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1.
Food Chem ; 409: 135271, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-36587513

RESUMO

This study aims to explore whether ultra-high pressure (UHP) pre-treatment strengthened the bioaccessibility and bioactivities of the free (QF), esterified (QE) and insoluble-bound phenolics (QIB) from Que Zui tea (QT). The results revealed that the extraction yields, the total phenolic (TPC) and total flavonoid contents (TFC) of three phenolic fractions from QT were markedly increased after ultra-high pressure (UHP) processing (p < 0.05). A total of 19 and 20 compounds were characterized and quantified in non- and UHP-treated QT, respectively, including the content of 6'-O-caffeoylarbutin (11775.68 and 13248.87 µg/g of dry extract) was highest in QF, the content of caffeic acid was highest in QE (2131.58 and 7362.99 µg/g of dry extract) and QIB (9151.89 and 10930.82 µg/g of dry extract). QF, QE and QIB from QT after UHP processing had better antioxidant, ROS scavenging, and anti-apoptosis effects. The possible mechanism of cytoprotective effect was related to Keap1-Nrf2 pathway.


Assuntos
Antioxidantes , Fator 2 Relacionado a NF-E2 , Antioxidantes/farmacologia , Antioxidantes/análise , Proteína 1 Associada a ECH Semelhante a Kelch , Fenóis/farmacologia , Fenóis/análise , Extratos Vegetais/farmacologia , Chá , Cromatografia Líquida de Alta Pressão/métodos
3.
Anal Bioanal Chem ; 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333614

RESUMO

Developing simple, efficient, and inexpensive method for trace amount organophosphorus pesticides' (OPs) detection with high sensitivity and specificity is of significant importance for guaranteeing food safety. Herein, an Ag/Au bimetallic nanoparticle-based acetylcholinesterase (AChE) surface-enhanced Raman scattering (SERS) biosensor was constructed for in situ simple and sensitive detection of pesticide residues in food. The principle of this biosensor exploited 4-mercaptophenylboronic acid (4-MPBA)-modified Ag/Au bimetallic nanoprobes as SERS signal probe to improve sensitivity and stability. The combination of AChE and choline oxidase (CHO) can hydrolyze acetylcholine (ATCh) to generate H2O2. The product of H2O2 selectively oxidizes the boronate ester of 4-MPBA, decreasing the Raman intensity of the B-O symmetric stretching. In the presence of OPs, it could inhibit the production of H2O2 by destroying the AChE activity, so the reduction of the SERS signal was also alleviated. Based on the principle, an Ag/Au bimetallic nanoparticle-based AChE SERS sensor was established without any complicated pretreatments. Benefiting from the synergistic effects of Ag/Au bimetallic hybrids, a linear detection range from 5×10-9 to 5×10-4 M was achieved with a limit of detection down to 1.7×10-9 M using parathion-methyl (PM) as the representative model of OPs. Moreover, the SERS biosensor uses readily available reagents and is simple to implement. Importantly, the proposed SERS biosensor was used to quantitatively analyze OP residues in apple peels. The levels of OPs detected in real samples by this method were consistent with those obtained using gas chromatography-mass spectrometry (GC-MS), suggesting the proposed assay has great potential applications for OPs in situ detection in food safety fields.

