The analysis of methylxanthine fractions obtained from Camellia sinensis cultivated in Turkey and effects on the in vitro inhibition of CYP2D6 enzyme.

Tea is a worldwide consumed herbal beverage and it was aimed in this study to reveal the major fractions of green and black tea in order to enlighten the in vitro inhibition potency on the well-known drug metabolizing enzyme CYP2D6 activity. Methylxanthine fractions were extracted from green and black tea and a yield of 0.265 g (1.06%) for 25 g of dried black tea and 0.302 g (1.2%) for 25 g of green tea was calculated. High-performance liquid chromatography analysis represented that the major components of the methylxanthine fractions were caffeine, theobromine, and theophylline. Methylxanthine content of black tea was 368.25 ± 4.6 µg/ml caffeine, 89.30 ± 2.3 µg/ml theobromine, and 3.40 ± 0.5 µg/ml theophylline, whereas that of green tea was 176.50 ± 3.7 µg/ml caffeine, 53.85 ± 1.4 µg/ml theobromine, and 2.06 ± 0.7 µg/ml theophylline. The results of concentration-dependent inhibition studies were 76% green tea, 75% black tea, and 55% caffeine at concentration of 10 mg/ml. The inhibition rates of green and black tea on CYP2D6 activity were 76% and 75%, respectively, where that of quinidine, the well-known inhibitor of CYP2D6, was 82%. Our results indicate that green and black tea is very likely to modify the CYP2D6 enzyme activity.

Phytosynthesis of CuONPs via Laurus nobilis: Determination of antioxidant content, antibacterial activity, and dye decolorization potential.

Copper oxide nanoparticles (CuONPs) were phytosynthesized by Laurus nobilis leaf extract, which was used as a reducing and capping agent. UV-vis spectroscopy was applied, and the spectrum of CuONPs gave a peak around 300 and 325 nm. An intense Fourier transform infrared spectroscopy between 4000 and 500 cm-1 wavelengths exhibited exterior functional groups of CuONPs. The results of scanning electron microscopy and transmission electron microscopy revealed that the green synthesized CuONPs were spherical in shape with sizes between 90 and 250 nm. Antibacterial activity of CuONPs was evaluated against both Gram-positive and Gram-negative bacteria. Brilliant Blue R-250 was employed in the dye decolorization studies, and CuONPs achieved 69% decolorization in 60 Min. The antioxidant activity of CuONPs was calculated by analyzing total phenolic compounds and flavonoid content. Furthermore, the reducing power of extract and nanoparticles was determined. Total phenolic compounds of CuONPs were determined as 6.7 µg of pyrocatechol equivalent/mg, while total flavonoids were measured as 236.62 µg catechin/mg sample. Results indicated that the method of CuONP formation is simple and low cost and the phytosynthesized CuONPs had antibacterial, antioxidant, and dye decolorization activity.

Complexes of glucose oxidase with chitosan and dextran possessing enhanced stability.

In this study, the different mole ratios of glucose oxidase/chitosan/dextran-aldehyde and glucose oxidase/chitosan/dextran-sulfate complexes were synthesized. The modification of glucose oxidase by non-covalent complexation with dextran and chitosan in different molar ratios was studied in order to increase the enzyme activity. The enzyme/polymer complexes obtained were investigated by UV spectrophotometer and dynamic light scattering. Activity determination of synthesized complexes and free enzyme were performed at a temperature range. The best results were obtained by Cchitosan/Cdextran-aldehyde = 10/1 ratio and Cchitosan/Cdextran-sulfate = 1/5 ratio that were used in thermal stability, shelf life, salt stress, and ethanol effect experiments. The results demonstrated that both complexes were thermally stable at 60 °C and had superior storage stability compared to the free glucose oxidase. Complexes showed higher enzymatic activity than free enzyme in the organic solvent environment using 10% ethanol. The complexes were resistant to salt stress containing 0.1 M NaCl or CaCl2. The particle size distribution results of the triple complex evaluated the complexation of the chitosan, dextran derivative, and glucose oxidase. The average size of the triple complex in diameter was found to be 325.8 ± 9.3 nm. Overall findings suggest that the complexes of glucose oxidase, chitosan, and dextran showed significant enhancement in the enzyme activity.

