1-[4-(1H-Benzoimidazol-2-yl)-phenyl]-3-[4-(1H-benzoimidazol-2-yl)-phenyl]-urea derivatives as small molecule heparanase inhibitors

A novel class of 1-[4-(1H-benzoimidazol-2-yl)-phenyl]-3-[4-(1H-benzoimidazol-2-yl)-phenyl]-ureas are described as potent inhibitors of heparanase. Among them are 1,3-bis-[4-(1H-benzoimidazol-2-yl)-phenyl]-urea (7a) and 1,3-bis-[4-(5,6-dimethyl-1H-benzoimidazol-2-yl)-phenyl]-urea (7d), which displayed good heparanase inhibitory activity (IC(50) 0.075-0.27 microM). Compound 7a showed good efficacy in a B16 metastasis model.     

2-(2-[3-(pyridin-3-yloxy)phenyl]-2H-tetrazol-5-yl) pyridine: a highly potent, orally active, metabotropic glutamate subtype 5 (mGlu5) receptor antagonist

Structure-activity relationship studies on 3-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile 2 led to the discovery of 2-(2-[3-(pyridin-3-yloxy)phenyl]-2H-tetrazol-5-yl)pyridine (10)-a highly potent and selective mGlu5 receptor antagonist with good brain penetration and in vivo receptor occupancy in rat and cross-species oral bioavailability.     

4-Hydroxy-1-[3-(5-(1,2,4-triazol-4-yl)-1H-indol-3-yl)propyl]piperidines: selective h5-HT1D agonists for the treatment of migraine

A series of 4-hydroxy-1-[3-(5-(1,2,4-triazol-4-yl)-1H-indol-3-yl)propyl] piperidines was investigated as potential selective h5-HT1D agonists for the treatment of migraine. The 4-[(N-benzyl-N-methyl)amino]methyl analog 12a was found to be a full agonist at the h5-HT1D receptor with good binding selectivity over the h5-HT1B receptor.     

Synthesis and antibacterial activity of 1-[1,2,4-triazol-3-yl] and 1-[1,3,4-thiadiazol-2-yl]-3-methylthio-6,7-dihydrobenzo[c]thiophen-4(5H)ones

A series of 1-[1,2,4-triazol-3-yl] and 1-[1,3,4-thiadiazol-2-yl]-3-methylthio-6,7-dihydrobenzo[c]thiophen-4(5H)ones were synthesized and tested to demonstrate in vitro antimicrobial activity. Some of these compounds exhibited a good activity against Staphylococcus aureus, S. epidermidis and Bacillus subtilis.     

Discovery and preclinical profile of teneligliptin (3-[(2S,4S)-4-[4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazin-1-yl]pyrrolidin-2-ylcarbonyl]thiazolidine): A highly potent,selective, long-lasting and orally active dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes

Dipeptidyl peptidase IV (DPP-4) inhibition is suitable mechanism for once daily oral dosing regimen because of its low risk of hypoglycemia. We explored linked bicyclic heteroarylpiperazines substituted at the γ-position of the proline structure in the course of the investigation of l-prolylthiazolidines. The efforts led to the discovery of a highly potent, selective, long-lasting and orally active DPP-4 inhibitor, 3-[(2S,4S)-4-[4-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazin-1-yl]pyrrolidin-2-ylcarbonyl]thiazolidine (8g), which has a unique structure characterized by five consecutive rings. An X-ray co-crystal structure of 8g in DPP-4 demonstrated that the key interaction between the phenyl ring on the pyrazole and the S₂ extensive subsite of DPP-4 not only boosted potency, but also increased selectivity. Compound 8g, at 0.03 mg/kg or higher doses, significantly inhibited the increase of plasma glucose levels after an oral glucose load in Zucker fatty rats. Compound 8g (teneligliptin) has been approved for the treatment of type 2 diabetes in Japan.     

Discovery of N-[(3R,5R)-1-azabicyclo[3.2.1]oct-3-yl]furo[2,3-c]pyridine-5-carboxamide as an agonist of the alpha7 nicotinic acetylcholine receptor: in vitro and in vivo activity

A novel alpha7 nAChR agonist, N-[(3R,5R)-1-azabicyclo[3.2.1]oct-3-yl]furo[2,3-c]pyridine-5-carboxamide (3a, PHA-709829), has been identified for the potential treatment of cognitive deficits in schizophrenia. The compound shows potent and selective alpha7 in vitro activity, excellent brain penetration, good rat oral bioavailability and robust in vivo efficacy in a rat auditory sensory gating model.     

