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1.
Int J Mol Sci ; 25(7)2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38612924

RESUMO

Vasorin (VASN), a transmembrane protein heavily expressed in endothelial cells, has garnered recent interest due to its key role in vascular development and pathology. The oligomeric state of VASN is a crucial piece of knowledge given that receptor clustering is a frequent regulatory mechanism in downstream signaling activation and amplification. However, documentation of VASN oligomerization is currently absent. In this brief report, we describe the measurement of VASN oligomerization in its native membranous environment, leveraging a class of fluorescence fluctuation spectroscopy. Our investigation revealed that the majority of VASN resides in a monomeric state, while a minority of VASN forms homodimers in the cellular membrane. This result raises the intriguing possibility that ligand-independent clustering of VASN may play a role in transforming growth factor signaling.


Assuntos
Células Endoteliais , Proteínas de Membrana , Membrana Celular , Transdução de Sinais , Espectrometria de Fluorescência
2.
J Chem Phys ; 160(15)2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38624117

RESUMO

Bio-templated luminescent noble metal nanoclusters (NCs) have attracted great attention for their intriguing physicochemical properties. Continuous efforts are being made to prepare NCs with high fluorescence quantum yield (QY), good biocompatibility, and tunable emission properties for their widespread practical applications as new-generation environment-friendly photoluminescent materials in materials chemistry and biological systems. Herein, we explored the unique photophysical properties of silver nanoclusters (AgNCs) templated by cytosine-rich customized hairpin DNA. Our results indicate that a 36-nucleotide containing hairpin DNA with 20 cytosine (C20) in the loop can encapsulate photostable red-emitting AgNCs with an absolute QY of ∼24%. The luminescent properties in these DNA-templated AgNCs were found to be linked to the coupling between the surface plasmon and the emitter. These AgNCs exhibited excellent thermal sensitivity and were employed to produce high-quality white light emission with an impressive color rendering index of 90 in the presence of dansyl chloride. In addition, the as-prepared luminescent AgNCs possessing excellent biocompatibility can effectively mark the nuclear region of HeLa cells and can be employed as a luminescent probe to monitor the cellular dynamics at a single molecular resolution.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Humanos , Prata/química , Citosina/química , Células HeLa , DNA/química , Replicação do DNA , Nanopartículas Metálicas/química , Espectrometria de Fluorescência/métodos , Técnicas Biossensoriais/métodos
3.
Sci Rep ; 14(1): 8493, 2024 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605135

RESUMO

This study involved the production of 20 biochar samples derived from secondary medicinal residues of Snow Lotus Oral Liquid, processed within the temperature range of 200-600 °C. Additionally, four medicinal residues, including dissolved organic matter (DOM), from 24 samples obtained using the shaking method, served as the primary source material. The investigation focused on two key factors: the modifier and preparation temperature. These factors were examined to elucidate the spectral characteristics and chemical properties of the pharmaceutical residues, biochar, and DOM. To analyze the alterations in the spectral attributes of biochar and medicinal residues, we employed near-infrared spectroscopy (NIR) in conjunction with Fourier-infrared one-dimensional and two-dimensional correlation spectroscopy. These findings revealed that modifiers enhanced the aromaticity of biochar, and the influence of preparation temperature on biochar was diminished. This observation indicates the stability of the aromatic functional group structure. Comparative analysis indicated that Na2CO3 had a more pronounced structural effect on biochar, which is consistent with its adsorption properties. Furthermore, we utilized the fluorescence indices from UV-visible spectroscopy and excitation-emission-matrix spectra with the PARAFAC model to elucidate the characteristics of the fluorescence components in the DOM released from the samples. The results demonstrated that the DOM released from biochar primarily originated externally. Aromaticity reduction and increased decay will enhance the ability of the biochar to bind pollutants. Those results confirmed the link between the substantial increase in the adsorption performance of the high-temperature modified charcoal in the previous study and the structural changes in the biochar. We investigated the structural changes of biochar and derivative DOM in the presence of two perturbing factors, modifier and preparation temperature. Suitable modifiers were selected. Preparation for the study of adsorption properties of snow lotus medicinal residues.


