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In synthesizing novel derivatives of the natural cyclic peptides the ogipeptins, we established a simple and practical solid-phase peptide synthesis and macrocyclization method. By using this method, it became possible to obtain skeleton-modified ogipeptin derivatives with dehydroxylation of the β-hydroxy-α,γ-diaminobutyric acid, replacement of the (Z)-dehydrobutyrine residue, or replacement of the arginine residue.

A practical method for synthesizing 7-azaserotonin and 7-azamelatonin was developed by using 3-bromo-5-methoxy-1-tosyl-2,3-dihydro-1H-pyrrolo[2,3-b]pyridin-2-ol as a starting material. This compound is a useful reactant for the formal C3-electrophilic reaction. The lactone derivative obtained by the reaction with Meldrum’s acid was used as a key intermediate, in which the C2 unit was introduced into the 7-azaindole skeleton.

The first total synthesis of ogipeptin A was achieved. Recently, using the advanced Marfey's method, we determined the absolute configuration patterns of three β-hydroxy-α,γ-diaminobutyric acids (β-OH Dabs) composing ogipeptins. On the basis of this result, we conducted solid-phase total synthesis of three diastereomers of ogipeptin A. The analytical data of one diastereomer exactly corresponded with those of natural ogipeptin A. Therefore, the absolute configurations of ogipeptins have been elucidated.

We herein describe a practical synthetic method to access oxazolidinone-2,3-fused indoline and azaindoline derivatives via one-pot cyclization. These derivatives, which contain sp3-hybridized carbons, may be useful as new scaffolds in medicinal chemistry.

We describe a practical method for synthesizing heterocycle-2,3-fused indoline or azaindoline derivatives through haloetherification and cyclization. We applied this method in syntheses of six- to eight-membered heterocycle-2,3-fused indoline and azaindoline derivatives. These derivatives, which contain sp3-hybridized carbons, might be useful as new scaffolds in medicinal chemistry.

We disclose a silver-mediated intramolecular Friedel–Crafts-type cyclization of 2-benzyloxy-3-bromoindolines to afford an untapped family of isochromeno[3,4-b]indolines and 3-arylindoles, in which deformylative arylation of 2-(4-methoxybenzyloxy)-3-bromoindolines is reported for the first time. The isochromeno[3,4-b]indolines can be readily transformed into other heterocyclic moieties.

We herein report a practical one-step glucuronidation method by biotransformation using Streptomyces sp. SANK 60895. This novel direct method of biotransformation has been shown to be more practical and scalable for glucuronidation than previously reported chemical and enzymatic procedures given its simplicity, high β-selectivity, cost-effectiveness, and reproducibility. We applied the present method to the synthesis of acyl glucuronide and hydroxy-β-glucuronide of mycophenolic acid and compound 4, respectively. This method was also shown to be applicable to the N-glucuronidation of various compounds.

FimH is a type I fimbrial lectin located at the tip of type-1 pili of Gram-negative uropathogenic Escherichia coli (UPEC) guiding its ability to adhere and infect urothelial cells. Accordingly, blocking FimH with small molecule inhibitor is considered as a promising new therapeutic alternative to treat urinary tract infections caused by UPEC. Herein, we report that compounds having the S-glycosidic bond (thiomannosides) had improved metabolic stability and plasma exposures when dosed orally. Especially compound 5h showed the potential to inhibit biofilm formation and also to disrupt the preformed biofilm. And compound 5h showed prophylactic effect in UTI model in mice.

Herein we describe a practical synthetic method for 3-bromo-2-hydroxy-1-tosylazaindolines and 2-hydroxy-1-tosylazaindoline-3-triethylammonium bromides. 3-Bromo-2-hydroxy-1-tosylazaindolines were found to be stable crystals and could be stored at ambient temperature without consideration of moisture in the air. These indolines are useful reagents for the formal C3-electrophilic reactions of azaindoles with various nucleophiles. We used this method to synthesize various key intermediates of biologically active 3-substituted 7-azaindole derivatives.