4.
Anal Methods ; 14(44): 4523-4530, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36318214

RESUMO

Single miRNAs are not specific and accurate enough to meet the strict diagnosis requirements in practice. Therefore, simultaneous monitoring of multiplexed miRNA in biological samples can not only improve the accuracy and specificity of bioassays but also avoid the squandering of valuable biological specimens. Herein, we designed a metal sulfide nanoparticle-based dual barcode-triggered DNAzyme cascade strategy for the sensitive and simultaneous multiplex miRNA detection in a single assay. Firstly, the capture probes (H1, H2) specifically recognize targets (miRNA-21, miRNA-141), exposing the stem of H1 and H2. Then, with the introduction of a detection probe (CuS-H3, ZnS-H4), the exposed H1 and H2 catalyze the hairpin assembly (CHA) reaction, realizing target miRNA recycling, and forming H1/H3-CuS and H2/H4-ZnS complexes. Subsequently, the formed H1/H3-CuS and H2/H4-ZnS complexes are encoded on magnetic beads through the biotin/streptavidin interaction. The CuS and ZnS nanoparticles captured by magnetic beads release thousands of Cu2+ and Zn2+via the cation exchange reaction. Finally, the released Cu2+ and Zn2+ specially activate the DNAzyme of the catalytic and molecular beacon (CAMB) system. The CAMB system affords an amplified fluorescence signal output by cycling and regenerating the metal ion-dependent DNAzyme to realize multiple enzymatic turnovers. Benefiting from target recycling, nanoparticle amplification, and catalytic and molecular beacon amplification, there is substantial amplification and the target miRNAs can be detected at 0.06 fM (miRNA-21) and 0.048 fM (miRNA-141) in a single assay. Furthermore, the high selectivity and accuracy of the assay were proved by practical analysis of different cancer cells, which exhibited good practicability in multiplex miRNA detection in clinical sera. The results indicate that the proposed strategy holds great potential for the sensitive detection of multiplex cancer biomarkers and offers the opportunity for future applications in clinical diagnosis.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , Nanopartículas Metálicas , MicroRNAs , DNA Catalítico/genética , MicroRNAs/análise , MicroRNAs/genética , Hibridização de Ácido Nucleico , Técnicas Biossensoriais/métodos , Sulfetos , Bioensaio
5.
Anal Chem ; 94(37): 12845-12851, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36067524

RESUMO

Ratiometric electrochemiluminescence (ECL) sensors can efficiently remove environmental interference to attain precise detection. Nonetheless, two eligible luminophores or coreactants were usually needed, increasing the complexity and restricting their practical application. In this study, a single luminophore of luminol with a single coreactant of H2O2 was employed to construct a dual-potential ratiometric ECL sensor for the detection of carcinoembryonic antigen (CEA). The produced palladium nanoclusters (Pd NCs) employing a DNA duplex as a template could not only stimulate luminol to produce cathodic ECL (Icathodic) but also quench its anodic ECL (Ianodic). During the detection process, CEA could damage the double-stranded structure and reduce the Pd NCs' amount, triggering a significant decrease in the ratio of Icathodic to Ianodic (Icathodic/Ianodic) and thereby achieving sensitive CEA's detection. Furthermore, the Icathodic/Ianodic was independent of the H2O2 concentration, which avoided a prejudicial effect from H2O2 decomposition and considerably enhanced the detection's reliability. The developed ratiometric ECL sensor demonstrated a sensitive detection toward CEA with a wide linear range from 100 ag/mL to 10 ng/mL and a detection limit of 87.1 ag/mL (S/N = 3). In conclusion, this study offers a new idea for constructing ratiometric ECL sensors based on a single luminophore and technical support for cancer's early diagnosis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Antígeno Carcinoembrionário , DNA/química , Técnicas Eletroquímicas , Peróxido de Hidrogênio , Limite de Detecção , Medições Luminescentes , Luminol/química , Nanopartículas Metálicas/química , Paládio/química , Reprodutibilidade dos Testes
6.
Analyst ; 147(15): 3415-3419, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35766147

RESUMO

Highly sensitive and reliable PEC detection of miRNAs still faces some challenges like the inaccuracy caused by coexisting interferences in the PEC system. Herein, we developed a split-type "turn-off" PEC biosensor based on spatially-extended 3D magnetic DNA nanodevices with high-order DNA amplifiers for sensitive detection of miRNAs in cancer cells.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Neoplasias , DNA/genética , Técnicas Eletroquímicas , Limite de Detecção , Fenômenos Magnéticos , MicroRNAs/genética , Neoplasias/diagnóstico , Neoplasias/genética
7.
Food Chem ; 368: 130864, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34438172

RESUMO

Ultra-high pressure (UHP) is a novel non-thermal pretreatment method in food processing for improving the extraction yield of polyphenols and functional properties. The present work investigated the phenolic profiles, antioxidant activities, and cytoprotective effects of the free, esterified, and insoluble-bound phenolic fractions from mango leaves before and after ultra-high pressure (UHP) treatment. UHPLC-Q-Orbitrap-MS/MS analysis resulted in the identification of 42 phenolic compounds in the different phenolic forms. UHP pretreatment could significantly influence the contents of total phenols, total flavonoids and individual compounds in the different phenolic fractions (p < 0.05). After UHP pretreatment, these phenolic fractions exhibited greater antioxidant activity, and inhibited reactive oxygen species production and cell apoptosis (p < 0.05). Meanwhile, IBP were the most potential antioxidative and cytoprotective ingredients. Therefore, UHP pretreated mango leaves with enhanced bioactivity could be used as biological agents in the health food industry to improve its application and economic values.


