ASP1126, a Novel Sphingosine-1-Phosphate-Selective Agonist With a Favorable Safety Profile, Prolongs Allograft Survival in Rats and Nonhuman Primates in Combination With Tacrolimus With a Broad Safety Margin for Bradycardia.

Sphingosine-1-phosphate (S1P) is a biologically active sphingolipid that acts through the members of a family of 5 G protein-coupled receptors (S1P1 to S1P5). Among these, S1P1 is a major regulator of lymphocyte trafficking. Fingolimod, whose active metabolite, fingolimod phosphate, acts as a nonselective S1P-receptor agonist, exerts its immunomodulatory effect, at least in part, by regulating lymphocyte trafficking via downregulation of S1P1 expression on lymphocytes. Here, we describe the pharmacologic profile of a novel S1P1 agonist, ASP1126. ASP1126 preferentially activated S1P1 compared to S1P3 in rat and human guanosine-5'-(γ-thio)-triphosphate (GTPγS) assays. Oral single administration of ASP1126 decreased the number of peripheral lymphocytes and repeated dosing showed a cumulative effect on lymphopenia in both rats and monkeys. ASP1126 prolonged allograft survival in a rat heterotopic heart transplantation model in combination with a subtherapeutic dose of tacrolimus that was independent of drug-drug interactions. In addition, in nonhuman primate (NHP) renal transplantation, pretreatment with ASP1126 reduced not only the number of naive T cells and central memory T cells but also effector memory T cells in the peripheral blood, all of which could contribute to acute graft rejection and prolonged allograft survival in combination with tacrolimus. Further, we confirmed that ASP1126 has a broad ranging safety margin with respect to its effect on lung weight in rats and bradycardia in NHPs, which were the adverse events found in clinical studies of fingolimod. ASP1126 with improved safety profile has the potential to be an adjunct therapy in combination with tacrolimus in clinical transplantation.

Inhibition of c-Rel DNA binding is critical for the anti-inflammatory effects of novel PIKfyve inhibitor.

Aberrant production of proinflammatory cytokines is linked to many autoimmune diseases, and their inhibition by small molecule compounds is considered beneficial. Here, we performed phenotypic screening in IFNγ/LPS-activated RAW264.7, mouse macrophage cells, and discovered AS2677131 and AS2795440 as novel and potent inhibitors of IL-12p40, a subunit of IL-23. Interestingly, these compounds exhibited unique pharmacological activities in their inhibition of the production of IL-12p40, IL-6 and IL-1ß but not TNFα in activated macrophages or dendritic cells, and expression of IgM-induced MHC class II on B cells. To reveal these mechanisms, we synthesized two different activity probes which were structurally related to the AS compounds, and identified probe-specific binding proteins, including PIKfyve, a Class III PI kinase. The AS compounds inhibited PIKfyve activity and mimicked the properties of PIKfyve-deficient cells, eventually validating PIKfyve as target molecule. Regarding mechanism, AS2677131 regulated DNA binding activity of c-Rel on IL-12p40 and IL-1ß promoter. As expected, a PIKfyve inhibitor prevented the development of arthritis in rats. Taken together, our findings of the novel and potent PIKfyve inhibitors AS2677131 and AS2795440 reveal the critical role of PIKfyve in proinflammatory cytokine production and B cell activation, and may indicate a potential new therapeutic option for treatment of inflammatory diseases.

ASP4058, a novel agonist for sphingosine 1-phosphate receptors 1 and 5, ameliorates rodent experimental autoimmune encephalomyelitis with a favorable safety profile.

