93397-90-1Relevant articles and documents
Substituted 9-Diethylaminobenzo[ a]phenoxazin-5-ones (Nile Red Analogues): Synthesis and Photophysical Properties
Hornum, Mick,Mulberg, Mads W.,Szomek, Maria,Reinholdt, Peter,Brewer, Jonathan R.,Wüstner, Daniel,Kongsted, Jacob,Nielsen, Poul
, p. 1471 - 1488 (2021/01/13)
Nile Red is a benzo[a]phenoxazone dye containing a diethylamino substituent at the 9-position. In recent years, it has become a popular histological stain for cellular membranes and lipid droplets due to its unrivaled fluorescent properties in lipophilic environments. This makes it an attractive lead for chemical decoration to tweak its attributes and optimize it for more specialized microscopy techniques, e.g., fluorescence lifetime imaging or two-photon excited fluorescence microscopy, to which Nile Red has never been optimized. Herein, we present synthesis approaches to a series of monosubstituted Nile Red derivatives (9-diethylbenzo[a]phenoxazin-5-ones) starting from 1-naphthols or 1,3-naphthalenediols. The solvatochromic responsiveness of these fluorophores is reported with focus on how the substituents affect the absorption and emission spectra, luminosity, fluorescence lifetimes, and two-photon absorptivity. Several of the analogues emerge as strong candidates for reporting the polarity of their local environment. Specifically, the one- and two-photon excited fluorescence of Nile Red turns out to be very responsive to substitution, and the spectroscopic features can be finely tuned by judiciously introducing substituents of distinct electronic character at specific positions. This new toolkit of 9-diethylbenzo[a]phenoxazine-5-ones constitutes a step toward the next generation of optical molecular probes for advancing the understanding of lipid structures and cellular processes.
Structural modifications of nile red carbon monoxide fluorescent probe: Sensing mechanism and applications
Klán, Petr,Madea, Dominik,Martínek, Marek,Muchová, Lucie,Váňa, Ji?í,Vítek, Libor
, p. 3473 - 3489 (2020/03/25)
Carbon monoxide (CO) is a cell-signaling molecule (gasotransmitter) produced endogenously by oxidative catabolism of heme, and the understanding of its spatial and temporal sensing at the cellular level is still an open challenge. Synthesis, optical properties, and study of the sensing mechanism of Nile red Pd-based CO chemosensors, structurally modified by core and bridge substituents, in methanol and aqueous solutions are reported in this work. The sensing fluorescence "off-on" response of palladacycle-based sensors possessing low-background fluorescence arises from their reaction with CO to release the corresponding highly fluorescent Nile red derivatives in the final step. Our mechanistic study showed that electron-withdrawing and electron-donating core substituents affect the rate-determining step of the reaction. More importantly, the substituents were found to have a substantial effect on the Nile red sensor fluorescence quantum yields, hereby defining the sensing detection limit. The highest overall fluorescence and sensing rate enhancements were found for a 2-hydroxy palladacycle derivative, which was used in subsequent biological studies on mouse hepatoma cells as it easily crosses the cell membrane and qualitatively traces the localization of CO within the intracellular compartment with the linear quantitative response to increasing CO concentrations.
Polymerizable liquid crystal composition, polarized light-emitting coating material, novel naphtholactam derivative novel coumarin derivative, novel nile red derivative, and novel anthracene derivative
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Page/Page column 147; 148, (2016/11/14)
Provided are a polymerizable liquid crystal composition, a coating material, a medium, and a polarizing device each produced using a polymerizable liquid crystal compound and a colorant and each capable of producing polarized light suitable for polarizing devices, and also a novel naphtholactam derivative, a novel coumarin derivative, a novel Nile Red derivative, and a novel anthracene derivative each suitable for use as the colorant. Specifically provided are a polymerizable liquid crystal composition containing (A) at least one liquid crystal compound having a polymerizable functional group, (B) at least one colorant, and (C) a polymerization initiator, and a novel naphtholactam derivative of formula (IV′), a novel coumarin derivative of formula (VI′), a novel Nile Red derivative of formula (VII′), and a novel anthracene derivative of formula (VIII′) each suitable for use as the colorant (B).
