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In this work, we have designed and synthesized the fluorescent probe 1, which was capable to selectively detect fluoride anion (F−). More importantly, the probe 1 possessed near-infrared excitation and emission wavelengths (excitation at 650 nm and emission at 695), and the probe solution had changed dramatically from yellow to cyan with the addition of F–. In addition, the fluorescence intensity exhibited perfectly positive correlation with concentration of F− concentration from 0 to 40 μM (R2 = 0.9972), which offered the important condition for quantitative analysis. The probe 1 owned detection limit of 46 nM. Therefore, this near-infrared probe can be of great benefit for detecting F− in practical application. [ABSTRACT FROM AUTHOR]

A fluorescent probe, with simplicity of structure and convenience of synthesis, is capable of detecting cysteine over other biothiols, such as homocysteine and glutathione. The detection limit of 60 nM and 190-fold increase in fluorescence intensity offer advantage for detection of Cys in biological systems. Furthermore, the probe 1 could be applied in bioimaging. Graphical abstract: We designed and synthesized the fluorescent probe 1, which displayed a highly selective and sensitive response to Cys over Hcy/GSH. The detection limit of 60 nM and 190-fold increase in fluorescence intensity offer advantage for detection of Cys in biological systems. Furthermore, the probe 1 could be applied in bioimaging. [ABSTRACT FROM AUTHOR]

Red fluorescence emission and functionality are critically required for the development and applications of carbon quantum dots (CQDs), as most CQDs show blue and green excitation dependent emissions. In this research, gadolinium (Gd) containing CQDs were prepared with p-phenylenediamine, diethylene triamine pentaacetic acid (DTPA), and Gd3+ ions as the precursors using a simple hydrothermal strategy. The hybrid CQDs showed excitation independent red fluorescence. Using DTPA–Gd it was possible to functionalize hybrid CQDs with a magnetic resonance (MR) response. The red fluorescence and biocompatibility of the CQDs were validated using HepG2 (liver hepatocellular carcinoma) cells, zebrafish embryos and larvae as models. The hybrid CQDs did not interfere with the development of zebrafish embryos and the different affinity of the CQDs towards the different tissues of the embryos and larvae was clearly observed. Fluorescence and MR images were recorded using mice as the model. While the liver and kidney of the mice were clearly outlined on the MR image, the red fluorescence could penetrate the skin of mice easily. Further strategies that tune the emission, especially the red and the near-infrared emission, functionalize the CQDs using an easy procedure, and improve the quantum yield of CQDs, are still needed to promote their development and applications. [ABSTRACT FROM AUTHOR]

Biomolecule-mimicking nitrogen-doped carbon dots (N-Cdots) were synthesized from dopamine by a neutralization heat strategy. Fluorescence imaging of various cells validated their nucleus-staining efficiency. The dopamine-mimicking N-Cdots “trick” nuclear membranes to achieve nuclear localization and imaging. [ABSTRACT FROM AUTHOR]

Four novel compounds were designed by 'tailoring' 3,3′-dihydroxyisorenieratene (a natural carotenoid) based on an isoprene unit retention truncation strategy. Among them, the smallest molecule 1 (2,3,6,2′,3′,6′-hexamethyl-4,4′-dihydroxy-trans-stilbene) was concisely synthesized in a one-pot Stille-Heck tandem sequence, and surfaced as a promising lead molecule in terms of its selective antiproliferative activity mediated by blocking the NCI-H460 cell cycle in G1 phase. Additionally, theoretical calculations and cell uptake experiments indicate that the unique polymethylation pattern of compound 1 significantly induces a conformational change shift out of planarity and increases its cell uptake and metabolic stability. The observation should be helpful to rationally design resveratrol-inspired antiproliferative agents. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (C-QDs) are becoming a desirable alternative to metal-based QDs and dye probes owing to their high biocompatibility, low toxicity, ease of preparation, and unique photophysical properties. Herein, we describe fluorescence bioimaging of zebrafish using C-QDs as probe in terms of the preparation of C-QDs, zebrafish husbandry, embryo harvesting, and introduction of C-QDs into embryos and larvae by soaking and microinjection. The multicolor of C-QDs was validated with their imaging for zebrafish embryo. The distribution of C-QDs in zebrafish embryos and larvae were successfully observed from their fluorescence emission. the bio-toxicity of C-QDs was tested with zebrafish as model and C-QDs do not interfere to the development of zebrafish embryo. All of the results confirmed the high biocompatibility and low toxicity of C-QDs as imaging probe. The absorption, distribution, metabolism and excretion route (ADME) of C-QDs in zebrafish was revealed by their distribution. Our work provides the useful information for the researchers interested in studying with zebrafish as a model and the applications of C-QDs. The operations related zebrafish are suitable for the study of the toxicity, adverse effects, transport, and biocompatibility of nanomaterials as well as for drug screening with zebrafish as model. [ABSTRACT FROM AUTHOR]