Assuntos
Antioxidantes , Mangifera , Antioxidantes/farmacologia , Cromatografia Líquida de Alta Pressão , Flavonoides/análise , Fenóis/análise , Extratos Vegetais/farmacologia , Folhas de Planta/química , Espectrometria de Massas em Tandem
8.
Chem Commun (Camb) ; 58(3): 407-410, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34897319

RESUMO

Developing sensing platforms that simultaneously integrate high sensitivity and accuracy has been a promising but challenging task for the detection of protein biomarkers in clinical samples. Herein, we engineered an Au nanostar-based liquid phase interfacial ratiometric SERS platform with programmable entropy-driven DNA circuits to detect the protein biomarker Mucin 1 (MUC1) in clinical samples.


Assuntos
Biomarcadores Tumorais/análise , DNA/química , Entropia , Ouro/química , Nanopartículas Metálicas/química , Mucina-1/análise , Humanos , Tamanho da Partícula , Análise Espectral Raman
9.
Small ; 18(5): e2104524, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34816615

RESUMO

Structural modulation of core-shell silver nanoclusters from the inside is a huge challenge but of great importance in their syntheses. Herein, two silver nanoclusters [Ag3 S9 @Ag42 ] (SD/Ag45b) and [Ag9 S9 @Ag42 ] (SD/Ag51a) are isolated in the presence of different kinds of sulfonic acids. Uniquely, SD/Ag45b and SD/Ag51a show typical core-shell structures with the similar Ag42 shell but different cores. The outer shell of 42 silver atoms comprises two Ag3 trigons at two poles encircled by three equatorial distorted square cupolas (J4 , Ag12 ). The core in SD/Ag45b is a silver trigon ligated by nine S2- ions (Ag3 S9 ), while a tricapped triangular prismatic Ag9 also ligated by the same amount of S2- ions (Ag9 S9 ) is observed in the inner core of SD/Ag51a. The electrospray ionization mass spectrometry (ESI-MS) indicates that the introduction of p-toluenesulfonic acid can realize the transformation from SD/Ag45b to Ag51 . SD/Ag45b and SD/Ag51a show inverse luminescence thermochromic behaviors in the near-infrared (NIR) region, mainly dictated by the inner silver cores. This work not only realizes the synthesis of new silver nanoclusters by core modulation but also provides a prototype to get molecular-level insight into the correlation between structure and luminescence thermochromism.


Assuntos
Luminescência , Prata , Prata/química
10.
Mikrochim Acta ; 189(1): 17, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34873664

RESUMO

As well known, the electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)32+) heavily relies on highly positive or negative triggered voltage, prejudicing the detection toward the bio-molecules. In this work, Ru(bpy)32+ could generate enhanced and stable ECL at a low potential of 0.05 V (vs. Ag/AgCl) on graphene-PtPd hybrid, attributing to its excellent electrocatalysis from the synergistic effect between Pt and Pd. The obtained low-potential-driven ECL could be quenched by MoS2 nanoflowers. Based on the quenching effect, a sandwich "signal-off" ECL immunosensor was fabricated to sensitively detect carcinoembryonic antigen (CEA). A linear calibration curve from 1 fg mL-1 to 1 ng mL-1 was obtained along with a low detection limit of 0.54 fg mL-1 (S/N = 3) under optimal conditions. The sensor showed satisfactory specificity, stability, and reproducibility and was successfully applied to determine CEA in actual samples. The recoveries ranged from 98.80 to 100.23%, and the relative standard deviation (RSD) was lower than 5%. Above all, this work explored new materials in low-potential-driven ECL system and provided a reliable sensing strategy for clinical applications.


