Satoshi Nagato

Discovery of 2-(2-Oxo-1-phenyl-5-pyridin-2-yl-1,2-dihydropyridin-3-yl)benzonitrile (Perampanel): A Novel, Noncompetitive α-Amino-3-hydroxy-5-methyl-4-isoxazolepropanoic Acid (AMPA) Receptor Antagonist

Dysfunction of glutamatergic neurotransmission has been implicated in the pathogenesis of epilepsy and numerous other neurological diseases. Here we describe the discovery of a series of 1,3,5-triaryl-1H-pyridin-2-one derivatives as noncompetitive antagonists of AMPA-type ionotropic glutamate receptors. The structure-activity relationships for this series of compounds were investigated by manipulating individual aromatic rings located at positions 1, 3, and 5 of the pyridone ring. This culminated in the discovery of 2-(2-oxo-1-phenyl-5-pyridin-2-yl-1,2-dihydropyridin-3-yl)benzonitrile (perampanel, 6), a novel, noncompetitive AMPA receptor antagonist that showed potent activity in an in vitro AMPA-induced Ca2+ influx assay (IC50=60 nM) and in an in vivo AMPA-induced seizure model (minimum effective dose of 2 mg/kg po). Perampanel is currently in regulatory submission for partial-onset seizures associated with epilepsy.

Application of pharmacokinetic studies to a novel antidepressant, E2011

1. The original drug tested here, (5R)-3-[2-(3-cyanopropyl)benzothiazol-6-yl]-5-methoxymethyl-2-oxaz olidinone (ER-4539), exhibited strong MAO-A inhibitory activity in vitro, but its bioavailability in rat was very low. After ER-4539 was administered orally to dog, a metabolite was found in plasma. 2. The metabolite was isolated by hplc after incubation with dog liver microsomal preparations. Its structure, determined by ms and nmr analysis, was alpha-hydroxy-ER-4539. The configuration of the alpha-hydroxy metabolite was (S), determined in comparison with the authentic sample of (R) and (S) by hplc. The isolated metabolite had potent MAO-A inhibitory action in vitro, indicating that it would have antidepressant action. 3. (5R)-3-[2-((1S)-3-Cyano-1-hydroxypropyl)benzothiazol-6-yl]-5- methoxymethyl-2-oxazolidinone (E2011), the synthesized metabolite, has been improved in regard to biopharmaceutical characteristics in rat and dog.

Enantioselective synthesis of (2S)-5-{4-[2-(4-fluorophenoxy)ethyl]piperazin-1-yl}-2-isopropyl-2-phenyl-pentanenitrile dihydrochloride (E2050) using enzyme-catalyzed kinetic resolution

Abstract Immobilized lipase ( Pseudomonas sp.)-catalyzed transesterification of ( RS )-4-cyano-4-isopropyl-4-phenyl-1-butanol 4 in vinyl acetate gave ( S )-4-cyano-4-isopropyl-4-phenyl-1-butyl acetate 3a with high enantiomeric excess values and conversions (95–97% ee, 30–47%, E =90–93), leaving the enantiomerically pure ( R )-alcohol 4 (>99% ee) unreacted. As 3a can be efficiently converted to E2050, use of the immobilized lipase should provide an economical route for large-scale synthesis of E2050.

Discovery of Novel Neuronal Voltage-Dependent Calcium Channel Blockers Based on Emopamil Left Hand as a Bioactive Template

A series of novel neuronal voltage-dependent calcium channel (VDCC) blockers, with inhibitory activity at low micromolar and moderate solubility in water, was discovered by constructing and screening a focused library based on emopamil (1) left hand (ELH) as a bioactive template.