Intracellular microenvironment (viscosity and polarity) and peroxynitrite ions (ONOO−) are involved in maintaining cell morphology, cell function, and signaling so that it is crucial to explore their level changes in vitro and vivo. In this work, we designed and synthesized a mitochondria-targeted fluorescence probe XBL for monitoring the dynamic changes of viscosity, polarity, and ONOO− based on TICT and ICT mechanism. The fluorescence spectra showed obvious changes for polarity at 500 nm as well as ONOO− and viscosity at 660 nm, respectively. The XBL can image simultaneously viscosity, polarity, and ONOO− in cells, and the results showed excess ONOO− leaded to the increase of viscosity in mitochondrial. The ferroptosis process was accompanied by increase of intracellular viscosity and ONOO− levels (or decrease of polarity), which allowed us to better understand the relevant physiological and pathological processes. The XBL can distinguish normal cells and cancerous cells by the fluorescence intensity changes in green and red channels, and image viscosity in inflamed mice. Thus, XBL can provided the chemical tool to understand the physiological and pathological mechanisms of disease by simultaneous detection of viscosity, polarity and ONOO−. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The probe P-1 can selectively detect H 2 O 2 with colorimetric change. • the P-1 can be used for on-site and visual detection of H 2 O 2. • The P-1 can image H 2 O 2 in cells and distinguish cancer cells and normal cells. • The P-1 probe was applied to monitor H 2 O 2 of tumor in mice. We designed and developed the probe P-1 for detecting H 2 O 2. The probe can selectively detect H 2 O 2 with colorimetric change. In addition, the combination of portable test strips with a smartphone platform provided great convenience for on-site and visual detection of H 2 O 2 with satisfactory sensitivity and reliability. The P-1 can image exogenous and endogenous H 2 O 2 in cells and distinguish cancer cells and normal cells by fluorescence image of H 2 O 2 and flow cytometry. Meanwhile, the P-1 probe has been successfully applied to monitor H 2 O 2 levels of tumor in mice, and the results showed the level of H 2 O 2 in tumor tissue increased significantly. Therefore, P-1 provided a potential chemical tool to understand pathological and physiological mechanisms of diseases by imaging H 2 O 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • We designed and developed the probe W-3 for selectively detecting Cu2+. • The combination of test strips and a smartphone facilitates on-site testing of Cu2+. • The W-3 can be used for the detection of Cu2+ in cells and mice. We designed and developed the probe W-3 for detection of Cu2+. The results showed probe can selectively detect Cu2+, accompanied by noticeable color change. The probe can detect the Cu2+ in water samples and drinks based on absorption detection. In addition, the combination of portable test paper and the smartphone platform obtained great convenience for on-site and visual detection of Cu2+, with satisfactory sensitivity and reliability. More importantly, the fluorescence probe W-3 can be used for the detection of Cu2+ in cells and mice. Therefore, the W-3 provided potential chemical tools for detecting Cu2+ in vitro and vivo. [ABSTRACT FROM AUTHOR]

Diabetes has become one of the most common endocrine and metabolic diseases threatening human health, which can induce mitochondrial dysfunction and exacerbate the excessive production of reactive oxygen species (ROS). Among them, ONOO− level fluctuation was closely related to diabetes. Hence, it is of great significance to develop a near-infrared fluorescence probe for visualizing ONOO− level fluctuations in diabetes. In this paper, we constructed a fluorescence probe YBL with dicyano-isophorone derivative as fluorophore and diphenyl phosphate as ONOO− response site, which can detect ONOO− with the low detection limit (39.8 nM) and exhibit excellent selectivity and sensitivity. The probe YBL has been applied to monitor intracellular ONOO− level fluctuations. Meanwhile, the image results showed that high sugar promoted the increase of ONOO− level in cells. More important, the probe YBL can be used for imaging in mice, and the results showed that content of ONOO− was increased in diabetic mice. Therefore, the probe YBL provided a tool for understanding diabetes progression by imaging ONOO−. [Display omitted] • The near infrared fluorescence probe YBL can detect ONOO−. • The YBL was able to image ONOO− in cells and distinguish normal cells and cancer cells. • The YBL can be used for imaging diabetes in mice. [ABSTRACT FROM AUTHOR]

