Logo: to the web site of Uppsala University

uu.sePublications from Uppsala University
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
An Indolin-3-imine Photobase and pH Sensitive Fluorophore
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry.ORCID iD: 0000-0003-2000-5258
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Neurooncology and neurodegeneration.
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Neurooncology and neurodegeneration.
Show others and affiliations
2023 (English)In: ChemPhotoChem, E-ISSN 2367-0932, article id e202300171Article in journal (Refereed) Epub ahead of print
Abstract [en]

This work presents the pH sensing ability of a fluorescent indolin-3-imine derivative. Protonation of the weakly basic imine (pKa = 8.3 of its conjugate acid) results in a significant redshift of the absorption band. The fluorophore acts as a photobase, with a basicity increase of approximately 6 units upon photoexcitation. This behavior promotes excited state proton transfer from weak acids such as protic solvents. The characteristics of the fluorophore enable sensing of water fractions in organic solvents and differentiation between methanol, ethanol, and longer chain alcohols. Initial cell studies indicated the future potential of indolin-3-imines as fluorophores for bioimaging applications.

Place, publisher, year, edition, pages
John Wiley & Sons, 2023. article id e202300171
Keywords [en]
Indolin-3-imine, fluorophore, pHsensor, excited state proton transfer, photobase
National Category
Organic Chemistry
Identifiers
URN: urn:nbn:se:uu:diva-508682DOI: 10.1002/cptc.202300171OAI: oai:DiVA.org:uu-508682DiVA, id: diva2:1786065
Funder
Swedish Research Council, 2018-03524Available from: 2023-08-07 Created: 2023-08-07 Last updated: 2023-09-27
In thesis
1. Shining Light on Benzothiadiazoles and Indolines: Photophysical Properties and Cancer Cell Imaging
Open this publication in new window or tab >>Shining Light on Benzothiadiazoles and Indolines: Photophysical Properties and Cancer Cell Imaging
2023 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Fluorescent molecules, also called fluorophores, play an important role in life sciences. As crucial tools in fluorescence microscopy, they can be used to study biological processes on a cellular level, which is a fundamental aspect of cancer research. Depending on the specific research question, the requirements for fluorophores can be very diverse. Expanding the toolbox of fluorescent probes can therefore contribute to the possibilities of fluorescence imaging in general, especially since no single fluorophore is perfect for all applications.

In this thesis, donor-acceptor fluorophores based on two different core structures, 2,1,3-benzothiadiazole and indoline, were investigated. The compounds were photophysically studied by steady-state absorption and fluorescence spectroscopy and examined in fluorescence cell microscopy.

Monosubstituted benzothiadiazole derivatives with nitrogen-based substituents were synthesized and photophysically studied in various solvents. Fluorescence microscopy experiments revealed three promising new compounds that specifically stain lipid droplets in cancer cells. Lipid droplets are interesting cellular targets for imaging because of their high relevance in the energy metabolism of cancer cells. 

Furthermore, two fluorescent indoline derivatives, which differ only by one functional group (imine vs ketone) were compared for their photophysical properties and cell imaging behavior. The indolin-3-imine derivative showed pH sensitivity due to protonation of the imine moiety, which was significantly enhanced in the excited state because of photobasicity. Fluorescence microscopy experiments showed ubiquitous cell staining with a tendency towards lysosomes, which are acidic cell organelles. In contrast, the indolin-3-one analogue featured lipid droplet-specific staining, although with rapid photobleaching. Spectroscopic studies in solution revealed photoisomerization through ring-opening upon irradiation, which explained the emission bleaching during microscopy. While this behavior is not beneficial for imaging applications, it was found that the indolin-3-one exhibited photoactivated cytotoxicity, which likely arises from singlet oxygen generation.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2023. p. 78
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 2291
National Category
Organic Chemistry
Research subject
Chemistry with specialization in Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-508762 (URN)978-91-513-1862-2 (ISBN)
Public defence
2023-09-22, A1:111a, BMC, Husargatan 3, Uppsala, 13:15 (English)
Opponent
Supervisors
Available from: 2023-08-31 Created: 2023-08-08 Last updated: 2023-09-12

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Authority records

Doloczki, SusanneHolmberg, Karl O.Zhao, MiaoSwartling, Fredrik J.Streuff, JanDyrager, Christine

Search in DiVA

By author/editor
Doloczki, SusanneHolmberg, Karl O.Zhao, MiaoSwartling, Fredrik J.Streuff, JanDyrager, Christine
By organisation
Organic ChemistryNeurooncology and neurodegeneration
In the same journal
ChemPhotoChem
Organic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 257 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf