96 results on '"Oliveira-Brett, A. M."'
Search Results
2. Analysis of Antioxidant Compounds in Vitex negundo Leaves Using Offline 2D-LC-ECD and LC-MS/MS.
- Author
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Qimei Wu, Jinfen Zheng, Yan Yu, Zhirong Li, Ying Li, Chengfeng Hu, Yaping Zhou, and Rongxiang Chen
- Abstract
Vitex negundo has strong antioxidant activity, but its primary antioxidant components are not clear. In this study, the antioxidant components were screened by offline two-dimensional liquid chromatography coupled with electrochemical detection (2D-LC-ECD) and subsequently assessed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) identification, radical scavenging capacity, and molecular docking. Various fractions were isolated from Vitex negundo leaves, and 39 antioxidant components were screened and identified. All of the fractions containing the antioxidant components exhibited certain antioxidant activity. Correlation analysis revealed a strong correlation between the response of LC-ECD and the in vitro antioxidant activity of the fractions. Molecular docking demonstrated that components with high response to LC-ECD exhibited robust interaction with antioxidant-related target proteins. The main antioxidant components of Vitex negundo leaves were isoorientin, chlorogenic acid, agnuside, cynaroside, and scutellarin. The 2D-LCE-CD combined with LC-MS/MS was rapid and effective in screening the antioxidant components in Vitex negundo leaves and could also provide technical support for the discovery of antioxidant components with different polarities and contents in other medicinal and edible plants. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Investigative didactic sequence for the teaching of electrochemistry addressing the disposal of batteries.
- Author
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Cordeiro Cavalcante de Oliveira, Marcela, Rufino de Freitas Filho, João, Rodrigues de Souza, Sandra, Mendes da Silva, Ivoneide, Luís Silva de Araújo, Arthur, and Silva de Freitas, Katia Cristina
- Subjects
ELECTROCHEMICAL experiments ,OXIDATION-reduction reaction ,ELECTRICAL energy ,AQUEOUS solutions ,ELECTROCHEMISTRY - Abstract
Electrochemistry is an essential context for understanding current energetic technological processes, especially those that use batteries. On the other hand, it is one of the most neglected subjects in the classroom for reasons of associated complexity. Because of this, we have sought new methodological strategies to overcome the difficulties encountered in teaching practice. Thus, this research aims to investigate the possible contributions of a didactic sequence on the disposal of batteries from the teaching by research for the learning of electrochemistry. A qualitative methodology, a case study, applied in a high school class was adopted. The sequence consisted of six methodological steps: implementation of the problem situation; developed hypotheses; a class on electrochemistry; investigative experiment on the decomposition of batteries in aqueous solutions; systematization and communication of results. The results showed that before the application of the didactic sequence, most of the students did not know the dangers that improper disposal of batteries causes to the environment and did not understand how galvanic cells generate electrical energy from a redox reaction. After the sequence was developed, most students were able to identify and conceptualize the main electrochemical terms studied from a critical thought about this problem. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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4. Electrochemical Study of the Antitumor Antibiotic Doxorubicin in Its Free Form and Encapsulated in a Biocompatible Copolymer of N-Vinylpyrrolidone and (di)Methacrylates.
- Author
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Kurmaz, V. A., Konev, D. V., Kurmaz, S. V., and Emel'yanova, N. S.
- Subjects
ANTINEOPLASTIC antibiotics ,CHEMICAL models ,METHACRYLIC acid ,METHACRYLATES ,CARBON electrodes ,COPOLYMER micelles ,DOXORUBICIN ,POLYMERS ,LACTAMS - Abstract
A comparative study of the electrochemical behavior of various forms of the antitumor antibiotic doxorubicin (DOX), both free and encapsulated in micelle-like nanoparticles of the biocompatible amphiphilic copolymer of N-vinylpyrrolidone (VP) and methacrylic acid, viz., triethylene glycol dimethacrylate (TEGDM), is carried out in aqueous neutral buffers on a glassy carbon electrode. The hydrodynamic radii R
h of the copolymer and the DOX polymeric nanostructures are determined using dynamic light scattering. Using cyclic and square wave voltammetry, for both forms of DOX at pH 7.24, the two main redox transitions are revealed namely, the irreversible oxidation/rereduction in the potential interval from 0.2 to 0.6 V and the reversible reduction/reoxidation in the interval from –0.4 to –0.7 V (vs. saturated Ag/AgCl), and their redox potentials are determined. For both redox transitions, the potential difference between the corresponding peaks does not exceed several tens (20–30) mV; and, moreover, the oxidation of the encapsulated form proceeds easier as compared with the free form, whereas its reduction is somewhat more difficult. The analysis of the dependence of the reduction current of both DOX forms on the potential scan rate shows that the electron transfer to a free DOX molecule is largely determined by the rate of reagent accumulation in the adsorption layer, whereas the electron transfer to the encapsulated form is characterized by the mixed adsorption-diffusion control. Based on voltammetric data and the results of quantum chemical modeling, it is concluded that a hydrogen bond is formed between the oxygen-containing groups of copolymer's monomeric units and the H atoms in OH and NH2 groups of DOX. The bond energy in these structures is calculated and shown to be close to the classical values, assuming that the carbonyl group in the VP lactam ring in the encapsulating polymer is the electron donor, and the hydrogen atoms in OH and NH2 groups of DOX are the electron acceptors. At the same time, the bonds involving oxygen of the ester group in the TEGDM unit are extremely weak. [ABSTRACT FROM AUTHOR]- Published
- 2024
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5. Antioxidant capacity of Myrciaria cauliflora seed extracts by spectrophotometric, biochemical, and electrochemical methods and its protective effect against oxidative damage in erythrocytes.
- Author
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Hacke ACM, Valério TP, Cubo MF, Lima D, Pessôa CA, Vellosa JCR, and Pereira RP
- Subjects
- Erythrocytes, Humans, Oxidative Stress, Plant Extracts chemistry, Seeds chemistry, Antioxidants chemistry, Myrtaceae chemistry
- Abstract
This study aimed to investigate the antioxidant activity of extracts obtained from jabuticaba (Myrciaria cauliflora) seeds. Ethanolic (ETJS), methanolic (MEJS), aqueous (AQJS), and propanone (PRJS) extracts was assessed by measuring spectrophotometrically their ability to scavenge DPPH
· , ABTS·+ , HOCl, and O2 radicals. Electrochemical methods were employed, and the obtained data presented a good correlation with the radical scavenging results. The extracts were also able to attenuate lipid peroxidation induced by Fe·- ions in phospholipids due to their chelation ability. The extracts protected human erythrocytes against oxidative cellular damage caused by AAPH, which was confirmed by using FESEM analysis. PRJS extract demonstrated the highest effect in all assays used in this work. Our findings prove that jabuticaba seeds are an important source of antioxidants which act by different mechanisms. This study opens new frontiers regarding the use of this fruit byproduct as a food additive. PRACTICAL APPLICATIONS: Jabuticaba seeds are usually discarded as waste by food industries, but they are rich in bioactive products and present interesting biological properties. Herein, we demonstrated that their extracts show remarkable antioxidant power against different reactive oxygen species, which are involved in several human pathologies. In this way, this by-product can be further used in the development of products to protect the human body against diseases related to oxidative stress.2+ ions in phospholipids due to their chelation ability. The extracts protected human erythrocytes against oxidative cellular damage caused by AAPH, which was confirmed by using FESEM analysis. PRJS extract demonstrated the highest effect in all assays used in this work. Our findings prove that jabuticaba seeds are an important source of antioxidants which act by different mechanisms. This study opens new frontiers regarding the use of this fruit byproduct as a food additive. PRACTICAL APPLICATIONS: Jabuticaba seeds are usually discarded as waste by food industries, but they are rich in bioactive products and present interesting biological properties. Herein, we demonstrated that their extracts show remarkable antioxidant power against different reactive oxygen species, which are involved in several human pathologies. In this way, this by-product can be further used in the development of products to protect the human body against diseases related to oxidative stress., (© 2022 Wiley Periodicals LLC.)- Published
- 2022
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6. Investigation of the ability of 3-((4-chloro-6-methyl pyrimidin-2-yl)amino) isobenzofuran-1(3H)-one to bind to double-stranded deoxyribonucleic acid.
- Author
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Şenel P, Al Faysal A, Yilmaz Z, Erdoğan T, Odabaşoğlu M, and Gölcü A
- Subjects
- Binding Sites, Density Functional Theory, Hydrogen Bonding, DNA metabolism, DNA chemistry, Benzofurans chemistry, Benzofurans metabolism, Benzofurans chemical synthesis
- Abstract
Phthalides represent a notable category of secondary metabolites that are prevalent in various plant species, certain fungi, and liverworts. The significant pharmacological properties of these compounds have led to the synthesis of a novel phthalide derivative. The current study focuses on investigating the binding interactions of a newly synthesized 3-substituted phthalide derivative, specifically 3-((4-chloro-6-methyl pyrimidine-2-yl)amino) isobenzofuran-1(3H)-one (Z11), with double-stranded deoxyribonucleic acid (dsDNA). Research in the pharmaceutical and biological fields aimed at developing more potent DNA-binding agents must take into account the mechanisms by which these newly synthesized compounds interact with DNA. This investigation seeks to explore the binding dynamics between dsDNA and our compound through a variety of analytical techniques, such as electrochemistry, UV spectroscopy, fluorescence spectroscopy, and thermal denaturation. The binding constant (K
b ) of Z11 with DNA was determined using both spectroscopic and voltammetric approaches. The research revealed that Z11 employs a groove binding mechanism to associate with dsDNA. To further explore the interactions between Z11 and dsDNA, the study utilized density functional theory (DFT) calculations, molecular docking, and molecular dynamics simulations. These analyses aimed to ascertain the potential for a stable complex formation between Z11 and dsDNA. The results indicate that Z11 is situated within the minor groove of the dsDNA, demonstrating the ability to establish a stable complex. Furthermore, the findings imply that both π-alkyl interactions and hydrogen bonding play significant roles in the stabilization of this complex., Competing Interests: Declarations Conflict of interest The authors report there are no conflict of interests to declare., (© 2024. The Author(s), under exclusive licence to the European Photochemistry Association, European Society for Photobiology.)- Published
- 2024
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7. A cluster-nanozyme-coenzyme system mimicking natural photosynthesis for CO 2 reduction under intermittent light irradiation.