Novel cyclic peptide derivatives based on ogipeptins A, B, C, and D were synthesized. Starting with a mixture of ogipeptins A–D, a practical four-step synthetic procedure was followed to prepare novel derivatives with various kinds of acyl side chains. Among the 45 new synthetic derivatives identified, the antibacterial activities of compounds 8-3 and 8-38 were comparable with those of ogipeptin A. In in vitro nephrotoxicity screening using LLC-PK1 cells, compounds 8-3 and 8-38 showed significantly lower cytotoxicity (LD20 > 480 μM) than colistin (LD20 = 44.2 μM).

We herein report the synthesis of a chiral phosphonium salt, {[(4 S )-4-methyl-2-oxo-1,3-oxazolidin-4-yl]methyl}(triphenyl)phosphonium iodide 13 to provide a new Wittig reagent for the general method of synthesizing α-substituted alaninol derivatives. Our method described here is widely applicable to reactions with various types of aldehyde to afford olefin products with high E -selectivity, enabling us to provide a new approach to the synthesis of chiral S1P 1 agonists including our key intermediates, and of the trace amine-associated receptor 1 (TAAR1) agonist.

We report herein the synthesis and structure-activity relationships (SAR) of a series of benzyl ether compounds as an S1P₁ receptor modulator. From our SAR studies, the installation of substituents onto the central benzene ring of 2a was revealed to potently influence the S1P₁ and S1P₃ agonistic activities, in particular, an ethyl group on the 2-position afforded satisfactory S1P₁/S1P₃ selectivity. These changes of the S1P₁ and S1P₃ agonistic activities caused by the alteration of substituents on the 2-position were reasonably explained by a docking study using an S1P₁ X-ray crystal structure and S1P₃ homology modeling. We found that compounds 2b and 2e had a potent in vivo immunosuppressive efficacy along with acceptable S1P₁/S1P₃ selectivity, and confirmed that these compounds had less in vivo bradycardia risk through the evaluation of heart rate change after oral administration of the compounds (30 mg/kg, p.o.) in rats.

Herein we report the asymmetric synthesis of (3S)-(tert-butyldimethylsilyloxy)methylcyclopentan-1-one (S)-3 as a practical chiral synthon for a wide range of pharmaceutical and/or natural products, using Lipshutz’s asymmetric copper-catalyzed conjugate reduction. This method makes it feasible to prepare a conformationally constrained cyclopentane analogue 12, which is one of the key intermediates for the synthesis of novel sphingosine 1-phosphate-1 receptor agonists.

A novel orally bioavailable renin inhibitor, DS-8108b (5), showing potent renin inhibitory activity and excellent in vivo efficacy is described. We report herein the synthesis and pharmacological effects of 5 including renin inhibitory activity in vitro, suppressive effects of ex vivo plasma renin activity (PRA) in cynomolgus monkey, pharmacokinetic data, and blood pressure-lowering effects in an animal model. Compound 5 demonstrated inhibitory activities toward human renin (IC50 = 0.9 nM) and human and monkey PRA (IC50 = 1.9 and 6.3 nM, respectively). Oral administration of single doses of 3 and 10 mg/kg of 5 in cynomolgus monkey on pretreatment with furosemide led to dose-dependent significant reductions in ex vivo PRA and sustained lowering of mean arterial blood pressure for more than 12 h.

We have previously disclosed 1,2,4-oxadiazole derivative 3 as a potent S1P3-sparing S1P1 agonist. Although compound 3 exhibits potent and manageable immunosuppressive efficacy in various in vivo models, recent studies have revealed that its 1,2,4-oxadiazole ring is subjected to enterobacterial decomposition. As provisions for unpredictable issues, a series of alternative compounds were synthesized on the basis of compound 3. Extensive SAR studies led to the finding of 1,3-thiazole 24c with the EC50 value of 3.4 nM for human S1P1, and over 5800-fold selectivity against S1P3. In rat on host versus graft reaction (HvGR), the ID50 value of 24c was determined at 0.07 mg/kg. The pharmacokinetics in rat and monkey is also reported. Compared to compound 3, 24c showed excellent stability against enterobacteria.

