Tecoma stans floral extract-mediated synthesis of MgFe2O4/ZnO nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue dye.

Toxic organic dyes-containing wastewater treatment by adsorption and photocatalytic techniques is widely applied, but adsorbents and photocatalysts are often synthesized through chemical methods, leading to secondary pollution by released chemicals. Here, we report a benign method using Tecoma stans floral extract to produce MgFe2O4/ZnO (MGFOZ) nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue (CBB) dye. Green MGFOZ owned a surface area of 9.65 m2/g and an average grain size of 54 nm. This bio-based nanomaterial showed higher removal percentage and better recyclability (up to five cycles) than green MgFe2O4 and ZnO nanoparticles. CBB adsorption by MGFOZ was examined by kinetic and isotherm models with better fittings of Bangham and Langmuir or Temkin. RSM-based optimization was conducted to reach an actual adsorption capacity of 147.68 mg/g. Moreover, MGFOZ/visible light system showed a degradation efficiency of 89% CBB dye after 120 min. CBB adsorption can be controlled by both physisorption and chemisorption while •O2- and •OH radicals are responsible for photo-degradation of CBB dye. This study suggested that MGFOZ can be a promising adsorbent and catalyst for removal of organic dyes in water.

Amino acid activation analysis of primitive aminoacyl-tRNA synthetases encoded by both strands of a single gene using the malachite green assay.

The Rodin-Ohno hypothesis postulates that two classes of aminoacyl-tRNA synthetases were encoded complementary to double-stranded DNA. Particularly, Geobacillus stearothermophilus tryptophanyl-tRNA synthetase (TrpRS, belonging to class I) and Escherichia coli histidyl-tRNA synthetase (HisRS, belonging to class II) show high complementarity of the middle base of the codons in the mRNA sequence encoding each ATP binding site. Here, for the reported 46-residue peptides designed from the three-dimensional structures of TrpRS and HisRS, amino acid activation analysis was performed using the malachite green assay, which detects the pyrophosphate departing from ATP in the forward reaction of the first step of tRNA aminoacylation. A maltose-binding protein fusion with the 46 residues of TrpRS (TrpRS46mer) exhibited high activation capacity for several amino acids in the presence of ATP and amino acids, but the activity of an alanine substitution mutant of the first histidine in the HIGH motif (TrpRS46merH15A) was largely reduced. In contrast, pyrophosphate release by HisRS46mer in the histidine activation step was lower than that in the case of TrpRS46mer. Both HisRS46mer and the alanine mutant at the 113th arginine (HisRS46merR113A) showed slightly higher levels of pyrophosphate release than the maltose-binding protein alone. These results do not rule out the Rodin-Ohno hypothesis, but may suggest the necessity of establishing unique evolutionary models from different perspectives.

Visual determination of oxidation of edible oil by a nanofiber mat prepared from polyvinyl alcohol and Schiff's reagent.

A fiber mat was developed to visually determine the oxidation of edible oils, based on the colorimetric reaction of Schiff's reagent and aldehydes - the major volatile formed during lipid oxidation. The mixtures of polyvinyl alcohol (PVA) and Schiff's reagent containing various amounts of glycerol were electrospun to form the fiber mats. The response of the PVA/Schiff's reagent fiber mats to gaseous hexanal (model aldehyde) was investigated. Oxidized soybean oils were used to evaluate the effectiveness of the PVA/Schiff's reagent fiber mat for indicating oxidation of the oils. The results showed that the fiber mats obtained had average fiber diameters of less than 100 nm. Upon hexanal exposure, the fiber mats turned from white to purple. Higher amount of glycerol led to larger color change of the fiber mats and shorter response time to hexanal. A linear relationship (R2 = 0.96) was observed between the color change of the mat and hexanal concentration (15-117 µmol L-1). The visual determination limit of the mat for hexanal was 29 µmol L-1. The color change of the PVA/Schiff's reagent fiber mat was increased with an increase of soybean oil oxidation. Out of the seven soybean oils tested, the PVA/Schiff's reagent fiber mat was able to correctly indicate the oxidation states of six oils. The result suggested that the visual determination method developed is a promising method to indicate the oxidation of edible oils, which can be performed easily by non-experts.Graphical abstract.

