Search results for "Pyridine"
showing 10 items of 2516 documents
Design, Synthesis and Evaluation of Enzyme-Responsive Fluorogenic Probes Based on Pyridine-Flanked Diketopyrrolopyrrole Dyes
2020
The ever-growing demand for fluorogenic dyes usable in the rapid construction of analyte-responsive fluorescent probes, has recently contributed to a revival of interest in the chemistry of diketopyrrolopyrrole (DPP) pigments. In this context, we have explored the potential of symmetrical and unsymmetrical DPP derivatives bearing two or one 4-pyridyl substituents acting as optically tunable group(s). The unique fluorogenic behavior of these molecules, closely linked to N-substitution/charge state of their pyridine unit (i.e., neutral pyridine or cationic pyridinium), has been used to design DPP-based fluorescent probes for detection of hypoxia-related redox enzymes and penicillin G acylase …
A fluorescent chemosensor based on a ruthenium(II)-terpyridine core containing peripheral amino groups that selectively sense ATP in an aqueous envir…
2000
The selective sensing of the ATP anion in an aqueous environment over phosphate, sulfate, and chloride using a fluorescence chemosensor based on Ru(tpy)22+ cores attached to polyammonium groups is reported.
Coligand Effects on the Field-Induced Double Slow Magnetic Relaxation in Six-Coordinate Cobalt(II) Single-Ion Magnets (SIMs) with Positive Magnetic A…
2019
Two mononuclear cobalt(II) compounds of formula [Co(dmphen)2(OOCPh)]ClO4·1/2H2O·1/2CH3OH (1) and [Co(dmbipy)2(OOCPh)]ClO4 (2) (dmphen = 2,9-dimethyl-1,10-phenanthroline, dmbipy = 6,6'-dimethyl-2,2'-bipyridine and HOOCPh = benzoic acid) are prepared and magnetostructurally investigated. Each cobalt(II) ion is six-coordinate with a distorted octahedral CoN4O2 environment. The complex cations are interlinked leading to supramolecular chains (1) and pairs (2) that grow along the crystallographic c-axis with racemic mixtures of (Δ,Λ)-Co units. FIRMS allowed us to directly measure the zero-field splitting between the two lowest Kramers doublets, which led to axial anisotropy values of 58.3 cm-1 ≤…
Mode and mechanism of neurotensin action in rat proximal colon
1997
Abstract This study examined the mechanism of action of neurotensin on intraluminal pressure in rat proximal colon. The direct and indirect contractile response to neurotensin (100 nM) was abolished in Ca 2+ -free solution, and was antagonized by nifedipine (1–5–10 nM) and potentiated by Bay K 8644 (methyl 1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)-pyridine-5-carboxylate) (10–100–1000 nM). Neurotensin, in the presence of nifedipine (10 nM) and atropine (1 μM), induced a tetrodotoxin-insensitive inhibitory effect, which was antagonized by SR 48692 (2[(1-(7-chloro-4-quinolinyl)-5-(2,6-dimethoxy-phenyl)pyrazol-3-yl) carbonyl amino]tricyclo (3.3.1.1. 3.7 ) decan-2-carboxylic a…
The size of aryl linker between two polyaza-cyclophane moieties controls the binding selectivity to ds-RNA vs ds-DNA
2013
Aryl-linked (pyridine- vs. phenanthroline-) bis-polyaza pyridinophane scorpiands PYPOD and PHENPOD strongly bind to the double stranded DNA and RNA, whereby very intriguing RNA over DNA selectivity is finely tuned by aryl-linker length and aromatic surface. Moreover, PYPOD and PHENPOD dimer formation at high compound/polynucleotide ratios is highly sensitive to the fine interplay between the steric and binding properties of compound-dimers and the DNA minor groove/RNA major groove. That is demonstrated by significantly different induced CD spectra, which allow spectroscopic differentiation between various DNA/RNA secondary structures. A significantly higher (micromolar) antiproliferative ef…
Therapeutic tools for oral candidiasis : current and new antifungal drugs
2019
