2. Academic Validation
  3. Fluorescent Isostere (Fluostere) of the Carboxylate: Design of h DHODH Fluorescent Inhibitors as Proof of Concept

Fluorescent Isostere (Fluostere) of the Carboxylate: Design of h DHODH Fluorescent Inhibitors as Proof of Concept

  • J Med Chem. 2025 Jul 10;68(13):13562-13590. doi: 10.1021/acs.jmedchem.5c00348.
Stefano Sainas 1,  Elena Martino 1,  Claudio Garino 2,  Paola Circosta 3 4,  Anna Luganini 5,  Marta Giorgis 1,  Francesco Bavo 6,  Marco Piccinini 7,  Cristina Ramondetti 7,  Marta Alberti 8,  Riccardo Miggiano 8,  Giorgio Gribaudo 5,  Donatella Boschi 1,  Bente Frølund 6,  Marco Lucio Lolli 1
Affiliations

Affiliations

  • 1 Department of Drug Science and Technology. University of Torino, Via Pietro Giuria 9, Torino 10125, Italy.
  • 2 Department of Chemistry, University of Torino, Via Pietro Giuria 7, Torino 10125, Italy.
  • 3 Department of Clinical and Biological Sciences, University of Torino, Regione Gonzole 10, Orbassano, Torino 10043, Italy.
  • 4 Molecular Biotechnology Center, University of Torino, Via Nizza 52, Torino 10126, Italy.
  • 5 Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, Torino 10123, Italy.
  • 6 Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen DK-2100, Denmark.
  • 7 Department of Oncology, University of Torino, Via Michelangelo 27/B, Torino 10125, Italy.
  • 8 Department of Pharmaceutical Sciences, University of Piemonte Orientale, Via G. Bovio 6, Novara 28100, Italy.
PMID: 40530899 DOI: 10.1021/acs.jmedchem.5c00348
Abstract

Fluorescent probes targeting proteins are used to investigate biological processes, requiring strong binding affinity and favorable fluorescence. In this study, we present the first fluostere with optimized fluorescence properties. We started exploring the fluorescence of acidic pyrazolo[1,5-a]pyridin-2-ol, and, by the introduction of EWGs, π-conjugation, incorporation of push-pull systems and rigid structures, we optimized emission profiles and QY, providing a first Structure-Fluorescence relationship (SFR) of the system. To provide proof of concept in biological applications, the established SFR was integrated with hDHODHi, an important oncology target, enabling the SAR designing fluorescent hDHODHi 11a and 14, with 11a being the most potent IC50 = 170 nM. These inhibitors were validated in vitro for their antileukemic and Antiviral activity. As they are both environmentally sensitive fluorescent probes that can highlight their binding to the target, their fluorescence was found to colocalize in the mitochondria, where hDHODH is located, in cellular experiments.

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