Novel spiropiperidine-based stearoyl-CoA desaturase-1 inhibitors: Identification of 1′-{6-[5-(pyridin-3-ylmethyl)-1,3,4-oxadiazol-2-yl]pyridazin-3-yl}-5-(trifluoromethyl)-3,4-dihydrospiro[chromene-2,4′-piperidine]

Cyclization of the benzoylpiperidine in lead compound 2 generated a series of novel and highly potent spiropiperidine-based stearoyl-CoA desaturase (SCD)-1 inhibitors. Among them, 1′-{6-[5-(pyridin-3-ylmethyl)-1,3,4-oxadiazol-2-yl]pyridazin-3-yl}-5-(trifluoromethyl)-3,4-dihydrospiro[chromene-2,4′-piperidine] (19) demonstrated the most powerful inhibitory activity against SCD-1, not only in vitro but also in vivo (C57BL/6 J mice). With regard to the pharmacological evaluation, 19 showed powerful reduction of the desaturation index in the plasma of C57BL/6 J mice on a non-fat diet after a 7-day oral administration (q.d.) without causing notable abnormalities in the eyes or skin up to the highest dose (3 mg/kg) in our preliminary analysis.     

Discovery of N-{5-[3-(3-hydroxypiperidin-1-yl)-1,2,4-oxadiazol-5-yl]-4-methyl-1,3-thiazol-2-yl}acetamide (TASP0415914) as an orally potent phosphoinositide 3-kinase γ inhibitor for the treatment of inflammatory diseases

Class I phosphoinositide 3-kinases (PI3Ks), particularly PI3Kγ, have become attractive drug targets for inflammatory and autoimmune disorders such as rheumatoid arthritis. Herein, we describe the synthesis and the structure–activity relationships (SAR) of a series of 2-amino-5-oxadiazolyl thiazoles, culminating in the identification of 8j (TASP0415914), an orally potent inhibitor of phosphoinositide 3-kinase γ (PI3Kγ). TASP0415914 demonstrated good potency in a cell-based assay and, furthermore, exhibited in vivo efficacy in a collagen induced arthritis (CIA) model in mice after oral administration.     

Discovery of 2-methyl-1-{1-[(5-methyl-1H-indol-2-yl)carbonyl]piperidin-4-yl}propan-2-ol: A novel,potent and selective type 5 17β-hydroxysteroid dehydrogenase inhibitor

Type 5 17β-hydroxysteroid dehydrogenase (17β-HSD5), also known as aldo-keto reductase 1C3 (AKR1C3), is a member of the aldo-keto reductase superfamily of enzymes and is expressed in the human prostate. One of the main functions of 17β-HSD5 is to catalyze the conversion of the weak androgen, androstenedione, to the potent androgen, testosterone. The concentration of intraprostatic 5α-dihydrotestosterone (DHT) in patients following chemical or surgical castration has been reported to remain as high as 39% of that of healthy men, with 17β-HSD5 shown to be involved in this androgen synthesis. Inhibition of 17β-HSD5 therefore represents a promising target for the treatment of castration-resistant prostate cancer (CRPC). To investigate this, we conducted high-throughput screening (HTS) and identified compound 2, which displayed a structure distinct from known 17β-HSD5 inhibitors. To optimize the inhibitory activity of compound 2, we first introduced a primary alcohol group. We then converted the primary alcohol group to a tertiary alcohol, which further enhanced the inhibitory activity, improved metabolic stability, and led to the identification of compound 17. Oral administration of compound 17 to castrated nude mice bearing the CWR22R xenograft resulted in the suppression of androstenedione (AD)-induced intratumoral testosterone production. Compound 17 also demonstrated good isoform selectivity, minimal inhibitory activity against either CYP or hERG, and enhanced pharmacokinetic and physicochemical properties.     

5-Lipoxygenase-activating protein inhibitors. Part 2: 3-{5-((S)-1-Acetyl-2,3-dihydro-1H-indol-2-ylmethoxy)-3-tert-butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-1H-indol-2-yl}-2,2-dimethyl-propionic acid (AM679)—A potent FLAP inhibitor

A series of potent 5-lipoxygenase-activating protein (FLAP) inhibitors are herein described. SAR studies focused on the discovery of novel alicyclic moieties appended to an indole core to optimize potency, physical properties and off-target activities. Subsequent SAR on the N-benzyl substituent of the indole led to the discovery of compound 39 (AM679) which showed potent inhibition of leukotrienes in human blood and in a rodent bronchoalvelolar lavage (BAL) challenge model.     