S1P(3)-sparing S1P(1) agonists have attracted attention as a suppressant of autoimmunity with reduced side effects. Our synthetic efforts and extensive SAR studies led to the discovery of 10b named CS-2100 with the EC(50) value of 4.0 nM for human S1P(1) and over 5000-fold selectivity against S1P(3). The in vivo immunosuppressive efficacy was evaluated in rats on host versus graft reaction and the ID(50) value was determined at 0.407mg/kg. The docking studies of CS-2100 with the homology model of S1P(1) and S1P(3) showed that the ethyl group on the thiophene ring of CS-2100 was sterically hindered by Phe263 in S1P(3), not in the case of Leu276 in S1P(1). This observation gives an explanation for the excellent S1P(3)-sparing characteristic of CS-2100.

CS-0777 (3) is phosphorylated in vivo, and the phosphate of CS-0777 (CS-0777-P) (4) acts as a selective S1P receptor-1 (S1P1) modulator. We report herein the synthesis of CS-0777 and CS-0777-P, pharmacological effects such as S1P1 and S1P3 agonist activity in vitro, peripheral blood lymphocyte lowering effects and the suppressive effect on experimental autoimmune encephalomyelitis (EAE), and also the pharmacokinetics in rats. CS-0777-P had ∼320-fold greater agonist activity for human S1P1 (EC50; 1.1 nM) relative to S1P3 (EC50; 350 nM). Following administration of single oral doses of 0.1 and 1 mg/kg of CS-0777 in rats, lymphocyte counts decreased significantly, with a nadir at 12 h postdose and recovery to vehicle control levels by 5 days postdose. In the EAE model compared to the vehicle-treated group, significant decreases in the cumulative EAE scores were observed for the 0.1 and 1 mg/kg CS-0777 groups in rats. CS-0777 is currently in clinical trials for the treatment of multiple sclerosis (MS).

With the aim of discovering a novel class of fructose-1,6-bisphosphatase (FBPase) inhibitors, a series of compounds based on tricyclic scaffolds was synthesized. Extensive SAR studies led to the finding of 8l with an IC50 value of 0.013 μM against human FBPase. An X-ray crystallographic study revealed that 8l bound at AMP binding sites of human liver FBPase with hydrogen bonding interactions similar to AMP.

We herein report an asymmetric synthesis of α,α-disubstituted α-amino alcohol derivatives 3, key intermediates of a novel immunomodulator, using enzymatic desymmetrization of 2-alkyl-2-tert-butoxycarbonylamino-1,3-propanediols 1a and 1b. This method makes it possible to prepare a chiral analogue of FTY720 4. These synthetic procedures allow for a broad structure variation in order to evaluate structure–activity relationships and the mechanism of action for sphingosine 1-phosphate-1 (S1P1) receptor agonist.

We report herein, the novel enzymatic desymmetrization of 2- tert -butoxycarbonylamino-2-methyl-1,3-propanediol 1 . This method makes it possible to prepare ( S )- N -Boc- N , O -isopropylidene-α-methylserinal 3 , which is a chiral building block for the synthesis of a variety of α-substituted alanine derivatives. Moreover, optically active (4 R )-methyl-4-[2-(thiophen-2-yl)ethyl]oxazolidin-2-one 4 , one of the key intermediates in the synthesis of a novel immunosuppressant, has been prepared by this methodology.

Tachykinin actions are mediated by at least three distinct receptors designated as NK1, NK2 and NK3. The endogeneous tachykinin ligands interact with all tachykinin receptors, although there is a defined agonist rank order of potency such that substance P (SP), neurokinin A (NKA), and neu-rokinin B (NKB) have the highest affinities for the NK1, NK2 and NK3 receptors, respectively. SP, NKA, and NKB have all been linked to numerous chronic diseases, including asthma and chronic obstructive pulmonary disease. Speculating that a combined tachykinin receptor antagonist may be of greater benefit than a selective antagonist in the treatment of pulmonary diseases, we designed a series of novel morpholine and oxazolidine analogues (I and II). We report herein the synthesis and structure-activity relationships of novel morpholine- and oxazolidine-based ana-logues with regards to NK1, NK2 and NK3 tachykinin receptor binding affinity. Efficient and practi-cal synthetic methods for the preparation of enantiomerically pure 2- [(2R) -arylmorpholin-2-yl] ethanols 8a-d and 2- [(5R) -aryloxazolidin-5-yl] ethanols 23a-d, key intermediates of I and II are described. Among these analogues, the compounds that possess properties such as spiro [benzo [c] thiophene-1 (3H), 4'-piperidine] - (2S) -oxide (S) -29 and spiro [((2S) -hydroxy) indane-1, 4'-piperidine] (S) -41 moiety had strong binding affinities to the tachykinin receptor. This report also describes efficient and practical synthetic methods for the preparation of enan-tiomerically pure (S) -29 and (S) -41. One of the enantiomers, (S, R) -42 HCl salt (R-113281), exhib-ited high binding affinities for NK1, NK2 and NK3 receptors in humans and guinea pigs. In vivo, R-113281 exerted highly potent antagonism toward SP-induced tracheal vascular hyperpermeabili-ty and NKA-, NKB- and capsaicin-induced bronchoconstriction in guinea pigs.