Assuntos
Antígeno Carcinoembrionário/sangue , Técnicas Eletroquímicas/métodos , Imunoensaio/métodos , Substâncias Luminescentes/química , Nanocompostos/química , Compostos Organometálicos/química , Anticorpos Imobilizados/imunologia , Antígeno Carcinoembrionário/imunologia , Dissulfetos/química , Grafite/química , Humanos , Limite de Detecção , Molibdênio/química , Paládio/química , Platina/química , Reprodutibilidade dos Testes
11.
Phytomedicine ; 91: 153684, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34400050

RESUMO

BACKGROUND: Melodinus cochinchinensis (Lour.) Merr. is a medicinal plant, which is used as a folk medicine for treating meningitis and fractures. However, the anti-inflammatory activity of total alkaloid extract from M. cochinchinensis (MCTA) and its molecular mechanism are still not studied. PURPOSE: The aim of this study is to investigate the main chemical constituents of MCTA and explore its anti-inflammatory potential in both in vitro and in vivo assessments. METHODS: UHPLC-ESI-HRMS/MS was applied to analyze the chemical profiling. The anti-inflammatory efficacy of MCTA was evaluated on lipopolysaccharide (LPS) induced RAW 264.7 cells and two common inflammation models in mice. The production of pro-inflammatory mediator and cytokine was tested using the ELISA method. The pathological change was analyzed by histological assessment. The expression of NF-κB, MAPKs and PPAR-γ proteins was evaluated using western blot analysis. RESULTS: A total of 21 monoterpenoid indole alkaloids (MIAs) were characterized by UHPLC-ESI-HRMS/MS. Aspidospermine- and quinolone-type alkaloids were found to be the major compounds. MCTA significantly decreased the production of NO, IL-1ß, IL-6 and TNF-α in LPS-induced RAW 264.7 macrophages. MCTA significantly inhibited the phosphorylation of ERK1/2, JNK and p38 MAPK, suppressed the NF-κB transcriptional activation and improved the PPAR-γ expression. Moreover, the in vivo experiment exhibited that MCTA pretreatment markedly alleviated the xylene-induced ear edema and carrageenan-induced paw edema in mice and decreased the IL-1ß, IL-6 and TNF-α expressions. CONCLUSION: MCTA is rich in MIAs and exhibited a significant inhibitory effect on the production proinflammatory cytokines. The mechanism might be related to the inhibition of activation of NF-κB and MAPK pathways.


Assuntos
Alcaloides , Anti-Inflamatórios , Apocynaceae/química , Edema , Extratos Vegetais , Alcaloides/farmacologia , Alcaloides/uso terapêutico , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Citocinas/metabolismo , Edema/tratamento farmacológico , Lipopolissacarídeos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , NF-kappa B/metabolismo , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Células RAW 264.7
12.
Nat Commun ; 12(1): 4966, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404784

RESUMO

Although chirality is an ever-present characteristic in biology and some artificial molecules, controlling the chirality and demystifying the chirality origin of complex assemblies remain challenging. Herein, we report two homochiral Ag14 nanoclusters with inherent chirality originated from identical rotation of six square faces on a Ag8 cube driven by intra-cluster π···π stacking interaction between pntp- (Hpntp = p-nitrothiophenol) ligands. The spontaneous resolution of the racemic (SD/rac-Ag14a) to homochiral nanoclusters (SD/L-Ag14 and SD/R-Ag14) can be realized by re-crystallizing SD/rac-Ag14a in acetonitrile, which promotes the homochiral crystallization in solid state by forming C-H···O/N hydrogen bonds with nitro oxygen atoms in pntp- or aromatic hydrogen atoms in dpph (dpph = 1,6-bis(diphenylphosphino)hexane) on Ag14 nanocluster. This work not only provides strategic guidance for the syntheses of chiral silver nanoclusters in an all-achiral environment, but also deciphers the origin of chirality at molecular level by identifying the special effects of intra- and inter-cluster supramolecular interactions.


Assuntos
Cristalização , Compostos Organometálicos/química , Fenômenos Físicos , Prata/química , Acetonitrilas/química , Cristalografia por Raios X , Hexanos , Hidrogênio , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Oxigênio , Rotação
13.
Food Chem Toxicol ; 156: 112506, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34389369

RESUMO

E Se tea, processed by the fresh leaves of Malus toringoides (Rehd.) Hughes, is a traditional herbal tea with various human benefits. The present study was aimed to evaluate the toxicity and hypolipidemic effect of aqueous-ethanol extract (EE) and hot-water extract (WE) from E Se tea. Eight main chemical constituents in EE and WE were respectively identified and quantified by UHPLC-HRMS/MS. EE is rich in TPC and TFC, while WE had higher TPS content. Both EE and WE exhibited strong antioxidant activity with no significant difference. The acute toxicity study revealed that the LD50 values were higher than 5000 mg/kg, while both WE and EE had no significant adverse effect in rats by subacute toxicity assay. However, the triglyceride (TG) content in experiment groups (male) and highest doses groups (female) significantly decreased. Furthermore, the hypolipidemic effect of WE and EE were performed on high fat diet induced hyperlipidemic rats. The result exhibited that either WE or EE could effectively regulate lipid droplet accumulation in liver, and reduce the adipocyte size. These results demonstrated that these two extracts from E Se tea could be regarded as a potential functional dietary supplement in preventing and treating diet induced metabolic diseases.