Assuntos
Carvão Vegetal , Lotus , Carvão Vegetal/química , Matéria Orgânica Dissolvida , Temperatura , Espectrometria de Fluorescência/métodos , Substâncias Húmicas/análise
4.
Luminescence ; 39(4): e4741, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38605268

RESUMO

In the present study, a first validated and green spectrofluorimetric approach for its assessment and evaluation in different matrices was investigated. After using an excitation wavelength of 345 nm, Roxadustat (ROX) demonstrates a highly native fluorescence at an emission of 410 nm. The influences of experimental factors such as pH, diluting solvents, and different organized media were tested, and the most appropriate solvent choice was ethanol. It was confirmed that there was a linear relationship between the concentration of ROX and the relative fluorescence intensity in the range 60.0-1000.0 ng ml-1, with the limit of detection and limit of quantitation, respectively, being 17.0 and 53.0 ng ml-1. The mean recoveries % [±standard deviation (SD), n = 5] for pharmaceutical preparations were 100.11% ± 2.24%, whereas for plasma samples, they were 100.08 ± 1.08% (±SD, n = 5). The results obtained after the application of four greenness criteria, Analytical Eco-Scale metric, NEMI, GAPI, and AGREE metric, confirmed its eco-friendliness. In addition, the whiteness meter (RGB12) confirmed its level of sustainability. The International Council for Harmonisation (ICH) criteria were used to verify the developed method through the study in both spiked plasma samples and content uniformity evaluation. An appropriate standard for various applications in industry and quality control laboratories was developed.


Assuntos
Hematínicos , Humanos , Limite de Detecção , Espectrometria de Fluorescência/métodos , Eritropoese , Concentração de Íons de Hidrogênio , Solventes/química , Comprimidos/química , Isoquinolinas
5.
Food Res Int ; 184: 114247, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38609226

RESUMO

Konjac glucomannan (KGM) can significantly prolong gastrointestinal digestion. However, it is still worth investigating whether the macromolecular crowding (MMC) induced by KGM is correlated with digestion. In this paper, the MMC effect was quantified by fluorescence resonance energy transfer and microrheology, and the digests of starch, protein, and oil were determined. The digestive enzymes were analyzed by enzyme reaction kinetic and fluorescence quenching. The results showed that higher molecular weight (604.85 âˆ¼ 1002.21 kDa) KGM created a larger MMC (>0.8), and influenced the digestion of macronutrients; the digests of starch, protein, and oil all decreased significantly. MMC induced by KGM decreased the Michaelis-Menten constants (Km and Vmax) of pancreatic α-amylase (PPA), pepsin (PEP), and pancreatic lipase (PPL). The larger MMC (>0.8) induced by KGM resulted in the decrease of fluorescence quenching constants (Ksv) in PPA and PPL, and the increase of Ksv in PEP. Therefore, varying degrees of MMC induced by KGM could play a role in regulating digestion and the inhibitory effect on digestion was more significant in a relatively more crowded environment induced by KGM. This study provides theoretical support for the strategies of nutrient digestion regulation from the perspective of MMC caused by dietary fiber.


Assuntos
Mananas , Pepsina A , Espectrometria de Fluorescência , Substâncias Macromoleculares , alfa-Amilases Pancreáticas , Amido
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124226, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38560950

RESUMO

Organophosphorus pesticides play an important role as broad-spectrum inactivating herbicides in agriculture. Developing a method for rapid and efficient organophosphorus pesticides detection is still urgent due to the increasing concern on food safety. An organo-probe (ZDA), synthesized by purine hydrazone derivative and 2,2'-dipyridylamine derivative, was applied in sensitive recognition of Cu2+ with detection limit of 300 nM. Mechanism study via density functional theory (DFT) and job's plot experiment revealed that ZDA and Cu2+ ions form a 1:2 complex quenching the fluorescence emission. Moreover, this fluorescent complex ZDA-Cu2+ was applicable for detecting glyphosate and glufosinate ammonium following fluorescence enhancement mechanism, with detection limits of 11.26 nM and 11.5 nM, respectively. Meanwhile, ZDA-Cu2+ was effective and sensitive when it is used for pesticide detection, reaching the maximum value and stabilizing in 1 min. Finally, the ZDA-Cu2+ probe could also be tolerated in cell assay environment, implying potential bio-application.


