title: Synthesis, antiplatelet activity and comparative molecular field analysis of substituted 2-amino-4H-pyrido[1,2-a]pyrimidin-4-ones, their congeners and isosteric analogues.
abstract: 2-(1-Piperazinyl)-4H-pyrido[1,2-a]pyrimidin-4-one (5a) is a recently described in vitro inhibitor of human platelet aggregation which specifically inhibits the activity of high affinity cAMP phosphodiesterase. A number of substitution derivatives, isosteres, and analogues of 5a were now synthesized and tested in vitro for their inhibitory activity on human platelet aggregation induced in platelet-rich plasma by ADP, collagen, or the Ca2+ ionophore A23187. Among the most effective compounds, the 6-methyl, 8-methyl and 6,8-dimethyl derivatives of 5a resulted nearly as active as the lead when platelet aggregation was induced by ADP or A23187, but less active when collagen was the inducer. On the basis of present results and those previously obtained by us in this and 2-aminochromone structural fields, we have developed a statistically significant 3-D QSAR model, using comparative molecular field analysis (CoMFA), describing the variation of the antiplatelet activity in terms of molecular steric and electrostatic potential changes.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Genova, Genoa, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Roma
authors.forename: N
authors.initials: N
authors.lastname: Cinone
authors.forename: M
authors.initials: M
authors.lastname: Di Braccio
authors.forename: G
authors.initials: G
authors.lastname: Grossi
authors.forename: G
authors.initials: G
authors.lastname: Leoncini
authors.forename: M G
authors.initials: MG
authors.lastname: Signorello
authors.forename: A
authors.initials: A
authors.lastname: Carotti
authors.forename: A
authors.initials: A
authors.lastname: Carott
mesh_terms: D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010975:Platelet Aggregation Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D011744:Pyrimidinones / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D010975:Platelet Aggregation Inhibitors; D011744:Pyrimidinones