- Author
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Cui X, Bai H, Zhang J, Liu R, Yu H, Wang Y, Kong T, Gao MY, Lu Z, and Xiong Y
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- Cobalt chemistry, Cobalt metabolism, Copper chemistry, Copper metabolism, Oxidation-Reduction, Carbon Monoxide metabolism, Photosynthesis, Carbon Dioxide metabolism, Ubiquinone metabolism, Ubiquinone analogs & derivatives, Ubiquinone chemistry, Light
- Abstract
Natural photosynthesis utilizes solar energy to convert water and atmospheric CO
2 into carbohydrates through all-weather light/dark reactions based on molecule-based enzymes and coenzymes, inspiring extensive development of artificial photosynthesis. However, development of efficient artificial photosynthetic systems free of noble metals, as well as rational integration of functional units into a single system at the molecular level, remain challenging. Here we report an artificial system, the assembly system of Cu6 cluster and cobalt terpyridine complex, that mimics natural photosynthesis through precise integration of nanozyme complexes and ubiquinone (coenzyme Q) on Cu6 clusters. This biomimetic system efficiently reduces CO2 to CO in light reaction, achieving a production rate of 740.7 μmol·g-1 ·h-1 with high durability for at least 188 hours. Notably, our system realizes the decoupling of light and dark reactions, utilizing the phenol-evolutive coenzyme Q acting as an electron reservoir. By regulating the stabilizer of coenzyme Q, the dark reaction time can be extended up to 8.5 hours, which fully meets the natural day/night cycle requirements. Our findings advance the molecular design of artificial systems that replicate the comprehensive functions of natural photosynthesis., (© 2024. The Author(s).)- Published
- 2024
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8. Step-by-step guide for electrochemical generation of highly oxidizing reactive species on BDD for beginners.
- Author
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Castillo-Cabrera, G. Xavier, Pliego-Cerdan, Caroline I., Mendez, Erika, Espinoza-Montero, Patricio J., Reyes, Jose Luis Tristancho, and Morales, Gabriela Roa
- Subjects
DOPING agents (Chemistry) ,ELECTROCHEMICAL analysis ,AMOXICILLIN ,HYDROXYL group ,REACTIVE oxygen species ,VOLTAMMETRY - Abstract
Selecting the ideal anodic potential conditions and corresponding limiting current density to generate reactive oxygen species, especially the hydroxyl radical (*OH), becomes a major challenge when venturing into advanced electrochemical oxidation processes. In this work, a step-by-step guide for the electrochemical generation of "OH on boron-doped diamond (BDD) for beginners is shown, in which the following steps are discussed: i) BDD activation (assuming it is new), ii) the electrochemical response of BDD (in electrolyte and ferri/ferro-cyanide), iii) Tafel plots using sampled current voltammetry to evaluate the overpotential region where *OH is mainly generated, iv) a study of radical entrapment in the overpotential region where "OH generation is predominant according to the Tafel plots, and v) finally, the previously found ideal conditions are applied in the electrochemical degradation of amoxicillin, and the instantaneous current efficiency and relative cost of the process are reported. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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9. Diagnosis of Blood Gastric Cancer Biomarkers via Nanomaterial-Based Electrochemical Immunosensor: A Review on Recent Advancements (A Review).
- Author
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Mojtaba Zehtabi and Mortaza Raeisi
- Subjects
TUMOR markers ,STOMACH cancer ,BIOELECTROCHEMISTRY ,ELECTROCHEMICAL electrodes ,DIAGNOSIS ,CELL analysis - Abstract
Gastric cancer (GC) is one of the considered enormously important cancer types in the world. A large number of mortality rates have revealed that there is a massive shortage in the prognosis and treatment of GC because the majority of GC cases are identified at an advanced stage. In this regard, the rapid platform for non-invasive detection of GC cells through the analysis of GC biomarkers in the first stages with high sensitivity is essential for the success in the treatment of GC. In recent years, different types of electrochemical immunosensors as efficient sensing devices with benefits including accuracy, reproducibility and low cost have played an extremely significant role in the monitoring of GC. One of the significant issues in the development of electrochemical immunosensors is to increase the system's sensitivity. A variety of nanomaterials based on carbon-based, silica-based and metallic-based nanomaterials have been used as sensing platforms on the different types of electrochemical electrodes for improving the properties of biodevices. This review highlighted the new progress and technical breakthroughs comprising electrochemical immunosensor for the determination of GC biomarkers including CA19-9, CA72-4, CA125 and CEA. In diverse matrices and proved how nanoprobes could enhance the performance of electrochemical immunsensing approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. EXPLORING THE POTENTIAL OF GRAPE POMACE POWDER AS A FUNCTIONAL INGREDIENT IN YOGURT.
- Author
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STOICA, Florina, RAȚU, Roxana Nicoleta, CARA, Irina Gabriela, ȚOPA, Denis, and JITĂREANU, Gerard
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VITIS vinifera ,PHENOLS ,DIETARY fiber ,BIOACTIVE compounds ,GRAPES ,YOGURT - Abstract
Consumer demand for functional yogurts has been rising recently, particularly for those made by adding plant-based ingredients or their bioactive components. Grape, Vitis vinifera L., is abundant in antioxidant-rich phenolic compounds and dietary fiber. Although grape pomace is an agro-industrial by-product and its handling can lead to socioeconomic and environmental issues, it can be possible to valorise by extracting its bioactive components. The goal of this study was to develop functional yogurt by adding 1 and 2% of grape pomace (YGP1 and YGP2). The impact of fortification was assessed on the enhanced yogurts' physicochemical properties, total phenolic content, antioxidant activity, and sensory acceptance. Grape pomace powder had high total polyphenols contents (20.39 ± 0.23 mg GAE/g d.w.) and antioxidant activity (88.16 ± 0.45%). Values of polyphenols (8.88± 0.06 mg GAE/g d.w.) and antioxidant activity (89.47 ± 0.39%) significantly increased in fortified yogurts compared to control sample. Therefore, it is possible to conclude that grape pomace powder can be used to produce novel, functional yogurt. [ABSTRACT FROM AUTHOR]
- Published
- 2024
11. Electrochemical evaluation of proton beam radiation effect on the B16 cell culture.
- Author
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Onea M, Bacalum M, Radulescu AL, Raileanu M, Craciun L, Esanu TR, and Enache TA
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- Animals, Mice, Cell Line radiation effects, Electrochemical Techniques, Melanoma, Experimental, Oxidative Stress, Proton Therapy
- Abstract
The interaction of radiation with matter takes place through energy transfer and is accomplished especially by ionized atoms or molecules. The effect of radiation on biological systems involves multiple physical, chemical and biological steps. Direct effects result in a large number of reactive oxygen species (ROS) within and outside and inside of the cells as well, which are responsible for oxidative stress. Indirect effects are defined as alteration of normal biological processes and cellular components (DNA, protein, lipids, etc.) caused by the reactive oxygen species directly induced by radiation. In this work, a classical design of an electrochemical (EC) three-electrodes system was employed for analyzing the effects of proton beam radiation on melanoma B16 cell line. In order to investigate the effect of proton radiation on the B16 cells, the cells were grown on the EC surface and irradiated. After optimization of the experimental set-up and dosimetry, the radiobiological experiments were performed at doses ranging between 0 and 2 Gy and the effect of proton beam irradiation on the cells was evaluated by the means of cyclic voltammetry and measuring the open circuit potential between working and reference electrodes., (© 2022. The Author(s).)
- Published
- 2022
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12. Application of Disposable Biosensor for Nivolumab–DNA Interaction Using Pencil Graphite Electrode.
- Author
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Aslan, M., Aydın, F., Aslan, F., and Levent, A.
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ELECTRON microscope techniques ,ADENINE ,ELECTRODES ,SCANNING electron microscopes ,GRAPHITE ,ELECTROLYTE solutions - Abstract
In this study, the interaction of the anticancer drug Nivolumab (NIVO) with dsDNA was investigated using differential pulse (DPV) technique by monitoring the changes in the oxidation signal of adenine and guanine bases on PG electrode. Surface characterization of the PG (pencil graphite) electrode was carried out using cyclic voltammetry, electrochemical impedance spectrometry techniques and scanning electron microscope, Energy Dispersive X-ray. DPV parameters, the effect of pH on the electrode surface, stirring speed, dsDNA immobilization time, immobilized dsDNA concentrations, NaCl concentration, NIVO concentration interacting with dsDNA were optimized with PG electrode. With the determined parameters, NIVO–dsDNA interaction in PBS (pH 3.0) supporting electrolyte solution was elucidated. In the NIVO–dsDNA interaction using UV technique, the K binding constant and free energy of binding value was found to be 8.93 × 10
4 and 6.754 kcal mol–1 , respectively. It was determined that the data obtained by electrochemical method were in parallel with the data obtained by spectrometric method. The results obtained electrochemically with high sensitivity, low cost, fast, simple, low detection limit will be the first example of NIVO–dsDNA interaction using PG electrode. [ABSTRACT FROM AUTHOR]- Published
- 2023
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13. EVALUATION OF ECO-EXTRACTION METHODS OF ANTIOXIDANTS AND THEIR ACTIVITIES FROM RETAMA RAETAM TWIGS.
- Author
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Zaoui, Oussama, Oughlissi-Dehak, Karima, Bouziane, Mebarka, Zaoui, Fatiha, Boudou, Farouk, Benras, Amina, Sehmi, Abdelghani, and Hadj-Mahammed, Mahfoud
- Subjects
PARKINSONIA aculeata ,ANTIOXIDANTS ,ULTRASONIC imaging ,MICROWAVES ,METABOLITES - Abstract
The purpose of this study is to compare the effectiveness of different conventional and nonconventional methods for the extraction of secondary metabolites and antioxidant activity of aqueous and hydro-ethanolic extract of Retama raetam twigs including maceration, reflux, Soxhlet, microwave assisted extraction (MAE) and ultrasonic assisted extraction. The aqueous and hydro-ethanolic extracts obtained by MAE showed the highest contents of total phenolics (160.43 ±1.42 and 175.71 ±2.09 mg EAG/g DR, respectively) and flavonoids of 12.28 ±0.92 and 39.97 ±1.11 mg EC/g DR, respectively. It also exhibited significant DPPH• scavenging capacity with IC50 values of 0.45 ±0.075 and 0.34 ±0.039 mg/mL and significant iron reducing capacity with EC50 of 0.358 ±0.02 and 0.28 ±0.01 mg/mL for the aqueous and hydro-ethanolic extracts, respectively. The MAE proved to be the most efficient extraction technique for the extraction of antioxidants from R. raetam twigs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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14. Determination of Sage Tea Polyphenols and Their Antioxidant Effects Using an Electrochemical DNA-Based Biosensor.
- Author
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Tomac, Ivana, Budić, Lea, Bobovec, Josipa, Jakobek, Lidija, and Matić, Petra
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POLYPHENOLS ,CARBON electrodes ,BIOSENSORS ,SAGE ,TEA - Abstract
This study describes two polyphenols, caffeic acid (CA) and (+)-catechin, as well as their antioxidant effects, detected by cyclic voltammetry (CV) using an electrochemical deoxyribonucleic acid (DNA)-based biosensor in sage tea. Square-wave voltammetry (SWV) was applied to investigate CA, as one of the derivatives of phenolic acids, and (+)-catechin, a representative of flavonoids, in sage tea. Square-wave voltammograms (SWVs) of CA showed one peak (0.197 V) and the presence of anodic and cathodic peaks, which suggests an unfolded reversible process on the surface of the glassy carbon electrode (GCE). Furthermore, SWVs of (+)-catechin showed two peaks, which proposes a reversible process at the first peak (0.232 V) and an irreversible process at the second peak (0.6 V) on the surface of the GCE. The determination of the antioxidant effects of sage tea polyphenols was carried out by a DNA-based biosensor. The obtained results indicated that the addition of sage tea to the cleavage solution significantly reduces the degree of DNA degradation. The adopted methods have proved to be simple and applicable tools for the electrochemical characterization of sage tea polyphenols and their antioxidant effects. The study also discusses total phenolic content. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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15. Increase in cysteine-mediated multimerization under attractive protein–protein interactions.
- Author
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Jakob, Leo A., Mesurado, Tomás, Jungbauer, Alois, and Lingg, Nico
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PROTEIN-protein interactions ,GEL permeation chromatography ,CHIMERIC proteins ,AMMONIUM sulfate ,DENATURATION of proteins - Abstract
The CASPON enzyme became an interesting enzyme for fusion protein processing because it generates an authentic N-terminus. However, the high cysteine content of the CASPON enzyme may induce aggregation via disulfide-bond formation, which can reduce enzymatic activity and be considered a critical quality attribute. Different multimerization states of the CASPON enzyme were isolated by preparative size exclusion chromatography and analyzed with respect to multimerization propensity and enzymatic activity. The impact of co-solutes on multimerization was studied in solution and in adsorbed state. Furthermore, protein–protein interactions in the presence of different co-solutes were measured by self-interaction chromatography and were then correlated to the multimerization propensity. The dimer was the most stable and active species with 50% higher enzymatic activity than the tetramer. Multimerization was mainly governed by a cysteine-mediated pathway, as indicated by DTT-induced reduction of most caspase multimers. In the presence of ammonium sulfate, attractive protein–protein interactions were consistent with those observed for higher multimerization when the cysteine-mediated pathway was followed. Multimerization was also observed under attractive conditions on a chromatographic stationary phase. These findings corroborate common rules to perform protein purification with low residence time to avoid disulfide bond formation and conformational change of the protein upon adsorption. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. Development of the IMP biosensor for rapid and stable analysis of IMP concentrations in fermentation broth.
- Author
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Jiang S, Lin Y, and Zheng S
- Subjects
- Escherichia coli genetics, Escherichia coli metabolism, Biosensing Techniques methods, Fermentation
- Abstract
IMP (inosinic acid) is a crucial intermediate in the purine metabolic pathway and is continuously synthesized in all cells. Besides its role as a precursor for DNA and RNA, IMP also plays a critical or essential role in cell growth, energy storage, conversion, and metabolism. In our study, we utilized the circularly permuted fluorescent protein (cpFP) and IMP dehydrogenase to screen and develop the IMP biosensor, IMPCP1. By introducing a mutation in the catalytically active site of IMPCP1, from Cys to Ala, we disrupted its ability to catalyze IMP while retaining its capability to bind to IMP without affecting the IMP concentration in the sample. To immobilize IMPCP1, we employed the SpyCatcher/SpyTag system and securely attached it to Magarose-Epoxy, resulting in the development of the IMP rapid test kit, referred to as IMPTK. The biosensor integrated into IMPTK offers enhanced stability, resistance to degradation activity, and specific recognition of IMP. It is also resistant to peroxides and temperature changes. IMPTK serves as a rapid and stable assay for analyzing IMP concentrations in fermentation broth. Within the linear range of IMP concentrations, it can be utilized as a substitute for HPLC. The IMPTK biosensor provides a reliable and efficient alternative for monitoring IMP levels, offering advantages such as speed, stability, and resistance to environmental factors., (© 2024 Wiley‐VCH GmbH.)
- Published
- 2024
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17. LC-MS/MS determination of N-acetyl-l-cysteine in chicken plasma.
- Author
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Roydeva A and Milanova A
- Subjects
- Animals, Limit of Detection, Linear Models, Liquid Chromatography-Mass Spectrometry, Reproducibility of Results, Tandem Mass Spectrometry, Acetylcysteine blood, Chickens
- Abstract
N-acetyl-l-cysteine (NAC) shows beneficial effects in cases of aflatoxicosis and heat stress in poultry but little is known about its pharmacokinetics in chickens. Therefore, the study aimed to develop and validate a sensitive LC-MS/MS analytical method for quantitative analysis of NAC in chicken plasma. A split calibration curve approach was used for determination of NAC in chicken plasma. Standard curves for low (0.05-2.5 μg/ml) and high (2.5-100 μg/ml) ranges of concentrations were prepared. The standard curves for low (r
2 = 0.9987) and high (r2 = 0.9899) concentrations were linear within the tested range. The limits of detection (LOD) and of quantification (LOQ) for the standard at low concentrations were 0.093 and 0.28 μg/ml, respectively. The accuracy was from 97.35 to 101.33%. The values of LOD and LOQ for the standard at high concentrations were 0.76 and 2.30 μg/ml, respectively. The accuracy was between 99.77 and 112.14%. The intra- and inter-day precisions for all concentrations from both standards did not exceed 8.57% and 10.69%, respectively. The recovery for all concentrations was between 92.45 and 105.52%. The validated method for determination of NAC in chicken plasma can be applied in future pharmacokinetic studies in chickens without dilution of samples and their repeated analysis., (© 2024 John Wiley & Sons Ltd.)- Published
- 2024
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18. The eel connection: Developing urban adolescents' sense of place through outdoor interactions with a local organism.
- Author
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Harris, Cornelia B., Oliveira, Alandeom W., Levy, Brett L. M., Berkowitz, Alan R., and Bowser, Chris
- Subjects
URBAN youth ,PLACE attachment (Psychology) ,AMERICAN eel ,TEENAGERS ,EELS ,RIVER ecology - Abstract
In response to growing concern about the increased disconnect between youth and their outdoor environment, this study examines how nature-based citizen science experiences with a local animal (American eels) influence urban adolescents' (high-school students) sense of place in a US city. The juvenile American eel is a unique animal due to its see-through body, small size, lengthy migratory pathway, high periodic population density, and conservation concern. Interview, written, and observational data were collected through a case study of ten high-school students during a citizen science project that lasted three months. Analyses of these data indicate that students developed greater -ecological place meaning and place attachment. Students developed greater ecological place meaning by learning more about the ecology of the river and the eels, and developed greater place attachment by developing pride and empathy. Based on these findings, we argue that nature-based citizen science programs can help environmental educators in the US foster more equitable access to nature by providing urban youth with much-needed opportunities to deeply experience local places and develop a closer and more meaningful relationship with their local environment. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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19. Influence of ultrasound‐assisted extraction techniques on the valorization of agro‐based industrial organic waste – A review.