We herein report the synthesis of a chiral phosphonium salt, {[(4 S )-4-methyl-2-oxo-1,3-oxazolidin-4-yl]methyl}(triphenyl)phosphonium iodide 13 to provide a new Wittig reagent for the general method of synthesizing α-substituted alaninol derivatives. Our method described here is widely applicable to reactions with various types of aldehyde to afford olefin products with high E -selectivity, enabling us to provide a new approach to the synthesis of chiral S1P 1 agonists including our key intermediates, and of the trace amine-associated receptor 1 (TAAR1) agonist.

We report herein the synthesis and structure-activity relationships (SAR) of a series of benzyl ether compounds as an S1P₁ receptor modulator. From our SAR studies, the installation of substituents onto the central benzene ring of 2a was revealed to potently influence the S1P₁ and S1P₃ agonistic activities, in particular, an ethyl group on the 2-position afforded satisfactory S1P₁/S1P₃ selectivity. These changes of the S1P₁ and S1P₃ agonistic activities caused by the alteration of substituents on the 2-position were reasonably explained by a docking study using an S1P₁ X-ray crystal structure and S1P₃ homology modeling. We found that compounds 2b and 2e had a potent in vivo immunosuppressive efficacy along with acceptable S1P₁/S1P₃ selectivity, and confirmed that these compounds had less in vivo bradycardia risk through the evaluation of heart rate change after oral administration of the compounds (30 mg/kg, p.o.) in rats.

We report herein the synthesis and stereochemical structure–activity relationships of novel morpholine analogues 12 and 13 with regards to NK1, NK2 and NK3 tachykinin receptor binding affinity. An essential requirement for more potent binding affinities was controlled by absolute configuration. (S,R)-12 and (S,R)-13 exhibited high binding affinities for NK1, NK2 and NK3 receptors.

We describe a versatile synthetic method for the preparation of 2,2-disubstituted morpholine analogues. Iodoetherification of 1,1-disubstituted olefin with N -Boc-aminoethanol using NIS proceeded smoothly in a regioselective manner and the following cyclization was accomplished in good yield. We successfully applied this method for the preparation of the key intermediate 2 of tachykinin receptor antagonist.

We report herein, an efficient synthetic method for the preparation of a 5-alkoxy-(3R)-hydroxy-2,3-dihydrospiro[indene-1,4'-piperidines] scaffold using a regioselective intermolecular reaction and a stereoselective reduction as key steps. Compound 2, based on this scaffold, showed moderate in vitro binding affinity for purified human renin.

We report herein practical phosphorylation methods for a,a-disubstituted α-amino alcohol derivatives which act as Sl P i receptor agonists. A novel direct phosphorylation method for a,a-disubstituted α-amino alcohol derivatives by biotransformation using Circinella muscae, Circinella minor, Circinella mucoroides, and Circinella umbellate was developed. We applied the present method to the synthesis of phosphates ofa,a-disubstituted α-amino alcohol derivatives.

We report herein, efficient and practical synthetic methods for the preparation of enantiomerically pure spiro[((2 S )-hydroxy)indane-1,4′-piperidine] ( S )- 1 , a key intermediate for the synthesis of a tachykinin receptor antagonist, using catalytic asymmetric reduction or catalytic asymmetric epoxidation as a key step.