Sphingosine-1-phosphate (S1P) is a biologically active sphingolipid that acts through the members of a family of five G protein-coupled receptors (S1P1-S1P5). S1P1 is a major regulator of lymphocyte trafficking, and fingolimod, whose active metabolite fingolimod phosphate acts as a nonselective S1P receptor agonist, exerts its immunomodulatory effect, at least in part, by regulating the lymphocyte trafficking by inducing down regulation of lymphocyte S1P1. Here, we detail the pharmacological profile of 5-{5-[3-(trifluoromethyl)-4-{[(2S)-1,1,1-trifluoropropan-2-yl]oxy}phenyl]-1,2,4-oxadiazol-3-yl}-1H-benzimidazole (ASP4058), a novel next-generation S1P receptor agonist selective for S1P1 and S1P5. ASP4058 preferentially activates S1P1 and S1P5 compared with S1P2, 3, 4 in GTPγS binding assays in vitro. Oral administration of ASP4058 reduced the number of peripheral lymphocytes and inhibited the development of experimental autoimmune encephalomyelitis (EAE) in Lewis rats. Further, ASP4058 prevented relapse of disease in a mouse model of relapsing-remitting EAE. Although these immunomodulatory effects were comparable to those of fingolimod, ASP4058 showed a wider safety margin than fingolimod for bradycardia and bronchoconstriction in rodents. These observations suggest that ASP4058 represents a new therapeutic option for treating multiple sclerosis that is safer than nonselective S1P receptor agonists such as fingolimod.

Acyclic monoterpenes in tree essential oils as a shrinking agent for waste-expanded polystyrene.

We examined the dissolution of polystyrene (PS) into acyclic monoterpenes present in tree essential oils, to develop an environmentally friendly shrinking agent for waste-expanded polystyrene (EPS). The dissolving powers of geranyl acetate, geranylacetone, and geranyl formate [221.8-241.2 g PS (100 g solvent)(-1)] compared favorably with that of (R)-limonene [181.7 g PS (100 g solvent)(-1)]. Their favorable dissolving powers for PS can be explained by their flexible linear structures, which may be more accessible to the inside of bulk PS compared with cyclic monoterpenes. These acyclic monoterpenes and PS were recovered almost quantitatively by simple steam distillation of the PS solution.

Synthesis of oligosaccharide-branched ribofuranan by ring-opening polymerization of a new anhydroribo trisaccharide monomer.

A new anhydroribotrisaccharide monomer, A2B3LR (1), was synthesized and ROP was carried out to elucidate the polymerizability and to obtain oligosaccharide-branched polysaccharides with defined structures. The new trisaccharide monomer was found to be polymerized readily with BF(3) . OEt(2) as a catalyst at -40 degrees C to give a lactose-branched polymer. Copolymerization with ADBR gave the corresponding copolymers in good yields. After removal of protective benzyl groups, D-lactose-branched ribofuranans with free hydroxyl groups were obtained in good yields. The structure of polymers was analyzed by (1)H, 13C, and two-dimensional NMR measurements, suggesting that D-lactose-branched ribofuranans had (1 --> 5)-alpha stereoregularity.

Potent and orally bioavailable CCR4 antagonists: Synthesis and structure-activity relationship study of 2-aminoquinazolines.

Starting with a series of CC chemokine receptor-4 (CCR4) antagonists developed in a previous study, the potency was improved by replacing the pyrrolidine moiety of N-(4-chlorophenyl)-6,7-dimethoxy-2-(4-pyrrolidin-1-ylpiperidin-1-yl)quinazolin-4-amine 2 with a 3-(hydroxymethyl)piperidine. The resulting compound (1'-{4-[(4-chlorophenyl)amino]-6,7-dimethoxyquinazolin-2-yl}-1,4'-bipiperidin-3-yl)methanol 8ic was a strong inhibitor of human/mouse chemotaxis. Oral administration of 8ic showed anti-inflammatory activity in a murine model of acute dermatitis (oxazolone-induced contact hypersensitivity test) in a dose-dependent manner.

Potent CCR4 antagonists: synthesis, evaluation, and docking study of 2,4-diaminoquinazolines.

A series of CC chemokine receptor-4 (CCR4) antagonists were examined in a previous report in an attempt to improve metabolic stability in human liver microsomes. In this study, the cycloheptylamine moiety of N-cycloheptyl-6,7-dimethoxy-2-(4-pyrrolidin-1-ylpiperidin-1-yl)quinazolin-4-amine 1 was replaced with the p-chloroaniline moiety, and the resulting compound, N-(4-chlorophenyl)-6,7-dimethoxy-2-(4-pyrrolidin-1-ylpiperidin-1-yl)quinazolin-4-amine (8c), retained its potency ([(35)S]GTPgammaS-binding inhibition and CCL22-induced chemotaxis in humans/mice). Based on the structure-activity relationships (SAR), a homology model was constructed for CCR4 to explain the binding mode of 8c. Overall, there was good agreement between the docking pose of the CCR4 homology model and the human [(35)S]GTPgammaS assay results. Administration of 8c in a murine model of acute dermatitis showed anti-inflammatory activity (oxazolone-induced contact hypersensitivity test).