- Author
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Buvaneshwaran, Malini, Radhakrishnan, Mahendran, and Natarajan, Venkatachalapathy
- Subjects
INDUSTRIAL wastes ,EXTRACTION techniques ,AGRICULTURAL wastes ,ORGANIC wastes ,WASTE recycling ,FARM produce - Abstract
One of the world's promising sectors is food processing. A huge amount of waste is generated during the handling and value addition of agricultural commodities. So researches focus on extracting valuable compounds from organic waste to increase the economical value. On the other hand, the amount of debris is also reduced, which helps sustainable development and carbon footprints. Extractable compounds can be used as an alternative to synthetic compounds in food applications. For this, Ultrasound‐Assisted Extraction (UAE) captures the researcher's attention because of its advantages like less solvent utilization, low‐temperature operation, and eco‐friendly end products. This review recapitulates the mechanism and the factors affecting the extraction and possibility of compounds extracted from waste. The green separation ultrasound‐aided technique has been proven to provide higher extractable compounds. Usage of water as a solvent further reduces environmental and economic problems. By considering all of these advantages, this article discusses the mechanism, elements affecting the extraction, and the effect of combination treatment on properties and the outcome of extraction. It presents the details about the application of the UAE in the valorization of waste compounds. Practical application: Food processing is one of the most promising sectors globally; the agricultural organic waste created by this sector plays a significant part in waste generation. Extracting valuable active compounds from this waste can improve the utilization of natural compounds in other foods, help obtain extra income, and help reuse industrial waste. Ultrasound‐assisted extraction is a suitable technology for extracting valuable compounds from organic waste. Optimum process conditions must be identified, which vary based on process conditions and extractable material nature to obtain the maximum extraction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Oxidative Stress Biomarker Levels of Simulated Artificial Body Fluids: Comparative HPLC-PDA and LC–MS/MS Approaches: Significance of Raw PDA and MS/MS Data for Chemometric Discrimination.
- Author
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Sengul, Ayse, Yengin, Cigdem, Egrilmez, Sait, and Kilinc, Emrah
- Subjects
BODY fluids ,OXIDATIVE stress ,CHEMOMETRICS ,LIQUID chromatography-mass spectrometry ,GRADIENT elution (Chromatography) ,AMMONIUM acetate - Abstract
HPLC-PDA, LC–MS/MS methods were developed for simultaneous determination of a group of oxidative stress biomarkers (OSBs); 2dA, 2dC, 2dU, 3NLT, 5HMU and 8OHdG in 10 simulated artificial body fluids. O-phosphoric acid and methanol composed mobile phases A and B for gradient elution in HPLC-PDA using ODS-2 column. Linearity obtained for 1.0×10
−6 –1.0×10−4 M range. LODs were 1.73×10−6 , 1.19×10−6 , 2.59×10−6 , 1.40×10−6 , 2.21×10−6 and 4.07×10−6 M for 2dU, 8OHdG, 2dA, 2dC, 5HMU and 3NLT, respectively. LOQs were 5.29×10−6 , 4.02×10−6 , 6.82×10−6 , 4.02×10−6 , 6.82×10−6 and 9.92×10−6 M. About 10 mM aqueous ammonium acetate solution and methanol containing 0.1% (v/v) formic acid composed mobile phases A and B for gradient elution in LC–MS/MS. Linearity obtained for 1.0×10−8 –1.0×10−6 M range. LODs were 2.88×10−10 , 1.01×10−8 , 3.38×10−9 , 1.36×10−7 , 1.81×10−7 and 1.40×10−8 M for 2dU, 8OHdG, 2dA, 2dC, 5HMU and 3NLT, respectively. LOQs were 9.37×10−10 , 3.22×10−8 , 1.91×10−8 , 4.53×10−7 , 5.90×10−7 and 2.18×10−8 M. Both methods were validated using ICH Q2(R1) guideline. Specificity, linearity, range, accuracy, precision, reproducibility, LOD, LOQ and recovery were achieved. Chemometric analysis was performed on raw PDA and MS data to check their significance for discrimination of OSBs. Sets of single and triple quadrupole fragmentations were evaluated for principle component analysis. Chosen number of PCs successfully distinguished OSBs of interest. [ABSTRACT FROM AUTHOR]- Published
- 2023
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21. Comparative Analysis of the Interaction between the Antiviral Drug Umifenovir and Umifenovir Encapsulated in Phospholipids Micelles (Nanosome/Umifenovir) with dsDNA as a Model for Pharmacogenomic Analysis by Electrochemical Methods.
- Author
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Shumyantseva, Victoria V., Bulko, Tatiana V., Agafonova, Lyubov E., Pronina, Veronika V., and Kostryukova, Lyubov V.
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ELECTROCHEMICAL analysis ,ANTIVIRAL agents ,MICELLES ,GIBBS' free energy ,PHOSPHOLIPIDS ,CARBON electrodes - Abstract
In the present study, the electrochemical behavior of antiviral drug umifenovir (Umi) and umifenovir encapsulated in phospholipids micelles (nanosome/umifenovir, NUmi) were investigated for the first time on screen-printed electrodes modified by carbon nanotubes. We have shown that Umi can be electro oxidized around the potential of +0.4 V in the concentration range of 50–500 µM (R
2 = 0.992). Non-overlapping signatures of DNA and umifenovir (10–150 µM) permit to register interaction between umifenovir (or umifenovir encapsulated in phospholipids micelles), purine, and pyrimidine heterocyclic bases of DNA separately. The type of interaction is most likely via electrostatic interactions and groove binding in drug-DNA formed complex, as was revealed based on the values of binding constants Kb and the cathodic shifts of oxidation potentials for heterocyclic bases with increasing Umi or NUmi concentration. The negative values of Gibbs free energy (ΔG) for all nucleobases confirm the process spontaneity. This study is the first one presenting the effect of antiviral drug umifenovir and umifenovir encapsulated in phospholipids micelles on dsDNA as a target of pharmacogenomics. [ABSTRACT FROM AUTHOR]- Published
- 2023
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22. Environmental Applications of Immobilized and Bio-Resourced Redox Mediators: A Review.
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Wenrui Guo and Jingang Huang
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OXIDATION-reduction reaction ,THERAPEUTIC immobilization ,BIOGEOCHEMICAL cycles ,WATER pollution ,WASTEWATER treatment - Abstract
Redox mediators (RMs), also known as electron shuttles, have been widely reported to promote both biotic and abiotic reductions of oxidized pollutants in water, soil, biogeochemical cycles, and wastewater treatment systems. However, the continuous addition of dissolved RMs is unaffordable and the potential environmental risks remain unknown because most applied RMs are synthetic chemicals. Immobilization technology enables RMs to be attached on non-dissolved supports, avoiding wash-out from the treatment systems. This realizes the reuse of RMs in scaled-up engineering applications and the in-situ remediation. Moreover, renewable natural biomass and their derivatives, such as biochar, have also aroused increased interest because they provide an economical and feasible way to solve the shortcomings of applying soluble RMs. This review presents different RM immobilization methods, which include entrapment, adsorption, and surface modification, as well as the use of bio-resourced RMs. The immobilization procedures and reaction mechanisms of the immobilized RMs and bio-resourced RMs in environmental applications are critically compared and summarized. [ABSTRACT FROM AUTHOR]
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- 2023
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23. Electrochemical Analysis in Studying β-Amyloid Aggregation.
- Author
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Suprun, Elena V., Radko, Sergey P., Kozin, Sergey A., Mitkevich, Vladimir A., and Makarov, Alexander A.
- Abstract
β-amyloid (Aβ) is comprised of a group of peptides formed as a result of cleavage of the amyloid precursor protein by secretases. Aβ aggregation is considered as a central event in pathogenesis of Alzheimer’s disease, the most common human neurodegenerative disorder. Molecular mechanisms of Aβ aggregation have intensively being investigated using synthetic Aβ peptides by methods based on monitoring of aggregates, including determination of their size and structure. In this review, an orthogonal approach to the study of Aβ aggregation is considered, which relies on electrochemical registration of the loss of peptide monomers. Electrochemical analysis of Aβ (by voltammetry and amperometric flow injection analysis) is based on registration of the oxidation signal of electroactive amino acid residues of the peptide on an electrode surface. The Aβ oxidation signal disappears, when the peptide is included in the aggregate. The advantages and disadvantages of electrochemical analysis for the study of spontaneous and metal-induced aggregation of Aβ, comparative analysis of various peptide isoforms, and study of the process of complexation of metal ions with the metal-binding domain of Aβ are discussed. It is concluded that the combined use of the electrochemical method and the methods based on detection of Aβ aggregates makes it possible to obtain more complete information about the mechanisms of peptide aggregation. [ABSTRACT FROM AUTHOR]
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- 2023
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24. Electrochemical Sensors for the Detection of Chemical Warfare Agents: Strategy and Exemples.