Biological thiols, such as homocysteine, cysteine, and glutathione play key roles in physiological processes. However, due to the similarity of their structures and chemical properties, it has been a challenge to distinguish these compounds. In this work, a new fluorescent probe (E)-4-(4-(diethylamino)-2-((7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)oxy) styryl)-1-methylpyridine iodide (Y-OH-NBD) is reported for the determination of cysteine. Based on the nucleophilic aromatic substitution and rearrangement cascade reaction, Y-OH-NBD was demonstrated to be a selective turn-on fluorescence probe for cysteine without interferences and probe consumption caused by high concentration of glutathione in phosphate buffer pH 7.4 containing 5% dimethyl sulfoxide. The Y-OH-NBD system determined cysteine with a response time of less than 5 min and a low limit of detection equal to 1.88 µM. Moreover, the probe showed low cytotoxicity and was conveniently applied to image intracellular cysteine in HeLa cells, indicating its significant potential biological applications. [ABSTRACT FROM AUTHOR]

In this work, we synthesized a simple fluorescent probe, which can selectively detect cysteine. With addition of cysteine, the probe solution showed marked color change from pale yellow to orange color by naked eye. There was an excellent linear relationship between fluorescence intensity of probe and cysteine concentration. Moreover, the probe displayed satisfactory detection limit. Low toxicity and cellular imaging offered the important conditions for detecting cysteine in biological system. [ABSTRACT FROM AUTHOR]

With the improvement and advance in cancer diagnosis and treatment, the cancer is still a major cause of morbidity and mortality throughout the world. Obviously, new breakthroughs in therapies remain be urgent needed. In this work, we designed and synthesized the compound 1–4, namely resveratrol analogues with methylation of hydroxy distyrene, to further explore its new anti-cancer potential. Encouragingly, compound 1 ((E)-4,4′-(ethene-1,2-diyl)bis(3,5-dimethylphenol)) exhibited cytotoxicity superior to resveratrol in MCF 7 cells. More importantly, the compound 1 showed greater toxicity to tumor cells than that to normal cells, which proved that it could selectively kill tumor cells. The favorable results encouraged us to explore the inhibitory mechanism of compound 1 on MCF 7 cells. The research finding indicated the compound 1 inhibited tumor cell proliferation by both arresting cell cycle in S phase and apoptosis via a prooxidant manner. In addition, the results further verified compound 1 caused cell cycle arrest in S phase and apoptosis by down-regulation of the cycling A1/cycling A2 expression and the rise of Bax/Bcl-2 ratio in a p21-dependant pathway in MCF 7 cells. Therefore, these results are helpful for the effective design of anticancer reagents and the better understanding of their mechanism of action. [ABSTRACT FROM AUTHOR]

A simple and coumarin-based fluorescence probe has been designed and synthesized with silyl group as recognition group of fluoride ions (F−) in this study. The results showed that the fluorescence intensity of the probe displayed prominent enhancement with addition of F− at 445 nm with incubation of 1 min. There was an excellent linear relationship between fluorescence intensity and fluoride concentration from 0 to 30 μM (0~0.57 ppm), which offered the important condition for the quantitative analysis. In addition, the highly selective response to fluorion, the low detection limit with 28 nM (0.532 ppb), low toxicity and bioimaging afforded an advantage for practical application and detecting fluoride in biological systerms. [ABSTRACT FROM AUTHOR]

