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1.
Int J Mol Sci ; 25(4)2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38396819

RESUMO

In this work, a novel fluorescence sensing strategy was proposed for the detection of gentamicin based on fluorescent carbon quantum dots (CQDs) and gold nanoparticles (AuNPs). Herein, the CQDs were green-synthesized for the first time via a one-step hydrothermal method utilizing brown sugar as the precursor. In the presence of citrate-stabilized AuNPs, the fluorescence of CQDs was quenched efficiently. Gentamicin, on the other hand, had a higher affinity for AuNPs and was able to compete with CQDs for a preferential binding to AuNPs, which ultimately led to the aggregation of AuNPs and freeing of CQDs in solution, causing the fluorescence recovery of CQDs. Based on the above phenomenon, the concentrations of gentamicin could be ascertained by detecting the variations in fluorescence intensity of CQDs. This sensing strategy exhibited excellent selectivity in various antibiotics. At the same time, the method displayed outstanding sensitivity for gentamicin, which was successfully applied to real samples detection.


Assuntos
Nanopartículas Metálicas , Pontos Quânticos , Ouro , Carbono , Gentamicinas , Limite de Detecção , Corantes Fluorescentes , Açúcares
2.
Int J Mol Sci ; 25(11)2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38892157

RESUMO

A dual-emission ratio-fluorescent sensing nanohybrid based on Radix Hedysari green-synthesized carbon quantum dots (CDs) and glutathione-functionalized gold nanoclusters (GSH-AuNCs) had been developed for the determination of cefodizime sodium (CDZM). The designed fluorescence nanohybrid had two significant fluorescence emission peaks at 458 nm and 569 nm when excited at 360 nm, which was attributed to the CDs and GSH-AuNCs. With the addition of CDZM, the fluorescence at 458 nm was slightly weakened while the fluorescence at 569 nm was enhanced obviously. Based on the relationship between the I569/I458 fluorescence intensity ratio and the concentration of CDZM, the designed nanohybrid exhibited a good linearity range of 1.0-1000.0 µM and the limit of detection (LOD) was 0.19 µM. The method was finally applied in the detection of CDZM in urine, showing the potential applications in complicated biological samples.


Assuntos
Glutationa , Ouro , Nanopartículas Metálicas , Pontos Quânticos , Pontos Quânticos/química , Humanos , Ouro/química , Nanopartículas Metálicas/química , Glutationa/urina , Glutationa/química , Limite de Detecção , Espectrometria de Fluorescência/métodos , Carbono/química , Cefalosporinas/urina , Cefalosporinas/química , Fluorescência
3.
Appl Opt ; 62(19): 5236-5243, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37707227

RESUMO

Most stereoscopic microscopes used for industrial component detection are large and have low detection efficiencies. The use of mobile phones as imaging systems (rather than conventional sensors) in industrial fields would make industrial testing more convenient. In this study, an external stereo microscope for mobile phones is designed. The proposed system can resolve details up to 0.01 mm with an 11 mm object field of view, -6.34× angular magnification, and quantitative 3D feature measurement. The combined system proposed in this paper is suitable for the microscopic observation of industrial components, with its low cost, high detection efficiency, and short installation steps.

4.
Arch Womens Ment Health ; 26(6): 755-766, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37566123

RESUMO

The post-pandemic era has transformed work-life boundaries, driven by factors such as working hours, an increased number of working women and single parents, the implementation of various ICTs, and the rise of flexible work arrangements. This study examines the role of female workers and entrepreneurs in establishing and managing coworking spaces (CSs) designed to improve work-life balance through flexible scheduling and location options. The challenges faced by female entrepreneurs in promoting an inclusive society and economic system are also explored, as well as the benefits experienced by independent workers and teleworkers in terms of networking, social interaction, knowledge exchange, and community building. The "She Economy" is analyzed in three stages: germination, growth, and maturity, considering challenges from both family and workplaces. This paper investigates the background of female identity and the ideological transformation of female identity in the consumption process after the pandemic, using mass media, especially female-focused media, as a lens. Finally, the paper proposes recommendations for the future development of the "She Economy" from the perspectives of communicators, women, and the social environment.