Synthesis of N-{2-O-2-Acetamido-1-O-acyl (or 1,6-di-O-acyl)-2,3-dideoxy-α-d-glucopyranose-3-yl]-d-lactoyl}-l-alanyl-d-isoglutamine Methyl Esters,and Their Immunoadjuvant Activities

A variety of 1-O-acyl and 1,6-di-O-acyl derivatives of N-acetylmuramoyl-l-alanyl-G-isoglutamine methyl esters were synthesized from N-[2-O-(2-acetamido-2,3-dideoxy-4,6-O-iso- propylidene-d-glucopyranose-3-yl)-d-lactoyl]-l-alanyl-d-isoglutamine methyl ester, and their biological activities were examined in guinea-pigs and mice.     

Fully relativistic rovibrational energies and spectroscopic constants of the lowest {\text{X}}:(1)0_g^{ + } , A′:(1)2 u , A:(1)1 u , {\text{B}}\prime :(1)0_u^{ - } and {\text{B}}:(1)0_u^{ + } states of molecular chlorine

The main goal of this paper is to present the rovibrational energies and spectroscopic constants of the Cl(2) molecular system in the relativistic states [Formula: see text], A':(1)2( u ), A:(1)1( u ), [Formula: see text] and [Formula: see text]. More precisely, we have evaluated the Cl(2) ω ( e ), ω ( e ) x ( e ), ω ( e ) y ( e ), α ( e ), γ ( e ) and B ( e ) rovibrational spectroscopic constants using two different procedures. The first was obtained by combining the rovibrational energies, calculated through solving Schr?dinger's nuclear equation and the diatomic rovibrational energy equation. The second was obtained by using the Dunham method. The calculated properties are in good agreement with available experimental data.     

Synthesis of 3′-Deoxy-3′-[4-(pyrimidin-1-yl)methyl-1,2,3-triazol-1-yl]thymidine via 1,3-Dipolar Cycloaddition

Abstract

The synthesis of new 3′-deoxy-3′-[4-(pyrimidin-1-yl)methyl-1,2,3-triazol-1-yl]thymidine 6a–f, from 3′-azido-3′-deoxy-5′-O-monomethoxytrityl-thymidine is described. The key step is the 1,3-dipolar cycloaddition between the azido group of the protected AZT 3 and N-1-propargylpyrimidine derivatives 2a–f. All new derivatives 6a–f were evaluated for their inhibitory effects against the replication of HIV-1 (IIIB), HIV-2 (ROD). No marked activity was found.     

5-Lipoxygenase-activating protein inhibitors. Part 3: 3-{3-tert-Butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-5-(5-methyl-pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid (AM643)—A potent FLAP inhibitor suitable for topical administration

AM643 (compound 6, 3-{3-tert-butylsulfanyl-1-[4-(5-methoxy-pyrimidin-2-yl)-benzyl]-5-(5-methyl-pyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethyl-propionic acid) was identified as a potential candidate for formulation as a topical agent for the treatment of skin disorders involving leukotriene production. Dermal application of 6 using a prototypical vehicle in a murine ear arachidonic acid model showed significant reduction in the concentrations of leukotrienes in mouse skin with concomitant reduction in ear swelling.     

Enantioselective enzymatic acetylation of racemic [4-[4α,6β (E)]]-6-[4,4-bis(4-fluorophenyl)-3-(1-methyl-1H-tetrazol-5-yl)-1,3-butadienyl]-tetrahydro-4-hydroxy-2H-pyran-2-one