Abstract Compared with normal cells, cancer cells harbor increased levels of reactive oxygen species (ROS) including hydrogen peroxide (H 2 O 2), and therefore are more vulnerable to further ROS production. This biochemical difference favors the idea of developing new powerful selective prooxidative anticancer agents. However, it still remains a challenge to design them by targeting this difference. Herein, we report the designed dichlorobinaphthoquinone as a prooxidative anticancer agent which is capable of exploiting increased levels of H 2 O 2 of cancer cells to produce in situ lethal hydroxyl radicals (HO•) and thereby kill them selectively, a design strategy inspired from Zhu et al.'s work on the molecular mechanism for metal-independent production of HO•. Graphical abstract Image 1 Highlights • Designing prooxidative anticancer agents by metal-independent production of HO•. • BQ-DC was designed based on the skeleton of natural conocurvone. • Preferential killing of cancer cells over normal cells by the designed BQ-DC. • BQ-DC can exploit increased levels of H 2 O 2 of cancer cells to in situ produce HO•. • The H 2 O 2 -responsive formation of HO• was evidenced by a series of experiments. [ABSTRACT FROM AUTHOR]

In this work, we have designed and synthesized the fluorescent probe 1 , which showed a highly selective and sensitive response to Cys over Hcy/GSH in the test. Moreover, the color of probe solution has changed dramatically from colorless to pink with the addition of Cys within 10 min. Meanwhile, the fluorescence intensity exhibited perfectly positive correlation with concentration of Cys from 0 to 200 μM, which offered the important condition for quantitative analysis. Finally, the bioimaging and fluorescence response of probe 1 for fetal calf serum are a powerful safeguard for practical detection of Cys. Therefore, this near-infrared probe will be of great benefit for detecting Cys in the biological systems. [ABSTRACT FROM AUTHOR]

In this work, we synthesized a fluorescent probe JQ-3 for detecting ONOO−. The probe JQ-3 can be successfully used for detecting exogenous and endogenous ONOO− in living cells and zebrafish. Moreover, the drug-induced liver injury was successfully recognized with JQ-3 by visualizing ONOO− in living cells and zebrafish. Therefore, the probe JQ-3 provides a potential tool for detecting ONOO− to understand physiological and pathology processes of disease. [Display omitted] • The probe JQ-3 possessed excellent selectivity, fast response time (10 min) and low detaction limit (32 nM). • The probe JQ-3 is almost unaffected by pH, showing the potential application in biological systems. • The probe JQ-3 can be successfully used for the detection of exogenous and endogenous ONOO− in living cells and zebrafish. • The drug-induced liver injury was successfully recognized by fluorescence imaging with JQ-3 in living cells and zebrafish. Peroxynitrite (ONOO−) as an active substance, is produced during normal physiological process, which plays an important role in maintaining cell REDOX balance and cell function. Moreover, the peroxynitrite is involved in many diseases and especially can be used as a biomarker of drug-induced liver injury (DILI). Therefore, in this work, we synthesized a fluorescent probe JQ-3 for detecting ONOO−. The results showed the probe JQ-3 possessed excellent selectivity, fast response time (10 min) and low detection limit (32 nM). The probe JQ-3 is almost unaffected by pH, showing the potential application in biological systems. Moreover, the probe JQ-3 can be successfully used for the detection of exogenous and endogenous ONOO− in living cells and zebrafish. At the same time, the DILI was successfully recognized by visualizing ONOO− with JQ-3 in living cells and zebrafish. Therefore, the probe JQ-3 provides a potential tool for detecting ONOO− to understand physiological and pathology processes of disease. [ABSTRACT FROM AUTHOR]

In this work, we designed and synthesized a ratiometric fluorescent probe JQ-2 for specifically detecting ONOO− over a panel of biological analytes. The probe JQ-2 possessed low cytotoxicity and excellent cell membrane permeability, which can detect the exogenous and endogenous ONOO− in living cells and zebrafish by emission in two channels. Meanwhile, JQ-2 can be used for diagnosing drug-induced liver injury by visualizing and monitoring the fluctuations of endogenous ONOO−. [Display omitted] • Fast response time (∼100 s). • The ratiometric fluorescent probe for detecting ONOO−. • Visualizing exogenous and endogenous ONOO− in living cells and zebrafish. • Visualizing drug-induced liver injury by bioimaging of ONOO− in two channels. In this study, we constructed and displayed a ratiometric fluorescent probe JQ-2 for detecting ONOO−. The probe JQ-2 showed a ratiometric signal for visualizing ONOO− with a rapid response and high selectivity over a panel of biological analytes. Moreover, the JQ-2 has near-infrared emission (657 nm), which provides an excellent basis for the practical application in biological systems. The probe JQ-2 possessed low cytotoxicity and excellent cell membrane permeability, which can specifically visualize the exogenous and endogenous ONOO− in vitro and vivo by emission in two channels. Meanwhile, JQ-2 can be used for diagnosing drug-induced liver injury by visualizing and monitoring the fluctuations of endogenous ONOO−. Therefore, JQ-2 provided a potential tool for precisely detecting the fluctuation of ONOO− in biological systems to understand physiological and pathological process. [ABSTRACT FROM AUTHOR]