3-[Substituted]-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitriles: identification of highly potent and selective metabotropic glutamate subtype 5 receptor antagonists

Structure-activity relationship studies on the phenyl ring of 3-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile 2 led to the discovery that small, non-hydrogen bond donor substituents at the 3-position led to a substantial increase in in vitro potency. In particular, 3-fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile (7) is a highly potent and selective mGlu5 receptor antagonist with good rat pharmacokinetics, brain penetration, and in vivo receptor occupancy.     

Synthesis and monoamine transporter binding properties of 2beta-[3'-(substituted benzyl)isoxazol-5-yl]- and 2beta-[3'-methyl-4'-(substituted phenyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes

A series of 2beta-[3'-(substituted benzyl)isoxazol-5-yl]- and 2beta-[3'-methyl-4'-(substituted phenyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes were prepared and evaluated for affinities at dopamine, serotonin, and norepinephrine transporters using competitive radioligand binding assays. The 2beta-[3'-(substituted benzyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes (3a-h) showed high binding affinities for the dopamine transporter (DAT). The IC(50) values ranged from 5.9 to 22nM. On the other hand, the 2beta-[3'-methyl-4'-(substituted phenyl)isoxazol-5-yl]-3beta-(substituted phenyl)tropanes (4a-h), with IC(50) values ranging from 65 to 173nM, were approximately 3- to 25-fold less potent than the corresponding 2beta-[3'-(substituted benzyl)isoxazol]tropanes. All tested compounds were selective for the DAT relative to the norepinephrine transporter (NET) and serotonin transporter (5-HTT). 3Beta-(4-Methylphenyl)-2beta-[3'-(4-fluorobenzyl)isoxazol-5-yl]tropane (3b) with IC(50) of 5.9nM at the DAT and K(i)s of 454 and 113nM at the NET and 5-HTT, respectively, was the most potent and DAT-selective analog. Molecular modeling studies suggested that the rigid conformation of the isoxazole side chain in 4a-h might play an important role on their low DAT binding affinities.     

N-[1-(2-Phenylethyl)pyrrolidin-3-yl]-1-adamantanecarboxamides as novel 5-HT2 receptor antagonists

A series of 1-adamantanecarboxamides was synthesized and examined for their potency as a selective 5-HT2 receptor antagonist. We found (S)-N-[1-[2-(4-fluorophenyl)ethyl]pyrrolidin-3-yl]-1-adamantane carboxamide hydrochloride hydrate (10-(S), Y-39241) to have a high affinity and selectivity for 5-HT2 receptors, and this potent anti-platelet effect of Y-39241 was confirmed both in vitro and in vivo.     

Diaryldimethylpiperazine ligands with mu- and delta-opioid receptor affinity: Synthesis of (+)-4-[(alphaR)-alpha-(4-allyl-(2S,5S)-dimethylpiperazin-1-yl)-(3-hydroxyphenyl)methyl]-N-ethyl-N-phenylbenzamide and (-)-4-[(alphaR)-alpha-(2S,5S)-dimethylpiperazin-1-yl)-(3-hydroxyphenyl)methyl]-N-ethyl-N-phenylbenzamide

We have explored the synthesis of compounds that have good affinity for both mu- and delta-opioid receptors from the (alphaR,2S,5S) class of diaryldimethylpiperazines. These non-selective compounds were related to opioids that have been found to interact selectively with mu- or delta-opioid receptors as agonists or antagonists. In our initial survey, we found two compounds, (+)-4-[(alphaR)-alpha-(4-allyl-(2S,5S)-dimethylpiperazin-1-yl)-(3-hydroxyphenyl)methyl]-N-ethyl-N-phenylbenzamide (14) and its N-H relative, (-)-4-[(alphaR)-alpha-(2S,5S)-dimethylpiperazin-1-yl)-(3-hydroxyphenyl)methyl]-N-ethyl-N-phenylbenzamide (15), that interacted with delta-receptors with good affinity, and, as we hoped, with much higher affinity at mu-receptors than SNC80. The relative configuration of the benzylic position in (+)-4-[(alphaR)-alpha-(4-allyl-(2S,5S)-dimethyl-1-piperazinyl)-(3-methoxyphenyl)methyl]-benzyl alcohol (10) was determined by X-ray crystallographic analysis of a crystal that was an unresolved twin. The absolute stereochemistry of that benzylic stereogenic center was unequivocally derived by the X-ray crystallographic analysis from the two other centers of asymmetry in the molecule that were known. Those were established from the synthesis via a dipeptide cyclo-L-Ala-L-Ala in which the absolute stereochemistry was established.     

