Redox Mechanism and Evaluation of Kinetic and Thermodynamic Parameters of 1,3‐Dioxolo[4,5‐g]pyrido[2,3‐b]quinoxaline Using Electrochemical Techniques

The electrochemical behavior of a biologically important heterocyclic compound, 1,3‐dioxolo[4,5‐g]pyrido[2,3‐b]quinoxaline was investigated by cyclic, square wave and differential pulse voltammetry in solutions of different pH. Kinetic and thermodynamic parameters like standard rate constant, diffusion coefficient, apparent energy of activation_, standard Gibbs free energy and enthalpy and entropy changes were evaluated. Limits of detection and quantification were determined by square wave voltammetry. The redox mechanism of the compound was proposed on the basis of experimental results. Computational chemistry was used as a tool for the verification of experimental outcomes and assessment of different theoretical parameters     

An explorative study on diarylquinoline-based inhibitor targeting Enterococcus faecium MurF

Structural Chemistry - Enterococcus faecium MurF (EfMurF) enzyme catalyzes the addition of d-alanyl-d-alanine to form murein UDP-N-acetylmuramoyl-pentapeptide. This is the last cytoplasmic step of...     

Comprehensive Biological Potential,Phytochemical Profiling Using GC-MS and LC-ESI-MS,and In-Silico Assessment of Strobilanthes glutinosus Nees: An Important Medicinal Plant

Plants of the genus Strobilanthes have notable use in folklore medicines as well as being used for pharmacological purposes. The present work explored the biological predispositions of Strobilanthes glutinosus and attempted to accomplish a comprehensive chemical profile through GC-MS of different fractions concerning polarity (chloroform and n-butanol) and LC-ESI-MS of methanolic extract by both positive and negative ionization modes. The biological characteristics such as antioxidant potential were assessed by applying six different methods. The potential for clinically relevant enzyme (α-amylase, α-glucosidase, and tyrosinase) inhibition was examined. The DPPH, ABTS, CUPRAC, and FRAP results revealed that the methanol fraction presented efficient results. The phosphomolybdenum assay revealed that the n-hexane fraction showed the most efficient results, while maximum metal chelation potential was observed for the chloroform fraction. The GC-MS profiling of n-butanol and chloroform fractions revealed the existence of several (110) important compounds presenting different classes (fatty acids, phenols, alkanes, monoterpenes, diterpenes, sesquiterpenoids, and sterols), while LC-ESI-MS tentatively identified the presence of 44 clinically important secondary metabolites. The n-hexane fraction exhibited the highest potential against α-amylase (497.98 mm ACAE/g extract) and α-glucosidase (605.85 mm ACAE/g extract). Significant inhibitory activity against tyrosinase enzyme was displayed by fraction. Six of the prevailing compounds from the GC-MS study (lupeol, beta-amyrin, stigmasterol, gamma sitosterol, 9,12-octadecadienoic acid, and n-hexadecanoic acid) were modelled against α-glucosidase and α-amylase enzymes along with a comparison of binding affinity to standard acarbose, while three compounds identified through LC-ESI-MS were docked to the mushroom tyrosinase enzyme and presented with significant biding affinities. Thus, it is assumed that S. glutinosus demonstrated effective antioxidant and enzyme inhibition prospects with effective bioactive molecules, potentially opening the door to a new application in the field of medicine.     

Green Tea Catechins Attenuate Neurodegenerative Diseases and Cognitive Deficits

Neurodegenerative diseases exert an overwhelming socioeconomic burden all around the globe. They are mainly characterized by modified protein accumulation that might trigger various biological responses, including oxidative stress, inflammation, regulation of signaling pathways, and excitotoxicity. These disorders have been widely studied during the last decade in the hopes of developing symptom-oriented therapeutics. However, no definitive cure has yet been discovered. Tea is one of the world’s most popular beverages. The same plant, Camellia Sinensis (L.).O. Kuntze, is used to make green, black, and oolong teas. Green tea has been most thoroughly studied because of its anti-cancer, anti-obesity, antidiabetic, anti-inflammatory, and neuroprotective properties. The beneficial effect of consumption of tea on neurodegenerative disorders has been reported in several human interventional and observational studies. The polyphenolic compounds found in green tea, known as catechins, have been demonstrated to have many therapeutic effects. They can help in preventing and, somehow, treating neurodegenerative diseases. Catechins show anti-inflammatory as well as antioxidant effects via blocking cytokines’ excessive production and inflammatory pathways, as well as chelating metal ions and free radical scavenging. They may inhibit tau protein phosphorylation, amyloid beta aggregation, and release of apoptotic proteins. They can also lower alpha-synuclein levels and boost dopamine levels. All these factors have the potential to affect neurodegenerative disorders. This review will examine catechins’ neuroprotective effects by highlighting their biological, pharmacological, antioxidant, and metal chelation abilities, with a focus on their ability to activate diverse cellular pathways in the brain. This review also points out the mechanisms of catechins in various neurodegenerative and cognitive diseases, including Alzheimer’s, Parkinson’s, multiple sclerosis, and cognitive deficit.     