An accomplished procedure of horseradish peroxidase immobilization for removal of acid yellow 11 in aqueous solutions.

Horseradish peroxidase (HRP) characteristics were improved by two techniques, Na-alginate entrapment and glutaraldehyde crosslinking prior to alginate entrapment, in order to enhance the stability, functionality and removal of dyes in waste water. Free, entrapped and crosslinked-entrapped enzymes were compared by activity assays, which indicated the optimum temperature is 25 °C and pH 4.0-5.0. Kinetics results showed that alginate entrapment and crosslinking prior to entrapment increased Vmax and did not cause any significant decrease in Km. The thermal resistance of the free enzyme was short-term, zero residual activity after 250 min, while the immobilized enzymes preserved more than 50% of their activity for 5 h at 60 °C. Immobilized HRP was resistant to methanol, ethanol, DMSO and THF. The storage stability of free HRP ended in 35 days whereas entrapped and crosslinked-entrapped HRPs had 87 and 92% residual activity at the 60th day, respectively. HRP was used in the decolorization of azo dye Acid yellow 11 and total decolorization (>99%) was obtained using crosslinked-entrapped HRP. Reusability studies presented the improvement that crosslinked-entrapped HRP reached 74% decolorization after 10 batches. The results demonstrated that the novel immobilized HRP can be used as an effective catalyst for dye degradation of industrial waste effluents.

Biosynthesis of palladium nanoparticles using Diospyros kaki leaf extract and determination of antibacterial efficacy.

Palladium, the building block of white gold, has been found to exhibit extraordinary properties in nanotechnological products produced in recent years. The most prominent feature of palladium is adsorbing and storing high levels of hydrogen. Therefore, the demand for palladium in the world increased excessively in the 2000s. In the present study, palladium nanoparticles (PdNPs) were biosynthesized by the extract of Diospyros kaki leaves as bio-stimulator. D. kaki, also called persimmon, was collected in a local area in Istanbul Turkey. PdNP formation was screened by analyzing UV-Vis spectrophotometer at 250-550 nm. The nanoparticles were characterized by scanning electron microscope which revealed that the biosynthesized PdNPs were in sizes ranging from 50 to 120 nm. Fourier transform infrared spectroscopy applied on both D. kaki leaf extract and PdNPs was used to decide on the reactive groups managing the reduction of the biosynthesized nanoparticles. Also, the PdNPs showed reasonably proficient antibacterial efficacy for both Escherichia coli and Staphylococcus aureus and the zones of inhibition were found as 18 and 10.5 mm, respectively.

Biofabrication of Acer palmatum-Mediated Multifunctional CuO Nanoparticles for Dye Removal, Antibacterial-Antifungal Activity, and Molecular Docking.