Synergic effect of Guggul gum based hydrogel nanocomposite: An approach towards adsorption-photocatalysis of Magenta-O.

The article is related to sunlight and UV-visible mineralization of harmful magenta-O (FB) dye. The nanocomposite used is a cross linked network of acrylic acid synthesized inside poly(acrylamide) grafted Guggul gum in the presence of UV-visible respondent bismuth ferrite nanoparticles. The synthesis of poly(acrylamide) grafted Guggul gum (Sample I) and synthesizing a crosslinked network inside it (Sample II) involved a two-step synthesis for optimizing various reaction parameters. The maximum % water uptake obtained for polymeric samples I and II was calculated as 1227.78% and 387.97%, respectively. Average particle size of bismuth ferrite nanoparticles was 47.34 nm. The nanocomposite could maximum uptake-mineralize FB dye as 97.3% and 98.8% under sunlight and photochemical reactor, respectively for 500 mg nanocomposite dose in 10 mg/L concentrated FB solution. Dye uptake occurs through ionic interactions. However, mineralization is a consequence of advanced oxidation process involving free radical species (OH and O2-.). The overall process of uptake-mineralization resembled second order kinetics and Langmuir theorem (monolayer adsorption). Intraparticle diffusion model gave an idea about the multistep (three steps) process of adsorption. Physico-chemical properties of FB dye got changed after mineralization except for the pH. The maximum uptake-mineralization was observed to be 76.2% after consecutive reuse of the nanocomposite hydrogel for five cycles.

Novel pararosaniline based optical sensor for the determination of sulfite in food extracts.

Sulfite, which is a protective agent in various food industries, also is known as an allergen. Therefore, sulfite content in food must be monitored and controlled. In this context, a novel optical sensor is designed for simple, rapid and sensitive determination of the sulfite content in food samples. Acidified pararosaniline (PRA) hydrochloride reagent in cationic form was immobilized on the surface of the Nafion cation exchanger membrane by electrostatic interactions. In formaldehyde medium, the pale purple PRA-Nafion film was converted to rich purple due to the highly conjugated alkyl amino sulfonic acid formation in the presence of sulfite and the absorbance change at 588 nm was recorded. The proposed optical sensor gave a linear response in a wide concentration range for sulfite. The limit of detection (LOD) and the limit of quantification (LOQ) values obtained for sulfite were 0.084 and 0.280 ppm SO2 equivalent, respectively. The proposed optical sensor was validated in terms of linearity, additivity, precision and recovery parameters. The sulfite contents obtained for real food extracts were found to be comparable to the conventional iodometric titration results (with the exception of highly colored samples containing reducing agents, where iodometry was shown to exhibit a systematic error while the proposed sensor could measure the true value). The proposed optical sensor is insensitive to positive interferences from turbidity and colored components of the sample. Sulfite determination in a complex food matrix can be performed using the rapid, simple and sensitive PRA-based sensor without a need for pre-treatment.

Synthesis of panos extract mediated ZnO nano-flowers as photocatalyst for industrial dye degradation by UV illumination.

Green synthesis of zinc oxide has gained extensive attention as a reliable, sustainable, and eco-friendly protocol to reduce the destructive effects associated with the traditional synthesis methods commonly utilized in laboratory and industry. Here for the first time, we have synthesized quaker ladies flower type ZnO (ZnO/QNF) from panos extract (extract from four panax plants such as Panax ginseng, Acanthopanax senticosus, Kalopanax septemlobus and Dendropanax morbifera). The synthesized ZnO materials was characterized using powder X-ray diffraction, Fourier infrared spectroscopy, X-ray photoelectron spectroscopy and Transmission electron microscope. The newly synthesized ZnO/QNF was applied for the removal of industrial dyes such as methylene blue (MB), Eosin Y (EY) and Malachite green (MG) under UV illumination. The photocatalyst degraded the 15 mg L-1 MB, EY and MG to >99% within 80, 90 and 110 min of contact time, respectively. In addition, the ZnO/QNF photocatalyst removed the low concentrated 5 mg L-1 of MB, EY, and MG within 30, 35 and 40 min of contact time, respectively. The pedal structure provided all the active sites available for the easy interaction with dye molecule under UV, and that enabled fast kinetics of dye degradation than the many other benchmark materials reported previously. The ZnO photocatalyst could be reused minimum of five cycles without any significant loss in degradation efficiency.