Surface characterization and heats of adsorption of chromatographic alumina gel

The porous nature of chromatographic alumina gel has been investigated by adsorption/condensation processes and electron microscopy. Having 63% porosity, the gel is very porous. Total pore volume as determined by the fluid-displacement method is 0.497 cm³ g^–1. Its specific surface area, as determined by water vapor adsorption, is 225 m² g^–1. Micropore volume, as determined by utilizing Gurwitsch's rule, turns out to be 0.262 cm³ g^–1. The greater portion of the surface area and pore volume occurs in small and transitional pores, with average pore radii (hydraulic) less than 2.1 nm.Organic vapors, such as methyl ethyl ketone, acetone, methyl acetate, and methyl alcohol, were adsorbed on the gel between 0 and 36°C under vacuum, and the data were recorded on a Cahn-1000 electrobalance device. Isosteric heats of adsorption were calculated by applying the Clausius Clapeyron equation to the adsorption isosters at different surface coverages. Two types of adsorption processes, one with low activation energy and other with high activation energy can be distinguished. The increase in values ofq _st indicates that increasing temperature changes physical adsorption into chemisorption.     

Effects of anti-GLUT antibodies on glucose transport into human erythrocyte ghosts

We have studied the effects of anti-GLUT1 antibodies on the uptake of glucose into erythrocytes. Glucose transport into human erythrocyte ghosts was measured directly using 3H-2-deoxy-glucose, or indirectly by monitoring associated volume changes using light scattering. The uptake of glucose was significantly inhibited in ghosts resealed in solutions containing specific antibodies against GLUT1. Such an effect was not observed when an antibody against the oestrogen receptor, lacking specificity towards GLUT1, was employed instead. The antibodies were also without effect on the efflux of preloaded glucose from erythrocyte ghosts. The demonstration that anti-GLUT antibodies can inhibit glucose uptake is support for the hypothesis that they exaggerate the cytoplasmic barrier to glucose uptake created by endofacial segments of GLUT1.     

Characterisation of bhringaraj and guduchi herb by ICP-MS analysis, optical absorption, infrared and EPR spectroscopic methods

Leaves of bhringaraj and guduchi herb of Kadapa district of Andhra Pradesh, India, are dried and powdered. ICP-MS analysis of samples indicates that copper is present in both the samples. An EPR study of guduchi sample also confirms the presence of Fe(III) whereas Eclipta alba confirms the presence of Fe(III), Mn(II) and Cu(II). Optical absorption spectrum of guduchi indicates that Cu(II) is present in rhombically distorted octahedral environment. NIR and IR results are due to carbonate fundamentals.     

Optical signal processing using four wave mixing in highly nonlinear silicon nano-wire

Silicon-on-insulator (SOI) waveguide devices are emerging for the realization of optical signal processing systems for the last couple of years. The recent technological advancement in silicon photonics is the main driving force at the back of these devices. Using non-linear optical phenomenon in silicon wires and their compatibility with CMOS devices provide the stage for integrated photonic devices. All-optical signal processing devices are being investigated at present, but the chip-scale solution provided by the silicon photonics is the most promising. In this research we have investigated all-optical signal processing in a 10 mm long SOI waveguide by exploiting well established coupled wave equations. We consider single pulsed pump to analyze frequency shifting by four-wave-mixing (FWM). For the wavelengths 20?30 nm far from the pump, the gain overcomes nonlinear losses resulting in higher frequency conversion efficiency.     

Structure-based virtual screening to identify inhibitors against Staphylococcus aureus MurD enzyme

Structural Chemistry - The MurD enzyme of Staphylococcus aureus is an attractive drug target as it is essential and ubiquitous in bacteria but absent in mammalian cells. In the present study, we...