In this work, we designed and synthesized a turn-on fluorescent probe for detecting H 2 O 2. The results demonstrated that probe JQ-1 exhibited a high selectivity for H 2 O 2. In addition, probe JQ-1 exhibited excellent sensitivity (detection limit: 87 nM) and a fast response time (∼10 min). Organelle co-localization experiment showed that JQ-1 mainly targeted mitochondria, which provided possibility to detect change of H 2 O 2 level in mitochondria. JQ-1 can be used to image exogenous and endogenous H 2 O 2 in vitro and vivo. Meanwhile, we used JQ-1 as fluorescence dye to investigate the change of H 2 O 2 level during immunogenic cell death for the first time by confocal laser scanning microscopy and flow cytometry, and the results showed that H 2 O 2 level had negligible change in process. Therefore, the results suggested that this probe is a reliable chemical tool for monitoring both endogenous and exogenous H 2 O 2. In this work, we designed and synthesized a localized mitochondrial probe, which showed excellent selectivity and anti-interference capability. The detection limit of 87 nM and reaction time of 10 min provided the advantage for real-time detection of H 2 O 2 in practical application. In addition, the probe can image exogenous and endogenous H 2 O 2 in vitro and vivo. [Display omitted] • Low detection limit (87 nM) and a fast response time (∼10 min). • The probe has mitochondrial targeting capability. • There was an excellent linear relationship between fluorescence intensity and H 2 O 2 concentration with 0–50 μM. • The probe is able to visualize exogenous and endogenous H 2 O 2 in living Hela cells and zebrafish. [ABSTRACT FROM AUTHOR]

In this work, we have designed and synthesized a large stokes shift and near-infrared (NIR) probe DCM-HNU for visualization of H 2 O 2 in both living HeLa cells and zebra fish. The probe DCM-HNU was structured based on phenylborate pincinol ester as the recognition group connecting DCM-OH via nucleophilic substitution reaction. The probe possessed large stokes shift (205 nm), near-infrared (NIR) emission (658 nm). 0.17 μM detection Limit, 10,550 L·mol−1cm−1 molar extinction coefficient, 2.06 × 10−3 S−1 reaction rate constant, and excellent selectivity proved the condition for practical application. There was a good linear relationship between fluorescence intensity and H 2 O 2 concentration from 0 to 200 μM (R2 = 0.9955) to facilitate quantitative analysis of H 2 O 2. More importantly, the probe is able to visualize exogenous and endogenous H 2 O 2 in living HeLa cells and zebra fish. The superior properties of the probe provide potential for exploring the function and participation of H 2 O 2 in biological systems. • Large stokes shift (205 nm), near-infrared (NIR) emission (658 nm). • The probe is able to visualize exogenous and endogenous H 2 O 2. [ABSTRACT FROM AUTHOR]

Abstract: Based on the observed biological activities of coumarins and resveratrol, we synthesized fourteen hydroxylated 3-phenylcoumarins (stilbene-coumarin hybrids) including six novel ortho-hydroxy-methoxy substituted derivatives, 1–14, by Perkin reaction. We characterized these compounds concerning their antioxidant activity against 2,2′-azobis(2-amidinopropane hydrochloride) (AAPH)-induced pBR322 DNA strand breakage, and their antiproliferative effects on human promyelocytic leukemia HL-60 and human lung adenocarcinoma epithelial A549 cells. Structure–activity relationship information suggests that the introduction of ortho-hydroxy-methoxy groups and ortho-dihydroxy groups on the aromatic A ring could efficiently improve antiproliferative activity. Interestingly, a new derivative, 6-methoxy-7-hydroxy-3-(4′-hydroxyphenyl)coumarin, 9, behaved as a poor antioxidant but appeared to be the most potent antiproliferative agent among the compounds examined, and this activity was mediated by deregulation in cell cycle and induction of apoptosis. [Copyright &y& Elsevier]