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Stoian, Ioan-Adrian, Moşteanu, Dănuț-Eugeniu, and Ilie, Florin Vasile
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CHEMICAL warfare ,ELECTROCHEMICAL analysis ,WORLD War I ,BIOSENSORS ,ROBUST control - Abstract
Since the addition of chemical warfare agents (CWAs) in the World War I, there has been a constant demand for the development of rapid and accurate analytical instruments for detecting and identifying these agents. The most common techniques used in CWAs determination are spectroscopic and chromatographic techniques. Although they possess remarkable robustness, they require prolonged analysis time, experienced personnel, expensive instrumentation and are not fit for on-field applications and fast early alert. Fortunately, electrochemical sensors represent a viable alternative due to their, simple instrumentation, high sensitivity and low cost. The aim of this article is to highlight some important aspects of electrochemical sensing and to present some electrochemical sensors developed for CWAs detection. The future perspectives and challenges in electrochemical sensor development for CWAs detection is also discussed. [ABSTRACT FROM AUTHOR]
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- 2022
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25. Nanoscale physical parameters of source rocks identified by atomic force microscopy: A review.
- Author
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Liu, Yanhai, Zou, Guangui, She, Jiasheng, Deng, Bowen, and Yang, Hao
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ATOMIC force microscopy ,ROCK properties ,THREE-dimensional imaging ,ACQUISITION of property ,SURFACE analysis ,SHALE gas ,NANOPORES - Abstract
The refinement of nanoscale physical parameters of source rocks has benefitted from continuous innovations in technology and methods. Traditional methods for detecting reservoir physical properties are limited by the properties of the instruments. Atomic force microscopy (AFM) provides new methods and approaches for furthering our understanding and exploring the nanoscale world. Its wide range of applications and gradually developed multiscenario application modes make it an ideal tool for the characterization of nanoscale physical properties of source rocks (coal, shale, mudstone, sandstone, etc.). We highlight the advantages of AFM in regard to performing nondestructive 3D imaging and mechanical property measurements with nanoscale resolution in any desired environment (air, vacuum, liquid). The limitations of AFM applied to source rocks are also summarized. The process has great potential in micro/nanopore characterization, surface morphology characterization, in situ micromechanical property acquisition, wettability research, and so on. The gradual development and improvement of this new model will expand new methods, bring enlightenment to basic research on unconventional oil and gas resources, and provide a scientific basis for the exploration and development of unconventional oil and gas resources. [ABSTRACT FROM AUTHOR]
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- 2022
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26. Insight into the binding mechanism of macrolide antibiotic; erythromycin to calf thymus DNA by multispectroscopic and computational approaches.
- Author
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Shahabadi, Nahid and Razlansari, Mahtab
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- 2022
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27. Study of Novel Peptides for Antimicrobial Protection in Solution and on Cotton Fabric.
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Todorov, Petar, Georgieva, Stela, Staneva, Desislava, Peneva, Petia, Grozdanov, Petar, Nikolova, Ivanka, Vasileva-Tonkova, Evgenia, and Grabchev, Ivo
- Subjects
COTTON ,ANTIMICROBIAL peptides ,COTTON textiles ,COTTON fibers ,TEXTILE fibers ,PEPTIDES ,NIACIN ,NATURAL dyes & dyeing - Abstract
Some new N- and C-modified biomolecular peptide analogues of both VV-hemorphin-5 and VV-hemorphin-7 with varied amino acids (Cys, Glu, His), 1-adamantanecarboxylic acid, and niacin (nicotinic acid) were synthesized by solid-phase peptide synthesis—Fmoc (9-fluorenylmethoxy-carbonyl) chemistry and were characterized in water solutions with different pH using spectroscopic and electrochemical techniques. Basic physicochemical properties related to the elucidation of the peptide structure at physiological pH have been also studied. The results showed that the interaction of peptide compounds with light and electricity preserves the structural and conformational integrity of the compounds in the solutions. Moreover, textile cotton fibers were modified with the new compounds and the binding of the peptides to the surface of the material was proved by FTIR and SEM analysis. Washing the material with an alkaline soap solution did not show a violation of the modified structure of the cotton. Antiviral activity against the human respiratory syncytial virus (HRSV-S2) and human adenovirus serotype 5 (HAdV-5), the antimicrobial activity against B. cereus and P. aeruginosa used as model bacterial strains and cytotoxic effect of the peptide derivatives and modified cotton textile material has been evaluated. Antimicrobial tests showed promising activity of the newly synthesized compounds against the used Gram-positive and Gram-negative bacteria. The compounds C-V, H-V, AC-V, and AH-V were found slightly more active than NH7C and NCH7. The activity has been retained after the deposition of the compounds on cotton fibers. [ABSTRACT FROM AUTHOR]
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- 2022
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28. Assessment of the Antioxidant Activity of Catechin in Nutraceuticals: Comparison between a Newly Developed Electrochemical Method and Spectrophotometric Methods.
- Author
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Munteanu, Irina Georgiana and Apetrei, Constantin
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CATECHIN ,GOLD nanoparticles ,CARBON nanotubes ,FUNCTIONAL foods ,AMINO group ,ANTIOXIDANT analysis ,PLEUROTUS ostreatus - Abstract
The analysis of antioxidants in different foodstuffs has become an active area of research, which has led to many recently developed antioxidant assays. Many antioxidants exhibit inherent electroactivity, and, therefore, the use of electrochemical methods could be a viable approach for evaluating the overall antioxidant activity of a matrix of nutraceuticals without the need for adding reactive species. Green tea is believed to be a healthy beverage due to a number of therapeutic benefits. Catechin, one of its constituents, is an important antioxidant and possesses free radical scavenging abilities. The present paper describes the electrochemical properties of three screen-printed electrodes (SPEs), the first one based on carbon nanotubes (CNTs), the second one based on gold nanoparticles (GNPs) and the third one based on carbon nanotubes and gold nanoparticles (CNTs-GNPs). All three electrodes were modified with the laccase (Lac) enzyme, using glutaraldehyde as a cross-linking agent between the amino groups on the laccase and aldehyde groups of the reticulation agent. As this enzyme is a thermostable catalyst, the performance of the biosensors has been greatly improved. Electro-oxidative properties of catechin were investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), and these demonstrated that the association of CNTs with GNPs significantly improved the sensitivity and selectivity of the biosensor. The corresponding limit of detection (LOD) was estimated to be 5.6 × 10
−8 M catechin at the CNT-Lac/SPE, 1.3 × 10−7 M at the GNP-Lac/SPE and 4.9 × 10−8 M at the CNT-GNP-Lac/SPE. The biosensors were subjected to nutraceutical formulations containing green tea in order to study their catechin content, using CNT-GNP-Lac/SPE, through DPV. Using a paired t-test, the catechin content estimated was in agreement with the manufacturer's specification. In addition, the relationship between the CNT-GNP-Lac/SPE response at a specific potential and the antioxidant activity of nutraceuticals, as determined by conventional spectrophotometric methods (DPPH, galvinoxyl and ABTS), is discussed in the context of developing a fast biosensor for the relative antioxidant activity quantification. [ABSTRACT FROM AUTHOR]- Published
- 2022
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29. QTOF-ESI MS Characterization and Antioxidant Activity of Physalis peruviana L. (Cape Gooseberry) Husks and Fruits from Costa Rica.
- Author
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Navarro-Hoyos, Mirtha, Arnáez-Serrano, Elizabeth, Quirós-Fallas, María Isabel, Vargas-Huertas, Felipe, Wilhelm-Romero, Krissia, Vásquez-Castro, Felipe, Alvarado-Corella, Diego, and Sánchez-Kopper, Andrés
- Subjects
CAPE gooseberry ,FRUIT ,ESTER derivatives ,PRINCIPAL components analysis ,METABOLITES - Abstract
There is increasing interest in research of secondary metabolites from Physalis peruviana (Cape gooseberry) because of their potential bioactivities. In this study, the profile of compounds found in fruits and husks from Costa Rica was determined through ultra-performance liquid chromatography coupled with high-resolution mass spectrometry using a quadrupole time-of-flight analyzer (UPLC-ESI-QTOF MS) on extracts (n = 10) obtained through pressurized liquid extraction (PLE) conditions. In total, 66 different compounds were identified, comprising 34 withanolides, 23 sucrose ester derivatives and 9 flavonoids. UPLC-DAD analysis was performed to determine the β-carotene in fruits and to quantify the flavonoids in all 10 samples, with the results showing higher contents in samples from the Dota region (58.6–60.1 μg/g of dry material versus 1.6–2.8 mg/g of dry material). The Folin–Ciocalteau total polyphenolic content (FC) and antioxidant activity using the DPPH method showed better results for the husk extracts, with the ones from the Dota region holding the best values (4.3–5.1 mg GAE/g of dry material versus IC
50 = 1.6–2.3 mg of dry material/mL). In addition, a significant negative correlation was found between the RU, FC and DPPH values (r = −0.902, p < 0.05), aligning with previous reports on the role of polyphenols in antioxidant activity. Principal correlation analysis (PCoA) and hierarchical clustering (HC) analysis were performed on HRMS results, and they indicated that the D1 and D2 fruit samples from the Dota region were clustered with husks related to a higher presence of the analyzed metabolites. In turn, principal component analysis (PCA) performed on the flavonoid content and antioxidant activity yielded results indicating that the D1 and D2 husks and fruit samples from the Dota region stood out significantly, showing the highest antioxidant activity. In summation, our findings suggest that P. peruviana husks and fruits from Costa Rica constitute a substrate of interest for further studies on their potential health benefits. [ABSTRACT FROM AUTHOR]- Published
- 2022
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30. In Vitro Antioxidant and Prooxidant Activities of Red Raspberry (Rubus idaeus L.) Stem Extracts.
