A Fluorescent Furan-based Probe with Protected Functional Groups for Highly Selective and Non-Toxic Imaging of HT-29 Cancer Cells and 4T1 Tumors.

Most of the previously reported fluorescent organic probes for cancer cell and tumor imaging have significant limitations including chemical toxicity, structural instability, low Stokes shift value, and the inability for selective accumulations in tumors during in vivo imaging. To overcome the mentioned challenges, we synthesized the fluorescent probes with protected polar functional groups to enhance the non-toxicity nature and increase the selectivity toward tumors. In addition, the structural rigidity of the fluorescent probes was increased by embedding aromatic rings in the probe structure. This issue enables us to obtain ultrabright cell images due to enhanced fluorescence quantum yield (ΦFL) values. After synthesis and spectral characterizations, the applicability of two furan-based and imidazole-based fluorescent probes ( abbreviated as DCPEF and DBPPI, respectively) was investigated for ultrabright in vitro and in vivo imaging of cancer cells. The probe DCPEF shows the ΦFL value of 0.946 and the Stocks shift of 86 nm. In addition, probe DBPPI offers the ΦFL value of 0.400 and a Stocks shift of 150 nm. The MTT colorimetric cytotoxicity assay showed that probe DCPEF has minimal effects against HT-29 (cancer) and Vero (normal) cells. The probe DCPEF produced ultrabright fluorescence images from HT-29 cells. In addition, in vivo imaging of cancer cells showed that probe DCPEF selectively accumulates in the 4T1 tumor in mice. The spectral and chemical stability, minimal cytotoxicity, significant Stokes shift, and high degree of selectivity for tumor cells during in vivo imaging make DCPEF an appropriate candidate to be used as a standard probe for cancer cell imaging.

Ring Opening Polymerization Used for the Production of VOC Free High-Performance Ecofriendly Novel PBZ/PDA/CeO2 Nanocomposites.

This study analyzed the fabrication and characterization of polybenzoxazine/polydopamine/ceria as tertiary nanocomposites. To this end, a new benzoxazine monomer (MBZ) was fabricated based on the well-known Mannich reaction of naphthalene-1-amine, 2-tert-butylbenzene-1,4-diol and formaldehyde under ultrasonic-assisted process. Polydopamine (PDA) was used as dispersing polymer nanoparticles and surface modifier for CeO2 by in-situ polymerization of dopamine with the assistance of ultrasonic waves. Then, nanocomposites (NC)s were manufactured by in-situ route under thermal conditions. The FT-IR and 1H-NMR spectra confirmed the preparation of the designed MBZ monomer. The FE-SEM and TEM results showed the morphological aspects of prepared NCs and illustrated the distribution of CeO2 NPs in the polymer matrix. The XRD patterns of NCs showed the presence of crystalline phases of nanoscale CeO2 in an amorphous matrix. The TGA results reveal that the prepared NCs are classified as thermally stable materials.

Synthesis and application of the fluorescent furan and imidazole probes for selective in vivo and in vitro cancer cell imaging.

Development of imaging probes for identification of tumors in the early stages of growth can significantly reduce the tumor-related health hazards and improve our capacity for treatment of cancer. In this work, three different furan and imidazole fluorescent derivatives abbreviated as Cyclo X, SAC and SNO are introduced for in vivo and in vitro imaging of cancer cells. The fluorescence quantum yield values were 0.226, 0.400 and 0.479 for Cyclo X, SAC and SNO, respectively. The excitation and emission wavelengths of maximum intensity were (360, 452), (350, 428) and (350, 432) nm for Cyclo X, SAC and SNO, respectively. The MTT reduction assay was used to estimate the cytotoxic activity of the proposed derivatives against HT-29 (cancer) and Vero (normal) cell lines. Cyclo X showed no cytotoxic effect, while SAC and SNO showed significantly higher cytotoxicity against the tested cell lines than cisplatin as a well-known anticancer drug. In vitro fluorescence microscopic images obtained using HT-29 cells showed that Cyclo X produced very bright images. The in vivo cancer cell imaging using 4T1 tumor-bearing mice revealed that Cyclo X is selectively accumulated in the tumor without distribution in the mice body organs. The spectral and structural stability, large Stokes shift, non-cytotoxicity and high level of selectivity for in vivo imaging are properties that make Cyclo X a suitable candidate to be used for long-term monitoring of cancer cells.

One-pot synthesis of γ -spiroiminolactones and γ -dispiroiminolactones using N,N'-disubstituted parabanic acid and thioparabanic acid derivatives.

A direct entry and simple process for the synthesis of [Formula: see text]-spiroiminolactones present in a large number of natural products has been developed. In the first step, the synthesis of parabanic acid derivatives was commenced from the reaction of [Formula: see text]-disubstituted urea and thiourea with oxalyl chloride, then a three-component reaction was carried out with isocyanides, acetylenic esters, and [Formula: see text]-disubstituted parabanic acid derivatives. The method allows the construction of a variety of [Formula: see text]-spiroiminolactone structures in good to high yields starting from readily available precursors. It was found that in the case of [Formula: see text]-diphenyl thioparabanic acid, additional products of [Formula: see text]-dispiroiminolactones have been formed due to the higher electrophilicity of [Formula: see text]-dicarbonyl groups. The structures were fully established using spectroscopic analysis NMR, IR, and Mass spectrometry. The crystal structure of [Formula: see text]-dispiroiminolactone was confirmed from single-crystal X-ray diffraction study.

