Fluorescent Isostere (<i>Fluostere</i>) of the Carboxylate: Design of <i>h</i>DHODH Fluorescent Inhibitors as Proof of Concept
Fluorescent probes targeting proteins are used to investigate biological processes, requiring strong binding affinity and favorable fluorescence. In this study, we present the first <i>fluostere</i> with optimized fluorescence properties. We started exploring the fluorescence of acidic pyrazolo[1,5-<i>a</i>]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 <i>Structure-Fluorescence relationship</i> (SFR) of the system. To provide proof of concept in biological applications, the established SFR was integrated with <i>h</i>DHODH<i>i</i>, an important oncology target, enabling the SAR designing fluorescent <i>h</i>DHODH<i>i</i> <b>11a</b> and <b>14</b>, with <b>11a</b> being the most potent IC<sub>50</sub> = 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 <i>h</i>DHODH is located, in cellular experiments.
Authors
- Bente Frølund (ORCID: https://orcid.org/0000-0001-5476-6288)
- Stefano Sainas (ORCID: https://orcid.org/0000-0001-5010-8536)
- Anna Luganini (ORCID: https://orcid.org/0000-0003-4256-5774)
- Marta Alberti (ORCID: https://orcid.org/0000-0003-3827-7243)
- Cristina Ramondetti (ORCID: https://orcid.org/0000-0002-0501-5696)
- Paola Circosta (ORCID: https://orcid.org/0000-0001-8251-6905)
- Donatella Boschi (ORCID: https://orcid.org/0000-0003-4929-4460)
- Marco Piccinini (ORCID: https://orcid.org/0000-0003-2287-0704)
- Giorgio Gribaudo (ORCID: https://orcid.org/0000-0002-1583-9146)
- Elena Martino (ORCID: https://orcid.org/0000-0003-3446-2994)
- Francesco Bavo (ORCID: https://orcid.org/0000-0003-3797-0900)
- Marta Giorgis (ORCID: https://orcid.org/0000-0002-3282-1220)
- Marco L. Lolli (ORCID: https://orcid.org/0000-0002-3030-3163)
- Claudio Garino (ORCID: https://orcid.org/0000-0002-7854-6076)
- Riccardo Miggiano (ORCID: https://orcid.org/0000-0002-2159-3314)
Institutions
- Università degli Studi del Piemonte Orientale “Amedeo Avogadro” (IT)
- University of Copenhagen (DK)
- Accademia Albertina delle Belle Arti (IT)
- University of Turin (IT)
Publication Details
- Journal
- Journal of Medicinal Chemistry
- Published
- 2025-06-18
- DOI
- https://doi.org/10.1021/acs.jmedchem.5c00348
- Citations
- 3
- Primary Topic
- Click Chemistry and Applications
- Type
- article
- Field-Weighted Citation Impact
- 2.81
Funders
- North Atlantic Treaty Organization
- Compagnia di San Paolo
- Associazione Italiana per la Ricerca sul Cancro
- Università degli Studi di Torino
- Ministero dell'Università e della Ricerca