Peptide based interleukin-1 beta converting enzyme (ICE) inhibitors: synthesis, structure activity relationships and crystallographic study of the ICE-inhibitor complex

Based on the X-ray structure of the complex of Ac-Tyr-Val-Ala-Asp-H (L-709049) and interleukin-1 beta converting enzyme (ICE), we synthesized compounds which were derived from 2-NapCO-Val-Pro-Asp-CH2OPh (1) to obtain a potent inhibitor in the cell assay. Among these compounds, (3S)-N-methanesulfonyl-3-[[1-[N-(2-naphthoyl)-L-valyl]-L-prolyl]amino]- 4-oxobutanamide (27c) showed high potency not only in the enzyme assay but also cell assay with IC50 values of 38 nM and 0.23 microM, respectively. Compound 27c, with a c log P value of 1.76, had a more hydrophilic character compared with 1. Compound 27c also dose dependently inhibited LPS-primed ATP-induced IL-1 beta release in mice. The crystal structure of the complex of compound 27c and ICE revealed that compound 27c had further interactions with ICE in the naphthoyl group at the P4 position and in the methyl group of the methanesulfonamidecarbonyl group at the P1 position, compared with L-709049. To our knowledge, compound 27c is the first example that shows a strong inhibitory activity without the carboxyl group at the P1 position.

Synthesis of C-ring aromatic taxoids and evaluation of their multi-drug resistance reversing activity

The C-aromatic taxoids were synthesized to develop effective inhibitors against drug efflux mediated by p-glycoproteins. Among those tested using multi-drug resistant tumor cells (2780AD), the benzoate 11 exhibited significant activity as potent as verapamil, a well-established MDR reversing agent.

Synthesis and evaluation of artificial taxoids with antitumor and multi-drug resistance reversing activities

Artificial taxoids were synthesized and subjected to evaluation of their ability of multi-drug resistance reversing and antitumor activities. While the taxoid 4 could not increase cellular accumulation of vincristine in multi-drug resistant tumor cells, the C4-hydroxy analog 15 showed significant effect. However, these compounds showed weak activities on growth inhibition of cancer cells.

Selective muscarinic antagonists. I. Synthesis and antimuscarinic properties of 4-piperidyl benzhydrylcarbamate derivatives

A series of 1-substituted-4-piperidyl benzhydrylcarbamate derivatives were synthesized and evaluated for binding affinity to M1, M2 and M3 receptors, and for antimuscarinic activities. Receptor binding assays indicated that 1-benzyl-4-piperidyl benzhydrylcarbamate derivatives showed higher affinities for M1 and M3 receptors, and good selectivities for M3 over M2 receptor, than the corresponding ester analog. These results indicate that the urethane bond is a novel linker for muscarinic antagonists, and serves to lock the molecular conformation and allows the hydrophobic portion and cationic site of the molecule to bind to M1 and M3 muscarinic receptors. Among the prepared compounds, 1-(4-methylaminobenzyl)-4-piperidyl benzhydrylcarbamate monohydrochloride (18b, YM-58790) exhibited potent inhibitory activity on bladder pressure in reflexly-evoked rhythmic contraction, comparable to oxybutynin and was approximately ten times less inhibitory on oxotremorine-induced salivary secretion than oxybutynin in rats. Further evaluation of antimuscarinic effects on bradycardia and pressor in pithed rats, and on tremor in mice, demonstrated that YM-58790 can be useful for treatment of urinary urge incontinence as a bladder-selective M3 antagonist with fewer side effects.

Selective muscarinic antagonists. II. Synthesis and antimuscarinic properties of biphenylylcarbamate derivatives

A novel series of biphenylylcarbamate derivatives were synthesized and evaluated for binding to M1, M2 and M3 receptors and for antimuscarinic activities. Receptor binding assays indicated that biphenyl-2-ylcarbamate derivatives had high affinities for M1 and M3 receptors and good selectivities for M3 receptor over M2 receptor, indicating that the biphenyl-2-yl group is a novel hydrophobic replacement for the benzhydryl group in the muscarinic antagonist field. In this series, quinuclidin-4-yl biphenyl-2-ylcarbamate monohydrochloride (8l, YM-46303) exhibited the highest affinities for M1 and M3 receptors, and selectivity for M3 over M2 receptor. Compared to oxybutynin, YM-46303 showed approximately ten times higher inhibitory activity on bladder pressure in reflexly-evoked rhythmic contraction, and about 5-fold greater selectivity for urinary bladder contraction against salivary secretion in rats. Moreover, selective antagonistic activity was also observed in vitro. Further evaluation of antimuscarinic effects on bradycardia and pressor in pithed rats, and on tremor in mice, showed that YM-46303 can be useful for the treatment of urinary urge incontinence as a bladder-selective M3 antagonist with potent activities and fewer side effects.