Summary A chiral compound [4R-[4,6ß(E)]]-6-[4,4-bis(4-fluorophenyl)-3-(1-methyl-1H-tetrazol-5-yl)-1,3-butadienyl]-tetrahydro-4-hydroxy-2H-pyran-2-one (R-(+)-1) was prepared by the lipase-catalysed stereoselective acetylation of racemic 1 in an organic solvent. Chiral R-(+)-1 is a hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase inhibitor and a potential anticholesterol drug candidate. Among various lipases evaluated, lipase PS-30 from Pseudomonas species efficiently catalysed acetylation of the undesired enantiomer of racemic 1 to yield the S-(–)-acetylated product 2 and unreacted desired R-(+)-1. A reaction yield of 48 mol% and an optical purity of 98% were obtained for R-(+)-1 when the reaction was conducted in toluence as solvent in the presence of isopropenyl acetate as acyl donor. Lipase PS-30 was immobilized on Accurel polypropylene (PP) and the immobilized enzyme was reused (five cycles) in the acetylation reaction without loss of enzyme activity, productivity, or optical purity of the R-(+)-1. The enzymatic acetylation process was scaled-up to 501 and a 640-l volume (preparative batches) at a substrate concentration of 4 g/l. R-(+)–1 was recovered from the preparative batches in 68–71% recovery yield with 98.5% gas chromatography homogeneity index and 98.5% optical purity. The S-(–) acetate 2 produced by the acetylation reaction was enzymatically hydrolysed by lipase PS-30 in a biphasic system to prepare the corresponding S-(–)-1.Correspondence to: R. N. Patel     

Synthesis of 7-(tetrahydropyran-2-yl)- and 7-(4-acetoxytetrahydropyran-2-yl)-ε-rhodomycinone and 7-(tetrahydropyran-2-yl)-ε-pyrromycinone

The ¹³C.n.m.r spectra of water-soluble and -insoluble glucans synthesized by enzymes isolated from six strains of Streptococcus mutans are interpreted. The glucans are shown to be composed primarily of α(1→3)- and α-(1→6)-linked glucosyl residues, and the relative abundance of each linkage is estimated from peak areas. Treatment of water-insoluble glucans with dextranase is found to result in water-soluble and -insoluble products, the former enriched in α-(1→6)-linkages and the latter in α-(1→3)-linkages. The structural conclusions arrived at by ¹³C-n.m.r. spectroscopy are consistent with data from methylation analysis and ¹H-n.m.r. spectroscopy.     

3-O-phosphate ester conjugates of 17-β-O-{1-[2-carboxy-(2-hydroxy-4-methoxy-3-carboxamido)anilido]ethyl}1,3,5(10)-estratriene as novel bone-targeting agents

A series of 3-O-phosphorylated analogs (4-10) of a novel bone-targeting estradiol analog (3) were synthesized after a thorough study of the reaction of 3 with a selection of phosphoryl chlorides under a variety of reaction conditions. Evaluation of these novel phosphate analogs for affinity for hydroxyapatite revealed that they bind with equal or higher affinity when compared to the bone tissue accumulator, tetracycline.     

Synthesis and antiproliferative evaluation of N,N-disubstituted-N′-[1-aryl-1H-pyrazol-5-yl]-methnimidamides

A series of N,N-disubstituted-N′-[1-aryl-1H-pyrazol-5-yl]-methnimidamides was synthesized by a newly developed microwave reaction and their antiproliferative activities were evaluated. Microwave irradiation of 5-amino-1,3-disubstituted pyrazoles with various amide solvents in the presence of POCl₃ provided the corresponding 2a–2k, 3a–3c, and 4a–4f in good to excellent yields. The obtained methnimidamides were tested against NCI-H661, NPC-TW01, and Jurkat cancer cell lines and the results indicated that compounds 2d and 2e were the most potent with IC₅₀ values in low micromolar range.     

Novel biocatalyst for productions of S-(-)-2-[6-benzyloxy -2,5,7,8-tetramethylchroman -2-yl] ethanol—precursor of natural α-tocols

A novel promising strain of actinobacteria Rhodococcus sp. 77-32 was identified. Its acetonetreated biomass the could be used as a biocatalyst for production of S-(-)-2-[6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl] ethanol (S-BCE), a precursor of natural α-tocols. It was established that a reaction of enantioselective hydrolysis of racemic (±)-2-(2-acetoxyethyl)-6-benzyloxy-2,5,7,8-tetramethylchroman (BCEA) occurred in the phosphate buffer–acetone system, resulting in enrichment of the residual substrate by S-enantiomer (S-(+)-2-(2-acetoxyethyl)-6-benzyloxy-2,5,7,8-tetramethylchroman, S-BCEA). It was shown that the hydrolysis was accompanied by stereoinversion of the formed product, R-(+)-2-[6-benzyloxy-2,5,7,8-tetramethylchroman-2-yl] ethanol (R-BCE), into the S-BCE. The transformation conditions (acetone content, acidity, temperature, reaction duration) were optimized, providing simultaneous production of optically pure S-BCE and S-BCEA with an almost quantitative yield.     

