A Fluorescent Flavonoid for Lysosome Imaging: the Effect of Substituents on Selectivity and Optical Properties.
J Fluoresc
; 29(3): 599-607, 2019 May.
Article
em En
| MEDLINE
| ID: mdl-30955153
ABSTRACT
Lysosome selective bright orange-red emitting flavonoid (2) was synthesized by attaching a strong donor (NPh2) group into flavonoid skeleton. As a result of efficient intra molecular charge transfer due to the strong donor group, a significant bathochromic shift was observed from the emission of 2b (with a -NPh2 group, λem ≈ 590 nm), in comparison that of 1b (with a -NMe2 group, λem ≈ 519 nm). The role of the substituent effect towards ICT was further studied by low temperature spectral analysis. Fluorescence spectra at low temperature confirmed that large Stokes shift for probe 2 (Δλ ≈ 150 nm) was due to strong ICT. Probe 2b exhibited exceptional selectivity towards cellular lysosomes in live cells studies thus generating bright orange-red emission upon localization. Intra-cellular pH analysis results confirmed that probe 2b did not participate in the elevation of lysosomal pH upon staining with different probe concentrations (0.5 µM - 2.0 µM) which is a potential advantage compared to acidotropic commercial LysoTracker® probes. This study further illustrated that the substituents in probe 2 play a significant role towards probe's organelle selectivity since probe 2a (R = OH) did not show any lysosomal localization compared with 2b. In addition, the calculated cytotoxicity data further revealed that this new probe design is highly biocompatible (LC50 > 50 µM) and suitable for long term imaging. Graphical Abstract.
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Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Flavonoides
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Fenômenos Ópticos
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Imagem Óptica
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Corantes Fluorescentes
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Lisossomos
Limite:
Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article