89303-50-4Relevant articles and documents
Photophysics and biological applications of the environment-sensitive fluorophore 6-N,N-dimethylamino-2,3-naphthalimide
Vazquez, M. Eugenio,Blanco, Juan B.,Imperiali
, p. 1300 - 1306 (2007/10/03)
We have synthesized a new environment-sensitive fluorophore, 6-N,N-dimethylamino-2,3-naphthalimide (6DMN). This chromophore exhibits valuable fluorescent properties as a biological probe with emission in the 500-600 nm range and a marked response to changes in the environment polarity. The 6DMN fluorescence is red-shifted in polar protic environments, with the maximum emission intensity shifting more than 100 nm from 491 nm in toluene to 592 nm in water. Additionally, the fluorescence quantum yield decreases more than 100-fold from chloroform (Φ = 0.225) to water (Φ = 0.002). The scope and applications of the 6DMN probe are expanded with the synthesis of an Fmoc-protected amino acid derivative (5), which contains the fluorophore. This unnatural amino acid has been introduced into several peptides, demonstrating that it can be manipulated under standard solid-phase peptide synthesis conditions. Peptides incorporating the new residue can be implemented for monitoring protein-protein interactions as exemplified in studies with Src homology 2 (SH2) phosphotyrosine binding domains. The designed peptides exhibit a significant increase in the quantum yield of the long wavelength fluorescence emission band (596 nm) upon binding to selected SH2 domains (e.g., Crk SH2, AbI SH2, and PI3K SH2). The peptides can be used as ratiometric sensors, since the short wavelength band (460 nm) was found almost invariable throughout the titrations.
Vicarious Nucleophilic Substitution of Hydrogen in Nitroarenes with Carbanions of α-Haloalkyl Phenyl Sulfones
Makosza, Mieczyslaw,Golinski, Jerzy,Baran, Janusz
, p. 1488 - 1494 (2007/10/02)
Carbanions of α-chloroalkyl phenyl sulfones and N,N-dialkyl-α-chloroalkanesulfonamides react with nitrobenzenes to effect direct nucleophilic replacement of hydrogen ortho and para to the nitro group, with vicarious loss of chloride anion, to give the corresponding nitrobenzylsulfonyl derivatives.The reaction occurs much more rapidly than the replacement of such good leaving groups as halogen, methoxy, and phenoxy.Most substituents in the nitrobenzene ring do not interfere with the reaction.The effect of substituents in the nitrobenzene and the carbanion on the orientation of the substitution is discussed.
