RESUMO
Cells of most eukaryotic species contain mitochondria, which play a role in physiological processes such as cellular senescence, metabolism, and autophagy. Viscosity is considered a key marker for many illnesses and is involved in several crucial physiological processes. Cyanide (CN-) can target cytochrome-c oxidase, disrupting the mitochondrial electron transport chain and causing cell death through asphyxiation. In this study, a fluorescent probe named HL-1, which targets mitochondria and measures viscosity and CN- levels, was designed and synthesized. HL-1 is viscosity-sensitive, with a linear correlation coefficient of up to 0.992. In addition, HL-1 was found to change color substantially during a nucleophilic addition reaction with CN-, which has a low detection limit of 47 nM. HL-1 not only detects viscosity and exogenous CN- in SKOV-3 cells and zebrafish but also monitors viscosity changes during mitochondrial autophagy in real time. Furthermore, HL-1 has been used successfully to monitor changes in mitochondrial membrane potential during apoptosis. Endogenous CN- in plant samples was quantified. HL-1 provides new ideas for studying viscosity and CN-.
Assuntos
Corantes Fluorescentes , Peixe-Zebra , Animais , Humanos , Corantes Fluorescentes/metabolismo , Viscosidade , Cianetos , Mitocôndrias/metabolismo , Células HeLa , Carbazóis/metabolismoRESUMO
Reactive oxygen species (ROS) are pivotal signaling molecules that control a variety of physiological functions. As a member of the ROS family, peroxynitrite (ONOO-) possesses strong oxidation and nitrification abilities. Abnormally elevated levels of ONOO- can lead to cellular oxidative stress, which may cause several diseases. In this work, based on the rhodamine fluorophore, we designed and synthesized a novel small-molecule fluorescent probe (DH-1) for ONOO-. Upon reaction with ONOO-, DH-1 exhibited a significant fluorescence signal enhancement (approximately 34-fold). Moreover, DH-1 showed an excellent mitochondria-targeting capability. Confocal fluorescence imaging validated its ability to detect ONOO- changes in HeLa and RAW264.7 cells. Notably, we observed the ONOO- generation during the ferroptosis process by taking advantage of the probe. DH-1 displayed good biocompatibility, facile synthesis, and high selectivity, and may have potential applications in the study of ONOO--associated diseases in biosystems.
Assuntos
Corantes Fluorescentes , Ácido Peroxinitroso , Humanos , Espécies Reativas de Oxigênio , Mitocôndrias , RodaminasRESUMO
A new ratiometric fluorescent probe based on Förster resonance energy transfer (FRET) for sensing lysosomal pH has been developed. The probe (RMPM) was composed of imidazo[1,5-α]pyridine quaternary ammonium salt fluorophore as the FRET donor and the rhodamine moiety as the FRET acceptor. It's the first time to report that imidazo[1,5-α]pyridine quaternary ammonium salt acts as the FRET donor. The ratio of fluorescence intensity of the probe at two wavelengths (I424/I581) changed significantly and responded linearly toward minor pH changes in the range of 5.4-6.6. It should be noted that it's rare to report that a ratiometric pH probe could detect so weak acidic pH with pKa = 6.31. In addition, probe RMPM exhibited excellent water-solubility, fast-response, all-right selectivity and brilliant reversibility. Moreover, RMPM has been successfully applied to sensing lysosomal pH in HeLa cells and has low cytotoxicity.
Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Lisossomos/química , Compostos de Amônio Quaternário/química , Espectrometria de Fluorescência/métodos , Água/química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Processamento de Imagem Assistida por ComputadorRESUMO
A series of novel imidazo[1,5-a]pyridine-hydrazone derivatives were synthesized and characterized by infrared spectroscopy (IR), 1H NMR, 13C NMR and high resolution mass spectrometer (HRMS). Typically, the spatial structure of compound 3j was determined using X-ray diffraction analysis. The UV-vis absorption and fluorescence spectral characteristics of the compounds in dichloromethane and acetonitrile were investigated. Absorption peaks could be observed in the wavelength range 290-450 nm. It can also be seen that they display very similar maximum emission. The group attached to hydrazone hardly influenced the maximum emission. Furthermore, all the compounds were evaluated for antibacterial activity and were found to be more effective against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa and Shigella compared with chloramphenicol.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Hidrazonas/química , Piridinas/química , Antibacterianos/química , Bactérias/efeitos dos fármacos , Cristalografia por Raios X , Hidrazonas/farmacologia , Estrutura Molecular , Piridinas/farmacologiaRESUMO
Ulcerative colitis, a kind of inflammatory bowel disease (IBD), is caused by dysregulated immune response of intestinal bacteria. This chronic disorder can lead to a deficiency of O2 (hypoxia) in the colon microenvironment. Nitroreductase (NTR) is a highly expressed endogenous enzyme under hypoxia, so the detection of NTR can provide diagnostic information about ulcerative colitis. Herein, an ultrasensitive NTR-triggered fluorescence probe (WS-1-NO2) is developed for hypoxia imaging in ulcerative colitis. The probe shows a significant fluorescence enhancement (45-fold) after reacting with NTR, with an extremely low detection limit of 0.096 ng/mL. Furthermore, we apply it for fluorescence imaging of hypoxia in living cells, tumors and dextran sulphate sodium (DSS)-induced ulcerative colitis mouse models. We believe that the probe may be investigated as an effective potential tool for gaining insight into the hypoxia-relevant diseases, such as cancer and ulcerative colitis.
Assuntos
Colite Ulcerativa , Corantes Fluorescentes , Camundongos , Animais , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/diagnóstico por imagem , Nitrorredutases , Imagem Óptica/métodos , Hipóxia/diagnóstico por imagem , Sulfato de DextranaRESUMO
Novel imidazo[1,5-a]pyridinyl 1,3,4-Oxadiazole derivatives were synthesized and characterised by IR, (1)H NMR and HRMS.UV-vis absorption and fluorescence properties of these compounds in different solutions showed that the maximal emission wavelength was not significantly changed in different solvents; however, maximum absorption wavelength was blue-shifted with the increase of solvent polarity. Absorption λ(max) and emission λ(max) was less correlated with substituent groups on benzene rings. The calculated molecular orbital correlates well with their absorption.
Assuntos
Modelos Moleculares , Fenômenos Ópticos , Oxidiazóis/química , Oxidiazóis/síntese química , Absorção , Técnicas de Química Sintética , Conformação Molecular , Imagem Molecular , Espectrometria de FluorescênciaRESUMO
Mitochondria are the powerhouses in cells, providing the energy needed for cellular activities. However, the abnormalities in the mitochondrial microenvironment (e.g., the increased viscosity) can lead to mitochondrial dysfunctions and diseases. Herein, we develop a series of near-infrared (NIR) fluorescence probes for the detection of viscosity. After screening, probe CQ-4 is selected since it shows a great fluorescence enhancement (89-fold) in the NIR window. Its specific response to viscosity is not influenced by pH, polarity and biological species. Under stimulation with monensin or nystatin, CQ-4 can measure the cellular viscosity changes with good biocompatibility. In addition, we can observe an increase of viscosity during starvation. CQ-4 is applied to distinguish cancer cells from normal cells based on the viscosity differences. Furthermore, the probe has been successfully applied to image viscosity in inflamed and tumor-bearing mice in vivo. Therefore, CQ-4 may contribute to the future study about viscosity in the physiological and pathological processes.
Assuntos
Corantes Fluorescentes , Monensin , Animais , Fluorescência , Células HeLa , Humanos , Camundongos , Mitocôndrias , Nistatina , ViscosidadeRESUMO
Ulcerative colitis is a prevalent inflammatory disease caused by the intestinal bacterial infection. And it is related to the hypoxic degrees in the colon microenvironment. Hypoxia, a condition of imbalance in O2 supply and consumption, is accompanied by the overexpressed level of nitroreductase (NTR). Therefore, the NTR detection has been widely applied for the diagnosis of hypoxia-related diseases. In this study, we developed a novel near-infrared fluorescent probe (IW-1) for NTR. Upon reaction with NTR, IW-1 exhibited a significant fluorescence off-on response at 740 nm with a low detection limit of 0.043 µg/mL. Confocal fluorescence imaging verified its ability to detect the overexpression of NTR in cancer cells. More significantly, IW-1 was applied for in vivo hypoxia imaging in tumors and dextran sulphate sodium (DSS)-induced ulcerative colitis mouse model. We expect that the probe may present a new tool for better understanding the biological functions of NTR as well as revealing essential information about hypoxia-related pathological processes, including cancer and ulcerative colitis.
