Carbon nanoparticles (CNPs) emitting pH-dependent blue photoluminescence (PL) in aqueous solutions were solvothermally prepared and modified with a new fluorophore molecule, N-chlorobenzyl dithiomaleimide dimethyl diacetate (NCBDTM), with pH-dependent yellow-green PL in aqueous solutions and irreversible PL emission quenching in alkaline aqueous solutions at basic pHs. In the pi-complex system formed by donor CNPs and acceptor NCBDTM molecules, energy transfer occurs by the FRET mechanism. Due to the implementation of the FRET mechanism, a significant Stokes shift of 170 nm is observed, making this and similar systems promising for the visualization of pH-dependent processes in the green-yellow visible light region.
A new one-pot approach for the synthesis of the Zn2+-sensitive probes 2-azahetaryl-2-(oxoindolin-2-ylidene)acetonitriles 3a-c and 4 is described. The method includes the in situ formation of imidoylchloride and its further condensation with azahetarylacetonitrile 1. The structure of the obtained compounds is studied using 1H nuclear magnetic resonance (NMR), 13C NMR, infrared (IR), high-resolution mass spectrometry (HRMS), and UV-Vis spectroscopy techniques. Two model ligands both exhibiting the highest extinction coefficient and the best solubility in a Tris buffer pH 7.2/dimethyl sulfoxide (DMSO) solution, namely 5-methyl-benzothiazole derivative 3b and benzoxazole derivative 4, are thoroughly studied as colorimetric probes for Zn2+. The probe 3b has the highest sensitivity to Zn2+, showing a limit of ion detection (LOD) calculated by the 3S criterion of 0.43 μM and selectivity upon masking Cu2+ ions with Na2S2O3. The composition of the complexes in the solution was determined by the limited logarithm method. The stability constant (lg K) values of 3b-Zn of 10.27 ± 0.02 and 4-Zn of 12.5 ± 0.2 indicate the formation of complexes of average stability.
Ability of C 60 fullerenes to scavenge free radicals and of multy-kinase inhibitor pyrrole derivative to regulate production and activation of immune cells producing damaging free radicals, could be a rationale of hybrid nanocomplex synthesis based on them. So, therapeutic potential of nanocomplex 3-{[4-chloro-1-(4-chlorobenzyl)-2,5dioxo-2,5-dihydro-1H-pyrrole-3-yl]amino}phenyl 4-[6, 6]phenyl-C61-butanoate (C60-MI-3OH) under rat acute ulcerative colitis has been investigated.C60-MI-3OH reduced systemic inflammation under acute colitis, as evidenced by normalization of the leukocytes count in blood due to the lowering of neutrophilic granulocytes and monocytes number with simultaneous reduction of colon damage area. C60-MI-3OH abolishes development of anemia under acute colitis probably due to the decreased volume of hemorrhages as a result of intensifying the processes of colon wall healing and erythropoiesis stimulation.Complexation of pyrrole derivative having multi-kinase inhibitory activity with C60-fullerenes could potentiate the efficacy of the first one and allow the complex to be applied in low dose (0.2 mg/kg)
An aberrant activity of growth factor receptors followed by excessive cell proliferation plays a significant role in pathogenesis of cholangitis. Therefore, inhibition of these processes could be a fruitful therapeutic strategy. The effects of multi-kinase inhibitor 1-(4-Cl-benzyl)-3-chloro-4-(CF3-phenylamino)-1H-pyrrole-2,5-dione (MI-1) on the hepatic and systemic manifestations of acute and chronic cholangitis in rats were addressed. MI-1 (2.7 mg/kg per day) was applied to male rats that experienced α-naphthylisothiocyanate-induced acute (3 days) or chronic (28 days) cholangitis. Liver autopsy samples, blood serum markers, and leukograms were studied. MI-1 localization in liver cells and its impact on viability of HepG2 (human hepatoma), HL60 (human leukemia), and NIH3T3 (normal murine fibroblasts) cell lines and lymphocytes of human peripheral blood (MTT, DNA fragmentation, DNA comet assays, Propidium Iodide staining) were assessed. Under both acute and chronic cholangitis, MI-1 substantially reduced liver injury, fibrosis, and inflammatory scores (by 46–86%) and normalized blood serum markers and leukograms. Moreover, these effects were preserved after a 28-day recovery period (without any treatment). MI-1 inhibited the HL60, HepG2 cells, and human lymphocytes viability (IC50 0.6, 9.5 and 8.3 µg/ml, respectively), while NIH3T3 cells were resistant to that. Additionally, HepG2 cells and lymphocytes being incubated with MI-1 demonstrated insignificant pro-apoptotic and pro-necrotic changes and DNA single-strand breaks, suggesting that MI-1 effects in liver might be partly caused by its cytotoxic action towards liver cells and lymphocytes. In conclusion, MI-1 attenuated the systemic inflammation and signs of acute and chronic cholangitis partly through cytotoxicity towards cells of hepatic and leukocytic origin.