Photo-catalytic, anti-bacterial, and anti-cancer properties of phyto-mediated synthesis of silver nanoparticles from Artemisia tournefortiana Rchb extract.

Metal nanoparticles have largely been investigated due to their potential medicinal activities. This study demonstrates the biological properties of green-synthesized silver nanoparticles (AgNPs) by using Artemisia tournefortiana Rchb ethanol extract. Instrumentations such as ultraviolet-visible spectra analysis, high-resolution transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, and Fourier transform infrared spectroscopy were used to reveal the synthesized AgNPs. Microscopic results showed that the particles were mostly spherical in shape, having an average diameter of 22.89±14.82nm. The antibacterial activity of the phyto-fabricated AgNPs was investigated by the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The in vitro cytotoxicity effect was investigated against normal human embryonic kidney (HEK293) cells and human colon adenocarcinoma cancer (HT29) cells. The apoptotic cells were identified by annexin V/PI FITC staining, and morphological assessment. The expressions of Bax and Bcl2 were evaluated by quantitative real time PCR method. The phyto-synthesized AgNPs have shown increased cell apoptosis and demonstrated dose-dependent cytotoxicity in HT29 cancer cells. Moreover, the photocatalytic activity of the phyto-synthesized AgNPs was evaluated by degradation of Coomassie Brilliant Blue G-250 under UV light exposure and these fabricated Ag nanoparticles demonstrated efficacy in degrading the dye within 60min. Overall, the present results highlighted the antibacterial and anticancer properties of fabricated AgNPs, suggesting that phyto-synthesized silver nanoparticles could possess potent anti-pathogenic bacteria and anti-colon cancer activities.

Adsorptive Removal of Malachite Green from Model Aqueous Solutions by Chemically Modified Waste Green Tea Biomass.

The adsorption of malachite green (MG) from aqueous solution by waste green tea (WGT) biomass was investigated. A series of experiments in batch conditions were conducted in order to assess the MG removal on WGT, following adsorbent quantity and temperature influences. Maximum removal efficiency for untreated WGT was 89% (4 g biomass, 100 mL solution of 94 mg/L, 316 K). It was found that the adsorption of MG increased by increasing temperature from 296 to 316 K. Thermodynamic parameters (ΔH°, ΔS°, ΔG°) were calculated, and indicated that dye adsorption onto the studied biomass was endothermic and non-spontaneous. Six chemical treatments were tested (four acidic - H3PO4, H2SO4, HCl, and tartaric acid, one oxidant - H2O2, and one basic - NaOH) in order to study the chemical groups responsible for MG adsorption onto WGT biomass. The alkali and acidic treatments led to an increase of adsorption efficiency up to 92% and 95% (H2SO4) respectively. The FTIR spectroscopy results emphasized the modifications of the biomass surface and how these are influencing the adsorption process.

Physicochemical properties and cell-based bioactivity of Pu'erh tea polysaccharide conjugates.

Polysaccharide conjugates were prepared from Pu'erh tea and fractionated by DEAE-cellulose DE-52 column chromatography to yield one unexplored polysaccharide-conjugate fraction termed TPC-P with a molecular weight of 251,200Da. DVS (dynamic vapour sorption) result discovered that the humidity condition of long-term preservation for TPC-P is below 70% RH. Although it contained proteins, TPC-P could not bind to the Coomassie Brilliant Blue dyes G250 and R250. The "shoulder-shaped" ultroviolet absorption peak in TPC-P UV-vis scanning spectum ascribe theabrownins that inevitably adsorbed the polysaccharide conjugate. Zeta potential results demonstrated TPC-P aqueous solution merely presented the negative charge properties of polysaccharides instead of acid-base property of its protein section, and had more stability in greater than pH 5.5. No precipitation or haze occurred in the three TPC-P/EGCG aqueous mixtures during their being stored for 12h. The phase separation was observed in aqueous mixtures of TPC-P and type B gelatin. TPC-P possessed the fine stability as a function of temperature heating and cooling between 0 and 55°C. It is proposed that some properties of the covalent binding protein of TPC-P were "shielded" by its polysaccharide chains.