Assuntos
Aminobutiratos , 60658 , Praguicidas , Compostos Organofosforados , Fluorescência , Corantes Fluorescentes , Purinas , Espectrometria de Fluorescência , Cobre
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124175, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38565051

RESUMO

Copper is an essential trace element in the human body, and its level is directly related to many diseases. While the source of copper in human body is mainly intake from food, then the detection of copper ions (Cu2+) in food becomes crucial. Here, we synthesized a novel probe (E)-3-hydroxy-2-styryl-4H-benzo[h]chromen-4-one (NSHF) and explored the binding ability of NSHF for Cu2+ using nuclear magnetic resonance hydrogen spectroscopy (1H NMR), high-resolution mass spectrometry (HRMS), Job's plot method and density functional theory (DFT). NSHF shows the advantages of fast response time, good selectivity and high sensitivity for Cu2+. The fluorescence intensity ratio (F/F0) of NSHF shows a good linear relationship with the concentration of Cu2+ and the detection limit is 0.061 µM. NSHF was successfully applied to the detection of Cu2+ in real samples. In addition, a simple and convenient Cu2+ detection platform was constructed by combining NSHF with a smartphone and a UV lamp, which can realize the rapid detection of Cu2+. This work provides an effective tool for the real-time detection of Cu2+.


Assuntos
Cobre , Corantes Fluorescentes , Humanos , Cobre/análise , Corantes Fluorescentes/química , Espectrometria de Fluorescência , Íons/análise , Alimentos
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124221, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38569390

RESUMO

The toxicological effect between co-existed antibiotics and metal ions was dangerous to the ecological environment and public health. However, the rapid quantification tools with convenience, accuracy and low cost for the detection of multiple targets were still challenging. Herein, a portable tri-color ratiometric fluorescence paper sensor was constructed by coupling of blue carbon dots and fluorescence imprinted polymer for down/up conversion simultaneous detection of tetracycline and sulfamethazine. Interestingly, the cascade detection of aluminum ion was also realized based on the individual detection system of tetracycline without the assistance of complex coupling reagents. The detection limits of smartphone method for the visual detection of tetracycline, sulfamethazine and aluminum ion were calculated as 0.014 µM, 0.004 µM and 0.019 µM, respectively. The portable fluorescence paper sensor was applied for the visual detection of tetracycline, sulfamethazine and aluminum ion in actual samples successfully with satisfactory recoveries. With the advantages of rapidness, low cost, and portability, the developed portable fluorescence paper sensor provided a new strategy for the visual real-time detection of multiple targets.


Assuntos
Antibacterianos , Pontos Quânticos , Alumínio , Sulfametazina , Fluorescência , Tetraciclina , Carbono , Íons , Corantes Fluorescentes , Espectrometria de Fluorescência , Limite de Detecção
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124224, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38574611

RESUMO

Overuse of doxycycline (DOXY) can cause serious problems to human health, environment and food quality. So, it is essential to develop a new sensing methodology that is both sensitive and selective for the quantitative detection of DOXY. In our current research, we synthesized a simple fluorescent probe 4,4'-bis(benzyloxy)-1,1'-biphenyl (BBP) for the highly selective detection of doxycycline by through fluorescence spectroscopy. The probe BBP displayed ultra-sensitivity towards doxycycline due to Forster resonance energy transfer (FRET). Fluorescence spectroscopy, density functional theory (DFT), 1H NMR titration, UV-Vis, and Job's plot were used to confirm the sensing mechanism. The charge transfer between the probe and analyte was further examined qualitatively by electron density differences (EDD) and quantitively by natural bond orbital (NBO) analyses. Whereas the non-covalent nature of probe BBP towards DOXY was verified by theoretical non-covalent interaction (NCI) analysis as along with Bader's quantum theory of atoms in molecules (QTAIM) analysis. Furthermore, probe BBP was also practically employed for the detection of doxycycline in fish samples, pharmaceutical wastewater and blood samples.