Assuntos
Mulheres Trabalhadoras , Equilíbrio Trabalho-Vida , Humanos , Feminino , Pandemias , Identidade de Gênero , Meio Social
5.
Sensors (Basel) ; 23(15)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37571518

RESUMO

Subjected to the relentless impacts of typhoons and rough seas, offshore wind turbines' structures, particularly the tower, foundation, and blade, are at constant risk of damage. Full-field strain monitoring helps to discover potential structural defects, thereby reducing disasters caused by overall structural failure. This study introduces a novel method for assessing strain and temperature fields on these kinds of 3D surfaces of cylindrical structures. The method harnesses the capabilities of a high spatial resolution (0.65 mm) Optical Frequency Domain Reflectometer (OFDR)-based Distributed Optical Fiber Sensor (DOFS) in conjunction with a unique helical wiring layout. The core process begins with mapping the fiber optic path onto a plane corresponding to the unfolded cylinder. Fiber optic signals are then differentiated on this plane, deriving a two-dimensional strain distribution. The plane strain field is subsequently projected onto the 3D side of the cylinder. An experiment was carried out in which a 3.5 m long optical fiber was helically wound with a 10 mm pitch on the surface of a cantilever beam of a cylinder shell with a diameter of 36 mm and a length of 300 mm. The experiment collected about 5400 measurement points on the cylindrical surface of 340 cm2, approximately 15.9 measurement points per square centimeter. The reconstructed results successfully reveal the strain field of the pipe cantilever beam under bending and torsional loads, as well as the palm-shaped temperature field. This experimental validation of the method's efficacy lays the theoretical groundwork for its application to real wind turbines.

6.
Anal Chem ; 93(5): 3010-3017, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33499597

RESUMO

Lateral flow assay (LFA) has played pivotal roles in many emergency public safety incidents, such as coronavirus disease diagnostics; however, the present double-line (test and control line) design strategy for LFA strips greatly restricts their applications in high-throughput quantitative analysis because the limited sample diffusion distance on the strips constrains the number of test/control lines. Herein, a novel single-line-based LFA (sLFA) strip, which combines test and control line, is developed by exploiting an orthogonal emissive upconversion nanoparticle (UCNP) as a signal reporter on the test line, where one emission can be used as a reporting signal and the other as a calibrating signal. This UCNP-based test line with an interior reference also can play a validating role as a control line, and hence capturing antibodies are not needed for control lines, greatly saving fabrication costs. As a proof-of-concept, this novel sLFA strip is successfully explored to accurately and rapidly detect aflatoxin B1. Moreover, due to the removal of control lines, such a novel strategy greatly reduces the strip size, facilitating the design of a testing array for multiple detections of different samples. The test line herein is designed in a ring shape, and several test rings are assembled to be a chip for the testing of multiple samples. To our knowledge, this is the first demonstration of single-line-based LFA strips, which will significantly improve the detection capacities and accuracies and reduce the testing costs of LFA strips in real sample applications ranging from food analysis to in vitro diagnostics.


Assuntos
Aflatoxina B1/análise , Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , Aflatoxina B1/imunologia , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Técnicas Biossensoriais/instrumentação , COVID-19/diagnóstico , COVID-19/virologia , Análise de Alimentos/métodos , Ouro/química , Humanos , Medições Luminescentes , SARS-CoV-2/isolamento & purificação
7.
RSC Adv ; 14(16): 11122-11123, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38590357

RESUMO

[This corrects the article DOI: 10.1039/D3RA02647G.].

8.
Food Res Int ; 175: 113733, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38128990

RESUMO

Soy allergenicity is a public concern, and the combination of multiple processing methods may be a promising strategy for reducing soy allergenicity. In this study, a novel two-step enzymatic hydrolysis followed by lactic acid bacteria fermentation was proposed for the construction of hypoallergenic soybean protein microgel. ß-Conglycinin was used as the main soy allergen. The effects of different enzymatic hydrolysis (Alcalase, Neutrase, and Protamex) and LAB fermentation on ß-conglycinin microgel formation and its immunoreactivity were investigated. Results showed that the use of different enzymes and the attainment of different degrees of hydrolysis affected the particle distribution and zeta potential in the microgels and leads to differences in microstructure and immunoreactivity. All hydrolysates compared with intact protein accelerated the formation of gel during LAB fermentation. Among the three assayed enzymes, fermented Protamex hydrolysates at 60 min (PF-60) demonstrated a microgel with an overall reduced average particle size (741.20±7.18 nm), lower absolute values of zeta potential (10.43±0.65 mV), and regular gel network. The antigenicity and IgE-binding capacity decreased to the lowest value of 0.30 % and 6.93 %, respectively. Peptidomics and immunoinformatic analysis suggested that PF-60 disrupted 17/30, 16/44, and 23/75 epitopes in the α, α', and ß subunits, respectively. Unlike the LAB-fermented unhydrolyzed ß-conglycinin disrupted epitopes mostly located at the loop domain, PF-60 primarily promoted the exposure and disruption of allergen epitopes with ß-sheet structure located at the core barrel domain. These findings can provide new perspectives on the preparation of hypoallergenic soybean-gel products on edible particulate systems.


