Background Alzheimer’s disease (AD) is a complex challenge driven by amyloid/tau misfolding, oxidative stress, and neuroinflammation, requiring multi-target therapeutic strategies. MAO-B1 overexpression and depleted Nrf22 levels are key contributors to neurodegeneration. The Keap1/Nrf2 pathway represents a master regulator of cytoprotective enzymes, mitigating oxidative damage. Activation can be achieved via electrophilic modulation of Keap1-Cys151, a mechanism shared by several natural scaffolds. Therefore, targeting the Nrf2/Keap1 axis alongside other AD-related markers offers a promising approach to tackling this multifaceted pathology. Aims In this study, we aimed to develop multifunctional agents3 that both activate Nrf2 and inhibit MAO-B to effectively reduce oxidative stress and neuroinflammation, while providing neuroprotection. This offers a new chemical strategy to address the complex nature of AD. In particular, the chalcone scaffold2 was envisaged as suitable for concurrent modulation of the selected target. Methods A library of chalcone-based hybrids was designed by conjugating glypromate (GPE)-related amino acid residues4 to a 2,4’-dihydroxychalcone lead (CA19) via an acetoxylamido linker. Using a parallel synthesis approach, derivatives were functionalized at the ortho-, meta-, and para- positions of the B-ring to explore the SAR chemical space (Figure 1). All compounds were characterized by 1H and 13C NMR spectroscopy and mass spectrometry. Biological profiling included in vitro assays on SH-SY5Y cells for neurotoxicity and Nrf2 modulation, and LPS-stimulated microglia to assess anti-inflammatory effects. Additional investigations into MAO inhibition are currently ongoing to complete the multi-target characterization. Figure 1. General synthetic strategy for the structural diversification of chalcone-based hybrids starting from the dihydroxychalcone core (CA19). Results Regarding the preliminary toxicity study, the tested analogues displayed a quite safe profile, revealing that only the para-substitution with a glycine exhibited a cytotoxic impact similar to the starting hit CA19; conversely, other GPE-related substituents in the para-position significantly enhanced the neuroprotective profile compared to CA19. Furthermore, several tested analogues significantly increased Nrf2 levels and promoted its nuclear translocation; notably, the ethyl ester substitution proved suitable for eliciting robust activation of the Keap1/Nrf2 pathway. Regarding anti-inflammatory potential, some analogues effectively inhibited IL-1β release. Some hybrids exhibited multi-target potential since they showed a substantial decrease in IL-1β levels at low micromolar concentration, correlated closely with the previously observed Nrf2 activation, confirming the multi-target potential of this chemical series To further explore the multitarget profile of this scaffold, the chemical library is currently being expanded. Additional biological evaluations, including the assessment of the full series inhibitory activity against monoamine oxidases (MAO-A/B), are currently ongoing. Conclusion Overall, this study highlights the potential of novel chalcone-GPE derivatives as multifunctional agents against AD. By successfully combining Nrf2 activation, neuroprotective and anti-inflammatory properties, these hybrids underpin chalcone CA19 as a promising chemical scaffold to be properly functionalised. The newly designed compounds represent a valuable starting point for the development of disease-modifying therapeutics to address the multifaceted nature of neurodegenerative diseases. References 1. Tripathi, Rati Kailash Prasad, and Senthil Raja Ayyannan. “Monoamine oxidase-B inhibitors as potential neurotherapeutic agents: An overview and update.” Medicinal research reviews vol. 39,5 (2019): 1603-1706. doi:10.1002/med.21561 2. Wilson, Anthony J et al. “Keap calm, and carry on covalently.” Journal of medicinal chemistry vol. 56,19 (2013): 7463-76. doi:10.1021/jm400224q 3. De Lorenzi, E., Seghetti, F., Tarozzi, A., Pruccoli, L., Contardi, C., Serra, M., Bisi, A., Gobbi, S., Vistoli, G., Gervasoni, S., Argentini, C., Ghirardo, G., Guarato, G., Orso, G., Belluti, F., Di Martino, R. M. C., & Zusso, M. (2023). Targeting the multifaceted neurotoxicity of Alzheimer's disease by tailored functionalisation of the curcumin scaffold. European Journal of Medicinal Chemistry, 252, 115297. 4. Sampaio-Dias, I. E., Santejo, M., Silva-Reis, S. C., Liz, M. A., Alcoholado, C., Algarra, M., García-Mera, X., & Rodríguez-Borges, J. E. (2021). Design, synthesis, and biological evaluation of hybrid glypromate analogues using 2-azanorbornane as a prolyl and pipecolyl surrogate. ACS Chemical Neuroscience, 12(19), 3615–3624.
Da Fermo, A., Tarozzi, A., Pruccoli, L., Zusso, M., León Martínez, R., Marsella, G., et al. (2026). Targeting Alzheimer’s disease neurotoxicity by functionalization of the chalcone scaffold.
