Investigations to Explore Molecular Interactions and Sweetness Response of Polyhydroxy Compounds with Amino Acids in Aqueous Systems.

In conjunction with the development of people's living standards, the modern world demands good-quality food such as sweets, candies, chocolates, diet drinks, beverages, and so on, but because of obesity and other health issues people concentrate more on sugar-free or low-calorie products. Polyols are such a kind of food with desirable qualities, and they play a role in controlling the blood glucose level in diabetic patients. The density (ρ) and sound speed (u) of sugar alcohol in water and in (0.02, 0.04, and 0.06) mol kg-1l-arginine solutions at different temperatures (293.15-318.15 K) and atmospheric pressure were measured by using Anton Paar DSA5000M. Experimental density and sound velocity data were further used to compute volumetric and acoustic parameters such as apparent molar volume (ØV), partial molar volume (Ø V 0), compressibility (Ø k 0), expansibility (Ø E 0), and so on. The positive trends of apparent molar volume (Ø V ), and partial molar volume Ø V 0), values indicate strong hydrophilic interactions in ternary solutions. These interactions give a complete picture about solvation behavior, the effect of temperature, and hydrogen bonding present among (galactitol + l-arginine) mixtures. The apparent specific volume values were calculated, and it was found that these values of the investigated mixtures lie on the borderline with the reported values of sweeteners. This study may offer a new vision in elucidation of mechanistic modifications between sugar alcohol, amino acid, and their mode of interactions.

Biosorption of metribuzin pesticide by Cucumber (Cucumis sativus) peels-zinc oxide nanoparticles composite.

Herein, a biosorbent was prepared from cucumber peels modified with ZnO nanoparticles (CPZiONp-composite) for the biosorption of metribuzin. Characterization of the composite was accomplished using FTIR, SEM, EDX, surface area pore size analyzer and pH of point of zero charge (pHpzc). Biosorption study was executed in batch concerning the impact of pH, composite dose, contact time, initial metribuzin concentration and temperature. The biosorption depends on pH and maximum biosorption was acquired at pH 3.0. Surface chemistry of the composite was studied by determining the pHpzc and was found to be 6.1. The biosorption nature was investigated using isotherms and was assessed that Freundlich isotherm is well suited for the fitting of the biosorption data owing to the highest R2. The maximum biosorption capacity of CPZiONp-composite was found to be 200 mg g-1. The biosorption data were fitted in to different kinetic models and the outcomes suggesting that pseudo second order is a satisfactory model to interpret the biosorption data owing to the highest R2. Thermodynamic parameters for instance entropy, enthalpy and Gibbs free energy were computed and revealed that biosorption of metribuzin onto CPZiONp-composite is spontaneous and exothermic process.

Antimicrobial, selective antibiofilm, and antioxidant properties of plasticized PMMA/PVC and zinc oxide nano filler for biomedical applications.

The PMMA/PVC/ZnO-nanocomposites with zinc oxide nanoparticle (particle size < 50nm) was synthesized by solution casting technique. Morphology of the synthesized nano composites have been investigated by FT-IR and XRD techniques. After characterization, synthesized composites were applied for antibacterial, selective antibiofilm and free radical scavenging screening. Antibacterial studies were measured against different bacterial strains. Antibiofilms activities were studied against those bacterial model pathogenic strains which showed highest and minimum sensitivity as a (~94 and ~88 at 160 µg/ml). Antioxidant activity of synthesized nanocomposites were measured by DPPH and showed scavenging capacity with IC50, 110 to > 200 µg/mL. Thus PMMA/PVC/ZnO nanocomposite showed promising antimicrobial activity and antioxidant activity that can be used for biomedical applications.

Photocatalysis: an effective tool for photodegradation of dyes-a review.

The disposal of dye-contaminated wastewater is a major concern around the world for which a variety of techniques are used for its treatment. The photocatalytic treatment of dye-contaminated wastewater is one of the treatment methods. Semiconductor-assisted photocatalytic treatment of dye-contaminated wastewater has gained pronounced attention recently. This review outlines the recent advancements in the photocatalytic treatment of dye-contaminated wastewater. The photocatalytic degradation of dyes follows three types of mechanisms: (1) dye sensitization through charge injection, (2) indirect dye degradation through oxidation/reduction, and (3) direct photolysis of dye. Several experimental parameters like initial concentration of dyes, pH, and catalyst dosage significantly affect the photocatalytic degradation of dyes. The photocatalytic materials can be categorized into three generations. The single-component (e.g., ZnO, TiO2) and multiple component semiconductor metal oxides (e.g., ZnO-TiO2, Bi2O3-ZnO) are categorized as first-generation and second-generation photocatalysts, respectively. The photocatalysts dispersed on an inert solid substrate (e.g., Ag-Al2O3, ZnO-C) are classified as third-generation photocatalysts. Finally, we reviewed the challenges that affect the photocatalytic degradation of dyes.