Assuntos
Colite Ulcerativa , Corantes Fluorescentes , Animais , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/diagnóstico por imagem , Corantes Fluorescentes/toxicidade , Hipóxia/diagnóstico por imagem , Camundongos , Microscopia de Fluorescência/métodos , Nitrorredutases , Imagem Óptica/métodosRESUMO
Mitophagy, a mitochondria-selective autophagy process, plays critical roles in maintaining intracellular homeostasis by removing the damaged mitochondria and recycling the nutrients in a lysosome-dependent manner. Mitophagy process could result in the changes of mitochondrial pH. So fluorescent probes for detecting mitochondrial pH during mitophagy are highly needed for exploring the functions of mitochondria. Herein, a series of near-infrared pH probes were designed based on the rhodamine framework. The probes showed high sensitivity for pH with the tunable pKa from 4.74 to 6.54. Particularly, for probe 5 (with the pKa of 6.54), a linear relationship between fluorescence intensity and pH in the range of 5.6-7.2 was observed, which was suitable for mitochondrial pH detection. The probe displayed excellent mitochondria-targeting ability. It was applied to monitor pH changes during mitophagy caused by starvation. Besides, in vivo non-invasive visualization of tumor pH variations was achieved via the fluorescence imaging in the near-infrared region. We anticipate that the probe may be a useful tool for revealing essential information about mitophagy-related research and clinical tumor diagnosis.
Assuntos
Mitofagia , Neoplasias , Corantes Fluorescentes , Humanos , Concentração de Íons de Hidrogênio , Mitocôndrias/patologia , Neoplasias/diagnóstico por imagem , Neoplasias/patologiaRESUMO
As a member of the reactive oxygen species, hydrogen peroxide (H2O2) plays critical roles in oxidative stress and cell signaling. Intracellular abnormal levels of H2O2 production are closely related to many diseases. Therefore, the real-time monitoring of H2O2 in the cells is important. In this work, we designed a novel fluorescent probe (Mito-H2O2) for the specific detection of H2O2 based on the hemicyanine skeleton, with bright near-infrared fluorescence emission. Mito-H2O2 displayed fast response, excellent water-solubility and great fluorescence intensity enhancement after the addition of H2O2. Furthermore, Mito-H2O2 has been successfully applied to image both of the exogenous and endogenous H2O2 in cells and mice with negligible cytotoxity.
Assuntos
Corantes Fluorescentes , Peróxido de Hidrogênio , Animais , Carbocianinas , Células HeLa , Humanos , Camundongos , EsqueletoRESUMO
Cyanide (CN-) is a highly toxic compound that exists in many substances and is harmful to the environment and human health. Therefore, it is of great significance to develop excellent CN- ion probes, especially solvent-induced on-off fluorescent probes. Based on the condensation reaction of indolo[2,1-b][1,3]oxazine molecules with aldehydes, probes (E)-13a-(2-(9-ethyl-9H-carbazol-3-yl)vinyl)-14,14-dimethyl-10-nitro-13a,14-dihydro-8H-benzo[e]benzo[5,6][1,3]oxazino[3,2-a]indole (NCO) and (E)-13a-(2-(9-benzyl-9H-carbazol-3-yl)vinyl)-14,14-dimethyl-10-nitro-13a,14-dihydro-8H-benzo[e]benzo[5,6][1,3]oxazino[3,2-a]indole (NBO) were synthesized to detect CN-. Compared with other cyanogen ion probes, NCO and NBO have special carbazole ring structures and large conjugate systems. When CN- is added to the probe-detection solution, color changes that are visible to the naked eye can occur. The UV-vis spectrum test using differential spectroscopy shows that the probe (i) has excellent solvent-induced switching characteristics and stability (CH3OH-H2O) and (ii) high selectivity, anti-interference ability, and sensitivity for the detection of CN-. The fluorescence limit of detections (LODs) are 1.05 µM for NCO and 1.34 µM for NBO. The UV LODs are 0.83 µM for NCO and 0.87 µM for NBO. Fluorescence spectroscopy shows that the probe has remarkable fluorescence properties. Fluorescence titration experiments, liver cancer cell (Hep G2) imaging, and cytotoxicity experiments all show that the probes have high biocompatibility, low toxicity, high cell permeability, and high sensitivity for the detection of CN- in cells. In addition, NCO and NBO have been successfully used for the detection of cyanogenic glycosides in the seeds of ginkgo, crabapple, apple, and cherry. Test strips were fabricated to detect CN-. After adding CN-, the color of the test strip changed significantly-from brown to light yellow; thus, the test strips have a high application value in the fields of drug quality control, drug safety testing, and pharmacological research.