Assuntos
Lactobacillales , Microgéis , Proteínas de Soja/química , Alérgenos/química , Lactobacillales/metabolismo , Fermentação , Hidrólise , Epitopos
9.
RSC Adv ; 13(32): 22043-22053, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37483672

RESUMO

This study aimed at three representative pollutants, benzidine, cyromazine, and streptomycin, which were commonly used and posed a great threat to both environment and human health, mainly to explore a fast, simple, sensitive, visible naked-eye detection method. Colorimetric detection by gold nanoparticles (AuNPs) was first attempted. The cross-linking reaction occurred owing to the strong forces between the targets and AuNPs, leading to aggregation and color change. However, large-scale aggregation was easily formed and settled, which failed to achieve accurate quantification. Thus, AuNPs are considered to be used in fluorescence detection as reaction bridges. The introduction of AuNPs could effectively quench the fluorescence of Rhodamine B based on fluorescence resonance energy transfer (FRET). Moreover, a classical "on-off-on" fluorescence detection system was constructed based on nanomaterials. When AuNPs were added, the red fluorescence of the Rhodamine B solution could be effectively quenched (the "off" reaction). However, the tight cross-linking reaction between the three targets and AuNPs occurred through the strong affinity, causing Rhodamine B to dissociate in the solution. The fluorescence was rapidly restored, accompanied by a significant enhancement of fluorescence intensity (the "on" reaction). The fluorescent responses toward the three targets were established, resulting in good linearity in a wide range with low detection limits. Moreover, through the investigation of specificity, the fluorescence sensor exhibited satisfying selectivity and high binding affinity to the detected targets among the same types of inferences, indicating great potential for practical application. This simple, fast and sensitive fluorescence detection system was first used for simultaneously detecting three types of pollutants and finally successfully applied to real samples.

10.
Micromachines (Basel) ; 14(2)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36838050

RESUMO

In this paper, silver nanoparticles (AgNPs) were successfully green-synthesized for the first time using Hedysarum polysaccharide (HPS) as a reducing agent, stabilizer, and modifier (HPS-AgNP). Thiamazole could induce the aggregation of HPS-AgNPs in the residue on a cellulose membrane. A syringe paper-based analytical device was creatively established to ensure the tightness, stability, and good repeatability of the test. The color information remaining on the cellulose membrane was converted into gray values using ImageJ software. Hence, the linear regression curve for thiamazole was established as y = 1 + 0.179x with a detection limit (LOD) of 24.6 nM in the relatively wide range of 0.1~10 µM. This syringe paper-based analytical device was successfully applied to the biological samples.

11.
ACS Appl Bio Mater ; 6(6): 2394-2403, 2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37216601

RESUMO

Photodynamic therapy (PDT) is considered as a promising therapeutic approach for clinical cancer treatment. However, the hypoxia of the tumor microenvironment leads to the low effect of single PDT. Here, a dual-photosensitizer nanoplatform based on near-infrared excitation orthogonal emission nanomaterials is constructed by introducing two kinds of photosensitizers into the nanosystem. Orthogonal emission upconversion nanoparticles (OE-UCNPs) were used as light conversion reagents to generate red emission under 980 nm irradiation and green emission under 808 nm irradiation. On the one hand, merocyanine 540 (MC540) is introduced as a photosensitizer (PS), which can absorb green light to generate reactive oxygen species (ROS) and trigger PDT for tumor treatment. On the other hand, another photosensitizer, chlorophyll a (Chla), which can be excited by red light, has also been introduced into the system to build a dual PDT nanotherapeutic platform. The introduction of photosensitizer Chla can synergistically increase ROS concentration to accelerate cancer cell apoptosis. Our research shows that this dual PDT nanotherapeutic platform combined with Chla has better therapeutic effects and effectively destroys cancer.


Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Humanos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Espécies Reativas de Oxigênio , Clorofila A , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Microambiente Tumoral
12.
Eur J Pharmacol ; 956: 175970, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37549727

RESUMO

As a common progressive neurodegenerative disorder, the satisfied therapies for Parkinson's disease (PD) are still unavailable. As a natural acetylcholinesterase inhibitor, the neuroprotective characteristic of Huperzine A (HupA) was supported by previous studies. However, questions remain on whether HupA injection (HAI, a main preparation of HupA) intervention conduces to PD treatment and if so, the potential molecular mechanisms. In this study, the efficacies of HAI treatment on PD-like pathological phenotypes were evaluated in a MPTP-induced PD murine model. The network pharmacology, transcriptome sequencing and experimental verification were integrated to comprehensively reveal the primary molecular mechanisms. Therapeutically, HAI intervention significantly improved the impaired locomotor behaviors as well as learning and memory abilities, and prevented the degeneration of dopaminergic neurons of PD mice. The network pharmacology analysis combined with experimental results showed that HAI treatment could effectively restore the disordered transcriptional levels of inflammatory factors and apoptosis related genes in the SNpc and striatum tissues of PD mice. Transcriptome sequencing results found that inflammation and oxidative phosphorylation served as significant functional mechanisms involved in HAI administration. The experimental verification indicated that HAI treatment effectively regulated the abnormal transcription levels of inflammation and oxidative phosphorylation related hub genes in the hippocampal samples of PD mice. In addition, molecular docking suggested strong affinity between HupA and the above core targets. Overall, this work displayed the reliable therapeutic effects of HAI on ameliorating the pathological symptoms of PD mice via modulating multiple pathways. The current findings were expected to provide a potential anti-PD agent.


Assuntos
Fármacos Neuroprotetores , Doença de Parkinson , Camundongos , Animais , Doença de Parkinson/tratamento farmacológico , Modelos Animais de Doenças , Acetilcolinesterase/metabolismo , Simulação de Acoplamento Molecular , Inflamação/tratamento farmacológico , Neurônios Dopaminérgicos , Cognição , Camundongos Endogâmicos C57BL , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Fármacos Neuroprotetores/metabolismo , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia
13.
Front Cell Neurosci ; 17: 1145574, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37293627

RESUMO

Traumatic optic neuropathy (TON) is a condition that causes massive loss of retinal ganglion cells (RGCs) and their axonal fibers, leading to visual insufficiency. Several intrinsic and external factors can limit the regenerative ability of RGC after TON, subsequently resulting in RGC death. Hence, it is important to investigate a potential drug that can protect RGC after TON and enhance its regenerative capacity. Herein, we investigated whether Huperzine A (HupA), extracted from a Chinese herb, has neuroprotective effects and may enhance neuronal regeneration following the optic nerve crush (ONC) model. We compared the three modes of drug delivery and found that intravitreal injection of HupA could promote RGC survival and axonal regeneration after ONC. Mechanistically, HupA exerted its neuroprotective and axonal regenerative effects through the mTOR pathway; these effects could be blocked by rapamycin. To sum up, our findings suggest a promising application of HupA in the clinical treatment of traumatic optic nerve.

14.
Spectrochim Acta A Mol Biomol Spectrosc ; 282: 121703, 2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-35933781

RESUMO

This article first reported the green synthesis of N, S co-doped fluorescent carbon dots (N, S-CDs-Sop) and sought to establish the fluorescence detection system for amoxicillin (AMX). By using Sophorajaponica L. flower as the green precursor and dl-homocystine as the co-dopant, N, S-CDs-Sop were successfully prepared via a one-pot hydrothermal method, exhibiting good water solubility and excellent photoluminescence. It was revealed that the surface of N, S-CDs-Sop was abundant in amino, hydroxyl and carboxyl groups after being characterized by a variety of techniques. When Fe3+ was added, Fe3+ could be complexed with N, S-CDs-Sop to from N, S-CDs-Sop-Fe3+ chelation leading to a significant static quenching of fluorescence. However, when N, S-CDs-Sop, Fe3+ and AMX coexisted, AMX would coordinate with Fe3+ and form the strong chelate due to the favorable chemical structure, resulting in the rapid fluorescence recovery. Such a fast, simple and sensitive fluorescence "off-on" strategy with a low LOD and a relatively wide range was successfully applied to the detection of AMX, which is closely correlated with human health.