Synthesis and characterization of ZnO decorated reduced graphene oxide (ZnO-rGO) and evaluation of its photocatalytic activity toward photodegradation of methylene blue.

Photocatalytic treatment is one of the techniques used for the treatment of dyes-contaminated wastewater. It is important to develop an effective visible-light-driven catalyst for the treatment of dyes-contaminated wastewater. This study reports the synthesis of ZnO-reduced graphene oxide catalyst for the degradation of methylene blue. Graphene oxide was prepared by Hammer and Offeman process, while ZnO-rGO (1:1) was prepared by the chemical reduction method. The prepared ZnO-rGO composite was characterized by XRD, TEM, SEM, UV-Vis, DRS, N2 adsorption-desorption, FTIR, and XPS analyses. The photocatalytic activity was evaluated by photodegradation of methylene blue solution under irradiation. It was found that ZnO-rGO is capable of removing the dye from water and achieved the highest dye degradation efficiency of ~99% within 60 min. Furthermore, the ZnO-rGO was recycled in degradation experiments without any loss in its catalytic performance. The reaction kinetics was described in terms of the Langmuir-Hinshelwood mechanism, one of the kinetics mechanisms of surface catalyzed reaction. 36.2 and 13.1 kJ/mol were calculated as the apparent and true activation energy for photodegradation of methylene blue respectively.

Synthesis and Characterization of Co-ZnO and Evaluation of Its Photocatalytic Activity for Photodegradation of Methyl Orange.

Photocatalysis is one of the techniques used for the eradication of organic pollutants from wastewater. In this study, Co-ZnO was tested as a photocatalyst for the degradation of methyl orange under irradiation of visible light. Co-ZnO loaded with 5%, 10%, and 15% Co was prepared by the precipitation method. The advanced techniques including X-ray diffraction, X-ray photoelectron spectroscopy, diffuse reflectance UV-visible spectroscopy, photoelectrochemical measurements, temperature-programmed desorption, photoluminescence, and fluorescence spectroscopy related to OH• measurements were used for characterization of prepared Co-ZnO. Experiments showed that 10% Co-ZnO was a highly efficient catalyst for the photodegradation of methyl orange as compared to ZnO. The enhanced photocatalytic activity of Co-ZnO is attributed to the implantation of Co which inhibits the electron-hole recombination. A 100 mg/L solution of methyl orange dye was completely degraded within 130 min. The reaction kinetics has been described in terms of the Eley-Rideal mechanism.

Gamma and UV radiations induced treatment of anti-cancer methotrexate drug in aqueous medium: Effect of process variables on radiation efficiency evaluated using bioassays.

This studystudy focuses on the effect of radiation treatment and hydrogen peroxide (H2O2) on the toxicity of anticancer methotrexate. For cytotoxicity, different bioassays such as Allium cepa, hemolytic, brine shrimp were employed. The Ames test was used for mutagenicity analysis. The solutions having concentrations 5, 10 and 15 ppm were irradiated with UV radiation exposure time 15, 30, 45, 60, 75 and 90 min and gamma radiation absorbed doses 0.3, 0.6, 0.9, 1.2, 2, 3 and 4 kGy in combination with with H2O2. There was a clear difference observed for aqueous solution before and after treatment with reference to cytotoxicity and mutagenicity. In Allium cepa test, a 47.07, 44.36 and 38.23% increase in root length (RL), root count (RC) and mitotic index (MI) was observed, respectively, for UV/H2O2 treatment and in the case of gamma/H2O2 treatment, the RL, RC and MI were increased up to 49.39, 52.63 and 52.38%, respectively. Brine shrimp test has shown 85.95 and 91.30% decrease in toxicity using UV/H2O2 and gamma/H2O2 respectively, while hemolytic test has shown 19.21 and 26.32% hemolysis using UV/H2O2 and gamma/H2O2, respectively. The mutagenicity reduced up to 82.3, 86.46 and 89.59% (TA98) and 85.42, 87.5 and 90.63% (TA100) for UV/H2O2 while 89.59, 90.63 and 93.75% (TA98) and 84.38, 89.59 and 92.71% (TA100) for gamma/H2O2. The UV and gamma radiation along with H2O2 based AOPs are promising approaches to detoxify the wastewater which can be extended to real hospital liquid effluent effectively.

Sustainable application of cochineal-based anthraquinone dye for the coloration of bio-mordanted silk fabric.

