Synlett
DOI: 10.1055/a-2522-0571
letter
Small Molecules in Medicinal Chemistry

Phototriggered Migration of Indole-Based Cationic Fluorophore from Mitochondria to Nucleolus in Live Cells

a   Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, 700054, India
d   Organic & Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology (IICB), Kolkata, 700032, India
,
Bireswar Bhattacharya
b   Department of Natural Products, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, 700054, India
,
Uttam Samanta
c   Centre for Interdisciplinary Sciences, JIS Institute of Advanced Studies and Research (JISIASR), JIS University, W.B. 711112, India
,
Subhankar Singha
c   Centre for Interdisciplinary Sciences, JIS Institute of Advanced Studies and Research (JISIASR), JIS University, W.B. 711112, India
,
Dipanjan Ghosh
b   Department of Natural Products, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, 700054, India
,
Subhendu Bhowmik
a   Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, 700054, India
,
d   Organic & Medicinal Chemistry Division, CSIR-Indian Institute of Chemical Biology (IICB), Kolkata, 700032, India
,
Sreya Gupta
a   Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, 700054, India
› Author Affiliations
This project was funded by Council of Scientific and Industrial Research (CSIR), New Delhi entitled ‘Targeting RNA Driven Processes: Novel Chemical Biology Approaches to Identify New Classes of RNA Modulators’ (MLP-139). Aakriti Garg thanks the National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata and the Department of Pharmaceuticals (DoP), Ministry of Chemicals and Fertilizers (MoCF), India for providing the institutional fellowship. Subhankar Singha acknowledges the research funding from the Science and Engineering Research Board (SERB), Govt. of India (Grant No: CRG/2022/008799).


Abstract

Small-molecule fluorescence probes capable of migrating between subcellular organelles under varying cellular conditions are essential tools for investigating live cell events. In this work, we present TNK-01, synthesized from pyridinium salt and indole derivatives known for their affinity to nucleic acids and ability to target mitochondria. TNK-01 exhibits migration from mitochondria to the nucleolus upon continuous light irradiation, driven by its differential binding affinities for the negatively charged mitochondrial membrane and RNA. The photo-triggered migration of TNK-01 is enhanced by its RNA binding affinity, resulting in an approximate 32-fold increase in fluorescent signal with selectivity for RNA over DNA. Furthermore, TNK-01 demonstrates stable emission across a pH range of 3 to 8, allowing for effective monitoring of translocation across various cell lines. Its large Stokes shift, high photostability, wash-free imaging, and low cytotoxicity make TNK-01 a promising tool for cellular imaging in live cells. This photo-triggered indole-based fluorescent probe enables new research in mitochondrial studies and organelle communication, which are increasingly important for understanding metabolism and disease progression.

Supporting Information



Publication History

Received: 21 November 2024

Accepted after revision: 21 January 2025

Accepted Manuscript online:
21 January 2025

Article published online:
07 March 2025

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