Interaction between morin and AOT reversed micelles—Studies with UV–vis at 25°C

Unusual microwave heating of water in reverse micellar solution

Microwaves (MWs) are widely used for heating food, accelerating chemical reactions, drying materials, therapies, and so on. Water molecules absorb MWs and produce heat because of their substantial electric dipole moments. Recently, increasing attention has been paid to accelerating various catalytic reactions in water-containing porous materials using MW irradiation. Here, a critical question is whether water in nanoscale pores generates heat in the same way as liquid water. Is it valid that MW-heating behaviors of nanoconfined water are estimated solely by a dielectric constant of liquid water? There are almost no studies regarding this question. Here, we address it using reverse micellar (RM) solutions. Reverse micelles are water-containing nanoscale cages formed by self-assembled surfactant molecules in oil. We measured real-time temperature changes of liquid samples within a waveguide under MW irradiation at 2.45 GHz and at MW intensities of ~ 3 to ~ 12 W/cm². We found that the heat production and its rate per unit volume of water in the RM solution are about one order of magnitude larger than those of liquid water at all the MW intensities examined. This indicates that water spots that are much hotter than liquid water under MW irradiation at the same intensity, are formed in the RM solution. Our findings will give fundamental information to develop effective and energy-saving chemical reactions in nanoscale reactors with water under MW irradiation, and to study MW effects on various aqueous mediums with nanoconfined water. Furthermore, the RM solution will serve as a platform to study the impact of nanoconfined water on MW-assisted reactions.

Green tea silver nanoparticles improve physiological motor and cognitive function in BALB/c mice during inflammation

Information on the basic changes associated with green tea small molecules in acute inflammation is deficient. The purpose of the study was to characterize and establish the effects of green tea silver nanoparticles (AgNPs) following inflammation in BALB/c male mice. In this study, green tea silver nitrate nanoparticles were characterized and the extract were made up to constitute high (100%), medium (10%), and low (1%) concentrations for administration. Acute inflammation was induced in groups I-V of the experimental rodents by injecting 0.5 ml/kg of fresh egg albumin on the subplantar surface of the right hind paw and animals were monitored for 36 h. Group I-III were administered 100%, 10%, 1% green tea nanoparticles extract while group IV was given diclofenac. Group V was the positive control while group VI was the negative control that received the vehicle. Paw edema was measured at a 2 h interval for 3 days, while the pain was assessed by measuring the locomotion activity using the voluntary wheel running and the anxiety-like behavior. Hypersensitivity was measured through the temperature sensation experiment and a non-linear regression analysis was done. Here, synthesized green tea AgNPs registered an absorbance band at 460 nm, phytochemicals due to presence of organic functional groups of O[bond, double bond]C[bond, double bond]O of oxycarbons, of C[bond, double bond]C of a conjugate alkene, C[bond, double bond]O of a stretching bond of a secondary alcohol. The silver green tea nanoparticles were spherical, covered by a slimy layer, capped and stable. Green tea AgNPs significantly decreased temperature hypersensitivity in BALB/c male mice and this demonstrated their protective effects. Low concentrations of green tea nanoparticles inhibited edema thus mimicking effects of diclofenac, however, the percentage of inhibition was highest in medium and high silver-tea nanoparticles concentrations demonstration the importance of concentration in therapeutics. Anxiety was lowest in BALB/c male mice treated with high concentrations of silver green tea nanoparticles, and this led to increased locomotory activity in mice. Green tea AgNPs have strong anti-inflammatory effects at high concentrations. Concentrations of green tea AgNPs modulated basic sensory and motor behaviors in BALB/c male mice demonstrating their importance in complementary and integrative medical practice.

New Synthetic Quinoline (Qui) Derivatives as Novel Antioxidants and Potential HSA's Antioxidant Activity Modulators-Spectroscopic Studies

The antioxidant activity of drugs, as well as the influence of drugs on the activity of endogenous antioxidant mechanisms in the human body is of great importance for the course of the disease and the treatment process. Due to the need to search for new therapeutic methods, the study of newly synthesized substances with potential therapeutic activity is necessary. This study aimed to designate some properties and characteristic parameters of new, synthetic quinoline three derivatives-1-methyl-3-allylthio-4-(4'-methylphenylamino)quinolinium bromide (Qui1), 1-methyl-3-allylthio-4-(3'-hydroxyphenylamino)quinolinium bromide (Qui2) as well as 1-methyl-3-allylthio-4-(4'-hydroxyphenylamino)quinolinium bromide (Qui3), including their antioxidant properties, as well as to analyse their activity as the potential modulators of Human Serum Albumin (HSA) antioxidant activity. In order to achieve the goal of the study, spectroscopic methods such as UV-Vis and circular dichroism (CD) spectroscopy have been used and based on the obtained data only slight and probably some surface interaction of quinoline derivatives (Qui1-Qui3) with HSA have been observed. The effect of Qui1-Qui3 on the HSA secondary structure was also insignificant. All analysed quinine derivatives have antioxidant activity against ABTS cation radical, in turn against DPPH radical, only Qui3 has noticeable antioxidant potential. The highest reduction potential by Qui3 as well as (Qui3 + HSA)_complex has been shown. Qui3 mixed with HSA has mostly the synergistic effect against DPPH, ABTS and FRAP, while Qui1 and Qui2 in the presence of HSA mostly have a synergistic and additive effect towards ABTS, respectively. Based on the obtained results it can be concluded that Qui2 and Qui3 can be considered potential modulators of HSA antioxidant activity.