- Author
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Garjonyte, Rasa, Budiene, Jurga, Labanauskas, Linas, and Judzentiene, Asta
- Subjects
RUBUS ,RASPBERRIES ,GALLIC acid ,EXTRACTS ,TRADITIONAL medicine - Abstract
Leaves and stems of red raspberry (Rubus idaeus) are used in Lithuanian folk medicine. Healing properties of raspberry are related to the content of bioactive compounds, mainly polyphenols. Extracts of raspberry leaves contained higher total phenolic content (TPC) (1290 mg/L, expressed in gallic acid equivalent) compared to that in extracts of stems or peeled bark (up to 420 mg/L and 598 mg/L, respectively). To find out whether the collection time of herbal material was critical for the properties of the extracts, the stems were collected at different times of the year. TPC in the extracts depended more on extraction conditions rather than on the sampling time. Antioxidant activity of raspberry stem and bark extracts tested by spectrophotometric (DPPH
● scavenging) and electrochemical (cyclic and differential pulse voltammetry) assays correlated with TPC. DPPH radical scavenging activity values for stem, leaf, and bark extracts were as follows: ≤1.18 ± 0.07, 1.63 ± 0.10, and ≤1.90 ± 0.04 (mmol/L, TROLOX equivalent), respectively. Assessed electrochemically, hydrogen peroxide-scavenging activity of extracts was independent on TPC. The latter activity was related to the presence of some protein in the extract as revealed by gel electrophoresis. Prooxidant activity of raspberry stem extracts was dependent on solution pH and temperature. [ABSTRACT FROM AUTHOR]- Published
- 2022
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31. Heterophase Synthesis of Humic Substances at Low Substrate Concentrations and Flow-Through Conditions.
- Author
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Zavarzina, A. G., Demin, V. V., Belova, O. V., Leontievsky, A. A., and Lisov, A. V.
- Subjects
HUMUS ,HIGH performance liquid chromatography ,KAOLINITE ,PHENOLIC acids ,MOLECULES ,ORGANIC compounds - Abstract
Humic substances (HS) are heterogeneous and polydisperse compounds formed in soils, sediments and waters during the decay and transformation of organic residues (the process called humification). The role of extracellular free-radical condensation reactions (secondary synthesis) in the formation of HS is a subject of debate. Here we have studied the formation of HS from a mixture of monomers under the dynamic conditions and at low substrate concentrations in the presence of laccase from the fungus Coprinus comatus F-2940. Laccase was immobilized on kaolinite modified with aluminum hydroxide. We have investigated some properties of the enzyme, reactivity of phenolic acids and amino acids in the presence of laccase. The optimum of 2.6-dimethoxyphenol (2.6-DMP) oxidation by free laccase was at pH 6.0. Upon immobilization, it shifted to the acidic region (pH 4.4), the thermal stability decreased, however the kinetic parameters of 2.6-DMP oxidation remained unchanged. In terms of reactivity (% of substrate conversion by free laccase) the individual phenolic acids formed a series: caffeic (72) > ferulic (53) > gallic = syringic (43) > protocatechuic (5.5) > vanillic = p-hydroxybenzoic (0). In the mixture of phenolic acids, gallic acid was most efficiently oxidized (50%), while the other acids were oxidized in comparable amounts (13–17%). The conversion of phenolic acids increased in the presence of lysine. When a mixture of gallic, protocatechuic, syringic, ferulic acids (0.01 mM each) and lysine (0.02 mM) was passed through a flow-through microcolumn, immobilized laccase effectively oxidized the phenolic acids, the reaction products bound to the mineral phase, staining it dark. According to high performance liquid chromatography, the molecular weights of compounds extracted from the mineral phase did not exceed 900 Da, thus fulvic acid-like substances were formed. Results of the study suggest an important role of free-radical heterophase reactions in the formation of the molecular composition of the liquid phase and organo-mineral complexes. [ABSTRACT FROM AUTHOR]
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- 2022
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32. Synthesis, characterization and in vitro cytotoxicity studies of novel Cu(II) complex containing zonisamide drug: DNA interaction by multi spectroscopic and molecular docking methods.
- Author
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Shahabadi, Nahid and Razlansari, Mahtab
- Published
- 2022
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33. Aβ1–40 Oligomers Trigger Neutrophil Extracellular Trap Formation through TLR4- and NADPH Oxidase-Dependent Pathways in Age-Related Macular Degeneration.
- Author
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Chen, Jinquan, Zhao, Long, Ding, Xuanheng, Wen, Yan, Wang, Lingda, Shu, Qinxin, Xie, Wenxi, Liu, Yanyao, and Peng, H.
- Published
- 2022
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34. A Review on Recent Advances in the Applications of Boron-Doped Diamond Electrochemical Sensors in Food Analysis.
- Author
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Sarakhman, Olha and Švorc, Ľubomír
- Subjects
ELECTROCHEMICAL sensors ,SCIENTIFIC literature ,FLOW injection analysis ,FLAVOR ,ORGANIC foods ,HIGH performance liquid chromatography ,FOOD chemistry ,CHEMICAL properties - Abstract
The usage of boron-doped diamond (BDD) material has found to be very attractive in modern electroanalytical methods and received massive consideration as perspective electrochemical sensor due to its outstanding (electro)chemical properties. These generally known facilities include large potential window, low background currents, ability to withstand extreme potentials and strong tendency to resist fouling compared to conventional carbon-based electrodes. As evidence of superiority of this material, couple of reviews describing the overview of various applications of BDD electrodes in the field of analytical and material chemistry has been reported in scientific literature during last decade. However, herein proposed review predominantly focuses on the most recent developments (from 2009 to 2020) dealing with the application of BDD as an advanced and environmental-friendly sensor platform in food analysis. The main method characteristics of analysis of various organic food components with different chemical properties, including additives, flavor and aroma components, phenolic compounds, flavonoids and pesticides in food matrices are described in more details. The importance of BDD surface termination, presence of sp
2 content and boron doping level on electrochemical sensing is discussed. Apart from this, a special attention is paid to the evaluation of main analytical characteristics of the BDD electrochemical sensor in single- and multi-analyte detection mode in food analysis. The recent achievements in the utilizing of BDD electrodes in amperometric detection coupled to flow injection analysis, batch injection analysis, and high-performance liquid chromatography are also commented. Moreover, actual trends in sample preparation techniques prior to electrochemical sensing in food analysis are referred. [ABSTRACT FROM AUTHOR]- Published
- 2022
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35. Recent advancements in conducting polymer bionanocomposites and hydrogels for biomedical applications.
- Author
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Idumah, Christopher Igwe
- Subjects
CONDUCTING polymers ,HYDROGELS ,AGRICULTURAL engineering ,TISSUE scaffolds ,BIOMEDICAL materials ,BIODEGRADABLE plastics ,BIOMATERIALS ,BIOCOMPATIBILITY - Abstract
Recently electrically conducting polymeric bionanocomposites (ECPBs) have emerged as materials for use in biomedical, food and agricultural engineering due to their inherently plastic and biodegradable nature. ECPBs display biocompatibility, unique architecture, biodegradability, and so on, thereby improving their performance and opening novel horizons in their applicability especially in tissue engineering scaffolds, drug-conveying devices, and electrochemical biosensors and so on. In tissue engineering field, conductive hydrogels (CH) are biomaterials efficiently mimicking biologically and electrically inclined behavior of tissues in the human system. Therefore, this paper elucidates recently emerging trends in ECPBs, CH, novel applications in the biomedical field, and other relevant areas. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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36. Current Advances in Electrochemical Biosensors and Nanobiosensors.
- Author
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Bakirhan, Nurgul K., Topal, Burcu D., Ozcelikay, Goksu, Karadurmus, Leyla, and Ozkan, Sibel A.
- Subjects
BIOSENSORS ,POINT-of-care testing ,GLUCOSE oxidase ,HUMAN migration patterns ,ULTRAVIOLET spectrophotometry - Abstract
Electrochemical biosensors have wider interest in the last decades than other analytical techniques such as chromatography, spectrophotometry, fluorescence, migration techniques and flow systems. Since they provide practicality, sensitivity, and fast response, these systems can be integrated with labs-on-chips to obtain excellent point of care analytical platforms. They are excellent devices for wide range of analytes such as drugs, proteins, markers, bacteria, and viruses etc. due to their unique features. Electrochemical methods are also successful at molecular recognition, user friendliness, sensitive responses, requirement of small volume reactive of reagents, low cost, and applicability to point of care tests. DNA, enzyme and immunosensor based biosensors are widely used as well. According to recent studies of electrochemical biosensors, nanomaterials and polymers have been used to increase the performance of biosensors. In this review, the recent studies of electrochemical biosensors have been presented with their applications at various fields. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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37. The physicochemical and DNA binding studies of some medicinal compounds in solutions.
- Author
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Khan, Abbas, Naila, Humayun, Muhammad, Khan, Muhammad Sufaid, Shah, Luqman Ali, Malik, Abdul, and Sultana, Sabiha
- Subjects
CIPROFLOXACIN ,THERMODYNAMICS ,DNA ,MOLECULAR size ,MOLECULAR volume ,CRITICAL micelle concentration ,SURFACE tension measurement ,MOLECULAR shapes - Published
- 2022
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38. Poly(Thionine)-Modified Screen-Printed Electrodes for CA 19-9 Detection and Its Properties in Raman Spectroscopy.