Background Candidiasis is one of the most common opportunistic oral infections that presents different acute and chronic clinical presentations with diverse diagnostic and therapeutic approaches. The present study carries out a bibliographic review on the therapeutic tools available against oral candidiasis and their usefulness in each clinical situation. Material and Methods Recent studies on treatment of oral candidiasis were retrieved from PubMed and Cochrane Library. Results Nystatin and miconazole are the most commonly used topical antifungal drugs. Both antifungal drugs are very effective but need a long time of use to eradicate the infection. The pharmacological presentations of mico…
Translational readthrough of ciliopathy genes BBS2 and ALMS1 restores protein, ciliogenesis and function in patient fibroblasts
2021
Abstract Background Ciliary dysfunction underlies a range of genetic disorders collectively termed ciliopathies, for which there are no treatments available. Bardet-Biedl syndrome (BBS) is characterised by multisystemic involvement, including rod-cone dystrophy and renal abnormalities. Together with Alstrom syndrome (AS), they are known as the ‘obesity ciliopathies’ due to their common phenotype. Nonsense mutations are responsible for approximately 11% and 40% of BBS and AS cases, respectively. Translational readthrough inducing drugs (TRIDs) can restore full-length protein bypassing in-frame premature termination codons, and are a potential therapeutic approach for nonsense-mediated ciliop…
Lowest triplet excited states of a novel heteroleptic iridium(III) complex and their role in the emission colour
2009
Abstract The [Ir(ppy-F 2 ) 2 Me 4 phen] +1 complex, where ppy-F 2 is 2-(2′,4′-fluorophenyl)pyridine and Me 4 phen is 3,4,7,8-tetramethyl-1,10-phenanthroline, has been theoretically investigated by means of DFT calculations. The molecular and electronic properties calculated for [Ir(ppy-F 2 ) 2 Me 4 phen] +1 are compared with those obtained for the simpler [Ir(ppy)(bpy)] +1 complex. The introduction of fluorine substituents in the ppy ligands and the use of phenanthroline instead of 2,2′-bipyridine as the diimine ligand increase the HOMO–LUMO energy gap and blue-shift the emission colour. The phenanthroline ligand causes the appearance of two nearly-degenerate LUMO orbitals of different symm…
Highly Stable and Efficient Light-Emitting Electrochemical Cells Based on Cationic Iridium Complexes Bearing Arylazole Ancillary Ligands.
2017
A series of bis-cyclometalated iridium(III) complexes of general formula [Ir(ppy)2(N∧N)][PF6] (ppy− = 2-phenylpyridinate; N∧N = 2-(1H-imidazol-2-yl)pyridine (1), 2-(2-pyridyl)benzimidazole (2), 1-methyl-2-pyridin-2-yl- 1H-benzimidazole (3), 2-(4′-thiazolyl)benzimidazole (4), 1- methyl-2-(4′-thiazolyl)benzimidazole (5)) is reported, and their use as electroluminescent materials in light-emitting electrochemical cell (LEC) devices is investigated. [2][PF6] and [3][PF6] are orange emitters with intense unstructured emission around 590 nm in acetonitrile solution. [1][PF6], [4][PF6], and [5][PF6] are green weak emitters with structured emission bands peaking around 500 nm. The different photoph…
Synthesis and photovoltaic performance of the porphyrin based sensitizers with 2H-[1,2,3]triazolo[4,5-c]pyridine and benzotriazole as auxiliary accep…
2017
Abstract Two novel zinc porphyrin dyes containing either benzotriazole or 2 H -[1,2,3]triazolo[4,5- c ]pyridine as auxiliary acceptors, respectively, were synthesized for dye-sensitized solar cells. These two auxiliary acceptors were firstly applied into porphyrin based dyes. The photophysical and electrochemical properties of the dyes were investigated. These two dyes show the whole visible light absorption when they are adsorbed on the TiO 2 film, which means that they are promising sensitizers for dye-sensitized solar cells. The absorption intensity of the triazolopyridine containing dye is higher than that of the benzotriazole containing dye, resulting in a better light harvesting. Thus…