Interaction of homeopathic potencies with the water soluble solvatochromic dye bis-dimethylaminofuchsone. Part 1: pH studies.

INTRODUCTION: Previous studies have demonstrated the potential of solvatochromic dyes for investigating the physical chemistry of homeopathic potencies. RESULTS: Following examination of this class of dyes in organic solvents, results obtained using the positively solvatochromic dye Bis-dimethylaminofuchsone (BDF) in aqueous solution are now reported. Spectral changes observed with this dye in the presence of potencies are both substantial and reproducible. Studies across a wide range of pH values reveal an unusual pH dependence for the dye's interaction with homeopathic potencies. Results indicate potency enhances dye protonation at pH values below c. 7.0, whilst protecting the dye from attack by hydroxyl ions above c. pH 7.5. CONCLUSION: A possible explanation for these observations is offered in terms of a potency - induced electron density shift in BDF. The interaction of homeopathic potencies with solvatochromic dyes, particularly BDF, points towards a possible physico-chemical model for the nature of potencies, how they may be interacting with this class of dyes, and moreover how their biological effects may be mediated.

Facile green synthesis of functional nanoscale zero-valent iron and studies of its activity toward ultrasound-enhanced decolorization of cationic dyes.

For the first time, an integrated green technology by coupling functional nanoscale zero-valent iron (NZVI) with ultrasound (US) was innovatively developed for the enhanced decolorization of malachite green (MG) and methylene blue (MB). The functional NZVI (TP-Fe) was successfully fabricated via a facile, one-step and environmentally-benign approach by directly introducing high pure tea polyphenol (TP), where TP contenting abundant epicatechin was employed as reductant, dispersant and capping agent. Note that neither additional extraction procedure nor protection gas was needed during the entire synthesis process. Affecting factors (including US frequency, initial pH, dye concentration, and reaction temperature) were investigated. Results show that TP-Fe exhibited enhanced activity, antioxidizability and stability over the reaction course, which could be attributed to the functionalization of TP on NZVI and the invigorating effect of US (i.e., improving the mass transfer rate, breaking up the aggregates of TP-Fe nanoparticles, and maintaining the TP-Fe surface activity). The kinetics for MG and MB decolorization by the TP-Fe/US system could be well described by a two-parameter pseudo-first-order decay model, and the activation energies of MG and MB decolorization in this new system were determined to be 21 kJ mol-1 and 24 kJ mol-1, respectively. In addition, according to the identified reaction products, a possible mechanism associated with MG and MB decolorization with the TP-Fe/US system was proposed.

Phenolic compounds in drumstick peel for the evaluation of antibacterial, hemolytic and photocatalytic activities.

Most of the wastes emitted from the food processing industries are not utilized for any further purpose. The economic value of the food waste is very less when compared to the collection or reuse or discard. To increase the economic value we have to design the food waste as useful product or applicable in most of the current field. Nothing is waste in this world with this concept we have investigated the phytochemical analysis of drumstick peel (Moringa oleifera). The result supports the presence of phenols, alkaloids, flavanoids, glycosides and tannins. Since various functional groups containing molecules are present in the extract; it has been further subjected to antibacterial and hemolytic activities. To analysis the antibacterial studies we have employed human pathogenic Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacterium. The result of antibacterial activity clearly shows that it possesses significant activity on both bacterial cultures. The hemolytic activity was performed on red blood cells (RBCs). From this result we observed that drumstick peel extract has been considered as non-toxic on RBCs. Malachite green was selected to perform photocatalytic activity. The results stated that the drumstick peel extract possessed good behaviour towards photocatalytic investigation. The malachite green was degraded upto 99.7% using drumstick peel extract.

Novel guar gum/Al2O3 nanocomposite as an effective photocatalyst for the degradation of malachite green dye.