- Author
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Castaño-Guerrero, Yuselis, Romaguera-Barcelay, Yonny, Moreira, Felismina Teixeira Coelho, Brito, Walter Ricardo, Fortunato, Elvira, and Sales, Maria Goreti Ferreira
- Subjects
RAMAN spectroscopy ,THIONINE ,ELECTROACTIVE substances ,ELECTRODES ,GOLD films ,SERS spectroscopy - Abstract
Polythionine (PTH) is an electroactive compound known for its excellent electron transfer capacity. It has stable and redox centers in its structure, and it can also be generated by electropolymerization of thionine (TH). Due to its properties, it has been used in a large number of applications, including the construction of electrochemical biosensors. In this work, PTH is explored for its ability to generate electrons, which allows it to act as an electrochemical probe in a biosensor that detects CA 19-9 on two different substrates, carbon and gold, using differential pulse voltammetry (DPV) as a reading technique in phosphate buffer (PhB). The analytical features of the resulting electrodes are given, showing linear ranges from 0.010 to 10 U/mL. The Raman spectra of PTH films on gold (substrates or nanostars) and carbon (substrates) are also presented and discussed as a potential use for SERS readings as complementary information to electrochemical data. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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39. ASPECTOS METABÓLICOS DAS CATEQUINAS NA OBESIDADE E DOENÇAS CARDIOVASCULARES.
- Author
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de Paiva Sousa, Mickael, Aquino Brito, Joyce Sousa, Barbosa de Abreu, Bruna, do Nascimento Marreiro, Dilina, de Azevedo Paiva, Adriana, dos Reis Moreira-Araújo, Regilda Saraiva, Resende Gonçalves de Carvalho, Cecilia Maria, de Carvalho e Martins, Maria do Carmo, and Gonçalves Frota, Karoline de Macedo
- Subjects
HYDROPHILIC compounds ,GREEN tea ,TEA ,OXIDANT status ,FOOD consumption ,CATECHIN ,EPICATECHIN ,PLANT polyphenols - Abstract
Copyright of Revista Brasileira de Obesidade, Nutrição e Emagrecimento is the property of Instituto Brasileiro de Pesquisa e Ensino em Fisiologia do Exercicio and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
40. Sustainable application of electrocatalytic and photo-electrocatalytic oxidation systems for water and wastewater treatment: a review.
- Author
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Farissi S, Abubakar GA, Akhilghosh KA, Muthukumar A, and Muthuchamy M
- Subjects
- Wastewater, Waste Disposal, Fluid, Water analysis, Retrospective Studies, Environmental Monitoring, Oxidation-Reduction, Water Purification, Water Pollutants, Chemical analysis
- Abstract
Wastewater treatment and reuse have risen as a solution to the water crisis plaguing the world. Global warming-induced climate change, population explosion and fast depletion of groundwater resources are going to exacerbate the present global water problems for the forthcoming future. In this scenario, advanced electrochemical oxidation process (EAOP) utilising electrocatalytic (EC) and photoelectrocatalytic (PEC) technologies have caught hold of the interest of the scientific community. The interest stems from the global water management plans to scale down centralised water and wastewater treatment systems to decentralised and semicentralised treatment systems for better usage efficiency and less resource wastage. In an age of rising water pollution caused by contaminants of emerging concern (CECs), EC and PEC systems were found to be capable of optimal mineralisation of these pollutants rendering them environmentally benign. The present review treads into the conventional electrochemical treatment systems to identify their drawbacks and analyses the scope of the EC and PEC to mitigate them. Probable electrode materials, potential catalysts and optimal operational conditions for such applications were also examined. The review also discusses the possible retrospective application of EC and PEC as point-of-use and point-of-entry treatment systems during the transition from conventional centralised systems to decentralised and semi-centralised water and wastewater treatment systems., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
- Published
- 2023
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41. A first-principles DFT study on the adsorption behaviour of CO, CO2, and O3 on pristine B24N24 and silicon-decorated B24N24 nanosheet.
- Author
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Hasan, Md. Mehade, Kabir, Md. Humaun, Badsha, Md. Alamgir, and Hossain, Md. Rakib
- Subjects
ADSORPTION (Chemistry) ,GAS detectors ,REDSHIFT ,DIPOLE moments ,ADSORBATES - Abstract
Using first-principles within density functional (DFT) theory, adsorption of CO, CO
2 , and O3 gas molecules on pristine B24 N24 (BN) and Silicon-decorated B24 N24 (SiBN) nanosheets has been investigated. Adsorption energies, Mulliken charge, dipole moments, and global indicies are estimated to predict the adsorption behavior of CO, CO2 , and O3 by using DFT method at 6-31 G (d, p)/B3LYP level. After silicon doping, unlike CO and CO2 , sensing performance improves for the case of O3 . The findings reveal that the interaction between O3 and SiBN is stronger than that between O3 and bare BN, suggesting that silicon helps to strengthen the interaction of O3 molecule with BN nanosheet. DFT calculations clearly indicate that the Si-doped BN nanosheet would be a promising O3 gas sensor. To prove the successful interactions among the adsorbents (BN and SiBN) and adsorbates (CO, CO2 , and O3 ), the UV-vis spectra have been analyzed for every system where both the blue shift and red shift have been confirmed. Finally, it can be said that pristine BN nanosheet is a better sensor than SiBN for CO, CO2 gas molecules while SiBN is better for O3 molecules. [ABSTRACT FROM AUTHOR]- Published
- 2022
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42. Progress in the Development of Electrodeposited Catalysts for Direct Liquid Fuel Cell Applications.
- Author
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Maniam, Kranthi Kumar, Chetty, Raghuram, Thimmappa, Ravikumar, and Paul, Shiladitya
- Subjects
LIQUID fuels ,CATALYSTS ,ECONOMIC forecasting ,PRECIOUS metals ,FOSSIL fuels ,CATALYST supports ,ELECTROCHEMICAL sensors ,FUEL cells - Abstract
Fuel cells are a key enabling technology for the future economy, thereby providing power to portable, stationary, and transportation applications, which can be considered an important contributor towards reducing the high dependencies on fossil fuels. Electrocatalyst plays a vital role in improving the performance of the low temperature fuel cells. Noble metals (Pt, Pd) supported on carbon have shown promising performance owing to their high catalytic activity for both electroreduction and electrooxidation and have good stability. Catalyst preparation by electrodeposition is considered to be simple in terms of operation and scalability with relatively low cost to obtain high purity metal deposits. This review emphasises the role of electrodeposition as a cost-effective method for synthesising fuel cell catalysts, summarising the progress in the electrodeposited Pt and Pd catalysts for direct liquid fuel cells (DLFCs). Moreover, this review also discusses the technological advances made utilising these catalysts in the past three decades, and the factors that impede the technological advancement of the electrodeposition process are presented. The challenges and the fundamental research strategies needed to achieve the commercial potential of electrodeposition as an economical, efficient methodology for synthesising fuel cells catalysts are outlined with the necessary raw materials considering current and future savings scenario. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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43. Recent Analytical Methodologies for the Determination of Omeprazole and/or Its Active Isomer Esomeprazole in Different Matrices: A Critical Review.
- Author
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El-Kimary, Eman I. and Ragab, Marwa A. A.
- Subjects
OMEPRAZOLE ,ESOMEPRAZOLE ,CHIRAL drugs ,ISOMERS ,PHARMACOKINETICS ,ENANTIOMERS ,DRUG interactions - Abstract
The presented work comprehensively discusses omeprazole (OMZ) and its S-active isomer (esomeprazole, ESZ) different methods of analysis indexed in Web of science, Scopus and Pub-med from 2016 till now. Chromatographic methods with different detectors each to fulfill the aim of the analysis were discussed. These chromatographic methods aimed to analyze OMZ and ESZ in biological fluids in presence of other drugs and metabolites for studying drug kinetics or drug-drug interaction and enzyme polymorphism. Moreover, in-vitro chromatographic methods were discussed for analyzing OMZ and ESZ in pharmaceuticals alone or in presence of other drugs. In addition, different chiral chromatographic methods separating the two enantiomers of OMZ (R-OMZ and ESZ) alone or with other chiral drugs or chiral impurities have been thoroughly discussed where no previous reviews have dealt with the chiral separation methods for OMZ and ESZ. Also, environmental analysis of OMZ and ESZ in various environmental samples was found as they are from the most popular drugs used and there is a high incidence that they may be present in wastewater. Moreover, reported spectroscopic and electrochemical methods for OMZ and ESZ analysis were discussed showing the structural features of OMZ/ESZ that lead to their successful analysis using spectroscopy and electrochemistry. Finally, the important figures of merit of all the discussed articles are shown in comprehensive tables and the article comprises 4 sections (chromatographic, electrochemical, spectroscopic and miscellaneous methods) and 7 tables. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. Progress in the Pretreatment and Analysis of Flavonoids: An Update since 2013.