Assuntos
Bebidas/análise , Hiperlipidemias/tratamento farmacológico , Hipolipemiantes/uso terapêutico , Lipídeos/sangue , Malus/química , Extratos Vegetais/farmacologia , Animais , Bebidas/efeitos adversos , Dieta Hiperlipídica/efeitos adversos , Etanol/química , Feminino , Temperatura Alta , Hiperlipidemias/induzido quimicamente , Hipolipemiantes/administração & dosagem , Masculino , Estresse Oxidativo , Extratos Vegetais/efeitos adversos , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Água/química
14.
Analyst ; 146(15): 4858-4864, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34231571

RESUMO

DBP, one of the phthalic acid esters (PAEs), is known as an endocrine disruptor and is toxic to humans in abnormal concentrations. Here, a high-density and ordered SERS substrate based on the self-assembly of triangular Ag nanoplate (TAgNP) arrays is developed for DBP detection. Benefiting from the ordered arrangement and sharp corners of TAgNPS, the arrays can provide sufficient and uniform hotspots for reproducible and highly active SERS effects. Using Rhodamine 6G (R6G) as a reporter molecule, the SERS enhancement factor (EF) of the TAgNP arrays was found to be as high as 1.2 × 107 and the relative standard deviation was 6.56%. As a trial for practical applications, the TAgNP array substrates were used for the detection of dibutyl phthalate (DBP) in edible oils. In this assay, edible oil samples were added to hexane as an organic phase for the formation of the TAgNP arrays, which caused DBP to be loaded at hotspots. DBP in edible oils could be identified at concentrations as low as 10-7 M. This SERS substrate based on the TAgNP arrays has great potential applications in the high sensitivity and reproducible detection of contaminants in food.


Assuntos
Dibutilftalato , Disruptores Endócrinos , Óleos Vegetais , Prata
15.
Analyst ; 146(11): 3679-3685, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-33955434

RESUMO

In the electrochemiluminescence (ECL) field, most reported luminophores were focused on high-triggering potential and short wavelength, which was adverse for the ECL theory study and application at low potentials. Perylene diimide derivatives could emit near-infrared (NIR) ECL at low-triggering potential; however, they are always highly aggregated into a microrod structure and stacked together, which largely limited their application in biological fields such as bio-sensing and bio-imaging. To overcome these obstacles, we designed a novel perylene diimide molecule, namely N,N'-dicaproate sodium-3,4,9,10-perylenedicarboximide (PDI-COONa). This molecule self-assembled into a two-dimensional network nanostructure, which largely decreased the aggregation degree of PDI molecules and provided solid bases for designing lowly-aggregated PDI molecules. Also, the formed nanoluminophore produced strong emission at -0.26 V with an NIR wavelength 700 nm, which should be due to the excited J-type PDI-COO- dimers. Moreover, this network nanoluminophore well-dispersed on graphene oxide (GO) as an ECL nanomaterial to label secondary antibodies and fabricate a sandwiched immunosensor for alpha-fetoprotein (AFP) detection between 0 and -0.6 V. This immunosensor showed a wider linear response for AFP ranging from 0.1 fg mL-1 to 1 µg mL-1 with a low detection limit 0.0353 fg mL-1 compared with other immunosensors based on PDI microrod-modified GO ECL materials. The fabricated immunosensor also showed good feasibility in human serum samples.


Assuntos
Técnicas Biossensoriais , Perileno , Técnicas Eletroquímicas , Humanos , Imunoensaio , Limite de Detecção , Medições Luminescentes
16.
Luminescence ; 36(5): 1272-1276, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33837604

RESUMO

A simple, rapid and highly sensitive method for detection of double-stranded DNA (dsDNA) was developed using a novel fluorescence probe composed of a RecA-GFP fusion protein that had specific recognition of ssDNA complexes (RecA-GFP-DNA filament). The RecA-GFP fusion protein not only had strong fluorescence, but could also occur by homologous recombination. In the presence of the target dsDNA, the complementary ssDNA of the RecA-GFP-DNA filaments invaded one end of the dsDNA chain. In addition, the other end of the ssDNA dissociated the RecA-GFP filaments. An assay of the probe showed a linear relationship with dsDNA concentration in the range 1-11 nM, with a correlation coefficient of 0.9923. The limit of detection for dsDNA was determined experimentally to be 0.3 nM (3δ). Compared with conventional methods, this method has the advantages of simple operation, high specificity, and high sensitivity.