Synthesis and biological evaluation of 1-substituted-3-(6-methylpyridin-2-yl)-4-([1,2,4]triazolo[1,5-a]pyridin-6-yl)pyrazoles as transforming growth factor-β type 1 receptor kinase inhibitors

A series of 1-substituted-3-(6-methylpyridin-2-yl)-4-([1,2,4]triazolo[1,5-a]pyridin-6-yl)pyrazoles 14a-ae, 16a, 16b, and 21a-c has been prepared and evaluated for their ALK5 inhibitory activity in an enzyme assay and in a cell-based luciferase reporter assay. The 4-([1,2,4]triazolo[1,5-a]pyridin-6-yl)-N-(4-methoxyphenyl)-3-(6-methylpyridin-2-yl)-1H-pyrazole-1-carbothioamide (14n) inhibited ALK5 phosphorylation with IC(50) value of 0.57 nM and showed 94% inhibition at 100 nM in a luciferase reporter assay using HaCaT cells permanently transfected with p3TP-luc reporter construct.     

Structure–activity relationship and interaction studies of new SIRT1 inhibitors with the scaffold of 3-(furan-2-yl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole

SIRT1 is a NAD⁺-dependent deacetylase. It deacetylates a broad range of substrates and is involved in multiple diseases such as type 2 diabetes and cancer. Here we discovered a new class of SIRT1 inhibitors with the scaffold of 3-(furan-2-yl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole. The inhibitors up-regulate acetyl p53 level in human breast cells MCF-7. The docking simulations indicated that the scaffold and the R-substituents of the inhibitors bind in the C and D pocket of SIRT1, respectively, which was supported by the structure–activity relationship and SIRT1 mutagenesis studies. We propose that binding of the inhibitors repels the entering of the nicotinamide moiety of NAD⁺ to the C pocket, prevents its transformation to the productive conformation and therefore inhibits the deacetylation catalyzed by SIRT1.     

Discovery of 5-(2-chloro-4′-(1H-imidazol-1-yl)-[1,1′-biphenyl]-4-yl)-1H-tetrazole as potent and orally efficacious S-nitrosoglutathione reductase (GSNOR) inhibitors for the potential treatment of COPD

Endogenous nitrosothiols (SNOs) including S-nitrosoglutathione (GSNO) serve as reservoir for bioavailable nitric oxide (NO) and mediate NO-based signaling, inflammatory status and smooth muscle function in the lung. GSNOR inhibition increases pulmonary GSNO and induces bronchodilation while reducing inflammation in lung diseases. In this letter, design, synthesis and structure–activity relationships (SAR) of novel imidazole-biaryl-tetrazole based GSNOR inhibitors are described. Many potent inhibitors (30, 39, 41, 42, 44, 45 and 58) were identified with low nanomolar activity (IC₅₀s: <15?nM) along with adequate metabolic stability. Lead compounds 30 and 58 exhibited good exposure and oral bioavailability in mouse pharmacokinetic (PK) study. Compound 30 was selected for further profiling and revealed comparable mouse and rat GSNOR potency, high selectivity against alcohol dehydrogenase (ADH) and carbonyl reductase (CBR1) family of enzymes, low efflux ratio and permeability in PAMPA, a high permeability in CALU-3 assay, significantly low hERG activity and minimal off-target activity. Further, an in vivo efficacy of compound 30 is disclosed in cigarette smoke (CS) induced mouse model for COPD.     