- Author
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Bian, Yu, Zhang, Yuan, Zhou, Yu, Li, Guo-Hui, and Feng, Xue-Song
- Subjects
SUPERCRITICAL fluid chromatography ,FLAVONOIDS ,SOLID phase extraction ,LIQUID-liquid extraction ,CHINESE medicine ,LIQUID chromatography - Abstract
Flavonoids, among the major bioactive ingredients in many traditional Chinese medicines, have been widely considered due to their pharmacological and biochemical effects: antioxidant, anti-vascular disease and anti-inflammatory effects. To get a better understanding of the role of flavonoids in medicine, food safety and public health, valid and sensitive methods for their pretreatment and determination in different matrices are necessary. This review provides a comprehensive summary of flavonoid pretreatment and analytical methods in different samples since 2013. Pretreatment technologies include simple methods: precipitation protein and acid hydrolysis, and more elaborated ones: solid-liquid extraction, liquid-liquid extraction, solid-phase extraction, matrix solid phase dispersion, and different micro-extraction methods. Determination methods include liquid chromatography, gas chromatography, supercritical fluid chromatography, and electrochemical methods. Moreover, we discuss and compare the strengths and weaknesses of the different pretreatment and analytical methods and suggest a prospect. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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45. Chemical fingerprinting, quantification, and antioxidant activity evaluation of Osmanthus fragrans (Thunb.) Lour. Flowers by UPLC-ECD.
- Author
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Wang, Ming-Yang, Zhang, Ping, Zhang, Yu-Zhu, Yuan, Xiao-Yan, and Chen, Rong-Xiang
- Subjects
CHEMICAL fingerprinting ,GREY relational analysis ,OXIDANT status ,PHENOLS ,FLOWERS ,SPECTROPHOTOMETRY ,ELECTROACTIVE substances ,PHENOL content of food - Abstract
Osmanthus fragrans (Thunb.) Lour. flowers are important natural resource of phenolic compounds, which have antioxidant activities and have been consumed as functional food and dietary supplements for thousand years. Ultra-performance liquid chromatography coupled with electrochemical detection (UPLC-ECD) was developed to simultaneously analyze the eight phenolic compounds in Osmanthus fragrans flowers collected from different regions across China. The UPLC-ECD fingerprint was established for identification and comprehensive quality control. The antioxidant capacities of Osmanthus fragrans flowers were evaluated, and results were compared with those spectrophotometric antioxidant methods. A highly positive relationship was confirmed between the total peak area of characteristic components in chromatogram and the antioxidant potential determined by spectrophotometry with correlation coefficient greater than 0.80 (p <.01). Grey relational analysis showed that acteoside had the highest degree of correlation with antioxidant capacity. These results provided evidence to support the use of UPLC-ECD as a simple, rapid, and reliable method for electroactive phenolic component determination and antioxidant capacity quantification in vitro system. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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46. Antimicrobial activity of Lafoensia pacari phenolics-containing extract against common bean phytopathogens.
- Author
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Nogueira de Souza, Waléria Ramos, da Silva Vaz, Priscila Dias, Wendland, Adriane, de Carvalho Barros Cortes, Marcio Vinicius, and Freitas Bara, Maria Teresa
- Subjects
ANTHRACNOSE ,COMMON bean ,ANTI-infective agents ,MACROPHOMINA phaseolina ,BACTERIAL growth ,FUSARIUM oxysporum ,PHENOLS ,XANTHOMONAS - Abstract
Copyright of Agricultural Research in the Tropics / Pesquisa Agropecuária Tropical is the property of Pesquisa Agropecuaria Tropical and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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47. Selective Oxidation of L-Methionine, L-Ethionine, N-Acetyl-L-Methionine, L-Buthionine Catalyzed by [FeIII-Salen]Cl Complexes: A Spectral, Kinetic, and Electrochemical Study.
- Author
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Karuppasamy, Periyakaruppan
- Abstract
This present study aims to report the spectral, kinetic, and electrochemical results of the selective oxidation of substrates such as L-methionine (I), L-ethinonine (II), L-buthionine (III), and N-acetyl-L-methionine (IV) with [O=Fe
IV -salen] oxidant species 1a–5a in aqueous CH3 CN under biological conditions. Reactions between oxidants and the substrates follow saturation kinetics (Michalis-Menton type), and this reaction is very sensitive with the substituents present in salen ligand of the complex, structure of substrates I–IV, the effects of pH, substrate concentration, the polarity of the solvent, and temperature. The [O=FeIV -salen] oxidant species is confirmed by spectral and electrochemical techniques. The positive reaction constants (ρ = 0.79–0.90) are obtained from the plot of rate constant (k) values versus substituent constants (σ) values, which indicates the development of negative charge in the transition state (TS). The formation of the product during the course of reaction is analyzed by FT-IR, ESI-MS, and1 H-NMR techniques. Based on the experimental evidences a plausible electron transfer (ET) and oxygen atom transfer (OAT) mechanisms have been proposed. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
48. Humic Substances: Hypotheses and Reality (a Review).
- Author
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Zavarzina, A. G., Danchenko, N. N., Demin, V. V., Artemyeva, Z. S., and Kogut, B. M.
- Subjects
FREE radical reactions ,FULVIC acids ,HUMIC acid ,NATURAL products ,ORGANIC compounds - Abstract
The term humic substances (HS) refers to a group of heterogeneous, dark-colored polydisperse substances found in soils, peats, natural waters, and sediments. It is hypothesized that HSs are formed as a result of degradation and transformation of biomolecules of organic residues and free radical condensation reactions (a process called humification). Humic substances are classified as a special category of natural compounds that are dissimilar to the biomolecules of plant and microbial tissues, and are resistant to biodegradation. On the basis of their solubility in alkalis, HSs are divided into humic acids (HAs, soluble, precipitated at pH < 2), fulvic acids (FAs, soluble at all pH values), and humin (insoluble residue). The review provides a critical analysis of the HS terminology and nomenclature, the method of extraction of HS from natural objects, and the hypotheses describing their formation. The ambiguity and duality of the concept of HSs (specific compounds and the sum of operational fractions) are demonstrated, as well as an arbitrary character of the division of organic matter (OM) into the dark-colored compounds of poorly defined structure (HSs) and the substances with a known structure (non-HSs). The interpretation of HSs as mass products of a secondary synthesis requires revision. The possibility of extracellular free radical reactions in soils leaves no doubt; however, a quantitative contribution of the corresponding products to the natural OM has not been established yet. The traditional alkaline extraction should be considered as a method for isolation of hydrophilic polar substances, while the precipitation with acid as their concentration for further analysis. The historical names of humic fractions (HAs, FAs, and humin) should be retained as well-established generic terms and names of the preparations obtained in a certain way without attaching unique features and specificity to all components of these fractions. The C
HA /CFA (or CHA /Corg ) ratios are simple and convenient indicators of the types of humus reflecting bioclimatic conditions of its formation. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
49. Role of Iron Phthalocyanine Coordination in Catecholamines Detection.
- Author
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Martin, Cibely S., Rubira, Rafael J. G., Silva, Jaqueline N., and Aléssio, Priscila
- Subjects
PHTHALOCYANINES ,CATECHOLAMINES ,NEUROTRANSMITTERS ,ATMOSPHERIC temperature ,DOPAMINE - Abstract
Catecholamines are an important class of neurotransmitters responsible for regularizing, controlling, and treating neural diseases. Based on control and diseases treatment, the development of methodology and dives to sensing is a promissory technology area. This work evaluated the role of iron phthalocyanine coordination (FePc) with the specific groups from catecholamine molecules (L-dopa, dopamine, epinephrine, and the amino acid tyrosine) and the effect of this coordination on electrochemical behavior. The in situ coordination analysis was performed through isotherms π-A of FePc Langmuir films in the absence and presence of catecholamines. The π-A isotherm indicates a strong interaction between FePc monolayer and L-Dopa and DA, which present a catechol group and a side chain with a protonated amino group (-NH
3 + ). These strong interactions with catechol and amine groups were confirmed by characterization at the molecular level using the surface-enhanced Raman spectroscopy (SERS) from a Langmuir--Schaefer monolayer deposited onto Ag surfaces. The electrochemical measurements present a similar tendency, with lower oxidation potential observed to DA>L-Dopa>Ep. The results corroborate that the coordination of the analyte on the electron mediator surface plays an essential role in an electrochemical sensing application. The FePc LS film was applied as a sensor in tablet drug samples, showing a uniformity of content of 96% for detecting active compounds present in the L-Dopa drug samples. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
50. Procyanidins: From Agro-Industrial Waste to Food as Bioactive Molecules.
- Author
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Johana Valencia-Hernandez, Leidy, Wong-Paz, Jorge E., Alberto Ascacio-Valdés, Juan, Chávez-González, Mónica L., Carlos Contreras-Esquivel, Juan, and Aguilar, Cristóbal N.
- Abstract
Procyanidins are an important group of bioactive molecules known for their benefits to human health. These compounds are promising in the treatment of chronic metabolic diseases such as cancer, diabetes, and cardiovascular disease, as they prevent cell damage related to oxidative stress. It is necessary to study effective extraction methods for the recovery of these components. In this review, advances in the recovery of procyanidins from agro-industrial wastes are presented, which are obtained through ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, pressurized fluid extraction and subcritical water extraction. Current trends focus on the extraction of procyanidins from seeds, peels, pomaces, leaves and bark in agro-industrial wastes, which are extracted by ultrasound. Some techniques have been coupled with environmentally friendly techniques. There are few studies focused on the extraction and evaluation of biological activities of procyanidins. The identification and quantification of these compounds are the result of the study of the polyphenolic profile of plant sources. Antioxidant, antibiotic, and anti-inflammatory activity are presented as the biological properties of greatest interest. Agro-industrial wastes can be an economical and easily accessible source for the extraction of procyanidins. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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