Assuntos
Doxiciclina , Corantes Fluorescentes , Animais , Humanos , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Transferência Ressonante de Energia de Fluorescência , Espectroscopia de Ressonância Magnética
10.
Luminescence ; 39(4): e4742, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38637644

RESUMO

A simple, rapid, and low-cost technique was developed to allow reliable analysis of the anti-hepatitis C drug sofosbuvir in bulk, tablet form, and spiked human plasma. This method depends on the ability of sofosbuvir to quench the fluorescence of the newly synthesized 2-amino-3-cyano-4,6-dimethylpyridine (reagent 3). Elemental analysis and spectral data were used to validate the structure of the synthesized reagent. The newly synthesized reagent exhibited a satisfactory level of fluorescence emission at 365 nm after excitation at 247 nm. All experimental variables that might affect the quenching process were analyzed and optimized. Linearity, range, accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ) were all validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. The concentration range was shown to be linear between 0.1 and 1.5 µg/mL. The technique was effectively utilized for sofosbuvir analysis in both its tablet dosage form and spiked human plasma, with mean percentage recoveries of 100.13 ± 0.35 and 94.26 ± 1.69, respectively.


Assuntos
Corantes Fluorescentes , Sofosbuvir , Humanos , Espectrometria de Fluorescência/métodos , Comprimidos
11.
Lasers Med Sci ; 39(1): 99, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602564

RESUMO

In recent years, there has been a growing interest in traditional medicinal practices such as Ayurveda, which emphasizes the use of natural ingredients for various therapeutic purposes. Vegetable oils are an integral part of our diet and have several applications in the cosmetics and healthcare industries. These oils have also been prescribed in ancient Ayurveda texts to treat various health problems. Ayurveda prescribes a processing technique called 'Murchana' to improve the therapeutic nature of the oils. Spectroscopic techniques have been used for quality assessment in many fields. High sensitivity and a low detection rate make spectroscopy a formidable analytical technique. This study focusses on the spectroscopic analysis of sesame and mustard oils prepared using the ayurvedic processing method 'Murchana'. Spectroscopic analysis techniques including UV-Vis absorbance spectroscopy, fluorescence spectroscopy, and FTIR spectroscopy were employed to study the oils. Origin software was used to plot graphs of the spectra. The results indicated that the murchana process may reduce the components of the oil responsible for its oxidation, thereby increasing the shelf life of the oils. However, further investigations, including other spectroscopy and chromatography techniques, will prove beneficial in ascertaining the effects of the murchana process on vegetable oils. The study's findings also suggest that spectroscopic techniques can be used to supplement chemical techniques to investigate the characteristics of vegetable oils.


Assuntos
Mostardeira , Sesamum , Óleos de Plantas , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Anal Chim Acta ; 1304: 342579, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38637044

RESUMO

Plasmon enhanced fluorescent (PEF) with more "hot spots" play a critical role in signal amplified technology to avoid the intrinsic limitation of fluorophore which ascribed to a strong electromagnetic field at the tip structure. However, application of PEF technique to obtain a highly sensitive analysis of medicine was still at a very early stage. Herein, a simple but versatile Ag nanocubes (Agcubes)-based PEF sensor combined with aptamer (Agcubes@SiO2-QDs-Apt) was proposed for highly sensitive detection of berberine hydrochloride (BH). The distance between the plasma Agcubes and the red-emitted CdTe quantum dots (QDs) were regulated by the thickness of silica spacer. The three-dimensional finite-difference time-domain (3D-FDTD) simulation further revealed that Agcubes have a higher electromagnetic field than Ag nanospheres. Compared with PEF sensor, signal QDs-modified aptamer without Agcubes (QDs-Apt) showed a 10-fold higher detection limit. The linear range and detection limit of the Agcubes@SiO2-QDs-Apt were 0.1-100 µM, 87.3 nM, respectively. Furthermore, the PEF sensor was applied to analysis BH in the berberine hydrochloride tablets, compound berberine tablet and urine with good recoveries of 98.25-102.05%. These results demonstrated that the prepared PEF sensor has great potential for drug quality control and clinical analysis.


