title: 1,2,3,4-Tetrahydrobenzo[h][1,6]naphthyridines as a new family of potent peripheral-to-midgorge-site inhibitors of acetylcholinesterase: synthesis, pharmacological evaluation and mechanistic studies.
abstract: A series of 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridines differently substituted at positions 1, 5, and 9 have been designed from the pyrano[3,2-c]quinoline derivative 1, a weak inhibitor of acetylcholinesterase (AChE) with predicted ability to bind to the AChE peripheral anionic site (PAS), at the entrance of the catalytic gorge. Fourteen novel benzonaphthyridines have been synthesized through synthetic sequences involving as the key step a multicomponent Povarov reaction between an aldehyde, an aniline and an enamine or an enamide as the activated alkene. The novel compounds have been tested against Electrophorus electricus AChE (EeAChE), human recombinant AChE (hAChE), and human serum butyrylcholinesterase (hBChE), and their brain penetration has been assessed using the PAMPA-BBB assay. Also, the mechanism of AChE inhibition of the most potent compounds has been thoroughly studied by kinetic studies, a propidium displacement assay, and molecular modelling. We have found that a seemingly small structural change such as a double O → NH bioisosteric replacement from the hit 1 to 16a results in a dramatic increase of EeAChE and hAChE inhibitory activities (>217- and >154-fold, respectively), and in a notable increase in hBChE inhibitory activity (>11-fold), as well. An optimized binding at the PAS besides additional interactions with AChE midgorge residues seem to account for the high hAChE inhibitory potency of 16a (IC50 = 65 nM), which emerges as an interesting anti-Alzheimer lead compound with potent dual AChE and BChE inhibitory activities.
authors.affiliation: Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain.
authors.forename: Ornella
authors.initials: O
authors.lastname: Di Pietro
authors.affiliation: Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Viayna
authors.affiliation: Barcelona Science Park, Baldiri Reixac 10-12, E-08028 Barcelona, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Vicente-García
authors.affiliation: Department of Pharmacy and Biotechnology, Alma Mater Studiorum, University of Bologna, Via Belmeloro 6, I-40126 Bologna, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Bartolini
authors.affiliation: Barcelona Science Park, Baldiri Reixac 10-12, E-08028 Barcelona, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Ramón
authors.affiliation: Departament de Fisicoquímica, Facultat de Farmàcia, and IBUB, Universitat de Barcelona, Prat de la Riba 171, E-08921 Santa Coloma de Gramenet, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Juárez-Jiménez
authors.affiliation: Departament de Farmacologia, de Terapèutica i de Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
authors.forename: M Victòria
authors.initials: MV
authors.lastname: Clos
authors.affiliation: Departament de Farmacologia, de Terapèutica i de Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Pérez
authors.affiliation: Department for Life Quality Studies, University of Bologna, Corso d'Augusto 237, I-47921 Rimini, Italy.
authors.forename: Vincenza
authors.initials: V
authors.lastname: Andrisano
authors.affiliation: Departament de Fisicoquímica, Facultat de Farmàcia, and IBUB, Universitat de Barcelona, Prat de la Riba 171, E-08921 Santa Coloma de Gramenet, Spain.
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Luque
authors.affiliation: Barcelona Science Park, Baldiri Reixac 10-12, E-08028 Barcelona, Spain; Laboratori de Química Orgànica, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain. Electronic address: rlavilla@pcb.ub.es.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Lavilla
authors.affiliation: Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII 27-31, E-08028 Barcelona, Spain. Electronic address: dmunoztorrero@ub.edu.
authors.forename: Diego
authors.initials: D
authors.lastname: Muñoz-Torrero
mesh_terms: D000110:Acetylcholinesterase / Q000097:blood / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000201:enzymology; D002091:Butyrylcholinesterase / Q000737:chemistry / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry; D015195:Drug Design; D004593:Electrophorus; D006801:Humans; D008567:Membranes, Artificial; D008954:Models, Biological; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D009287:Naphthyridines / Q000138:chemical synthesis* / Q000737:chemistry; D010539:Permeability; D011485:Protein Binding
chemical_list: D002800:Cholinesterase Inhibitors; D008567:Membranes, Artificial; D009287:Naphthyridines; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase
keywords: AChE PAS binding; AChE midgorge binding; Benzo[h][1,6]naphthyridines; Dual inhibitors; Povarov reaction