Copper oxide nanoparticles (CuONPs) are used in many fields from electronics to medicine due to their multifunctionality, and therefore, their production with environmentally friendly methods is a current issue. In this study, biofabricated CuONPs were obtained by using the leaf extract of Acer palmatum plant originating from the Far East to enlighten the characteristics of the novel nanoparticles differentiating from those existing in the literature. Multifunctional nature of the CuONPs was evaluated by the antibacterial, antifungal, and decolorative applications and also by performing molecular docking analysis. The fabricated CuONPs were characterized using ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and dynamic light scattering (DLS). The absorbance seen at 270 nm in the SPR band obtained by UV-vis spectroscopy proved the presence of CuONPs, while the 602, 560, and 540 cm-1 vibrations obtained in the FT-IR spectroscopy indicated the same result. SEM images proved that the nanoparticles were in spherical form with sizes ranging from 140 to 225 nm. The result of DLS analysis showed that the average particle size was 229 nm in diameter, and CuONPs had monodisperse systems (polydispersity index, 0.184). The dye removal potency of CuONPs was also investigated by using remazol brilliant blue R (RBBR) and napthol blue black (NBB). Decolorizations (74 and 86%) of RBBR and NBB were obtained in 90 min at 50 °C, respectively. The strong antibacterial properties of the synthesized CuONPs were observed on both Gram (-) and Gram (+) bacterial strains by disk diffusion and optical analyses, and their antifungal activity was close to that of Amphotericin B, which was applied as a positive control. Molecular docking analysis was performed with Escherichia coli dihydrofolate reductase and Staphylococcus aureus DNA Gyrase B to analyze the antibacterial mechanisms of CuONP and observed that they exhibit good interactions with their targets with binding energies of -12.562 and -8.797 kcal/mol, respectively. Our findings suggested that CuONPs are crucial in the mechanisms of folate metabolism and DNA replication associated with bacterial proliferation. This work will provide significant guidance for the biofabrication of CuONPs and their medical and industrial applications.

Bioinspired fabrication of CuONPs synthesized via Cotoneaster and application in dye removal: antioxidant and antibacterial studies.

In this study, bioinspired fabrication of copper oxide nanoparticles (CuONPs) which are widely researched in nanotechnology field with Cotoneaster extract was performed. Cotoneaster plant extract was chosen as a good antioxidant and antibacterial agent in terms of the amount of phenolic and flavonoid compounds it contains. The obtained CuONPs were characterized by UV-Vis, FTIR, and SEM analyses. Antibacterial activity of the fabricated nanoparticles was evaluated against Escherichia coli and Staphylococcus aureus. Total phenolic compound, total flavonoid amount, and reducing power of the CuONPs were determined. Furthermore, paint removal properties of copper oxide nanoparticles on various dyes were investigated. Fabrication of the CuONPs was evaluated morphologically by color change and in UV spectrum by SPR band at 338 nm. The characteristic peak of CuONPs at 621 cm-1 was monitored employing FT-IR. SEM results showed that the fabricated CuONPs were spherical and between 50 and 160 nm. The CuONPs represented notable antibacterial efficiency against E. coli and S. aureus with inhibition zone of 19 ± 1 and 23 ± 2, respectively employing disk diffusion. The antioxidant properties of the CuONPs were also confirmed. Total phenolic substance content of the CuONP solution was 6.04 µg pyrocathecol equivalent/mg nanoparticle and total flavonoid content value was found as 122.46 µg catechin equivalent/mg nanoparticle. The reducing power of the fabricated CuONPs was found to be good when compared to the standard antioxidants BHA and α-tocopherol. In addition, the decolorization efficiency of the fabricated CuONPs has a strong potential on the industrial dye removal of neutral red and naphthol blue black.

Chitosan/calcium nanoparticles as advanced antimicrobial coating for paper documents.

Preservation of paper-based historical artifacts against deterioration due to the presence of bacteria and fungi colonies has been one of the major issues for the importance of protecting the cultural heritage of humankind. Advances in nanotechnology have enabled the implementation of nanomaterials for this purpose. In this work, calcium/chitosan nanoparticles (Ca/CS NPs) were prepared and well-characterized to investigate their potential as a novel approach for preserving paper-based documents. Following the fundamental characterizations, it was found that Ca/CS NPs are spherical nanoparticles with ~65 nm average size and homogenous dispersion (PdI: 0.2). Besides, minimum inhibition concentration results revealed that Ca/CS NPs show a superior antimicrobial effect against specific bacteria and fungi strains commonly found on paper documents compared to the effect of bare chitosan nanoparticles (CS NPs). After the deposition of Ca/CS NPs onto the paper the pH level was increased and stabilized, and only a limited amount of microbial colony formation was observed for up to 20 days. Moreover, molecular docking analysis provided a better insight into the antibacterial and antifungal activities of these nanoparticles. The antimicrobial activity of CS NPs and Ca/CS NPs was investigated through their interactions with E. coli DNA gyrase B and C. albicans dihydrofolate reductase. The binding modes and all possible interactions of active sites were confirmed by in silico molecular docking method. Collectively, our findings revealed that the formulated Ca/CS NPs are promising candidates for preserving paper documents.