Assuntos
Aptâmeros de Nucleotídeos , Berberina , Compostos de Cádmio , Pontos Quânticos , Fluorescência , Pontos Quânticos/química , Compostos de Cádmio/química , Dióxido de Silício , Telúrio/química , Espectrometria de Fluorescência/métodos , Aptâmeros de Nucleotídeos/química , Limite de Detecção
13.
Luminescence ; 39(3): e4728, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38516711

RESUMO

A novel spectrofluorimetric method has been developed for determination of antazoline (ANT) and tetryzoline (TET) in their pharmaceutical formulation. A combined application of synchronous spectrofluorimetry and second derivative mathematical treatment was developed. The proposed method depends on reacting the cited drugs with dansyl chloride (DNS-Cl) being a suitable derivatizing agent generating highly fluorescent derivatives measured at emission wavelengths of 703.0 and 642.0 nm after excitation wavelengths of 350.0 and 320.0 nm for ANT and TET, respectively. The joint use of synchronous spectrofluorimetry with second derivative mathematical treatment is for the first time to be developed and optimized in aid of using fluorescence data manager software generating second derivative peak amplitudes at 556.5 nm for ANT and 516.7 nm for TET. Linear responses have been represented over a wide range of concentration (0.5-12.0 µg/mL for ANT and 0.5-10.0 µg/mL for TET). Additionally, statistical comparison of the developed method with the official ones has been carried out where no significant difference was found. Additionally, greenness profile assessment was accomplished by means of four metric tools. Indeed, the method developed is found to be precise, sensitive, and discriminating to assess the cited drugs for regular analysis.


Assuntos
Antazolina , Antazolina/análise , Espectrometria de Fluorescência/métodos , Imidazóis
14.
Luminescence ; 39(3): e4727, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38527806

RESUMO

Green tea extract (GTE) contains antioxidants that are present in green tea. The active constituents of green tea extract are catechins. This study demonstrates a spectrofluorimetric method for measuring GTE's catechin concentration based on its native fluorescence. To design a quick, sensitive, and ecological spectrofluorimetric approach, all features were investigated and adjusted. This method relies on determining the GTE ethanolic solution's native fluorescence at 312 nm after excitation at 227 nm. The calibration graph displayed a linear regression for values between 0.05 and 1.0 µg mL-1. The detection and quantification limits of the proposed technique were 0.008 and 0.026 µg mL-1, respectively. Two pure catechins present in GTE, (-)-epicatechin and (-)-epigallocatechin gallate, were examined by the proposed method. The analytical estimation of GTE in the pharmaceutical tablet was achieved effectively using this approach. An adequate degree of agreement was found when the findings were compared to those obtained by the comparative technique. Therefore, the novel strategy may be used in the GTE quality control study with minimal risks to people or the environment. The quantum yields of catechins were estimated. The validated technique was accepted by the International Council of Harmonization criteria.


Assuntos
Camellia sinensis , Catequina , Humanos , Catequina/análise , Espectrometria de Fluorescência , Extratos Vegetais , Chá , Antioxidantes/análise
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 312: 124040, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38428211

RESUMO

In this paper, an isophorone-based NIR fluorescent and colormetric probe BDDH for Al3+ was synthesized and characterized, it showed highly selectivity and sensitivity through significant fluorescence enhancement and visible color change towards Al3+. The job plot confirmed that the binding ratio of BDDH with Al3+ was 1:1. Furthermore, the limit of detection (LOD) of Al3+ was determined to be 4.01 × 10-8 M. Moreover, BDDH was successfully applicated in identification of Al3+ in the different water samples, cell imaging in alive MCF-7 cells and plant imaging in soybean roots.