A series of 2-phenylbenzofuran derivatives with a carbamoyl, alkylamino, or alkyloxy group at the 5 or 6 position of the benzofuran ring were synthesized and evaluated for rat and human testosterone 5 alpha-reductase inhibitory activities in vitro. Against rat enzyme, the carbamoyl derivatives had more potent inhibitory activities than the alkylamino or alkyloxy derivatives, and the 6-carbamoyl derivatives tended to be more potent than the 5-carbamoyl derivatives. Against human enzyme, the 6-substituted derivatives had more potent inhibitory activities than the 5-substituted derivatives. The 6-carbamoyl and 6-alkylamino derivatives tended to show stronger inhibitory activities against human type 1 enzyme than against type 2 enzyme, but they were not largely selective.

We report herein an efficient and practical synthetic method for the preparation of enantiomerically pure 2-[(2R)-arylmorpholin-2-yl]ethanols 1a–d, key intermediates of tachykinin receptor antagonist. Sharpless catalytic asymmetric dihydroxylation of 4a–d was employed to introduce the required absolute stereochemistry, and cyclization of 7a–d was accomplished by the Mitsunobu reaction.

We report simple and efficient methods for the preparation of enantiomerically pure spiro[benzo[ c ]thiophene-1(3 H ),4′-piperidine]-(2 S )-oxide ( S )- 1 , a key intermediate for the synthesis of tachykinin receptor antagonist, by resolution and asymmetric sulfoxidation. Racemic ( RS )- 1 can be resolved with ( S )-(+)-mandelic acid in acetonitrile to give ( S )- 1 of >99% ee . We also describe the asymmetric sulfoxidation of sulfide 5 in excellent enantiomeric excess and high chemical yield by the use of the Davis reagent.

A series of 2-phenylbenzofuran derivatives with a diphenylmethylcarbamoyl group at the 5 or 6 position of the benzofuran ring were synthesized and evaluated for rat and human testosterone 5α-reductase inhibitory activities in vitro. They had inhibitory activities against both enzymes and the 6-carbamoyl derivatives tended to be more potent than the 5-carbamoyl compounds.

Full details of an enantioselective total synthesis of (+)-duocarmycin A (1) are described in which a solution to the control of the relative and absolute stereochemistry of the remote stereocenters is provided. Catalytic asymmetric dihydroxylation of 15 was employed to introduce the absolute stereochemistry required for the activated cyclopropane, and a diastereoselective Dieckmann-type condensation of 61 was employed to control the absolute stereochemistry of the C6 quaternary center. The complementary diastereoselectivity of a thermodynamic versus kinetic condensation of 61 permitted the divergent synthesis of (+)-duocarmycin A or epi-(+)-duocarmycin A from common intermediates. Final introduction of the reactive cyclopropane was accomplished by transannular spirocyclization of the mesylate 44 upon treatment with base or directly from the corresponding free alcohol itself, duocarmycin D1 (42), upon Mitsunobu activation. Notably, the asymmetric dihydroxylation of 15 employing (DHQD)2-PHAL/(DHQ)2-PHAL wa...

We report synthesis and optimization of a series of (3 S ,5 R )-5-(2,2-dimethyl-5-oxo-4-phenylpiperazin-1-yl)piperidine-3-carboxamides as renin inhibitors. Chemical modification of P 1 ′ P 1 ′ , P 2 ′ P 2 ′ and P 3 portions led to a promising 3,5-disubstituted piperidine 32o showing high renin inhibitory activity and favorable oral exposure in both rats and cynomolgus monkeys with acceptable CYP and hERG current inhibition. Compound 32o exhibited a significant blood pressure lowering effect by oral administration in two hypertensive animal models, double transgenic rats and furosemide pretreated cynomolgus monkeys.

With the aim to address an undesired cardiac issue observed with our related compound in the recently disclosed novel series of renin inhibitors, further chemical modifications of this series were performed. Extensive structure–activity relationships studies as well as in vivo cardiac studies using the electrophysiology rat model led to the discovery of clinical candidate trans-adamantan-1-ol analogue 56 (DS-8108b) as a potent renin inhibitor with reduced potential cardiac risk. Oral administration of single doses of 3 and 10 mg/kg of 56 in cynomolgus monkeys pre-treated with furosemide led to significant reduction of mean arterial blood pressure for more than 12 h.