Investigation of antibacterial and photocatalytic efficiency of green ZnO nanoparticles that synthesized with Celosia Cristata flower extract.

Increasing interest in green chemistry has led scientists to an environmentally friendly nanoparticle synthesis approach that has many advantages, such as simple, affordable and versatility for a wide range of commercial production. In this study, green synthesis of zinc oxide nanoparticles (ZnO NPs), which is widely researched in the field of nanotechnology, was performed under different conditions (volume ratio of CC flower extract to Zn(CH3COO)2 solution, time, pH and temperature) using the aqueous extract of Amarant (Celosia cristata L., CC, cockscome) plant flowers. Produced ZnO NPs were characterized by UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) analysis. The characteristic absorption peak seen at λmax: 364 nm in the UV-Vis absorption spectrum and the band seen at 381 cm-1 in the FTIR spectrum indicate that ZnO NPs were synthesized. TEM image also confirmed the formation of nanoparticles. The average size of nanoparticles is approximately 22-27 nm and the shape of the ZnO NPs as nearly spherical. The effect of different calcination temperatures (100, 200, 300, 400, and 500 °C) on the size of ZnO NPs was investigated and it was observed that the particle size decreased as the calcination temperature increased. ZnO NPs were also used as photo catalyst for removal of basic yellow28 (BY28) and basic violet39 (BV39) dyestuffs which are used in textile industry and ecologically toxic. The decolorization efficiency was found 95%-100% and 62% respectively when the BV39 and BY28 dyestuffs were exposed to UV light for 160 min. Antibacterial activity of ZnO NPs produced with different amounts of CC flower extract and calcined at different temperatures (100, 200, 300, 400, and 500 °C) was investigated using modified disc diffusion method. Produced ZnO NPs displayed antibacterial activity against Staphylococcus aureus and Escherichia coli bacterial strains and were more effective against gram-positive pathogens. The findings displayed that the antibacterial activity of ZnO NPs is related to the particle size. This new environmentally friendly synthesis approach is a suitable technique for large-scale commercial production and can be considered as an alternative to chemical methods.

Dual antimicrobial effects induced by hydrogel incorporated with UV-curable quaternary ammonium polyethyleneimine and AgNO3.

This study presents a simple method for fabricating a highly potent dual effect antibacterial hydrogel consisting of a UV-curable cationic polyethyleneimine (QUV-PEI) and embedded silver nitrate (AgNO3). In the first part of this study, polyethyleneimine (PEI) was reacted with 3-(acryloyloxy)-2-hydroxypropyl methacrylate (ACOM) to introduce methacryl functionality onto the backbone. UV-curable PEI was further quaternized by N-methylation with methyl iodate. Hydrogels based on QUV-PEI and AgNO3were found to have impressive biocidal properties. The antibacterial properties were assessed by spraying aqueous suspensions of bacterial cells on the surface, followed by air drying and counting the number of remaining viable cells (i.e. capable of growing into colonies). In a manner depending on the QUV-PEI content in the gel formulation, up to 99±1% of Escherichia coli and Staphylococcus aureus cells sprayed on the resulting hydrogel surfaces were killed. The inclusion of AgNO3 in the QUV-PEI based hydrogel not only enhanced the antimicrobial property against adherent bacteria but also led to the inhibition of bacterial growth in suspended culture via the long-term release of Ag/Ag(+) to the surrounding media. Cytotoxicity studies on human umbilical vein endothelial cells and MTS cell lines were also performed with hydrogels. These findings confirm that hydrogels are potentially useful as antimicrobial agents in a wide variety of applications.