Assuntos
Carbono , Pontos Quânticos , Amoxicilina , Carbono/química , Flores , Corantes Fluorescentes/química , Humanos , Nitrogênio/química , Pontos Quânticos/química , Enxofre/química
15.
Environ Sci Pollut Res Int ; 29(39): 59317-59327, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35384541

RESUMO

Most studies have shown that improper disposal of e-waste can accelerate the release of high concentrations of polybrominated diphenyl ethers (PBDEs), and this situation causes environmental pollution and human health risks. The recycling technology of waste electronic plastics based on solvent processes can reduce environmental pollution and health risks from PBDEs. In this study, high impact polystyrene (HIPS) from waste TV sets was taken as the research object, and d-limonene and n-propanol were used as solvent and precipitant, respectively. We studied the relationship between the precipitation conditions and the size of precipitate particles, and the effect laws of precipitation conditions on the removal percentage of PBDEs were discussed. Transferring behavior of PBDEs during precipitation was investigated, and the parameters suitable for removing PBDEs from HIPS solution were confirmed. Results showed that lower HIPS concentration in d-limonene, lower precipitation temperature, higher mass ratio of n-propanol to HIPS solution, and greater stirring speed were conducive to form smaller and more uniform precipitate particles. All conditions (concentration, temperature, mass ratio, and stirring rate) that could increase the solubility of PBDEs in the mixed solvent of limonene and n-propanol or decrease the swelling degree of HIPS precipitate particles, or reduce the size of particles could improve the removal percentage of PBDEs. The investigated results indicated that insoluble PBDEs (e.g., decabromodiphenyl ether) transferred into the HIPS precipitate mainly through the generated crystals and then precipitated together with the HIPS particles, and soluble PBDEs (e.g., octabromodiphenyl ether) migrated into the precipitate by the solution entrained. The precipitate particles, which measured approximately 1.0 mm (on average), were obtained when the solution containing 10% of HIPS from waste TV shell was precipitated by adding n-propanol equivalent to twice the mass of the solution at 40 °C and 3000 r/min stirring speed. The total concentration of PBDEs in the precipitate particles (dried) was reduced to 2369 mg/kg, and 88.06% of the PBDEs in the original plastic solution was successfully removed by this process.


Assuntos
Resíduo Eletrônico , Éteres Difenil Halogenados , 1-Propanol , Resíduo Eletrônico/análise , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Humanos , Limoneno , Plásticos/química , Poliestirenos , Solventes
16.
Phytomedicine ; 99: 154034, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35276592

RESUMO

BACKGROUND: As a leading cause of death and disability, alternative therapies for stroke are still limited by its complicated pathophysiological manifestations. Guhong injection (GHI), consisting of safflower aqueous extract and aceglutamide, has been widely applied for the clinical treatment of cerebrovascular diseases, especially ischemic stroke and post-stroke recovery, in China. Recently, a series of studies have reported the positive effect of GHI against cerebral ischemia/reperfusion injury via targeting various molecular mechanisms. However, questions remain on whether treatment with GHI contributes to better functional recovery after stroke and if so, the potential mechanisms and active substances. PURPOSE: The aim of this work was to explore the potential therapeutic possibilities of GHI for the neurological and behavioral recovery after stroke and to investigate the underlying molecular mechanisms as well as active substances. METHODS: The neural and motor deficits as well as cortical lesions after GHI treatment were investigated in a mouse model of transient ischemic stroke. Based on the substance identification of GHI, network pharmacology combined with an experimental verification method was used to systematically decipher the biological processes and signaling pathways closely related to GHI intervention in response to post-stroke functional outcomes. Subsequently, ingenuity pathway analysis (IPA) analysis was performed to determine the anti-stroke active substances targeting to the hub targets involved in the significant molecular pathways regulated by GHI treatment. RESULTS: Therapeutically, administration of GHI observably ameliorated the post-stroke recovery of neural and locomotor function as well as reduced infarct volume and histopathological damage to the cerebral cortex in subacute stroke mice. According to 26 identified or tentatively characterized substances in GHI, the compound-target-pathway network was built. Bioinformatics analysis suggested that inflammatory and apoptotic pathways were tightly associated with the anti-stroke effect of GHI. Based on protein-protein interaction network analysis, the hub targets (such as NF-κB p65, TNF-α, IL-6, IL-1ß, Bax, Bcl-2, and Caspase-3) involved in inflammation and apoptosis were selected. On the one hand, immunofluorescence and ELISA results showed that GHI (10 ml/kg) treatment obviously reduced NF-κB p65 nuclear translocation as well as decreased the abnormally elevated concentrations of proinflammatory cytokines (TNF-α, IL-6, and IL-1ß) in damaged cortex tissues. On the other hand, GHI (10 ml/kg) treatment significantly downregulated the number of TUNEL-positive apoptotic cells in ischemic cortex and effectively restored the abnormal expression of Bax, Bcl-2, and Caspase-3. Based on the results of IPA, hydroxysafflor yellow A, baicalin, scutellarin, gallic acid, syringin, chlorogenic acid, kaempferol, kaempferol-3-O-ß-rutinoside, and rutin acted synergistically on core targets, which could be considered as the active substances of GHI. CONCLUSION: Overall, the current findings showed that the beneficial action of GHI on improving post-stroke functional recovery of subacute stroke mice partly via the modulation of cortical inflammation and apoptosis. These findings not only provide a reliable reference for the clinical application of GHI, but also shed light on a promising alternative therapeutic strategy for ischemic stroke patients.

