, and average fluorescence lifetimes. Thermal unfolding of the intramolecular CT probe bound HSA produces almost opposite spectral changes. The spectral responses of the molecule reveal that it can be used as an extrinsic fluorescent reporter for similar biological systems.

Study of microheterogeneous environment of protein Human Serum Albumin by an extrinsic fluorescent reporter: a spectroscopic study in combination with Molecular Docking and Molecular Dynamics Simulation.

We report extrinsic fluorescent probe 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid (DMAPPDA) as a molecular reporter for studying microheterogeneous environment of protein Human Serum Albumin (HSA) via spectral modification of the probe under physiological condition. Steady state emission, fluorescence anisotropy, Red Edge Excitation Shift (REES), far-UV Circular Dichroism (CD), Atomic Force Microscopy (AFM) imaging, time resolved spectral measurements, Molecular Docking and Molecular Dynamics (MD) Simulation techniques have been used to fulfill this achievement. Interaction of the probe with HSA is signaled by the blue shift of the fluorophore emission maxima with enhancement of fluorescence intensity.

Exploring structural change of protein bovine serum albumin by external perturbation using extrinsic fluorescence probe: spectroscopic measurement, molecular docking and molecular dynamics simulation.

Structural modification through binding interaction of plasma protein bovine serum albumin (BSA) with an extrinsic charge transfer fluorophore 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid (DMAPPDA) and its response to external perturbation due to interactions with surfactant sodium dodecyl sulphate (SDS) have been explored at physiological pH by steady state absorption, emission, fluorescence anisotropy, red edge excitation shift, far-UV circular dichroism and time resolved spectral measurements in combination with Molecular Docking and Molecular Dynamics (MD) simulation. Interaction of the probe with BSA is reflected by a small change in protein secondary structure with fluorescence enhancement and blue shift of probe emission. Molecular docking studies revealed that the probe binds to the hydrophobic cavity of sub-domain IIA of BSA.

Domain specific association of small fluorescent probe trans-3-(4-monomethylaminophenyl)-acrylonitrile (MMAPA) with bovine serum albumin (BSA) and its dissociation from protein binding sites by Ag nanoparticles: spectroscopic and molecular docking study.

Photoinduced intramolecular charge transfer produced a polar excited state in trans-3-(4-monomethylaminophenyl)acrylonitrile (MMAPA), rendering the resulting emission sensitive to the medium polarity. Strong binding interaction of silver nanoparticles with the probe was observed, causing fluorescence quenching through the static quenching process. The probe MMAPA was found to bind to the less polar hydrophobic, restricted proteinous environment of bovine serum albumin (BSA) resulting in the blue shift of the emission maximum with an increase in emission intensity and fluorescence anisotropy.

Constrained photophysics of partially and fully encapsulated charge transfer probe (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester inside cyclodextrin nano-cavities: evidence of cyclodextrins cavity dependent complex stoichiometry.

The polarity sensitive intra-molecular charge transfer (ICT) emission from (E)-3-(4-Methylaminophenyl) acrylic acid methyl ester (MAPAME) is found to show distinct changes once introduced into the nano-cavities of cyclodextrins in aqueous environment. Movement of the molecule from the more polar aqueous environment to the less polar, hydrophobic cyclodextrin interior is marked by the blue shift of the CT emission band with simultaneous fluorescence intensity enhancement. The emission spectral changes on complexation with the α- and β-CD show different stoichiometries as observed from the Benesi-Hildebrand plots.

Photoinduced intramolecular charge transfer phenomena in 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid.

A donor acceptor substituted aromatic system 5-(4-dimethylamino-phenyl)-penta-2,4-dienoic acid (DMAPPDA) has been synthesized and its spectral properties have been explored on the basis of steady state absorption and fluorescence spectroscopy. Spectral features point largely towards a possible occurrence of photoinduced intramolecular charge transfer process from the donor NMe2 group to the acceptor acid group. Solvent dependency of the large Stokes' shifted emission band and the calculated large excited state dipole moment support the polar character of the charge transfer excited state.

Fluorescent probing of protein bovine serum albumin stability and denaturation using polarity sensitive spectral response of a charge transfer probe.

The polarity sensitive photo-induced intra-molecular charge transfer (ICT) fluorescence probe (E)-3-(4-methylamino-phenyl)-acrylic acid ethyl ester (MAPAEE) has been used to study the model protein Bovine Serum Albumin (BSA) in its native and thermal and urea induced denatured states. The interaction between BSA and the regular surfactant Sodium Dodecyl Sulphate (SDS) as well as the biologically relevant steroid-based amphiphile Sodium Deoxycholate (NaDC) has also been very keenly followed using this ICT probe. The variation of micellar properties of both SDS and NaDC with increasing ionic strengths and in presence of the chaotrope urea has also been well documemted by the same probe.

Fluorescent probing of urea-induced chemical unfolding of bovine serum albumin by intramolecular charge transfer fluorescence probe E-3-(4-dimethylamino-naphthalen-1-yl)-acrylic acid.

Changes in polarity at the immediate binding site in protein bovine serum albumin (BSA) produces distinct changes in the solvent polarity-dependent emission band of fluorescence probe E-3-(4-dimethylamino-naphthalen-1-yl)-acrylic acid. Steady-state spectroscopy and time-resolved spectroscopy have been used to investigate this binding process. Attaching the probe to BSA and then monitoring its spectral changes with increasing urea concentration and raising temperature has also tracked the denaturation of BSA chemically and thermally.

Photoinduced properties of methyl ester of 2,6-dimethyl-1-amino-4-benzoic acid: evidence of charge transfer emission from a weak primary amino donor.

Photophysical properties of methyl ester of 2,6-dimethyl-1-amino-4-benzoic acid (M26DMB) have been investigated using steady state absorption and emission spectroscopy and time-resolved emission spectroscopy. Interestingly, not only in polar solvents, the molecule M26DMB having a weak primary amino donor group shows broad red-shifted emission band even in non-polar environment which in all probability arises from closely spaced local and charge transfer (CT) states. Clear dual fluorescence in polar protic solvents comprises of less intense local emission band and strong red-shifted CT band.

Chemically induced unfolding of bovine serum albumin by urea and sodium dodecyl sulfate: a spectral study with the polarity-sensitive charge-transfer fluorescent probe (E)-3-(4-methylaminophenyl)acrylic acid methyl ester.

Sensitivity of the charge-transfer (CT) band of the fluorescence probe (E)-3-(4-methylaminophenyl)acrylic acid methyl ester (MAPAME) towards the polarity of its immediate environment is employed to investigate the binding interaction of the probe with bovine serum albumin (BSA) and uncoiling of BSA by the denaturants urea and sodium dodecyl sulfate micelles. Binding of the probe with BSA produces a blue shift and enhanced intensity of the CT emission band which clearly point toward a decrease in polarity of the immediate environment of MAPAME. This is expected, since binding with BSA moves the probe from a polar water environment to a much less polar, hydrophobic protein interior, where the CT band is expected to be blue-shifted.