Guar gum/Al2O3 (GG/AO) nanocomposite was prepared using simple and cost effective sol-gel method. This nanocomposite was characterized by several analytical techniques viz. scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-vis). The FTIR analysis confirmed that GG/AO composite material was formed. TEM images inferred the particle size in the range between 20 and 45nm. GG/AO nanocomposite exhibited good photocatalytic performance for malachite green (MG) dye (dye initial concentration 1.5×10(-5)M) degradation from aqueous phase. The adsorption followed by photocatalysis and coupled adsorption/photocatalysis reaction achieved about 80% and 90% degradation of MG dye under solar irradiation. Antibacterial test showed the excellent activity of GG/AO nanocomposite against Staphylococcus aureus.

Development of a Fluorescent Quenching Based High Throughput Assay to Screen for Calcineurin Inhibitors.

Currently there is no effective treatment available for major neurodegenerative disorders associated to protein misfolding, including Alzheimer's and Parkinson's disease. One of most promising therapeutic approaches under development focuses on inhibiting the misfolding and aggregation pathway. However, it is likely that by the time clinical symptoms appear, there is a large accumulation of misfolded aggregates and a very substantial damage to the brain. Thus, it seems that at the clinical stage of the disease it is necessary also to develop strategies aiming to prevent the neuronal damage produced by already formed misfolded aggregates. Chronic activation of calcineurin (CaN), a type IIB phosphatase, has been implicated as a pivotal molecule connecting synaptic loss and neuronal damage to protein misfolding. The fact that the crystal structure of CaN is also well established makes it an ideal target for drug discovery. CaN activity assays for High Throughput Screening (HTS) reported so far are based on absorbance. In this article we report the development of a fluorescent quenching based CaN activity assay suitable for robotic screening of large chemical libraries to find novel inhibitors. The assay yielded a Z score of 0.84 with coefficient of variance ≤ 15%. Our results also show that this assay can be used to identify CaN inhibitors with a wide range of potencies.

Characterization of Periodic Acid-Schiff-Positive Granular Deposits in the Hippocampus of SJL/J Mice.

Periodic acid-Schiff (PAS)-positive granular deposits in the hippocampus have been reported previously in certain inbred mouse strains such as C57BL/6 and the senescent-accelerated mouse prone-8. Here, we report for the first time that similar PAS-positive granules age dependently occur in SJL/J mice, a mouse strain, for instance, used for central nervous system disease research. Moreover, similar granules stained intensely positive with a polyclonal antibody directed against p75 neurotrophin receptor (p75(NTR)). Granular deposits were absent in young mice and developed with aging in CA1 and CA2 regions of the hippocampus. Interestingly, granules significantly diminished in SJL/J mice previously treated with cuprizone, a copper chelator, which is a useful model for toxic demyelination. The presented data support the idea that granules might be the result of an imbalance of redox-active metals and/or a dysregulation of complementary mechanisms that regulate their homeostasis in astrocyte-neuron coupling, respectively. It remains to be determined whether the unsuspected immunoreactivity for p75(NTR) represents a false-positive reaction or whether p75(NTR) is crucially involved in the pathogenesis of age-related hippocampal granular deposits in mice.

Green synthesized conditions impacting on the reactivity of Fe NPs for the degradation of malachite green.

This study investigates green tea extract synthesized conditions impacting on the reactivity of iron nanoparticles (Fe NPs) used for the degradation of malachite green (MG), including the volume ratio of Fe(2+) and tea extract, the solution pH and temperature. Results indicated that the reactivity of Fe NPs increased with higher temperature, but fell with increasing pH and the volume ratio of Fe(2+) and tea extract. Scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), Fourier transform infrared spectroscope (FTIR) and X-ray diffraction (XRD) indicated that Fe NPs were spherical in shape, their diameter was 70-80 nm and they were mainly composed of iron oxide nanoparticles. UV-visible (UV-vis) indicated that reactivity of Fe NPs used in degradation of MG significantly depended on the synthesized conditions of Fe NPs. This was due to their impact on the reactivity and morphology of Fe NPs. Finally, degradation of MG showed that 90.56% of MG was removed using Fe NPs.

Green synthesis of iron nanoparticles by various tea extracts: comparative study of the reactivity.