Discovery of potent CCR4 antagonists: Synthesis and structure-activity relationship study of 2,4-diaminoquinazolines.

A new series of quinazolines that function as CCR4 antagonists were discovered during the screening of our corporate compound libraries. Subsequent compound optimization elucidated the structure-activity relationships and led the identification of 2-(1,4'-bipiperidine-1'-yl)-N-cycloheptyl-6,7-dimethoxyquinazolin-4-amine 14a, which showed potent inhibition in the [(35)S]GTPgammaS-binding assay (IC(50)=18nM). This compound also inhibited the chemotaxis of human and mouse CCR4-expressing cells (IC(50)=140nM, 39nM).

Efficient and convenient heterogeneous palladium-catalyzed regioselective deuteration at the benzylic position.

The Pd/C-catalyzed efficient and regioselective hydrogen-deuterium (H-D) exchange reaction on the benzylic site proceeded in D2O in the presence of a small amount of H2 gas. The use of the Pd/C-ethylenediamine complex [Pd/C(en)] as a catalyst instead of Pd/C led to the efficient deuterium incorporation into the benzylic site of O-benzyl protective groups without hydrogenolysis. These H-D exchange reactions provide a post synthetic and D(2)-gas-free deuterium-labeling method on a wide variety of benzylic sites using D2O as the deuterium source and heterogeneous Pd/C or Pd/C(en) as a reusable heterogeneous palladium catalyst under mild and neutral conditions.

A remarkable solvent effect toward the Pd/C-catalyzed cleavage of silyl ethers.

Selective hydrogenation conditions of olefin, benzyl ether and acetylene functionalities in the presence of TBDMS or TES ether have been developed.

Functionalized cis- and trans-fused bicyclic alpha-amino acids via stereoselective double annulation and dequaternization reactions.

Fused bicyclic alpha-amino acids can be prepared by a double Michael reaction of p-anisyl ethynyl ketone and a tethered diacid, cyclization via hydrogenation or hydration of a CN group, and oxidation of the p-anisyl group. The substitution level of the alpha-amino acids can be adjusted by decyanation or decarboethoxylation of the intermediates. Bicyclic alpha-amino acids prepared in this way include cis- and trans-perhydroisoquinoline-3-carboxylic acids and cis-perhydro-2-pyrindine-3-carboxylic acids of various substitutions and oxidation levels. The bicyclic alpha-amino acids may be regarded as functionalized and conformationally restricted analogues of proline, pipecolic acid, 2-aminoadipic acid, or glutamic acid.

Phosphoramidites are efficient, green organocatalysts for the Michael reaction. Mechanistic insights into the phosphorus-catalyzed Michael reaction of alkynones and implications for asymmetric catalysis.

Hexamethylphosphorous triamide (HMPT) and other phosphoramidites and phosphites have been found to be efficient catalysts for the Michael reaction of alkenones and alkynones with malonates, alpha-cyano esters, beta-keto esters, and nitro compounds. The relatively nontoxic, easily hydrolyzed HMPT catalyzes the Michael reaction within seconds at room temperature in the absence of a solvent, and the reaction is worked up simply by removing the catalyst in vacuo. The Michael reactions of alkynones, unlike those of alkenones, are shown to be irreversible. The implications for asymmetric catalysis are discussed.

The bicyclic n,n'-diacylaminal: a new motif for molecular self-assembly.

A cage-shaped N,N'-diacylaminal crystallizes from some aromatic solvents as "supramolecular chair cyclohexanes", squat cylindrical hexamers with approximate D3d symmetry containing two arene molecules, and from other aromatic and nonaromatic solvents as infinite tapes. A homologous diacylaminal crystallizes only as an infinite tape. The hexamers represent the first examples of cyclic hexamers held together by %@mt;sys@%%@bold@%R%@rsf@%%@sx@%2%@be@%2%@sxx@%%@fn;(;vis;full;auto@%8%@fnx;);vis;full@%-type%@mx@% hydrogen bonds in which the hydrogen-bonded atoms are not coplanar. The diacylaminal represents a new supramolecular synthon, one perhaps more suited to the design of three-dimensional architectures.