17.
Int J Biol Macromol ; 201: 67-74, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34995661

RESUMO

Lignin, especially Brauns native lignin (BNL), from Chinese quince (Chaenomeles sinensis) fruit represents a potential source of natural antioxidants. However, the highly inhomogeneous structure and the carbohydrate impurity reduce the antioxidant properties of BNL. Accordingly, a sequential aqueous acetone fractionation was used to prepare pure lignin fractions with homogeneous molecular structures; these fractions showed strong antioxidant properties. Analytical results showed that the yields of F50% and F60% exceeded 20% (i.e., 20.6% and 24.1%, respectively). The sugar impurities in BNL were mainly retained in the F30% and F40% fractions. For all fractions, molecular weight increased as the acetone concentration increased. The results from 2D HSQC NMR and 31P NMR indicated that the number of lignin linkages (ß-O-4', ß-ß' and ß-5') and functional groups (S-OH, G-OH, H-OH, and COOH) of these fractions varied with their molecular weights. Antioxidant assays showed that F40%, F50% and F60% had higher antioxidant properties than BNL. Overall, the study provides a simple, environmentally friendly fractionation method to prepare lignin with various structural features and strong antioxidant properties from Chinese quince fruit. These lignin fractions have promising application in some fields with high value, such as antioxidants production, biomaterials, packaging materials, and drug delivery and so on.


Assuntos
Lignina , Rosaceae , Acetona , China , Frutas/química , Lignina/química , Estrutura Molecular , Rosaceae/química
18.
Int J Biol Macromol ; 164: 4348-4358, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931830

RESUMO

Chinese quince fruits (Chaenomeles sinensis) have an abundance of lignins with antioxidant activities. To facilitate the utilization of Chinese quince fruits, lignin was isolated from it by auto-catalyzed ethanol organosolv pretreatment. The effects of three processing conditions (temperature, time, and ethanol concentration) on yield, structural features and antioxidant activities of the auto-catalyzed ethanol organosolv lignin samples were assessed individually. Results showed the pretreatment temperature was the most significant factor; it affected the molecular weight, S/G ratio, number of ß-O-4' linkages, thermal stability, and antioxidant activities of lignin samples. According to the GPC analyses, the molecular weight of lignin samples had a negative correlation with pretreatment temperature. 2D-HSQC NMR and Py-GC/MS results revealed that the S/G ratios of lignin samples increased with temperature, while total phenolic hydroxyl content of lignin samples decreased. The structural characterization clearly indicated that the various pretreatment conditions affected the structures of organosolv lignin, which further resulted in differences in the antioxidant activities of the lignin samples. These results can be helpful for controlling and optimizing delignification during auto-catalyzed ethanol organosolv pretreatment, and they provide theoretical support for the potential applications of Chinese quince fruits lignin as a natural antioxidant in the food industry.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Frutas/química , Lignina/química , Lignina/farmacologia , Rosaceae/química , Catálise , Fenômenos Químicos , Cromatografia Gasosa-Espectrometria de Massas , Hidrólise , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Peso Molecular , Monossacarídeos , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-Atividade , Termogravimetria
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