Binding of gefitinib (GEF), a promising anticancer drug to human serum albumin (HSA), the major transport protein in blood circulation was investigated using fluorescence, UV-vis absorption and circular dichroism (CD) spectroscopy as well as computational modeling. Fluorescence quenching of HSA upon GEF addition was found to be a static quenching process, as revealed from the decreasing trend o...

Intrinsic fluorescence of LDH-C4 has been studied in the presence of optical isomers of gossypol. The study showed that fluorescence due to tryptophan residues after excitation of LDH at 282 nm is quenched by each gossypol enantiomere in a concentration dependent manner. Half of the maximum quench (Q50%) of enzyme occurred with gossypol (-) at 0.9 x 10(-4) mol/l and with gossypol (+) at 1.4 x 1...

We performed an investigation of the pH-dependent quenching of the fluorescence of tryptophan residues of TEM-1 beta-lactamase from E. coli by uncharged and charged quenchers. pH-dependent Stern-Volmer constants (Ksv/pH) of tryptophan residues allowed us to determine subtle but discrete structurally and functionally important processes.

Mechanistic information on reactions proceeding via photoredox catalysis has enabled rational optimizations of existing and revealed new synthetic pathways. One essential step in any reaction is catalyst quenching photoinduced electron transfer or energy with either a substrate, additive, cocatalyst. Identification the correct quencher using Stern–Volmer studies necessary for mechanistic unders...

Insight into the O2 quenching mechanism of a photosensitizer (static or dynamic) would be useful for the design of heterogeneous systems to control the mode of generation of 1O2 in water. Here, we describe the use of a photosensitizer, meso-tetra(N-methyl-4-pyridyl)porphine (1), which was adsorbed onto porous Vycor glass (PVG). A maximum loading of 1.1 x 10(-6) mol 1 per g PVG was achieved. Les...

The hydrophobic fluorescent dye 3-[4-(3-phenyl-2-pyrazolin-1-yl)benzene-1-sulfonylamido]phen ylboronic acid (PPBA) stoichiometrically binds to myosin subfragment-1 (S-1) with a dissociation constant (Kd) of 26 microns. Upon addition of nucleotides to the complex of S-1 with PPBA, the PPBA-binding site is converted to a more firm hydrophobic pocket accompanied by a large fluorescence change. For...

The mechanism of interaction of riboflavin (RF) with bovine serum albumin (BSA) using fluorometric and circular dichroism (CD) methods has been reported. The association constant (K) for RF-BSA binding shows that the interaction is non-covalent in nature. Stern-Volmer analysis of fluorescence quenching data shows that the fraction of fluorophore (BSA) accessible to the quencher (RF) is close to...

The Global Energy Crisis necessitated improving research into new, renewable and alternative energy sources. Due to that, our focus is on the area of some phenomena applications where different synthetic methods micro-structure property optimization achieved significant improvement in electro physical properties output materials components. This especially important for higher efficiency electr...

We study a nonlinear elliptic boundary value problem arising from electrochemistry in the study of heterogeneous electrode surfaces. The boundary condition is of exponential type (Butler–Volmer) and has a periodic structure. We find a limiting or effective problem as the period approaches zero, along with a first order correction. We establish convergence estimates and provide numerical experim...

3,5-Dihydroxyphenyl-5-(dimethylamino)naphthalene-1-sulfonate, also referred to as sensor R1, was synthesized and characterized by 1H- 13C-NMR, IR, HRMS, single-crystal X-ray diffraction. Connections in the packing crystal structure of R1 occur through hydrogen bonding interactions. However, no π-π stacking interactions between molecules were observed. Addition fluoride ion a solution resulted a...