Iron nanoparticles (Fe NPs) are often synthesized using sodium borohydride with aggregation, which is a high cost process and environmentally toxic. To address these issues, Fe NPs were synthesized using green methods based on tea extracts, including green, oolong and black teas. The best method for degrading malachite green (MG) was Fe NPs synthesized by green tea extracts because it contains a high concentration of caffeine/polyphenols which act as both reducing and capping agents in the synthesis of Fe NPs. These characteristics were confirmed by a scanning electron microscope (SEM), UV-visible (UV-vis) and specific surface area (BET). To understand the formation of Fe NPs using various tea extracts, the synthesized Fe NPs were characterized by SEM, X-ray energy-dispersive spectrometer (EDS), and X-ray diffraction (XRD). What emerged were different sizes and concentrations of Fe NPs being synthesized by tea extracts, leading to various degradations of MG. Furthermore, kinetics for the degradation of MG using these Fe NPs fitted well to the pseudo first-order reaction kinetics model with more than 20 kJ/mol activation energy, suggesting a chemically diffusion-controlled reaction. The degradation mechanism using these Fe NPs included adsorption of MG to Fe NPs, oxidation of iron, and cleaving the bond that was connected to the benzene ring.

Photothermal therapy of cancer cells mediated by blue hydrogel nanoparticles.

AIM: The aim of this study was to investigate in vitro the utility of biologically compatible, nontoxic and cell-specific targetable hydrogel nanoparticles (NPs), which have Coomassie® Brilliant Blue G dye (Sigma-Aldrich, MO, USA) covalently linked into their polyacrylamide matrix, as candidates for photothermal therapy (PTT) of cancer cells. MATERIALS & METHODS: Hydrogel NPs with Coomassie Brilliant Blue G dye covalently linked into their polyacrylamide matrix were fabricated using a reverse micelle microemulsion polymerization method and were found to be 80-95 nm in diameter, with an absorbance value of 0.52. PTT-induced hyperthermia/thermolysis was achieved at 37°C using an inexpensive, portable, light-emitting diode array light source (590 nm, 25 mW/cm(2)). RESULTS & CONCLUSION: Hydrogel NPs with Coomassie Brilliant Blue G dye linked into their polyacrylamide matrix are effective in causing PTT-induced thermolysis in immortalized human cervical cancer cell line (HeLa) cells for varying NP concentrations and treatment times. These multifunctional particles have previously been used in cancer studies to enable delineation, for glioma surgery and in photoacoustic imaging studies. The addition of the PTT function would enable a three-pronged theranostic approach to cancer medicine, such as guided tumor surgery with intra-operative photoacoustic imaging and intra-operative PTT.

Phytosynthesis of silver nanoparticles using Coccinia grandis leaf extract and its application in the photocatalytic degradation.

Silver nanoparticles were successfully synthesized from aqueous AgNO(3) through a simple green route using the leaf extract of Coccinia grandis as a reducing as well as capping agent. The results obtained from UV-vis spectrum, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier-transform infra red spectroscopy (FTIR) and high-resolution transmission electron microscopy (HRTEM) revealed that the biosynthesis of silver nanoparticles were in the size range of 20-30 nm and is crystallized in face centered cubic symmetry. Further, the thermal stability of nanoparticles was studied using thermo gravimetric analyzer (TGA) and differential scanning calorimeter (DSC). Photocatalytic property of the Ag nanoparticles was investigated by degradation of Coomassie Brilliant Blue G-250 under UV light. The results show that Ag nanoparticles have suitable activity for the degradation of Coomassie Brilliant Blue G-250.

A new fluorescent staining method for callose of microspore mother cells during meiosis.

To observe the dynamic behavior of callose of microspore mother cells during meiosis, we developed a convenient, rapid and efficient staining method using an improved carbol fuchsin/aniline blue solution. The stained microspore mother cells during meiosis showed yellowish green callose, red cytoplasm and dark red chromosomes when excited with blue light, which produced a contrasting image with a three-dimensional effect. When stained with only improved carbol fuchsin solution, the cells had red cytoplasm and chromosomes when excited with green light. The improved carbol fuchsin solution can be used to replace other more expensive DNA-specific dyes, such as DAPI and H33258, to reduce experimental costs.