Photophysical properties of curcumin, 1,7-bis-(4-hydroxy-3-methoxy phenyl)-1,6-heptadiene-2,5-dione, a pigment found in the rhizomes Curcuma longa (turmeric) have been studied different kinds organic solvent and also Triton X-100 aqueous micellar media using time-resolved fluorescence transient absorption techniques having pico nanosecond time resolution, addition to steady-state spectroscopic techniques. Steady-state characteristics curcumin be sensitive characteristics. Large change (delta...

Sesamol (from Sesamum indicum) is a dietary compound, which soluble in aqueous as well lipid phases. Free radical scavenging reactions of sesamol, 5-hydroxy-1,3-benzodioxole, have been studied using nanosecond pulse radiolysis technique. efficiently scavenges hydroxyl, one-electron oxidizing, organo-haloperoxyl, peroxyl, and tryptophanyl radicals. Its antioxidant activity has also evaluated with cyclic voltammetry. In biochemical studies, it found to inhibit peroxidation, hydroxyl...

Photodynamics of the S1 state 1,4- and 1,8-disubstituted hydroxyquinones aminoquinones have been studied in different organic solvents by absorption fluorescence spectroscopy. The internal conversion process is major deactivation path for state. solvent temperature dependence deuterium isotope effect on dynamics suggest that hydrogen stretching vibrations intra- inter-molecular bonds are responsible very fast non-radiative decay processes. Among intra-molecular hydrogen-bonded molecules only...

Excess-entropy scaling relationships for diffusivity and viscosity of Lennard-Jones chain fluids are tested using molecular dynamics simulations sizes that sufficiently small entanglement effects insignificant. The thermodynamic excess entropy S(e) is estimated self-associating fluid theory (SAFT). A structural measure the S(2) also computed from monomer-monomer pair correlation function, g(m)(r). estimators shown to be very strongly correlated. dimensionless center-of-mass diffusivities,...

Abstract Antioxidant activity of gentisic acid has been studied using fast chemical kinetics and two in vitro models, namely the isolated rat liver mitochondria (RLM) human erythrocytes. The presence (GA) during irradiation significantly reduced levels gamma radiation induced damages to lipids proteins RLM. Further, GA imparted protection erythrocytes against exposure radiation. Molecular mechanism free radical scavenging reactions evaluated with help rate constants transients obtained from...

Dynamic Stokes' shift measurements using coumarin 153 as the fluorescence probe have been carried out to study solvation dynamics in two nonionic micelles, viz., triton-X-100 (TX-100) and triton-X-165 (TX-165). In both solvent relaxation is biexponential nature. While fast time tau(s1) seen be almost similar for slow tau(s2) found appreciably smaller TX-165 than TX-100 micelle. light scattering indicate that micelles are substantially size of TX-100. Assuming core expected from chemical...

The temperature effect on solvation dynamics has been investigated in two neutral micelles, namely, Triton X-100 (TX100) and Brij-35 (BJ-35), using dynamic fluorescence Stokes' shift method, to explore the role of micellar size hydration process. In TX-100, C(t) is not only very strong but shows an unusual inversion around 298 K. On contrary, for BJ-35 micelle, that significant. Present results micelles have rationalized basis dependent changes hydration, which are reported be large TX-100...

We demonstrate that dihydroxy benzenes are excellent reducing agents and may be used to reduce silver ions synthesize stable nanoparticles in air-saturated aqueous solutions. The formation of Ag deaerated solution at high pH values suggests the reduction occurs due oxidation probably on surface Ag2O. Pulse radiolysis studies show semi-quinone radical does not participate short time scales. Nevertheless, results primary intermediates undergo slower transformation presence than their absence....

FTIR, Raman, and surface-enhanced Raman scattering (SERS) of methimazole (MMI) have been investigated. MMI is an important antithyroid drug that inhibits the formation thyroid hormone. It widely used clinically in treatment hyperthyroidism, thus it useful to study its surface adsorption characteristics. The experimental FTIR data are supported with DFT calculations using B3LYP functional LANL2DZ basis set. This first report on vibrational analysis thiol thione forms their various possible...

We report one pot synthesis of uniform and stable polyvinyl pyrolidone (PVP) protected gold nanoparticles (Au NPs) using environmental friendly, glycerol as reducing agent. The effect the presence a capping agent concentration reactants (glycerol, tetra chloroauric acid, NaOH) on size homogeneity Au NPs formed were investigated. Highly well-distributed obtained at higher NaOH in PVP with clear dependence glycerol, agent, whereas, large heterogeneous absence PVP. particle morphology,...

Reactions of sulfasalazine (SAZ) and its metabolites, 5-aminosalicylic acid (5-ASA) sulfapyridine (SP), with various oxidizing reducing free radicals (hydroxyl, haloperoxyl, one-electron oxidizing, lipid peroxyl, glutathiyl, superoxide, tryptophanyl, etc.) have been studied to understand the mechanistic aspects action against produced during inflammation. Nanosecond pulse radiolysis technique coupled transient spectrophotometry has used for in situ generation follow their reaction pathways....

Photoinduced electron transfer (ET) between coumarin dyes and aromatic amines has been investigated in Triton-X-100 micellar solutions the results have compared with those observed earlier homogeneous medium. Significant static quenching of fluorescence due to presence high concentration around fluorophore micelles steady-state studies. Time-resolved studies nanosecond resolutions mostly show dynamic part for excited by amine quenchers. A correlation rate constants, estimated from...