Takaaki Sumiyoshi

Total synthesis of (-)-lycorine and (-)-2-epi-lycorine by asymmetric conjugate addition cascade.

Total syntheses of (-)-lycorine and (-)-2-epi-lycorine were accomplished using chiral ligand-controlled asymmetric cascade conjugate addition methodology, which enables the formation of two C-C bonds and three stereogenic centers in one pot to give synthetically useful chiral cyclohexane derivatives.

Discovery of novel N-substituted oxindoles as selective m1 and m4 muscarinic acetylcholine receptors partial agonists.

Activation of the M1 and M4 muscarinic acetylcholine receptors is thought to play an important role in improving the symptoms of schizophrenia. However, discovery of selective agonists for these receptors has been a challenge, considering the high sequence homology and conservation of the orthosteric acetylcholine binding site among muscarinic acetylcholine receptor subtypes. We report in this study the discovery of novel N-substituted oxindoles as potent muscarinic acetylcholine receptor partial agonists selective for M1 and M4 over M2, M3, and M5. Among these oxindoles, compound 1 showed high selectivity for the M1 and M4 receptors with remarkable penetration into the central nervous system. Compound 1 reversed methamphetamine- and apomorphine-induced psychosis-like behaviors with low potency to extrapyramidical and peripheral side effects.

Discovery of dihydroquinazolinone derivatives as potent, selective, and CNS-penetrant M1 and M4 muscarinic acetylcholine receptors agonists

We designed and synthesized a series of dihydroquinazolinone derivatives as selective M1 and M4 muscarinic acetylcholine receptors agonists. Introduction of the N-carbethoxy piperidine unit into a HTS hit compound followed by optimization of the amine linker and the carbamoyl moiety led to the identification of compound 1 as a potential candidate. The identified compound 1 showed high selectivity for M1 and M4 muscarinic acetylcholine receptors with M4 partial agonistic activity. In addition, compound 1 showed good brain penetration and reversed methamphetamine-induced hyperlocomotion in rats (ED50=3.0 mg/kg, sc).

Discovery of N-sulfonyl-7-azaindoline derivatives as potent, orally available and selective M(4) muscarinic acetylcholine receptor agonists.

We designed and synthesized novel N-sulfonyl-7-azaindoline derivatives as selective M4 muscarinic acetylcholine receptor agonists. Modification of the N-carbethoxy piperidine moiety of compound 2, an M4 muscarinic acetylcholine receptor (mAChR)-preferring agonist, led to compound 1, a selective M4 mAChR agonist. Compound 1 showed a highly selective M4 mAChR agonistic activity with weak hERG inhibition in vitro. A pharmacokinetic study of compound 1 in vivo revealed good bioavailability and brain penetration in rats. Compound 1 reversed methamphetamine-induced locomotor hyperactivity in rats (1-10 mg/kg, po).

Identification of N-substituted 8-azatetrahydroquinolone derivatives as selective and orally active M1 and M4 muscarinic acetylcholine receptors agonists

We designed and synthesized N-substituted 8-azatetrahydroquinolone derivatives as selective M1 and M4 muscarinic acetylcholine receptors agonists. Optimization of selected derivatives led to the discovery of compound 7 as a highly potent M1 and M4 agonist with weak hERG inhibition. Oral administration of compound 7 improved psychosis-like behavior in rats.

Discovery of N-substituted 7-azaindoline derivatives as potent, orally available M1 and M4 muscarinic acetylcholine receptors selective agonists

We designed and synthesized novel N-substituted 7-azaindoline derivatives as selective M1 and M4 muscarinic acetylcholine receptors (mAChRs) agonists. Hybridization of compound 2 with the HTS hit compound 5 followed by optimization of the N-substituents of 7-azaindoline led to identification of compound 1, which showed highly selective M1 and M4 mAChRs agonistic activity, weak human ether-a-go-go related gene inhibition, and good bioavailability in multiple animal species.

Identification of 2,3-disubstituted pyridines as potent, orally active PDE4 inhibitors

A series of 2,3-disubstituted pyridines were synthesized and evaluated for their PDE4 inhibitory activity. We successfully modified undesirable cyano group of initial lead compound 2 to 4-pyridyl group with improvement of in vitro efficacy and optimized the position of nitrogen atoms in pyridine moiety and alkylene linker. The most potent compound showed significant efficacy in animal models of asthma and inflammation.

Discovery of new low-molecular-weight p53–Mdmx disruptors and their anti-cancer activities

Although several p53-Mdm2-binding disruptors have been identified to date, few studies have been published on p53-Mdmx-interaction inhibitors. In the present study, we demonstrated that o-aminothiophenol derivatives with molecular weights of 200-300 selectively inhibited the p53-Mdmx interaction. S-2-Isobutyramidophenyl 2-methylpropanethioate (K-178) (1c) activated p53, up-regulated the expression of its downstream genes such as p21 and Mdm2, and preferentially inhibited the growth of cancer cells with wild-type p53 over those with mutant p53. Furthermore, we found that the S-isobutyryl-deprotected forms 1b and 3b of 1c and S-2-benzamidophenyl 2-methylpropanethioate (K-181) (3c) preferentially inhibited the p53-Mdmx interaction over the p53-Mdm2 interaction, respectively, by using a Flag-p53 and glutathione S-transferase (GST)-fused protein complex (Mdm2, Mdmx, DAPK1, or PPID). In addition, the interaction of p53 with Mdmx was lost by replacing a sulfur atom with an oxygen atom in 1b and 1c. These results suggest that sulfides such as 1b, 3b, 4b, and 5b interfere with the binding of p53-Mdmx, resulting in the dissociation of the two proteins. Furthermore, the results of oral administration experiments using xenografts in nude mice indicated that 1c reduced the volume of tumor masses to 49.0% and 36.6% that of the control at 100 mg/kg and 150 mg/kg, respectively, in 40 days.

Identification of 2,3-disubstituted pyridines as potent, non-emetic PDE4 inhibitors

A series of 2,3-disubstituted pyridines were synthesized as potential non-emetic PDE4 inhibitors. To decrease brain exposure and minimize emesis, we modified the lipophilic moiety of a series of emetic PDE4 inhibitors and found that introduction of a hydroxy group into the pyridine moiety of the side chain led to non-emetic compounds with preserved PDE4 inhibitory activity. Following optimization at the phenoxy group, we identified compound 1 as a potent non-emetic PDE4 inhibitor. Compound 1 showed significant efficacy in an animal model of asthma without inducing emesis.

Asymmetric Synthesis of the Carbon-14-Labeled Selective Glucocorticoid Receptor Modulator using Cinchona Alkaloid Catalyzed Addition of 6-Bromoindole to Ethyl Trifluoropyruvate

We describe in this study the asymmetric synthesis of radioisotope (RI)-labeled selective glucocorticoid receptor modulator. This synthesis is based on optimization of the cinchona alkaloid catalyzed addition of 6-bromoindole to ethyl trifluoropyruvate and Negishi coupling of zinc cyanide to the 6-bromoindole moiety. [14C] Labeled (−)-{4-[(1-{2-[6-cyano-1-(cyclohexylmethyl)-1H-indol-3-yl]-3,3,3-trifluoro-2-hydroxypropyl}piperidin-4-yl)oxy]-3-methoxyphenyl}acetic acid (−)-1 was synthesized successfully with high enantioselectivity (>99% ee) and sufficient radiochemical purity.