Laccase is one of the enzymes that catalyze the oxidation of phenolic and non-phenolic substrates and show encouraging potential as a biocatalyst in the synthesis of bioactive compounds. It is known that phenolic acids have an antioxidant effect. Bovine serum albumin (BSA) shows gelling activity, and nutraceutical binding ability but it does not show antioxidant activity. In this study, BSA which has no antioxidant activity using laccase, started to show antioxidant activity with gallic acid (GA) conjugation. The synthesized conjugates were analyzed by polyacrylamide gel electrophoresis (PAGE), ultraviolet–visible spectrophotometry (UV-Vis), and Fourier-transform infrared spectroscopy (FTIR). Radical scavenging capacity for antioxidant activity was measured. GA-functionalized-BSA displayed greatly improved 2,2'-azinobis-(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2- picryl-hydrazyl (DPPH) radical scavenging capacities, compared with the untreated BSA. Protein–flavonoid conjugates can improve the natural properties of proteins, being promising products to be used in medical, food and polymer fields where antioxidant ability is an essential feature.
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The present paper reports the synthesis, characterization, and DFT calculations of two oxovanadium (IV) Schiff base complexes symbolized as VOL1 and VOL2, which prepared by the reaction of bivalent tridentate Schiff base ligands (E)-2-((5-chloro-2-hydroxybenzylidene)amino)acetic acid and (E)-2-((2-hydoxy-5-nitrobenzylidene)amino)acetic acid and VO(acac)2 as vanadium source. The Schiff base ligands and its oxovanadium (IV) complexes were characterized by the elemental analysis (C, H, N), FTIR, 1H NMR and 13C NMR, DFT calculations were performed to derive some of their molecular properties. Schiff base ligands coordinated to vanadium center via nitrogen from the azomethine group and one oxygen from the hydroxyl attached to the benzene ring and one oxygen from hydroxyl of carboxyl group. The catalytic activity of the two complexes were tested against cyclooctene and found that both complexes were highly effective and selective in optimized conditions when used as cyclooctene epoxidation catalysts with the conversion percentage of 91.85% (with VOL1) and 87.40% (with VOL2) at 78 °C within a period of ten hours. To understand the structural properties of the two complexes, the two complexes were well optimized at B3LYP/6-31G(d,p) level of theory, structural parameters such as electron affinity, global electrophilicity, global hardness, electronegativity, ionization potential, and electron chemical potential based on HOMO and LUMO energy values were calculated.
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Downconversion processes which include visible and near-infrared luminescence at high energy excitation have been investigated in Yb3+/Pr3+ doped TeO2-ZnO-BaO glasses. The decrease of the DC emission intensities of Pr3+ ions with increasing mole % amount of Pr3+ ions is attributed to the concentration quenching. The CIE chromaticity coordinates of the perceived emission of Pr3+ ions shifted from orange to the red region depending on the increase in the pump power. Consequently, Yb3+/Pr3+ doped TeO2-ZnO-BaO glasses could be used as functional optical materials for solid-state lighting applications.
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Lignocellulosic structures extracted from agricultural wastes have great potential in re-designing sustainable packaging materials. In this study, the utilization of kiwifruit peels (KFP) (unt) and lignocellulosic structures extracted from KFP, which were alkali-treated (al), acid-treated (ac), and acetylated (ace), in poly(lactic acid) (PLA) films were investigated. Untreated and treated lignocellulosic structures were added to PLA film-forming solutions at 5% (w/w based on PLA). The film samples were characterized by their mechanical, water vapor permeability (WVP), FTIR, and optical properties. FTIR results presented that the acid treatment and acetylation have changed the chemical structure of KPF, which resulted in changes in intensities and peak shifts between 1400-1900 cm-1. WVP of the films containing KPF-based lignocellulosic structures was lower than control PLA films (p<0.05). The addition of KPF-based lignocellulosic structures increased the tensile strength and elastic modulus (p>0.05) compared to PLA control films. Films including acid-treated lignocellulosic structures had high opacity and relatively low lightness values (p<0.05). These results showed that adding lignocellulosic structures into PLA films is a promising method to improve the film properties.
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This study covers the synthesis and release behavior of chitosan-graft-polyacrylamide copolymers in aqueous media at different pH values. The copolymers were synthesized using redox polymerization with ceric ammonium nitrate (CAN) in 1% aqueous acetic acid solution as the initiator. Optimum condition for the graft copolymer synthesis was determined as 3.85 g/L chitosan, 0.27 M acrylamide (AAm) monomer at 40 °C with a CAN per gram chitosan as 6 mmol using 0.05 M stock solution in 0.1 N HNO3. Then the crosslinked copolymers were synthesized using methylenebisacrylamide (MBA) as a crosslinker varying mass proportions of AAm:MBA as 15:1, 20:1, and 30:1. Obtained material amount (polymer yield) and molecular weight of crosslinked copolymers were lower than the graft copolymer as expected. Acetylsalicylic acid (ASA) release behaviors of all copolymers were monitored with UV-visible spectroscopy at different pH values (2, 6, and 8.5) corresponding to different media in the body (stomach, skin, and intestine, respectively). According to the results, the release behavior changed the least among the samples with respect to medium pH and of was the most affected.