Assuntos
Diagnóstico por Imagem , Corantes Fluorescentes , Corantes Fluorescentes/química , Cicloexanonas/química , Limite de Detecção , Espectrometria de Fluorescência
16.
Sensors (Basel) ; 24(6)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38543983

RESUMO

Opioid use, particularly morphine, is linked to CNS-related disorders, comorbidities, and premature death. Morphine, a widely abused opioid, poses a significant global health threat and serves as a key metabolite in various opioids. Here, we present a turn-off fluorescent sensor capable of detecting morphine with exceptional sensitivity and speed in various samples. The fluorescent sensor was developed through the dimerization process of 7-methoxy-1-tetralone and subsequent demethylation to produce the final product. Despite morphine possessing inherent fluorophoric properties and emitting light in an approximately similar wavelength as the sensor's fluorescent blue light, the introduction of the target molecule (morphine) in the presence of the sensor caused a reduction in the sensor's fluorescence intensity, which is attributable to the formation of the sensor-morphine complex. By utilizing this fluorescence quenching sensor, the chemo-selective detection of morphine becomes highly feasible, encompassing a linear range from 0.008 to 40 ppm with an impressive limit of detection of 8 ppb. Consequently, this molecular probe demonstrates a successful application in determining trace amounts of morphine within urine, yielding satisfactory analytical results. The study also explores the effect of several variables on the sensor's response and optimizes the detection of morphine in urine using a response surface methodology with a central composite design.


Assuntos
Líquidos Corporais , Morfina , Morfina/urina , Analgésicos Opioides , Corantes Fluorescentes , Espectrometria de Fluorescência , Líquidos Corporais/química
17.
Sci Total Environ ; 926: 172086, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38556025

RESUMO

Dissolved organic matter (DOM) in rainfall participates in many biogeochemical cycles in aquatic environments and affects biological activities in water bodies. Revealing the characteristics of rainfall DOM could broaden our understanding of the carbon cycle. Therefore, the distribution characteristics and response mechanisms of DOM to microorganisms were investigated in different regions of Hebei. The results indicated that the water quality of the northern region was worse than that of the middle and southern regions. The two protein like components (C1, C2) and one humic like component (C3) were obtained; at high molecular weight (MW), the fluorescence intensity is high in the northern region (0.03 ± 0.02 R.U.), while at low MW, the fluorescence intensity is highest in the southern region (0.50 ± 0.18 R.U.). Furthermore, C2 is significantly positively correlated with C1 (P < 0.01), while C2 is significantly negatively correlated with C3 (P < 0.05) was observed. The spectral index results indicated that rainfall DOM exhibited low humification and highly autochthonous characteristics. The southern region obtained higher richness and diversity of microbial species than northern region (P < 0.05). The community exhibits significant spatiotemporal differences, and the Acinetobacter, Enterobacter, and Massilia, were dominant genus. Redundancy and network analyses showed that the effects of C1, C2, and nitrate on microorganisms increased with decreasing MW, while low MW exhibited a more complex network between DOM and microorganisms than high MW. Meanwhile, C1, C2 had a large total effect on ß-diversity and function through structural equation modeling. The backward trajectory model indicates that the sources of air masses are from the northwest, local area, and sea in the northern, middle, and southern regions, respectively. This study broadened the understanding of the composition of summer rainfall DOM and its interactions with microorganisms during rainfall.


Assuntos
Matéria Orgânica Dissolvida , Rios , Rios/química , Espectrometria de Fluorescência , Qualidade da Água , Compostos Orgânicos/análise , Substâncias Húmicas/análise
18.
Chemosphere ; 355: 141724, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38499074

RESUMO

The pervasive use of pesticides like chlorpyrifos (CPY) has been associated with deleterious effects on biomolecules, posing significant risks to environmental integrity, public health, and overall ecosystem equilibrium. Accordingly, in this study, we investigated the potential binding interaction between the well-conserved enzyme, lysozyme (LSZ), and CPY through various spectroscopic techniques and molecular modeling. The UV-vis absorption and fluorescence experiments confirmed the complex formation and static quenching of the intrinsic fluorescence intensity. LSZ revealed a singular binding site for CPY, with binding constants around 105 M-1 across different temperature ranges. Analysis of thermodynamic parameters showed the spontaneous nature of the complexation process, while also revealing the pivotal role of hydrophobic interactions in stabilizing the LSZ-CPY system. According to circular dichroism and Fourier transform infrared studies, CPY binding changed the secondary structure of LSZ by boosting α-helix presence and reducing the levels of ß-sheet and ß-turn content. Further, CPY decreased the stability and activity of LSZ. Computational docking delineated the specific and highly preferred binding site of CPY within the structure of LSZ. Molecular dynamic simulation indicated the enduring stability of the LSZ/CPY complex and revealed structural modifications in the LSZ after binding with CPY. This research provides a detailed understanding of the intermolecular dynamics between CPY and LSZ, concurrently elucidating the molecular-level implications for the potential hazards of pesticides in the natural environment.