Natural colors particularly animal-based colorants are employed in the field of cosmetics, food, and flavors and also gaining popularity in textiles, due to their soothing nature. In this study, the microwave-assisted extraction of colorant from cochineal insects for dyeing of bio-mordanted silk has been carried out. Acidic, methanolic, and acidified methanol solubilized media were used to extract the natural colorant from cochineal under microwave irradiation for 1-6 min. Bio-mordants have been employed at optimized conditions to make the process greener and sustainable. It is found that acid solubilized extract of pH 4, employed at 55 °C for 55 min containing 5 g/100 mL of Glauber's salt as exhausting agent has given high color strength onto microwave-treated silk fabric. Suggested ISO standards for colorfastness have revealed that bio-mordants have given excellent color depth and excellent rating of fastness properties, compared with chemical mordants used. It is found that microwave treatment has not only improved the dyeing behavior of colorant extracted from cochineal in acid solubilized medium but also enhanced the color characteristics onto bio-mordanted silk fabric.

Decomposition byproducts induced by gamma radiation and their toxicity: the case of 2-nitrophenol.

The induced degradation and detoxification of 2-nitrophenol (2-NP) in aqueous media by gamma irradiation were carefully evaluated in this study. Gamma radiation at absorbed doses as low as 20 kGy was able to degrade 2-NP to reach a removal of at least 85% across the investigated range of concentration (50-150 ppm). 2-NP breaks down to aromatic-based compounds with increasing number of byproducts upon increasing the radiation treatment from the absorbed dose of 50% decomposition (D50) to the absorbed dose of 90% decomposition (D90), after which no byproducts could be detected, indicating the formation of undetectable aliphatic hydrocarbons, insoluble, or volatile byproducts. Toxicology studies showed that the degradation of 2-NP under absorbed doses up to D90 resulted in a more toxic byproduct than the parent compound, and a remarkable reduction in the toxicity was observed with the irradiated samples with absorbed doses above D90. Varying the pH of the media to acidic or basic conditions did not significantly alter the degradation behavior of 2-NP. However, a notable improvement of the detoxification was associated with the samples of acidic pH. Adding 0.5% of H2O2 to 2-NP solutions had a positive effect by reducing D90 by a factor of nine and diminishing the toxicity by twofolds.

Glucomannan based polyurethanes: A critical short review of recent advances and future perspectives.

Polysaccharides derived from plants are one of the largest groups of natural compounds that offer potentially beneficial functions and properties. Glucomannan, a bioactive polymer belonged to mannan family of polysaccharides is fairly abundant in nature along with superior gelling and film forming properties. Glucomannan and its derivative with several synthetic polymers are used in a biomedical and food sector especially. Polyurethanes (PUs), a commercially useful class of polymers are extensively used in both industry and everyday life because they retain exceptional properties of both plastics and elastomers. This review addresses the properties and applications of glucomannan based materials with the aim to be explored this less attempted polymer further. Furthermore this paper also presents an overview of current status and perspectives of glucomannan based polyurethane materials.

Synthesis, Spectral investigation (¹H, ¹³C) and Anti-microbial Screening of benzophenone imines.

New series of benzophenone imines with general formula Ph2-C=NR; R = Benzyl, 4-Fluorobenzyl, Naphthyl, Phenyl, 4-Nitrophenyl were synthesized by condensation of dichlorodiphenylmethane and different aromatic primary amines (1:1) Those imines were characterized by different physiochemical and spectroscopic techniques like melting point, elemental analysis, FT-IR, multinuclear NMR (¹H, ¹³C). After characterization, imines were subjected to anti-microbial activities. All compounds showed promising activity against different bacterial strains like Escherichia coli, Bacillussubtilis, Pasturellam ultocida and Staphylococcus aureus as well as fungal strains like Alternata alternaria, Ganoderma lucidium, Penicillium notatum and Trichoderma harzianum using Amoxicillin and Flucanazole as a standard drugs respectively.

Acoustical behavior of some amino acids in aqueous disodium citrate solutions over temperature range (298.15-313.15) K.

Sound velocity, U, and density, ρ of some amino acids viz. glycine, methionine, phenylalanine and tryptophan were determined in 0.1, 0.2 and 0.3 mol kg⁻¹ aqueous disodium citrate solutions as a function of concentration at 298-313.15K using DSA 5000M. The experimental data were further used to compute various acoustical parameters such as adiabatic compressibility, ß, apparent molar compressibility, ∅(k), partial molar compressibility, ∅(0)k, transfer adiabatic compressibility, Φ(0)(ktr), constant, Sk, and the hydration number, nH. The transfer adiabatic compressibility shows the supremacy of hydrophilic-ionic interactions under hydrophobic-ionic interactions. The above-mentioned parameters are relevant for the efficiency of mediation in pharmacology and can be interpreted in terms of structure-making or structure-breaking ability of these amino acids in the solution.