Free radical induced degradation and computational studies of hydroxychloroquine in aqueous solution.

Hydroxychloroquine (HCQ) is a potential drug molecule for treating malaria. Recently it has also been tried as adjustment in Covid 19 therapy. Interaction of HCQ with free radicals is very important, which controls its stability in the environment where free radicals are generated unintentionally.

Highly stable spherical shaped and blue photoluminescent cyclodextrin-coated tellurium nanocomposites prepared by generated solvated electrons: a rapid green method and mechanistic and anticancer studies.

Highly stable blue photoluminescent tellurium nanocomposites (Te NCs) coated with a molecular assembly of α-cyclodextrin (α-CD) have been prepared by using generated solvated electrons (e) in the reaction media. The methodology used is rapid and green as the preparation of colloids was over in a matter of a few seconds and no hazardous agents (reducing or stabilizing) were used. Furthermore, fine control over the size of Te NCs has been demonstrated by simply varying the absorbed irradiation dose.

Direct Observation of Solvated Electrons in Deep Eutectic Solvents: Efficient Capture of Presolvated Electrons by DNA Base.

The solvated electron being the simplest form of an extremely reactive intermediate is of great fundamental interest in chemistry, physics, and biology since its discovery. Recently, deep eutectic solvents (DESs) have been in focus as biodegradable and cost-effective alternative to ionic liquids (ILs) for different applications. These include areas where electron transport and transfer processes are involved.

Controlling the phase and morphology of amorphous Se nanoparticles: their prolonged stabilization and anticancer efficacy.

Applications of amorphous Se nanoparticles (NPs) are limited due to their meticulous synthetic procedures and rapid phase transformation leading to low stability. A highly facile one-pot green method is being reported, wherein apart from tuning the morphology and the phase of the Se NPs, their stabilization could be prolonged to months as compared to a few minutes-to-days, known hitherto.

Pulse Radiolysis and Computational Studies on a Pyrrolidinium Dicyanamide Ionic Liquid: Detection of the Dimer Radical Anion.

A pulse radiolysis study on pyrrolidinium cation based ionic liquids is presented herein. Time-resolved absorption spectra for 1-methyl-1-propylpyrrolidinium dicyanamide (DCA) at 500 ns after the electron pulse show broad absorption bands at wavelengths below 440 nm and at 640 nm. In pyrrolidinium bis(trifluoromethylsulfonyl)imide (NTf) and tris(perfluoroethyl)trifluorophosphate (FAP) ILs, the transient absorption below 440 nm is much weaker.

Size Selective Green Synthesis of Silver and Gold Nanoparticles: Enhanced Antibacterial Efficacy of Resveratrol Capped Silver Sol.

In view of potential biomedical application of the noble metal nanoparticles, we report a size controlled yet simple and green synthesis of resveratrol stabilized silver and gold nanoparticles having low polydispersity of size. Here, resveratrol plays two simultaneous roles, reducing the metal ions and providing efficient capping of the small nanoparticles. This gives rise to specific size of silver and gold nanoparticles at specific ratios of metal to resveratrol.

Rapid and One-Pot Synthesis of Self-Assembled CdSe Quantum Dots Functionalized with β-Cyclodextrin: Reduced Cytotoxicity and Band Gap Engineering.

We report a simple, rapid and one step method for the synthesis and in situ functionalization of CdSe quantum dots (QDs) with β-cyclodextrin (β-CD) in aqueous solution via electron beam (EB) irradiation technique. A probable mechanism has been elucidated for the formation of the QDs using pulse radiolysis technique. The average size of the QDs was found to be in the range of 2-3 nm with a size distribution of -14%.

Role of surfactant derived intermediates in the efficacy and mechanism for radiation chemical degradation of a hydrophobic azo dye, 1-phenylazo-2-naphthol.

A combined methodology involving gamma and pulse radiolysis, product analysis and toxicity studies has been adopted to comprehend the degradation process of a model hydrophobic azo dye, 1-phenylazo-2-naphthol, emphasizing the role of the surfactant, which is an integral part of textile waste. Two new and important findings are underlined in this article. The first is the direct attestation of the hydrazyl radical-parent adduct, formed in the reaction of the dye with e(-)aq followed by protonation and subsequent addition to the unreacted dye molecule.

Optical properties of irradiated imidazolium based room temperature ionic liquids: new microscopic insights into the radiation induced mutations.

Considering the future perspectives of room temperature ionic liquids (RTILs) in areas involving high radiation fields (such as the nuclear fuel cycle and space applications), it is essential to probe and have a microscopic understanding of the radiation induced perturbations in the molecular structures and the intrinsic bonding interactions existing in the ILs. Herein, a focused investigation concerning the photophysical behavior of post-irradiated FAP (fluoroalkyl phosphate) imidazolium ILs revealed considerable rearrangements and bonding realignments of the ionic moieties in the ILs on irradiation, however, their physicochemical properties do not change significantly even at high absorbed doses. Most interestingly, the well-established excitation wavelength dependent fluorescence (FL) behavior of the ILs was considerably perturbed on irradiation and this is attributed to the radiation induced decoupling of pre-existing different associated structures of ions, and the subsequent formation of oligomers and other species containing multiple bond order groups.

The role of structural and fluidic aspects of room temperature ionic liquids in influencing the morphology of CdSe nano/microstructures grown in situ.