Assuntos
Clorpirifos , Poluentes Ambientais , Praguicidas , Clorpirifos/toxicidade , Ligação Proteica , Muramidase/química , Ecossistema , Sítios de Ligação , Dicroísmo Circular , Termodinâmica , Praguicidas/toxicidade , Simulação de Acoplamento Molecular , Espectrometria de Fluorescência
19.
Int J Biol Macromol ; 265(Pt 2): 131111, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38522700

RESUMO

Iron ions play a crucial role in the environment and the human body. Therefore, developing an effective detection method is crucial. In this paper, we report CNS2, a chitosan-based fluorescent probe utilizing naphthalimide as a fluorophore. CNS2 is designed to "quench" its own yellow fluorescence through the specific binding of compounds containing enol structures to Fe3+. Studying the fluorescence lifetime of CNS2 in the presence or absence of Fe3+ reveals that the quenching mechanism is static. The presence of multiple recognition sites on the chitosan chain bound to Fe3+ gave CNS2 rapid recognition (1 min) and high sensitivity, with a detection limit as low as 0.211 µM. Moreover, the recognition of Fe3+ by CNS2 had a good specificity and was not affected by interferences. More importantly, in this study, CNS2 was successfully utilised to prepare fluorescent composite membranes and to detect Fe3+ in real water samples and a variety of food samples. The results show that the complex sample environment still does not affect the recognition of Fe3+ by CNS2. All the above experiments obtained more satisfactory results, which provide strong support for the detection of Fe3+ by the probe CNS2 in practical applications.


Assuntos
Quitosana , Corantes Fluorescentes , Humanos , Corantes Fluorescentes/química , Água , Quitosana/química , Ferro/química , Fluorescência , Espectrometria de Fluorescência/métodos
20.
Int J Biol Macromol ; 265(Pt 2): 131148, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38547949

RESUMO

Glucose interacts with human serum albumin (HSA, the main protein responsible for the biodistribution of drugs in the bloodstream) and consequently affects the binding capacity of exogenous compounds. Thus, in this work, the interactive profile between HSA and the anti-inflammatory drug nimesulide (NMD, used mainly by patients with diabetic neuropathy to relieve acute or chronic pains) was characterized in nonglycemic, normoglycemic (80 mg/dL), and hyperglycemic (320 mg/dL) conditions by biophysics techniques. There is a spontaneous and ground-state association HSA:NMD under physiological conditions. Therefore, the Stern-Volmer constant (Ksv) can also be used to estimate the binding affinity. The Ksv values for nonglycemic, normoglycemic, and hyperglycemic conditions are around 104 M-1, indicating a moderate affinity of NMD to albumin that was slightly improved by glucose levels. Additionally, the binding is enthalpically and entropically driven mainly into subdomains IIA or IIIA. The binding perturbs weakly the α-helix content of albumin, however, glucose potentially stabilizes the tertiary structure, decreasing the structural perturbation upon NMD binding and improves the complex HSA:NMD stability. Overall, the biophysical characterization indicated that glucose levels might slightly positively impact the pharmacokinetic profile of NMD, allowing NMD to achieve its therapeutical potential without affecting drastically its effective dosages.


Assuntos
Glucose , Albumina Sérica Humana , Sulfonamidas , Humanos , Albumina Sérica Humana/química , Distribuição Tecidual , Ligação Proteica , Anti-Inflamatórios não Esteroides/farmacologia , Sítios de Ligação , Espectrometria de Fluorescência , Termodinâmica , Dicroísmo Circular , Simulação de Acoplamento Molecular
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