The interaction of (2-aryl-5-(hydroxyalkylamino)-1,3-oxazol-4-yl)phosphonates with hydrogen chloride, hydrogen iodide and hydrogen thiocyanate in anhydrous medium led to formation of new phosphorylated peptidomimetics containing C-terminal ω-haloalkyl and ω-thiocyanoethyl residues.
4-Amino-3-chloro-1H-pyrrole-2,5-dione derivatives were designed and synthesized as potential tyrosine kinase inhibitors. One of them has been shown to inhibit growth of cancer cell lines and in vivo tumors. To determine the impact of side groups on biological activity the ability of different 4-amino-3-chloro-1H-pyrrole-2,5-diones to interact with ATP-binding domains of growth factor receptors and with model cell membranes were aimed to be discovered. The methods of molecular docking, short-molecular dynamics (in silico) and non-steady cyclic current–voltage characteristics (in vitro) were used. Five 4-amino-3-chloro-1H-pyrrole-2,5-diones were synthesized from 3,4-dichloro-1H-pyrrole-2,5-diones. All of them demonstrated the potential ability to form complexes with ATP-binding domains of EGFR and VEGFR2. These complexes were more stable compared to those with ANP. 4-Amino-3-chloro-1H-pyrrole-2,5-diones while interact with different bilayer lipid membranes caused an increase of their specific conductance and electric capacity, demonstrating the certain disturbance in lipid packing. Obtained data allowed us to suggest that proposed chemicals can interact with the surface of lipid bilayer, do likely intercalate into the membrane and form stable complexes with EGFR and VEGFR2. So, the prospect of developed chemicals to be effective EGFR and VEGFR2 inhibitors and therefore realize antitumor activity was concluded.
Pyrrole derivatives (PDs) chloro-1-(4-chlorobenzyl)-4-((3-(trifluoromethyl)phenyl)amino)-1H-pyrrole-2,5-dione (MI-1) and 5-amino-4-(1,3-benzothyazol-2-yn)-1-(3-methoxyphenyl)-1,2-dihydro-3H-pyrrole-3-one (D1) were synthesised as inhibitors of several protein kinases including EGFR and VEGFR. The aim of the study was to reveal the exact mechanisms of PDs' action EGFR and VEGFR are involved in. We observed, that both PDs could bind with EGFR and VEGFR and form stable complexes. PDs entered into electrostatic interactions with polar groups of phospholipid heads in cell membrane, and the power of interaction depended on the nature of PD radical substituents (greater for MI-1 and smaller for D1). Partial intercalation of MI-1 into the membrane hydrophobic zone also occurred. PDs concentrations induced apoptosis in malignant cells but normal ones had different sensitivity to those. MI-1 and D1 acted like antioxidants in inflamed colonic tissue, as evidenced by reduce of lipid and protein peroxidation products (by 43-67%) and increase of superoxide dismutase activity (by 40 and 58%) with restoring these values to control ones. MI-1 restored reduced haemoglobin and normalised elevated platelets and monocytes in settings of colorectal cancer, whereas D1 normalised only platelets. Thus, MI-1 and D1 could be used as competitive inhibitors of EGFR and VEGFR and antioxidants, which might contribute to realisation of their anti-inflammatory, proapoptotic and antitumor activity.
New method was developed for the synthesis of 2-hetaryl-2-(1-R-pyrrolidin-2-ylidene)acetonitriles by using a three-component condensation of hetarylacetonitrile, phosphorus oxychloride, and 1-R-pyrrolidin-2-one. This method is applicable to the synthesis of β-enaminonitriles containing azoles and six-membered azaheteroaromatic rings at the α-position relative to the nitrile group.
It was found that film composites of the copolymer of styrene with octyl methacrylate with additions of the monomers of pyrido[2,1-b]benzothiazole derivatives have hole-type photoconductivity while the internal photoelectric effect in this medium is determined by the photogeneration of charge carriers from the monomers and transfer of nonequilibrium charge carriers through these monomers. In transition to a monomer with a more efficient conjugation system the photoconductivity and photovoltaic response are increased.