Assuntos
Cianetos , Corantes Fluorescentes , Carbazóis/toxicidade , Humanos , Extratos Vegetais , Espectrometria de FluorescênciaRESUMO
The title compound, C(21)H(18)N(2)O(2), was synthesized using a novel tandem annulation reaction between (1H-benzimidazol-2-yl)(phen-yl)methanone and (E)-ethyl 4-bromo-but-2-enoate under mild conditions. The dihedral angles between the mean planes of the five-membered imidazole ring and the pyridine, benzene and phenyl rings are 0.45â (6), 1.69â (1) and 70.96â (8)°, respectively. In the crystal, mol-ecules are linked through inter-molecular C-Hâ¯N hydrogen bonds.
RESUMO
Hypochlorite (-OCl) has long been recognized as an effective microbicidal agent in immune system. Herein, we report the design, preparation and spectral characteristics of a -OCl fluorescent probe (FI-Mito). The probe exhibited remarkable fluorescence turn-on signal in the red region upon -OCl titration with the detection limit as low as 0.9 nM. FI-Mito displayed specific response for -OCl in completely aqueous solution. Meanwhile, the introduction of quaternized pyridine realized mitochondria-targeting ability. FI-Mito was further applied to monitor the generation of endogenous -OCl in the mitochondria of macrophage cells and mice. Therefore, it was established that FI-Mito may serve as a useful molecular tool for -OCl detection in vivo.
Assuntos
Corantes Fluorescentes , Ácido Hipocloroso , Animais , Camundongos , Microscopia de Fluorescência , Mitocôndrias , ÁguaRESUMO
Heat shock is a potentially fatal condition characterized by high body temperature (>40⯰C), which may lead to physical discomfort and dysfunctions of organ systems. Acidic pH environment in lysosomes can activate enzymes, thus facilitating the degradation of proteins in cellular metabolism. Owing to the lack of a practical research tool, it remains difficult to exploit relationship between heat shock and lysosome. Herein, a NIR lysosomal pH chemosensor (NRLH) was developed. One typical lysosome-locating group, morpholine, was incorporated into NRLH. The fluorescence intensity showed pH-dependent characteristics and responded sensitively to pH fluctuations in the pH range of 3.0-5.5. NRLH with a pKa of 4.24 displayed rapid response and high selectivity for H+ among common species. We also demonstrated NRLH was capable of targeting lysosomes. Importantly, NRLH was applied in cellular imaging and the data revealed that lysosomal pH increased but never decreased during the heat shock. Therefore, NRLH may act as an effective molecular tool for exploring the mechanisms of heat-related pathology in bio-systems.
Assuntos
Resposta ao Choque Térmico , Lisossomos/metabolismo , Sondas Moleculares/química , Rodaminas/química , Soluções Tampão , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Sondas Moleculares/síntese química , Soluções , Espectrometria de Fluorescência , Fatores de TempoRESUMO
In this paper, we synthesized a ratiometric fluorescence probe (IRh-Ly) for lysosomal hypochlorous acid (HOCl) by adopting a through-bond energy transfer (TBET) strategy on rhodamine-imidazo[1,5-a]pyridine platform. IRh-Ly showed brilliant selectivity, rapid response for HOCl. The probe also exhibited high sensitivity with the detection limit calculated to be 10.2â¯nM. Moreover, we demonstrated its successful application of detecting lysosomal HOCl in living RAW264.7â¯cells. Notably, the morpholine was integrated into the fluorescent probe IRh-Ly and the results revealed that IRh-Ly could target lysosome and detect the lysosomal HOCl. All the unique features made IRh-Ly particularly suitable for ratiometric HOCl detection and bio-imaging applications.