The development of a divergent approach to the introduction of the C-ring of the duocarmycin A and SA alkylation subunits is detailed and includes the development of a diastereoselective Dieckmann condensation suitable for introduction of the duocarmycin A C6 center with control of its relative and natural R absolute configuration.

Utilizing X-ray crystal structure analysis, (3S,5R)-5-[4-(2-chlorophenyl)-2,2-dimethyl-5-oxopiperazin-1-yl]piperidine-3-carboxamides were designed and identified as renin inhibitors. The most potent compound 15 demonstrated favorable pharmacokinetic and pharmacodynamic profiles in rat.

The route to the title agonist involves construction of the oxadiazole ring via esterification of key intermediate amidoxime (VII) with phenoxybenzoic acid (VIII) in the presence of WSC.HCl and HOBt.

Introduction of the 2,2-dimethyl-4-phenylpiperazin-5-one scaffold into the P(3)-P(1) portion of the (2S,4S,5S)-5-amino-6-dialkylamino-4-hydroxy-2-isopropylhexanamide backbone dramatically increased the renin inhibitory activity without using the interaction to the S(3)(sp) pocket. Compound 31 exhibited >10,000-fold selectivity over other human proteases, and 18.5% oral bioavailability in monkey.

We have previously disclosed 1,2,4-oxadiazole derivative 3 as a potent S1P(3)-sparing S1P(1) agonist. Although compound 3 exhibits potent and manageable immunosuppressive efficacy in various in vivo models, recent studies have revealed that its 1,2,4-oxadiazole ring is subjected to enterobacterial decomposition. As provisions for unpredictable issues, a series of alternative compounds were synthesized on the basis of compound 3. Extensive SAR studies led to the finding of 1,3-thiazole 24c with the EC(50) value of 3.4 nM for human S1P(1), and over 5800-fold selectivity against S1P(3). In rat on host versus graft reaction (HvGR), the ID(50) value of 24c was determined at 0.07 mg/kg. The pharmacokinetics in rat and monkey is also reported. Compared to compound 3, 24c showed excellent stability against enterobacteria.

Modulators of sphingosine phosphate receptor-1 (S1P(1)) have recently been focused as a suppressant of autoimmunity. We have discovered a 4-ethylthiophene-based S1P(1) agonist 1-({4-Ethyl-5-[5-(4-phenoxyphenyl)-1,2,4-oxadiazol-3-yl]-2-thienyl}methyl)azetidine-3-carboxylic acid (CS-2100, 8) showing potent S1P(1) agonist activity against S1P(3) and an excellent in vivo potency. We report herein the synthesis of CS-2100 (8) and pharmacological effects such as S1P(1) and S1P(3) agonist activity in vitro, peripheral blood lymphocyte lowering effects and the suppressive effects on adjuvant-induced arthritis and experimental autoimmune encephalomyelitis (EAE) in animal models. The pharmacokinetic data were also reported. CS-2100 (8) had >5000-fold greater agonist activity for human S1P(1) (EC(50); 4.0 nM) relative to S1P(3) (EC(50); >20,000 nM). Following administration of single oral doses of 0.1 and 1 mg/kg of CS-2100 (8) in rats, lymphocyte counts decreased significantly, with a nadir at 8 and/or 12 h post-dose and recovery to vehicle control levels by 24-48 h post-dose. CS-2100 (8) is efficacious in the adjuvant-induced arthritis model in rats (ID(50); 0.44 mg/kg). In the EAE model compared to the vehicle-treated group, significant decreases in the cumulative EAE scores were observed for 0.3 and 1 mg/kg CS-2100 (8) groups in mice. While CS-2100 (8) showed potent efficacy in various animal disease models, it was also revealed that the central 1,2,4-oxadiazole ring of CS-2100 (8) was decomposed by enterobacteria in intestine of rats and monkeys, implicating the latent concern about an external susceptibility in its metabolic process in the upcoming clinical studies.

An efficient and stereocontrolled synthesis of γ-lactones as precursors of the hydroxyethylene dipeptide isostere has been developed, starting from readily available 5-oxotetrahydrofuran-2-carboxylic acid 6.

A series of new tetracyclic indenothiazoles is designed and synthesized with the aid of structure-based drug design (14 examples).