Yoshinori Ikeura

Effects of TAK-637, a tachykinin receptor antagonist, on the micturition reflex in guinea pigs

The effects of a new tachykinin NK(1) receptor antagonist, (aR, 9R)-7-[3,5-bis(trifluoromethyl)benzyl]-8,9,10, 11-tetrahydro-9-methyl-5-(4-methylphenyl)-7H-[1,4]diazocino[2,1-g] [1, 7]naphthyridine-6,13-dione (TAK-637), on the micturition reflex were compared with those of drugs used for abnormally frequent micturition or incontinence. TAK-637 showed a characteristic effect on the distension-induced rhythmic bladder contractions in guinea pigs. The systemic administration of TAK-637 decreased the number but not the amplitude of the distension-induced rhythmic bladder contractions. A similar effect was observed in animals in which the spinal cord had been severed. TAK-637 also inhibited the micturition reflex induced by topical application of capsaicin onto the surface of bladder dome. From these results, it is concluded that TAK-637 inhibits sensory transmissions from the bladder evoked by both physiological and nociceptive stimuli by blocking tachykinin NK(1) receptors, possibly at the level of the spinal cord. On the other hand, the other drugs such as oxybutynin, tolterodine, propiverine, and inaperisone showed no effects on the frequency of the distension-induced rhythmic bladder contractions but decreased the contraction amplitude. Therefore, TAK-637 may represent a new class of drugs, which would be effective for abnormally frequent micturition without causing voiding difficulties due to decreased voiding pressure.

Effects of TAK-637, a tachykinin receptor antagonist, on lower urinary tract function in the guinea pig.

The effects of TAK-637 ((aR,9R)-7-[3,5-bis(trifluoromethyl)benzyl]-8, 9,10,11-tetrahydro-9-methyl-5-(4-methylphenyl)-7H-[1,4]diazocino[2 , 1-g][1,7]naphthyridine-6,13-dione), a novel tachykinin NK(1) receptor antagonist, on the micturition reflex in guinea pigs were studied in comparison with those of anti-pollakiuria agents. Cystometry was performed under urethane anesthesia. TAK-637 increased the volume threshold with a minimum effective dose of 0.03 mg/kg, i.v. without affecting voiding pressure. Oxybutynin, tolterodine, propiverine and inaperisone also increased the volume threshold in urethane-anesthetized guinea pigs, but they decreased voiding pressure, although the effect of propiverine was not statistically significant. A structurally unique tachykinin NK(1) receptor antagonist, (+/-)-CP-99,994 ((+/-)-(2S, 3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine), increased the volume threshold with a minimum effective dose of 0.3 mg/kg, i.v. TAK-637 increased the volume threshold with a minimum effective dose of 0.01 mg/kg, p.o. in unanesthetized guinea pigs. These results indicate that TAK-637 may be useful as pharmacotherapy for detrusor overactivity without decreasing voiding pressure or causing voiding difficulties.

Design, structure–activity relationship, and highly efficient asymmetric synthesis of 3-phenyl-4-benzylaminopiperidine derivatives as novel neurokinin-1 receptor antagonists

We synthesized a series of novel 3-phenyl-4-benzylaminopiperidine derivatives that were identified as potent tachykinin NK(1) receptor antagonists by structural modification of the 3-benzhydrylpiperidone derivative through high-throughput screening. N-{2-[(3R,4S)-4-({2-Methoxy-5-[5-(trifluoromethyl)-1H-tetrazol-1-yl]benzyl}amino)-3-phenyl-1-piperidinyl]-2-oxoethyl}acetamide ((+)-39) was found to be one of the most potent tachykinin NK(1) receptor antagonists with high metabolic stability. Highly efficient asymmetric synthesis of (+)-39 was achieved via dynamic kinetic resolution.

RETRACTED: 3-Benzhydryl-4-piperidones as novel neurokinin-1 receptor antagonists and their efficient synthesis

A series of novel 3-benzhydryl-4-piperidone derivatives were identified as potent tachykinin neurokinin-1 (NK(1)) receptor antagonists. An efficient and versatile synthesis of this series was achieved with a coupling reaction of 1-benzylpiperidones with benzhydryl bromides or benzhydrols in the presence of trifluoromethanesulfonate and a condensation reaction of piperidones with benzyl alcohols using ethyl o-phenylenephosphate. The 3-benzhydryl-4-piperidone skeleton, which has a 1,1-diphenylmethane moiety that is a known privileged substructure targeting G-protein coupled receptors, can be used for chemical library synthesis because of chemical accessibility and diversity.

Microbial synthesis of three metabolites of a tachykinin receptor antagonist, TAK-637.

The compound TAK-637 ((aR,9R)-7-[3,5-bis(trifluoromethyl)benzyl]-8,9,10,11-tetrahydro-9-methyl-5-(4-methylphenyl)-7H-[1,4]diazocino[2,1-g][1,7]naphthyridine-6,13-dione), a tachykinin receptor antagonist, has been shown to be converted into three metabolites in rats and guinea pigs. It was difficult to isolate the metabolites from rats and guinea pigs administered TAK-637 and elucidate the structures. A total of 100 actinomycete strains were screened for the ability to convert TAK-637 into its metabolites. Three strains, Streptomyces subrutilus IFO13388, Streptomyces tanashiensis subsp. cephalomyceticus IFO13929 and Streptomyces lavenduligriseus IFO13405, were found to convert TAK-637 into the metabolites consistent with the metabolites formed in rats and guinea pigs as determined by HPLC analyses. The metabolites were synthesized by microbial conversion using the actinomycetes. The structures of the metabolites were elucidated by spectral analyses. It was found that the methyl group at the C(5)-phenyl group of TAK-637 was hydroxylated and the resulting alcohol was converted to carboxylic acid via aldehyde. One of the metabolites (hydroxylated TAK-637) was obtained using a 200-l fermentor in a large-scale cultivation to evaluate its biological activity.

Enantioselective synthesis of an axially chiral 1,7-naphthyridine-6-carboxamide derivative having potent antagonist activity at the NK1 receptor

A new and highly potent NK1 antagonist, (aR,9R)-3 [(aR,9R)-7-[3,5-bis(trifluoromethyl)benzyl]-8,9,10,11-tetrahydro-9-methyl-5-(4-methylphenyl)-7H-[1,4]diazocino[2,1-g][1,7]naphthyridine-6,13-dione], was atropdiastereoselectively synthesized in good yield by cyclization of the chiral intermediate 6b.

Novel 3-phenylpiperidine-4-carboxamides as highly potent and orally long-acting neurokinin-1 receptor antagonists with reduced CYP3A induction.

The synthesis and biological evaluation of a series of novel 3-phenylpiperidine-4-carboxamide derivatives are described. These compounds are generated by hybridization of the substructures from two types of tachykinin NK(1) receptor antagonists. Compound 42 showed high metabolic stability and excellent efficacy in the guinea-pig GR-73637-induced locomotive activity assay at 1 and 24h after oral administration. It also exhibited good pharmacokinetic profiles in four animal species, and a low potential in a pregnane X receptor induction assay.