Solid-phase synthesis and insights into structure-activity relationships of safinamide analogues as potent and selective inhibitors of type B monoamine oxidase.

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Citation

Leonetti F, Capaldi C, Pisani L, Nicolotti O, Muncipinto G, Stefanachi A, Cellamare S, Caccia C, Carotti A

Solid-phase synthesis and insights into structure-activity relationships of safinamide analogues as potent and selective inhibitors of type B monoamine oxidase.

J Med Chem. 2007 Oct 4;50(20):4909-16. Epub 2007 Sep 7.

PubMed ID
17824599 [ View in PubMed
]
Abstract

Safinamide, (S)-N2-{4-[(3-fluorobenzyl)oxy]benzyl}alaninamide methanesulfonate, which is in phase III clinical trials as an anti-Parkinson drug, and a library of alkanamidic analogues were prepared through an expeditious solid-phase synthesis and evaluated for their monoamine oxidase B (MAO-B) and monoamine oxidase A (MAO-A) inhibitory activity and selectivity. (S)-3-Chlorobenzyloxyalaninamide (8) and (S)-3-chlorobenzyloxyserinamide (13) derivatives proved to be more potent MAO-B inhibitors than safinamide (IC50 = 33 and 43 nM, respectively, vs 98 nM) but with a lower MAO-B selectivity (SI = 3455 and 1967, respectively, vs 5918). The highest MAO-B inhibitory potency (IC50 = 17 nM) and a good selectivity (SI = 2941) were displayed by (R)-21, a tetrahydroisoquinoline analogue of safinamide. Structure-affinity relationships and docking simulations pointed out strong negative steric effects of alpha-aminoamide side chains and para substituents of the benzyloxy groups and favorable hydrophobic interactions of meta substituents. The significantly diverse MAO-B affinities of a number of R and S alpha-aminoamide enantiomers, including the two rigid analogues (21) of safinamide, indicated likely enantioselective interactions at the enzymatic binding sites.

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
SafinamideAmine oxidase [flavin-containing] AProteinHumans
Unknown
Inhibitor
Details