Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The synthesis of a new fluorescein carboxaldehyde asymmetrically substituted on the xanthene (top) ring is reported. This molecule is a key precursor for two of three monofunctionally derivatized fluorescein-based Zn(II) sensors presented in this work. Detailed preparative routes to, and photophysical characterization of, these sensors are described. The sensors are based on the previously reported ZP4 motif (Burdette, S. C.; Frederickson, C. J.; Bu, W.; Lippard, S. J. J. Am. Chem. Soc. 2003, 125, 1778-1787) and incorporate a di(2-picolyl)amine-containing aniline-derivatized ligand framework. By varying the nature of the substituent (X) para to the aniline nitrogen atom, which is responsible for PET quenching of the unbound ZP dye, we investigated the extent to which such electronic tuning might improve the fluorescent properties of asymmetrical ZP sensors. Although a comparison of probes with X = H, F, Cl, OMe reveals that the photophysical behavior of these dyes is not readily predictable, our methodology illustrates the ease with which aniline-based ligands may be linked to fluorescein dyes.
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PMID:Synthesis and characterization of zinc sensors based on a monosubstituted fluorescein platform. 1507 81

The syntheses and photophysical characterization of ZP9, 2-{2-chloro-6-hydroxy-3-oxo-5-[(2-{[pyridin-2-ylmethyl-(1H-pyrrol-2-ylmethyl)amino]methyl}phenylamino)methyl]-3H-xanthen-9-yl}benzoic acid, and ZP10, 2-{2-chloro-6-hydroxy-5-[(2-{[(1-methyl-1H-pyrrol-2-ylmethyl)pyridin-2-ylmethylamino]methyl}phenylamino)methyl]-3-oxo-3H-xanthen-9-yl}benzoic acid, two asymmetrically derivatized fluorescein-based dyes, are described. These sensors each contain an aniline-based ligand moiety functionalized with a pyridyl-amine-pyrrole group and have dissociation constants for Zn(II) in the sub-micromolar (ZP9) and low-micromolar (ZP10) range, which we define as "midrange". They give approximately 12- (ZP9) and approximately 7-fold (ZP10) fluorescence turn-on immediately following Zn(II) addition at neutral pH and exhibit improved selectivity for Zn(II) compared to the di-(2-picolyl)amine-based Zinpyr (ZP) sensors. Confocal microscopy studies indicate that such asymmetrical fluorescein-based probes are cell permeable and Zn(II) responsive in vivo.
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PMID:Midrange affinity fluorescent Zn(II) sensors of the Zinpyr family: syntheses, characterization, and biological imaging applications. 1711 71

Electron donor-acceptor compounds 1 (asymmetrical push-pull derivative) and 2 (symmetrical push-pull-push derivative) were studied in which one (push-pull) or two aniline units (push-pull-push) are connected to a biphenyl group via triazole linkers, made by "click" chemistry. Steady-state and time-resolved spectroscopies indicate that highly dipolar charge separated excited states are populated in moderately polar solvents. The very similar photophysical behavior of both compounds implies symmetry breaking in the excited state of 2. The polarity of the solvent determines the efficiency of formation of the charge separated state. While in toluene it is very low, it becomes very high in acetonitrile. The bis-triazole substituted biphenyl unit in 2 behaves as a better electron acceptor than the mono-triazole substituted biphenyl in 1, which leads to a more facile charge separation in 2. Rates of charge separation are of the order of 10(11)-10(12) s(-1), and increase with solvent polarity.
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PMID:Fast photo-processes in triazole-based push-pull systems. 2020 Jul 48