Assuntos
DNA de Cadeia Simples , Recombinases Rec A , DNA/genética , Recombinases Rec A/genética , Recombinases Rec A/metabolismo
17.
Molecules ; 26(7)2021 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-33916551

RESUMO

Vaccinium dunalianum Wight, usually processed as a traditional folk tea beverage, is widely distributed in the southwest of China. The present study aimed to investigate the antioxidant, α-glucosidase and pancreatic lipase inhibitory activities of V.dunalianum extract and isolate the bioactive components. In this study, the crude extract (CE) from the buds of V. dunalianum was prepared by the ultrasound-assisted extraction method in 70% methanol and then purified with macroporous resin D101 to obtain the purified extract (PM). Five fractions (Fr. A-E) were further obtained by MPLC column (RP-C18). Bioactivity assays revealed that Fr. B with 40% methanol and Fr. D with 80% methanol had better antioxidant with 0.48 ± 0.03 and 0.62 ± 0.01 nM Trolox equivalent (TE)/mg extract for DPPH, 0.87 ± 0.02 and 1.58 ± 0.02 nM TE/mg extract for FRAP, 14.42 ± 0.41 and 19.25 ± 0.23 nM TE/mg extract for ABTS, and enzyme inhibitory effects with IC50 values of 95.21 ± 2.21 and 74.55 ± 3.85 for α-glucosidase, and 142.53 ± 11.45 and 128.76 ± 13.85 µg/mL for pancreatic lipase. Multivariate analysis indicated that the TPC and TFC were positively related to the antioxidant activities. Further phytochemical purification led to the isolation of ten compounds (1-10). 6-O-Caffeoylarbutin (7) showed significant inhibitory effects on α-glucosidase and pancreatic lipase enzymes with values of 38.38 ± 1.84 and 97.56 ± 7.53 µg/mL, and had the highest antioxidant capacity compared to the other compounds.


Assuntos
Antioxidantes/isolamento & purificação , Arbutina/análogos & derivados , Ácidos Cafeicos/isolamento & purificação , Flavonoides/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Lipase/química , Vaccinium/química , alfa-Glucosidases/química , Antioxidantes/química , Arbutina/química , Arbutina/isolamento & purificação , Benzotiazóis/antagonistas & inibidores , Benzotiazóis/química , Compostos de Bifenilo/química , Ácidos Cafeicos/química , Flavonoides/química , Inibidores de Glicosídeo Hidrolases/química , Lipase/antagonistas & inibidores , Lipase/metabolismo , Extração Líquido-Líquido/métodos , Metanol/química , Picratos/química , Extratos Vegetais/química , Folhas de Planta/química , Solventes/química , Sonicação , Ácidos Sulfônicos/antagonistas & inibidores , Ácidos Sulfônicos/química , alfa-Glucosidases/metabolismo
18.
Analyst ; 146(8): 2705-2711, 2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33751013

RESUMO

A novel ratiometric electrochemical biosensing strategy based on T7 exonuclease (T7 Exo)-assisted homogenous target recycling coupling hairpin assembly triggered dual-signal output was proposed for the accurate and sensitive detection of microRNA-141 (miRNA-141). Concretely, in the presence of target miRNA, abundant signal transduction probes were released via the T7 Exo-assisted homogenous target recycling amplification, which could be captured by the specially designed ferrocene-labeled hairpin probe (Fc-H1) on -electrode interface and triggered the nonenzymatic catalytic hairpin assembly (Fc-H1 + MB-H2) to realize the cascade signal amplification and dual-signal output. Through such a conformational change process, the electrochemical signal of Fc (IFc) and MB (IMB) is proportionally and substantially decreased and increased. Therefore, the signal ratio of IMB/IFc can be employed to accurately reflect the true level of original miRNA. Benefiting from the efficient integration of the T7 Exo-assisted target recycle, nonenzymatic hairpin assembly and dual-signal output mode, the proposed sensor could realize the amplified detection of miRNA-141 effectively with a wide detection range from 1 fM to 100 pM, and a detection limit of 200 aM. Furthermore, it exhibits outstanding sequence specificity to discriminate mismatched RNA, acceptable reproducibility and feasibility for real sample. This strategy effectively integrated the advantages of multiple amplification and ratiometric output modes, which could provide an accurate and efficient method in biosensing and clinical diagnosis.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Técnicas Eletroquímicas , Exodesoxirribonucleases , Limite de Detecção , MicroRNAs/genética , Reprodutibilidade dos Testes
19.
NanoImpact ; 21: 100295, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33458449

