title: Synthesis and monoamine oxidase inhibitory activity of new pyridazine-, pyrimidine- and 1,2,4-triazine-containing tricyclic derivatives.
abstract: A number of condensed azines, mostly belonging to the families of indeno-fused pyridazines (1), pyrimidines (2, 3), and 1,2,4-triazines (4, 5), were synthesized and evaluated in vitro as monoamine oxidase (MAO) A and B inhibitors. Most of them showed higher inhibition potency toward MAO-B, the most effective one being 3-(3-nitrophenyl)-9H-indeno[1,2-e] [1,2,4]triazin-9-one (4c), which displayed an IC50 value of 80 nM and proved to be 10-fold more potent than its [2,1-e] fusion isomer 5. Replacing the 3-phenyl group of the known indeno[1,2-c]pyridazin-5-one MAO-B inhibitors with a flexible phenoxymethyl group enhanced the inhibitory potency. The inhibition data highlighted the importance of the aza-heterocyclic scaffold in affecting the MAO isoform selectivity. The 3-phenyl derivatives with type 1, 4, and 5 scaffolds were inhibitors of MAO-B with little or no MAO-A effect, whereas 2- or 3-phenyl derivatives of type 2 and 3 pyrimidine-containing fusion isomers inhibited both isoenzymes with a structure-dependent preference toward MAO-A.
authors.affiliation: Dipartimento Farmaco-chimico, University of Bari, Via E. Orabona 4, I-70125 Bari, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carotti
authors.forename: Marco
authors.initials: M
authors.lastname: Catto
authors.forename: Francesco
authors.initials: F
authors.lastname: Leonetti
authors.forename: Francesco
authors.initials: F
authors.lastname: Campagna
authors.forename: Ramón
authors.initials: R
authors.lastname: Soto-Otero
authors.forename: Estefanía
authors.initials: E
authors.lastname: Méndez-Alvarez
authors.forename: Ulrike
authors.initials: U
authors.lastname: Thull
authors.forename: Bernard
authors.initials: B
authors.lastname: Testa
authors.forename: Cosimo
authors.initials: C
authors.lastname: Altomare
mesh_terms: D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D006575:Heterocyclic Compounds, 3-Ring / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D066298:In Vitro Techniques; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry; D008928:Mitochondria / Q000187:drug effects / Q000201:enzymology; D008958:Models, Molecular; D008996:Monoamine Oxidase Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011724:Pyridazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D021281:Quantitative Structure-Activity Relationship; D051381:Rats; D014227:Triazines / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology
chemical_list: C524707:3-(3-nitrophenyl)-9H-indeno(1,2-e)(1,2,4)triazin-9-one; D006575:Heterocyclic Compounds, 3-Ring; D007527:Isoenzymes; D008996:Monoamine Oxidase Inhibitors; D011724:Pyridazines; D011743:Pyrimidines; D014227:Triazines