Discovery of N-{N-[(3-cyanobenzene) sulfonyl]-4(R)-(3,3-difluoropiperidin-1-yl)-(l)-prolyl}-4-[(3′,5′-dichloro-isonicotinoyl) amino]-(l)-phenylalanine (MK-0617), a highly potent and orally active VLA-4 antagonist

A series of prolyl-N-isonicotinoyl-(L)-4-aminophenylalanine derivatives substituted at the proline 4-position with cyclic amines was evaluated as VLA-4 antagonists. The ring size and presence or absence of fluorine affected potency and receptor occupancy. The analog with 3,3-difluoropiperidine at the proline 4-position (13) was the most potent compound and had very good duration of receptor occupancy in vitro. The ethyl ester prodrug of 13 demonstrated excellent receptor occupancy after oral dosing in rats.     

2-Benzamido-N-(1H-benzo[d]imidazol-2-yl)thiazole-4-carboxamide derivatives as potent inhibitors of CK1δ/ε

In this study we identified two heterocyclic compounds (5 and 6) as potent and specific inhibitors of CK1δ (IC(50)?=?0.040 and 0.042?μM, respectively). Whereas compound 5 exhibited fivefold higher affinity towards CK1δ than to CK1ε (IC(50) CK1ε?=?0.199?μM), compound 6 also inhibited CK1ε (IC(50)?=?0.0326?μM) in the same range as CK1δ. Selected compound 5 was screened over 442 kinases identifying 5 as a highly potent and selective inhibitor of CK1δ. X-ray analysis of 5 bound to CK1δ demonstrated its binding mode. In addition, characterization of 5 and 6 in a cell biological approach revealed the ability of both compounds to inhibit proliferation of tumor cell lines in a dose and cell line specific manner. In summary, our optimizations lead to the development of new highly selective CK1δ and ε specific inhibitors with biological activity.     

Synthesis, spectroscopy, tandem mass spectrometry, and electrochemistry of the linearly bridged μ-{trans-1,4-bis[2-(4-pyridyl)ethenyl]-benzene}-{Ru3O(CH3COO)6(py)2}2 cluster

The novel polynuclear [{Ru₃O(CH₃COO)₆(py)₂}₂(BPEB)](PF₆)₂ species containing the linear bridging trans-1,4-bis[2-(4-pyridyl)ethenyl]-benzene ligand (BPEB) was synthesized and its structural characterization carried out by means of positive ion electrospray (ESI-MS) and tandem mass (ESI-MS/MS) spectrometry, as well as by ¹H NMR spectroscopy. The doubly charged cation [{Ru₃O(CH₃COO)₆(py)₂}₂(BPEB)]²⁺ was detected in the ESI-MS mass spectrum as a multiple-component isotopomeric ionic cluster centered at m/z 974, which ion abundance and m/z distribution matched perfectly the isotopic pattern calculated for this multiple isotope Ru₃-containing ion. The tandem mass spectrum of [{Ru₃O(CH₃COO)₆(py)₂}₂(BPEB)]²⁺ provided a structural diagnostic dissociation behavior, on the basis of the characteristic charge splitting and sequential ligand loss steps. The cyclic voltammograms of the complex exhibited a quasi-reversible multistep redox behavior, displaying three waves at 1.14, 0.08, and −1.21 V ascribed to the [Ru₃O]^2+/1+/0/1− processes and two waves at −1.56 and −1.78 V ascribed to the BPEB^0/1−/2− redox processes which are also observed in the free ligand, at −1.48 and 1.61 V, respectively. In spite of the conducting nature of the bridging ligand, the electrochemical and spectroelectrochemical results indicated a weak electronic coupling between the triangular cluster centers.     

2-Phenyl and 2-heterocyclic-4-(3-(pyridin-2-yl)-1H-pyrazol-4-yl)pyridines as inhibitors of TGF-β1 and activin A signalling

Novel inhibitors of TGF-β1 and activin A signalling based on a 2-aryl-4-(3-(pyridin-2-yl)-1H-pyrazol-4-yl)pyridine pharmacophore have been synthesised. Compounds containing phenyl or aromatic nitrogen heterocycle substituents inhibited both types of signalling with HEK-293T cells in culture, with a selectivity preference for TGF-β1. Synthetic compounds containing pyridin-3-yl, pyrazol-4-yl, pyrazol-1-yl or 1H-imidazoyl-1-yl substituents exhibited structural and functional attributes suitable for further investigation related to the development of more potent TGF-β inhibitors.