Targeting Alzheimer’s disease neurotoxicity by functionalization of the chalcone scaffold
Da Fermo A.;Tarozzi A.;Pruccoli L.;Marsella G.;Gobbi S.;Bisi A.;Belluti F.
2026
Abstract
Background Alzheimer’s disease (AD) is a complex challenge driven by amyloid/tau misfolding, oxidative stress, and neuroinflammation, requiring multi-target therapeutic strategies. MAO-B1 overexpression and depleted Nrf22 levels are key contributors to neurodegeneration. The Keap1/Nrf2 pathway represents a master regulator of cytoprotective enzymes, mitigating oxidative damage. Activation can be achieved via electrophilic modulation of Keap1-Cys151, a mechanism shared by several natural scaffolds. Therefore, targeting the Nrf2/Keap1 axis alongside other AD-related markers offers a promising approach to tackling this multifaceted pathology. Aims In this study, we aimed to develop multifunctional agents3 that both activate Nrf2 and inhibit MAO-B to effectively reduce oxidative stress and neuroinflammation, while providing neuroprotection. This offers a new chemical strategy to address the complex nature of AD. In particular, the chalcone scaffold2 was envisaged as suitable for concurrent modulation of the selected target. Methods A library of chalcone-based hybrids was designed by conjugating glypromate (GPE)-related amino acid residues4 to a 2,4’-dihydroxychalcone lead (CA19) via an acetoxylamido linker. Using a parallel synthesis approach, derivatives were functionalized at the ortho-, meta-, and para- positions of the B-ring to explore the SAR chemical space (Figure 1). All compounds were characterized by 1H and 13C NMR spectroscopy and mass spectrometry. Biological profiling included in vitro assays on SH-SY5Y cells for neurotoxicity and Nrf2 modulation, and LPS-stimulated microglia to assess anti-inflammatory effects. Additional investigations into MAO inhibition are currently ongoing to complete the multi-target characterization. Figure 1. General synthetic strategy for the structural diversification of chalcone-based hybrids starting from the dihydroxychalcone core (CA19). Results Regarding the preliminary toxicity study, the tested analogues displayed a quite safe profile, revealing that only the para-substitution with a glycine exhibited a cytotoxic impact similar to the starting hit CA19; conversely, other GPE-related substituents in the para-position significantly enhanced the neuroprotective profile compared to CA19. Furthermore, several tested analogues significantly increased Nrf2 levels and promoted its nuclear translocation; notably, the ethyl ester substitution proved suitable for eliciting robust activation of the Keap1/Nrf2 pathway. Regarding anti-inflammatory potential, some analogues effectively inhibited IL-1β release. Some hybrids exhibited multi-target potential since they showed a substantial decrease in IL-1β levels at low micromolar concentration, correlated closely with the previously observed Nrf2 activation, confirming the multi-target potential of this chemical series To further explore the multitarget profile of this scaffold, the chemical library is currently being expanded. Additional biological evaluations, including the assessment of the full series inhibitory activity against monoamine oxidases (MAO-A/B), are currently ongoing. Conclusion Overall, this study highlights the potential of novel chalcone-GPE derivatives as multifunctional agents against AD. By successfully combining Nrf2 activation, neuroprotective and anti-inflammatory properties, these hybrids underpin chalcone CA19 as a promising chemical scaffold to be properly functionalised. The newly designed compounds represent a valuable starting point for the development of disease-modifying therapeutics to address the multifaceted nature of neurodegenerative diseases. References 1. Tripathi, Rati Kailash Prasad, and Senthil Raja Ayyannan. “Monoamine oxidase-B inhibitors as potential neurotherapeutic agents: An overview and update.” Medicinal research reviews vol. 39,5 (2019): 1603-1706. doi:10.1002/med.21561 2. Wilson, Anthony J et al. “Keap calm, and carry on covalently.” Journal of medicinal chemistry vol. 56,19 (2013): 7463-76. doi:10.1021/jm400224q 3. De Lorenzi, E., Seghetti, F., Tarozzi, A., Pruccoli, L., Contardi, C., Serra, M., Bisi, A., Gobbi, S., Vistoli, G., Gervasoni, S., Argentini, C., Ghirardo, G., Guarato, G., Orso, G., Belluti, F., Di Martino, R. M. C., & Zusso, M. (2023). Targeting the multifaceted neurotoxicity of Alzheimer's disease by tailored functionalisation of the curcumin scaffold. European Journal of Medicinal Chemistry, 252, 115297. 4. Sampaio-Dias, I. E., Santejo, M., Silva-Reis, S. C., Liz, M. A., Alcoholado, C., Algarra, M., García-Mera, X., & Rodríguez-Borges, J. E. (2021). Design, synthesis, and biological evaluation of hybrid glypromate analogues using 2-azanorbornane as a prolyl and pipecolyl surrogate. ACS Chemical Neuroscience, 12(19), 3615–3624.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