RTILs as media to synthesize a variety of nanomaterials are gaining momentum owing to their unique physicochemical properties. However, the fundamental questions regarding the role of the inherent structure of the IL in directing the morphology and the growth mechanism of the nanoparticles are still unexplored. Therefore, an attempt was made in this respect wherein CdSe nanoparticles were synthesized in a neat room temperature ionic liquid (RTIL), 1-ethyl-3-methyl imidazolium ethylsulfate ([EMIM][EtSO4]), under ambient conditions.

Radiation induced physicochemical changes in FAP (fluoro alkyl phosphate) based imidazolium ionic liquids and their mechanistic pathways: influence of hydroxyl group functionalization of the cation.

Future applications of ionic liquids (ILs) in a variety of areas, especially those having high radiation fields such as the nuclear fuel cycle and in space technology, are under serious consideration nowadays. For such applications to be possible, however, radiation stability of the ILs is an important issue that needs to be addressed. We envisaged that the ultra-hydrophobic, bulky and hydrolytically stable FAP (tris(perfluoroalkyl)trifluorophosphate) anion might shield the radiolytically vulnerable imidazolium cations from degradation and our result shows that these anions indeed enhance their radiolytic stability.

Islands of CdSe nanoparticles within Se nanofibers: a room temperature ionic liquid templated synthesis.

Herein, we present the formation of cadmium selenide (CdSe) islands embedded in a porous structure of entangled selenium (Se) nanofibers in the host matrix of a room temperature ionic liquid (RTIL). Electron beam irradiation has been employed to initiate the formation of the nanostructure while RTIL simultaneously played the role of a solvent, stabilizer and a shape guiding template for such morphology. UV-Vis absorption spectra of the irradiated samples exhibited an excitonic absorption feature in the visible region.

Evaluation of antioxidant activity and characterization of phenolic constituents of Phyllanthus amarus root.

The antioxidant property of the 70% aqueous ethanol extract of Phyllanthus amarus roots and its ether-soluble, ethyl acetate-soluble, and aqueous fractions were investigated by various in vitro assays. The root extracts showed higher DPPH, hydroxyl, superoxide, and nitric oxide radical scavenging and reducing power activity. Among all the samples, the ethyl acetate-soluble fraction demonstrated highest radical scavenging activity and total phenolics content.

Bilirubin clearance and antioxidant activities of ethanol extract of Phyllanthus amarus root in phenylhydrazine-induced neonatal jaundice in mice.

The ability of ethanol extract of Phyllanthus amarus root (EEPA) to decrease bilirubin level and oxidative stress in phenylhydrazine-induced neonatal jaundice in mice was investigated. Administration of phenylhydrazine (75 mg/kg b.w.

Generation of counter ion radical (Br2(•-)) and its reactions in water-in-oil (CTAB or CPB)/n-butanol/cyclohexane/water) microemulsion.

Herein we report the generation of counterion radicals and their reactions in quaternary water-in-oil microemulsion. Hydrated electrons in the microemulsion CTAB/H(2)O/n-butanol/cyclohexane have a remarkably short half-life (∼1 μs) and lower yield as compared to that in the pure water system. Electrons are solvated in two regions: one is the water core and other the interface; however, the electrons in the water core have a shorter half-life than those in the interface.

Physico-chemical studies on the evaluation of the antioxidant activity of herbal extracts and active principles of some Indian medicinal plants.

Understanding of the efficacy and mechanism for the reaction of the biologically important radicals with natural and/or synthetic antioxidants is the first step towards the development of future therapeutic agents. The kinetic parameters e.g.

DNA protective properties of vanillin against gamma-radiation under different conditions: possible mechanisms.

Ionizing radiation is an important genotoxic agent. Protecting against this form of toxicant, especially by a dietary component, has several potential applications. In the present study, we have examined the ability of vanillin (4-hydroxy-3-methoxybenzaldehyde), a naturally occurring food flavouring agent, to inhibit radiation-induced DNA damage measured as strand breaks under in vitro, ex vivo and in vivo conditions besides the possible mechanisms behind the observed protection.

Folic acid as a Fenton-modulator: possible physiological implication.

Acting as a redox switch, folic acid (1) might be a promising iron modulator to protect cellular machinery against oxidative stress and iron overload. The vitamin 1 can directly control the iron concentration by oxidizing it even if present in chelated forms. In addition, during its role as a reducing agent for the biologically relevant reactive oxygen species (ROS), it furnishes 6-formyl pterin.

Possible role of hydroxyl radicals in the oxidative degradation of folic acid.

Hydroxyl radicals have been found to cause oxidative N-dealkylation of amines including folic acid via a hydrogen atom transfer mechanism.

Antioxidant properties of Plumbago zeylanica, an Indian medicinal plant and its active ingredient, plumbagin.

Plumbago zeylanica (known as "Chitrak") is a useful Indian medicinal plant. The root of the plant and its constituents are credited with potential therapeutic properties including anti-atherogenic, cardiotonic, hepatoprotective and neuroprotective properties. To examine possible mechanisms of action of P.

Protective activities of some phenolic 1,3-diketones against lipid peroxidation: possible involvement of the 1,3-diketone moiety.

The protective activities of four ginger-derived phenolic 1,3-diketones (1-4) and curcumin (5) against lipid peroxidation was studied by using different biologically relevant model systems and pulse radiolysis. The extraordinary activity of 5 vis-à-vis 1-4 against Fe(2+)-mediated peroxidation may be attributed to the additional phenolic hydroxy group in the former, which lends it better iron-chelating and radical-scavenging properties. In iron-independent peroxidation, however, the ginger constituent [6]-dehydrogingerdione (1) showed activity comparable to that of 5; this indicates its higher affinity for the lipid peroxide radical (LOO(.