RESUMO

The COVID-19 pandemic caused by SARS-CoV-2 has posed a huge threat to mankind, deeply endangering healthy states and influencing economic development. COVID-19 has important impacts on the environment as anthropic interventions to nature has been largely reduced after almost all countries implemented partial or complete blockade to curb the spread of the virus. Up to now, a series of studies have focused on the relationship between COVID-19 and the environment from different cities. In this review, we summarized the latest data on the correlation between COVID-19 and environmental changes. As a result, imposing necessary restrictions can help suppress the virus chain while improving air quality in some countries. The significant reduction in NO2 emission, PM2.5 level and other hazardous factors reflected the promising consequence of the efforts made during the lockdown period. It is, sometimes dark clouds have silver linings. It is worth noting that along with these positive outcomes, secondary pollutants such as ozone, however, remained unchanged or even increased significantly. Additionally, medical wastes and plastics pollutants would be increased substantially. The extensive use of masks in daily life and other medical materials is bound to increase the burden of waste disposal and environmental degradation. For the general public, in addition to the physical lesions caused by SARS-CoV-2, confirmed/suspected cases and even the normal group may suffer from mental problems. Based on those mentioned impacts, the way forward depends largely on our attitude and decision. It is indispensable to assess potential deleterious effects and to take preventive measures in time to respond to the post-pandemic era. In this way, potential silver linings will not become temporary.


Assuntos
COVID-19/epidemiologia , COVID-19/psicologia , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Ansiedade/epidemiologia , Ansiedade/psicologia , Biodegradação Ambiental , Depressão/epidemiologia , Depressão/psicologia , Exposição Ambiental , Monitoramento Ambiental , Poluentes Ambientais , Gases , Geografia , Humanos , Resíduos de Serviços de Saúde , Dióxido de Nitrogênio , Ozônio , Material Particulado , Plásticos , Saúde Pública , SARS-CoV-2
20.
Anal Methods ; 13(37): 4314-4319, 2021 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-34476425

RESUMO

A key challenge for the discrete distribution-based Förster resonance energy transfer system (D-FRET) is the reduced intensity and stability of signal probes in complex biological matrices. Here, we present a spatially confined FRET (SC-FRET) probe with a stable structure and strong signal output. It consists of multivalent FRET pairs labeled with FAM or TAMRA. In this assay, p53 DNA was chosen as a model hairpin probe (HP), and two kinds of branched DNA probes (ssDNA-FAM, ssDNA-TAMRA) were involved. Under the action of p53 DNA, the unfolded HP acts as a primer to initiate polymerization extension of KFP polymerase and cleavage of Nb.BbvCI endonuclease, which produces plenty of ssDNA (primer-DNA). The branched DNA is designed to have the same binding core and different sticky ends, the core part of which can self-assemble to form X-shaped branched DNA (X-FAM or X-TAMRA), and the sticky ends of which are complementary to the primer-DNA. Therefore, the primer-DNAs released during the polymerization cleavage process will combine a large number of X-FAM and X-TAMRA in a limited space through complementary base pairing. Fluorescence was transferred from FAM to TAMRA, and a strong FRET response was generated by the locational effects. The proposed SC-FRET system based on the multivalent assembly of branched DNA exhibited a strong FRET response with an LOD of 0.01394 pM. Importantly, it also showed a high-contrast and stable FRET response in HeLa cells. Its superior biological stability is attributed to the large steric hindrance of the compact and rigid frame of the SC-FRET probe, which helps prevent intracellular degradation and provides a powerful tool for biomedical research.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Proteína Supressora de Tumor p53 , DNA/genética , DNA de Cadeia Simples/genética , Células HeLa , Humanos , Proteína Supressora de Tumor p53/genética
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