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Metabolic syndrome (MetS) is a combination of several different metabolic disorders and considered one of the major public health problems worldwide. The underlying causes of MetS include being overweight and obesity, physical inactivity, and genetic factors. We aimed to examine the alterations in the levels of biomarkers of oxidative stress, activities of antioxidant defense enzymes, and metal contents of the liver in rats with MetS. Rats in control and MetS groups were fed with standard rat chow-drinking water and standard rat chow - 32% sucrose solution (instead of drinking water) ad libitum for 16 weeks, respectively. Following the confirmation of MetS, antioxidant enzyme activities and malondialdehyde (MDA), 3-nitrotyrosine (3-NT), phospho-Akt (pSer473) levels were measured in the homogenates of the liver. Distributions of elements in the liver were also analyzed. The stained hepatic tissue slides were examined by light microscopy. The activities of catalase and glutathione-S-transferase were significantly decreased in MetS-group (about 15% and 29%, respectively) compared to the control group, while the glutathione reductase activity and MDA and 3-NT levels were significantly increased (as the levels of 78%, 26%, and 67%, respectively) (p<0.05). The hepatocytes in the MetS group showed mild diffuse microvesicular steatosis. Furthermore, Cu, Fe, and Mn levels were significantly high in MetS-group while Zn level was significantly low compared to the control group. Our results showed increased oxidative stress, impaired antioxidant defense enzyme activities, and altered metals’ metabolisms which may have an important role in the pathogenesis of MetS.
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In this study, acetate derivatives were obtained from the reaction of acetophenones using diethyl carbonate. The acidic proton of CH2 moiety was abstracted using a suitable base and α-propargyl-β-ketoester (non-conjugated ynone) derivatives 3a-c were obtained from the reaction of the acetate derivatives with propargyl bromide. By removing the ester group of α propargyl-β-ketoester derivatives under suitable conditions, α-propargyl acetophenones (non-conjugated ynone) 4a-c were obtained. In this study, 6 different unconjugated ynone derivatives were synthesized as starting material with yield in a range of 60-95%. Cyclization reactions with propargyl amine in the presence of three different unconjugated ynone derivatives, metal catalysts were investigated. The synthesis of propargyl pyrroles 7a-c having substituents on C-2 and C-5 was completed.
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In the present study, waste by-products of one of the popular fruit juices in the World has been valorized for its high-added value ingredients. Peels of sour cherry (Prunus cerasus L.) have been extracted by means of deep eutectic solvent (DES)-based microwave-assisted extraction (MAE). DES system contained citric acid as hydrogen bond acceptor (HBA) and ethylene glycol as hydrogen bond donor (HBD) (1/4, molar ratio). In order to optimize the MAE system Central Composite design (CCD) of Response Surface Method (RSM) has been used. The measured variables were the yields of total phenolic (TPC), total anthocyanins (TA) and cyanidin-3-glucoside. Optimum conditions were determined as 0.1 g of peel and 50 % (v/v) water contribution to the DES for the maximum reovery of TPC (16.85 mg-GAE/g-FP), TA (3.39 mg-cyn-3-glu/g-FP) and cyanidin-3-glucoside (mg/g-FP) in the MAE of sour cherry peels. The relationship between the responses was also established.
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Tobacco is a commercial plant that can accumulate heavy metals in its leaves. In this study, we investigated the levels of selected heavy metals (Mn, Cu, Zn, Cd, and Pb) in tobacco leaves and their growing soils from Assosa District, Benshangul Gumuz Regional State, Ethiopia. Both samples were collected from five tobacco farmlands. The samples were digested before quantitative determinations of the metals via inductively coupled plasma optical emission spectroscopy (ICP-OES). Repeatability and recovery studies were used to evaluate the efficiency of the method. Repeatability was evaluated by analyzing replicate samples and expressed as relative standard deviations (RSD) were below 10.0. Recovery or percent recovery (%R) studies, which were performed by spiking known concentrations of metals into the samples, ranged from 85.67 - 111.33% and 84.25 - 114.00% for tobacco leaves and soil samples, respectively, indicating that the employed method is valid for the analysis of the metals. The concentrations of metals in tobacco leaf samples were: 0.75 -1.18 mg/kg, Mn; 0.11-0.21 mg/kg, Cu; 0.58-1.16 mg/kg, Zn; and not quantified (NQ) - 0.01 mg/kg, Cd. In soil samples, their concentrations were: 1.59-8.04 mg/kg, Mn; 0.32 - 0.38 mg/kg, Cu; and 0.29 - 1.26 mg/kg, Zn; and 0.17 - 0.31 mg/kg, Pb. Except in one tobacco leaf sample, Pb was below the limit of quantification (LOQ). Similarly, in all soil samples, the concentration of Cd was below LOQ. The findings indicate that the concentrations of the studied heavy metals in both tobacco leaves and soil samples are below their WHO permissible limits in soil and plants. However, the levels of Zn in Amba and Basha tobacco leaves were higher than the WHO permissible limit in plants.
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Radioactivity measurements for water, soil, and air have been completed in national and international regions. The radioactivity process is randomized and occurs naturally by primordial nuclides. Another case is hand-made reactions which realized by artificial reactions. The high rate of the total dose of radiation, whichever is exposed to humans, originates as Natural Radioactivity. In this case, environmental radioactivity measurements are important to investigate the background radiation level, especially for primordial radioactive sources. This radiation which measured outdoor gamma dose includes both cosmic rays and terrestrial elements. Terrestrial radiation can be measured via gamma-ray spectroscopy separately. By the way, cosmic effects would be calculated by subtracting terrestrial from measured outdoor gamma dose. Scientific Committee (UNSCEAR, 2000) declares the annual dose for humans as 2.4 mSv. The radionuclides present in soil samples (terrestrial components) are considered responsible for a portion of this amount (1). Rest amounts are originated water (2) and air, too.
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