The photoconductive and photovoltaic properties of film composites based on the new oligomer polyepoxypropylpyridobenzothiazole were compared with the known poly-N-epoxypropylcarbazole, which contains the squarylium dye as a photoconductivity sensitizer. It was found that these composites have hole-type photoconductivity, and the internal photoelectric effect is determined by the photogeneration of charge carriers from dye molecules and by transport of the holes along the donor fragments of the polymer matrix. The photoconductivity and photovoltaic response increase in the transition to the new oligomer with the more efficient conjugation system in the donor fragments.
The selective and sensitive hyphenated technique for Pd(II) fluorescence and spectrophotometric determination was proposed. The procedure was based on preliminary solid-phase extraction of [PdCl 4 ] 2− onto silica modified with quaternary ammonium salts, with the subsequent elution from the surface by 2,6-diamino-1- N -methylpyrimidine solution and measurement of the fluorescence intensity. The luminescence enhancement effect of 2,6-diamino-1- N -methylpyrimidine in the presence of Pd(II) due to the complex formation was applied to the development of sorption-spectroscopic techniques for detecting trace amounts of palladium in solution.
We report here an efficient and easily reproducible two-step approach to heterocycle-substituted amino-pyrazoles from heterocyclic acetonitriles and their unprecedented subsequent transformations to fully substituted pyrazoles. Such transformations include regioselective derivatization from polyamino derivatives, formation of tetracyclic compounds in up to 45% overall yield, and deaminative transformations through diazotization, followed by arylation through Suzuki-Miyaura cross-coupling and C-H activation, providing arylated pyrazoles in up to 71% yield over four steps. This strategy allows the swift introduction of significant molecular complexity to a range of scaffolds.
Synthetic approaches for the preparation of 6-amino-5-hetarylpyrimidine derivatives by the ring transformation reaction of 2-hetaryl-2-(tetrahydro-2-furanyliden)acetonitriles with amidines have been developed. Some of 2,6-diamino-5-(1,3-benzothiazol-2-yl)pyrimidines were found to exhibit modest inhibitory activity against human dihydrofolate reductase. Molecular docking was performed to evaluate the binding mode of compounds of this series in the enzyme’s active site.
This microreview is devoted to the recent developments in the synthesis of 5-imino- and 5-oxothiazolo-[3,2- a ]pyridines. General synthetic strategy toward fused thiazolopyridine ring system utilizing azahetaryl precursors is discussed.
The photovoltaic and photoconductive properties of film composites of a copolymer of styrene with octyl methacrylate and additions of the monomer (Z)-2-(4-methylthiazol-2-yl)-2-(pyrrolidin-2-ylidene)acetonitrile (HL) and complexes of NiL2, CoL2, and CuL2 were investigated. It was established that these composites have hole-type photoconductivity while the inner photoeffect is determined by photogeneration of charge carriers from the HL monomers and by transport of nonequilibrium charge carriers among these monomers. The photovoltaic response increases with the metal complexes in the following order: CuL2, NiL2, CoL2.
Luminescent properties of new organic reagents, 2, 6-diaminopyrimidines and benzimidazoles were investigated. The luminescence intensity of 1-amino-3-(3-hydroxypropyl)pyrido[1,2-a]benzimidazole-2,4-dicarbonitrile (I) 3-[2-(hydroxymethyl)phenyl]-1-imino-1H-pyrido[2,1-bill,3]benzothiazole-2,4-dicarbonitrile (II) 3-12,6-diamino-5-(1,3-benzothiazol-2-yl)-4-pyrimidinyl]-1-propanol (III) was decreased with adding hydrochloric acid. Reagent 346-amino-5-(1,3-benzothiazol-2-yl)-1-methyl-2-imino-1,2-dihydro-4-pyrimidinyl]-1-propanol (IV) was resistant to HCl. The reagent IV with platinum(II) and palladium(II) forms non-luminescent complexes in acidic media. It was found that IV with Pt(II) forms a complex 1:1, Pd(II) - 1:1 and 2:1, respectively.
The reaction of 2-hetaryl-2-(tetrahydro-2-furanyliden)acetonitriles with substituted acetonitriles as C-nucleophiles has been investigated and the mechanism of the reaction has been suggested. A base promoted Michael addition of the substituted acetonitriles to 2-hetaryl-2-(tetrahydro-2-furanyliden)acetonitriles followed by ring transformations has provided novel convenient synthetic methods to nitrogen bridgehead fused cyanopyridines bearing hydroxypropyl side chain. The structures of obtained compounds have been established based on NMR spectroscopy investigation and X-ray diffraction data.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.