Assuntos
Transferência de Energia , Corantes Fluorescentes/metabolismo , Ácido Hipocloroso/metabolismo , Lisossomos/metabolismo , Animais , Camundongos , Morfolinas/química , Morfolinas/metabolismo , Imagem Óptica , Células RAW 264.7RESUMO
A rhodamine B-based derivative (RL1) was developed as a specific fluorescent probe for HOCl. Meanwhile, morpholine moiety was introduced into the probe. It was found that the probe could display highly selective, sensitive and naked-eye detection upon the addition of HOCl. And the detection limit (LOD) was calculated to be as low as 2.8â¯nM. Furthermore, cellular confocal microscopic studies revealed that the introduction of morpholine moiety realized the lysosome-targeting capability. Moreover, RL1 was successfully applied for the imaging of endogenous HOCl with low cytotoxicity. Therefore, all the desirable features made probe RL1 particularly suitable for HOCl detection in aqueous buffer solution samples as well as the bio-imaging applications.
Assuntos
Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Lisossomos/química , Rodaminas/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Corantes Fluorescentes/farmacologia , Limite de Detecção , Camundongos , Microscopia Confocal , Microscopia de Fluorescência , Estrutura Molecular , Imagem Óptica , Células RAW 264.7 , Rodaminas/farmacologia , Relação Estrutura-AtividadeRESUMO
In this paper, ratiometric imaging of lysosomal HOCl was realized with a molecular probe (CR-Ly) based on fluorescence resonance energy transfer by using coumarin as the donor and rhodamine as acceptor. CR-Ly showed high sensitivity and fast response to HOCl. Moreover, CR-Ly exhibited excellent selectivity and sensitivity for HOCl over other biologically relevant species. Furthermore, it was successfully utilized to image the endogenous HOCl with low cytotoxity. And CR-Ly was capable of targeting lysosomes and monitoring lysosomal hypochlorous acid changes owing to the presence of the morpholine moiety. We believe that probe CR-Ly would be helpful to further research on the HOCl-associated diseases in lysosomes.
Assuntos
Transferência Ressonante de Energia de Fluorescência/métodos , Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Lisossomos/metabolismo , Animais , Morte Celular , Corantes Fluorescentes/síntese química , Ácido Hipocloroso/química , Camundongos , Células RAW 264.7RESUMO
A series of novel 2-acyl-6-aryl substituted indolizine derivatives was synthesized by a novel tandem reaction between 4-acyl-pyrrole-2-carbaldehyde derivatives and ethyl 4-bromo-3-arylbut-2-enoate under mild conditions. The compounds were characterized using IR, (1)H NMR (13)C NMR and HRMS. The crystal structure of 7a was determined using single crystal X-ray crystallography. The absorption results showed that compounds 7a-e presented their absorption maxima at ca. 270 nm, while compounds 7f and 7g with a larger conjugation system exhibited red-shifted absorption character (ca. 280 nm). Fluorescence spectra revealed that these compounds exhibited blue fluorescence (434-456 nm) in dilute solutions and showed quantum yields of fluorescence between 0.02 and 0.39 in dichloromethane.
Assuntos
Indolizinas/química , Indolizinas/síntese química , Fenômenos Ópticos , Cristalografia por Raios X , Elétrons , Cloreto de Metileno/química , Conformação Molecular , Solventes/química , Espectrometria de Fluorescência , Espectrofotometria UltravioletaRESUMO
A series of novel 5-aryl-3-benzimidazolyl-1-phenyl-pyrazoline derivatives were synthesized by the reaction of benzimidazolyl chalcone and phenylhydrazine in 41-72% yields. The compounds were characterized using IR, (1)H NMR and HRMS. Absorption and fluorescence spectra were measured in different organic solvent. An intense absorption maxima was noted at ca. 370 nm and emission maxima was noted at ca. 460 nm. The absorption spectra of the pyrazoline derivatives reveal that 5-aryl group attached to the pyrazoline ring hardly influenced the maximum absorption. The fluorescence spectra of these compounds indicated the emission wavelength was red shifted and the fluorescence intensity was decreased with the increase in solvent polarity.