Polyelectrolyte-Dye Interactions: An Overview

Polyelectrolytes are polymers with repeating units of ionizable groups coupled with counterions. Recently, polyelectrolytes have drawn significant attention as highly promising macromolecular materials with potential for applications in almost every sector of our daily lives. Dyes are another class of chemical compounds that can interact with substrates and subsequently impart color through the selective absorption of electromagnetic radiation in the visible range. This overview begins with an introduction to polyelectrolytes and dyes with their respective definitions, classifications (based on origin, molecular architecture, etc.), and applications in diverse fields. Thereafter, it explores the different possible interactions between polyelectrolytes and dyes, which is the main focus of this study. The various mechanisms involved in dye-polyelectrolyte interactions and the factors that influence them are also surveyed. Finally, these discussions are summarized, and their future perspectives are presented.

Physico-chemical and spectroscopic investigation of flavonoid dispersed C n TAB micelles

In this study, kaempferol (0.2 m/mmol kg-1) dispersed cationic surfactant micelles were prepared as a function of alkyltrimethylammonium bromide (C n TAB) hydrophobicity (C = 12 to C = 16). The dispersion study of kaempferol in different C n TAB, i.e. dodecyltrimethylammonium bromide (C = 12), tetradecyltrimethylammonium bromide (C = 14) and hexadecyltrimethylammonium bromide (C = 16), was conducted with the physico-chemical properties of density, sound velocity, viscosity, surface tension, isentropic compressibility, acoustic impedance, surface excess concentration and area occupied per molecule and thermodynamic parameters Gibbs free energy, enthalpy and activation energy measured at 298.15 K. These properties were measured with varying concentration of C n TAB from 0.0260 to 0.0305 mol kg-1 in a 10% (w/w) aqueous dimethyl sulfoxide solvent system. The variations in these measured properties have been used to infer the kaempferol dispersion stability via hydrophobic-hydrophilic, hydrophilic-hydrophilic, van der Waals, hydrogen bonding and other non-covalent interactions.

UV-Vis studies of methyl red in the presence of sodium dioctylsulfosuccinate/acetone and sodium dioctylsulfosuccinate/acetone/water

This paper reports the spectra of methyl red (MR) in the presence of sodium dioctylsulfosuccinate (AOT) by UV-Vis spectrophotometer at 298.15 ± 0.1 K. The experiment shows the effect of acetone, AOT and water concentration on methyl red. The spectral study was based on R parameter, which is defined as [H₂O]/[AOT]. The spectral study was possible in the range of R = 0-20 only because the solution appeared to be cloudy above this amount of water. When the concentration of AOT increased, the absorption of MR decreased, indicating a hypochromic shift, which is due to the interaction between AOT and MR. The absorbance increases with the increasing value of R, which indicates that the H₂O molecule hinders the interactional forces between AOT and MR. The distribution constant was calculated by using nonlinear regression analysis and its variation with different R values indicate the effect of water content in the distribution behavior of MR in between the solvent and micellar region whereas the variation of the binding constant with different R values indicates the affinity of micelles to bind MR molecule. The study of this binding affinity will be very helpful in textile dyeing, decolorization of industrial effluents and development of azo-based molecules in novel photonic and optoelectronic devices.

Flavonoid-surfactant interactions: A detailed physicochemical study

The aim of this article is to study the interactions between flavonoids and surfactants with attention of finding the probable location of flavonoids in micellar media that can be used for controlling their antioxidant behavior. In present study, the micellar and interfacial behavior of twin tailed anionic surfactants viz. sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and sodium bis(2-ethylhexyl)phosphate (NaDEHP) in the presence of two flavonoids, namely quercetin (QUE) and kaempferol (KFL) have been studied by surface tension measurements. UV-visible, fluorescence and differential pulse voltammetric (DPV) measurements have been employed to predict the probable location of flavonoids (QUE/KFL) within surfactant (AOT/NaDEHP) aggregates. Dynamic light scattering (DLS) measurements further confirmed the solubilization of QUE/KFL in AOT/NaDEHP aggregates deduced from increased hydrodynamic diameter (Dh) of aggregates in the presence of flavonoids. Both radical scavenging activity (RSA) and degradation rate constant (k) of flavonoids are found to be higher in NaDEHP micelles as compared to AOT micelles.