Investigation on Novel IE/Z/I 2-Benzylideneindan-1-One-Based Photoswitches with AChE and MAO-B Dual Inhibitory Activity

• Published in: Molecules (Basel, Switzerland) Switzerland), 2023-08, Vol.28 (15)
• Main Authors: Paolino, Marco, de Candia, Modesto, Purgatorio, Rosa, Catto, Marco, Saletti, Mario, Tondo, Anna Rita, Nicolotti, Orazio, Cappelli, Andrea, Brizzi, Antonella, Mugnaini, Claudia, Corelli, Federico, Altomare, Cosimo D
• Format: Article
• Language: English
• Subjects: Alzheimer's disease; Drug therapy; Monoamine oxidase; Nervous system diseases; Rasagiline
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules28155857

The multitarget therapeutic strategy, as opposed to the more traditional ‘one disease-one target-one drug’, may hold promise in treating multifactorial neurodegenerative syndromes, such as Alzheimer’s disease (AD) and related dementias. Recently, combining a photopharmacology approach with the multitarget-directed ligand (MTDL) design strategy, we disclosed a novel donepezil-like compound, namely 2-(4-((diethylamino)methyl)benzylidene)-5-methoxy-2,3-dihydro-1H-inden-1-one (1a), which in the E isomeric form (and about tenfold less in the UV-B photo-induced isomer Z) showed the best activity as dual inhibitor of the AD-related targets acetylcholinesterase (AChE) and monoamine oxidase B (MAO-B). Herein, we investigated further photoisomerizable 2-benzylideneindan-1-one analogs 1b–h with the unconjugated tertiary amino moiety bearing alkyls of different bulkiness and lipophilicity. For each compound, the thermal stable E geometric isomer, along with the E/Z mixture as produced by UV-B light irradiation in the photostationary state (PSS, 75% Z), was investigated for the inhibition of human ChEs and MAOs. The pure E-isomer of the N-benzyl(ethyl)amino analog 1h achieved low nanomolar AChE and high nanomolar MAO-B inhibition potencies (IC[sub.50]s 39 and 355 nM, respectively), whereas photoisomerization to the Z isomer (75% Z in the PSS mixture) resulted in a decrease (about 30%) of AChE inhibitory potency, and not in the MAO-B one. Molecular docking studies were performed to rationalize the different E/Z selectivity of 1h toward the two target enzymes.