Indirect chemiluminescence-based determination of catecholamines in pharmaceutical formulations by furandicarboxylate derivative as a novel blue fluorescer in peroxyoxalate-H2O2 system.

A novel, simple, cheap, and high sensitivity batch chemiluminescent method for the determination of catecholamine drugs, epinephrine (E), dopamine (DA) and methyldopa (MD) at microgram levels in pharmaceutical formulations is described. The method is based on a chemiluminescence (CL) system arising from the reaction of bis(2,4,6-trichlorophenyl) oxalate (TCPO) with H2O2 in the presence of a novel fluorescer, furandicarboxylate, and is proposed as a new analytical method for the determination of catecholamines. The method is based on the inhibition of CL emission by DA and its enhancement by E and MD. Under optimal conditions, good linear ranges were obtained, 0.5 - 12.7, 0.06 - 1.83 and 0.069 - 3.52 µg/mL with detection limits of 0.30, 0.03 and 0.04 µg/mL (S/N = 3) for DA, E and MD, respectively. Moreover, a pooled-intermediate model was used to determine the kinetic parameters of CL with and without catecholamines and a possible CL mechanism was discussed.

Simple and fast PO-CL method for the evaluation of antioxidant capacity of hydrophilic and hydrophobic antioxidants.

A simple and fast procedure is described for evaluating the antioxidant activity of hydrophilic and hydrophobic compounds by using the peroxyoxalate-chemiluminescence (PO-CL) reaction of Bis(2,4,6-trichlorophenyl) oxalate (TCPO) with hydrogen peroxide in the presence of di(tert-butyl)2-(tert-butylamino)-5-[(E)-2-phenyl-1-ethenyl]3,4-furandicarboxylate as a highly fluorescent fluorophore. The IC50 values of the well-known antioxidants were calculated and the results were expressed as gallic equivalent antioxidant capacity (GEAC). It was found that the proposed method is free of physical quenching and oxidant interference, for this reason, proposed method is able to determine the accurate scavenging activity of the antioxidants to the free radicals. Finally, the proposed method was applied to the evaluation of antioxidant activity of complex real samples such as soybean oil and sunflower oil (as hydrophobic samples) and honey (as hydrophilic sample). To the best of our knowledge, this is the first time that total antioxidant activity can be determined directly in soybean oil, sunflower oil and honey (not in their extracts) using PO-CL reactions.

Highly sensitive glucose biosensor based on the effective immobilization of glucose oxidase/carbon-nanotube and gold nanoparticle in nafion film and peroxyoxalate chemiluminescence reaction of a new fluorophore.

A novel glucose biosensor based on the chemiluminescence (CL) detection of enzymatically generated H(2)O(2) was constructed by the effective immobilization of glucose oxidase (GOD)/carbon-nanotubes (CNTs)/gold nanoparticles (GNPs) in nafion film on graphite support. The influences of various experimental parameters such as solution pH, the action time of the enzyme, interferents and the concentration of CL reagents were investigated. Carbon nanotubes and gold nanoparticles offer excellent catalytic activity toward hydrogen peroxide generation in enzymatic reaction between glucose oxidase and glucose, which would enable sensitive determination of glucose. Under the optimum condition, the linear response range of glucose was found to be 2.25 × 10(-6) to 1.75 × 10(-4 ) mol L(-1), and the detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) was 1.00 × 10(-6) mol L(-1). The CL biosensor exhibited good storage stability, i.e., 80% of its initial response was retained after 10 days storage at pH 7.0. The present CL biosensor has been used to determine the glucose concentrations in real serum and urine samples with satisfactory results.

Sensitive and selective determination of glucose in human serum and urine based on the peroxyoxalate chemiluminescence reaction of a new fluorophore.

A novel method for simple and sensitive determination of glucose based on the peroxyoxalate chemiluminescence (PO-CL) detection of enzymatically generated H(2)O(2) was investigated. Influence of various experimental parameters on glucose sensing, including the action time of the enzyme, solution pH, interferents and the concentration of CL reagents was investigated. Under the optimum condition, the linear response range of glucose was found to be 2.50×10(-6) to 1.75×10(-4) mol/L, and the detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) was 1.10×10(-6) mol/L. The present method has been used to determine the glucose concentrations in real serum and urine samples with satisfactory results.

One-pot synthesis of 4-arylquinolines from aromatic aminoketones and vinylphosphonium salts.

The addition of acetylenic esters to aromatic amines such as 2-amino benzophenone derivatives in the presence of triphenylphosphine leads to highly functionalized phosphoranes, which undergo an intramolecular Wittig reaction following oxidation to produce quinoline derivatives.