Optically active antifungal azoles: synthesis and antifungal activity of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazol-2-yl/1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol

A series of (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazol-2-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (11a-n) and (2R,3S)-2-(2,4-difluorophenyl)-3-(5-[2-[4-aryl-piperazin-1-yl]-ethyl]-tetrazole-1-yl)-1-[1,2,4]-triazol-1-yl-butan-2-ol (12a-n) has been synthesized. The antifungal activity of compounds was evaluated by in vitro agar diffusion and broth dilution assay. Compounds 11d and its positional isomer 12d having 3-trifluoromethyl substitution on the phenyl ring of piperazine demonstrated significant antifungal activity against variety of fungal cultures (Candida spp. C. neoformans and Aspergillus spp.). The compound 12d showed MIC value of 0.12 microg/mL for C. albicans, C. albicans V-01-191A-261 (resistant strain); 0.25 microg/mL for C. tropicalis, C. parapsilosis ATCC 22019 and C. krusei and MIC value of 0.5 microg/mL for C. glabrata, C. krusei ATCC 6258, which is comparable to itraconazole and better than fluconazole. Further, compound 11d showed significant activity (MIC; 0.25-0.5 microg/mL) against Candida spp. and strong anticryptococcal activity (MIC; 0.25 microg/mL) against C. neoformans.     

Pharmacokinetics and metabolism studies on (3-tert-butyl-7-(5-methylisoxazol-3-yl)-2-(1-methyl-1H-1,2,4-triazol-5-ylmethoxy) pyrazolo[1,5-d][1,2,4]triazine, a functionally selective GABA(A) alpha5 inverse agonist for cognitive dysfunction

(3-tert-Butyl-7-(5-methylisoxazol-3-yl)-2-(1-methyl-1H-1,2,4-triazol-5-ylmethoxy)pyrazolo[1,5-d][1,2,4]triazine (1) was recently identified as a functionally selective, inverse agonist at the benzodiazepine site of GABA(A) alpha5 receptors and enhances performance in animal models of cognition. The routes of metabolism of this compound in vivo in rat have been well characterised, the identities of the major metabolites are confirmed by synthesis and their biological profiles were evaluated. An unusual oxidation of the pyrazolo[1,5-d][1,2,4]triazine core to the corresponding pyrazolo[1,5-d][1,2,4]triazin-4(5H)-one scaffold by aldehyde oxidase has been observed.     

3-[2-Amino-2-imidazolin-4(5)-yl]alanine (enduracididine) and 2-[2-amino-2-imidazolin-4(5)-yl] acetic acid in seeds of Lonchocarpus sericeus

3-[2-Amino-2-imidazolin-4(5)-yl]alanine (enduracididine) and 2-[2-amino-2-imidazolin-4(5)-yl] acetic acid have been isolated from seeds of Lonchocarpus sericeus. The concentration of each compound was ca 0.5 % of the fresh seed weight.     

Discovery of novel antitubercular 1,5-dimethyl-2-phenyl-4-([5-(arylamino)-1,3,4-oxadiazol-2-yl]methylamino)-1,2-dihydro-3H-pyrazol-3-one analogues

In search of potential therapeutics for tuberculosis, we describe herewith the synthesis, characterization and antimycobacterial activity of 1,5-dimethyl-2-phenyl-4-([5-(arylamino)-1,3,4-oxadiazol-2-yl]methylamino)-1,2-dihydro-3H-pyrazol-3-one analogues. Among the synthesized compounds, 4-[(5-[(4-fluorophenylamino]-1,3,4-oxadiazol-2-yl)methylamino]-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (4a) was found to be the most promising compound active against Mycobacterium tuberculosis H(37)Rv and isoniazid resistant M. tuberculosis with minimum inhibitory concentrations, 0.78 and 3.12μg/mL, respectively, free from any cytotoxicity (>62.5μg/mL).     

Discovery of [7-(2,6-dichlorophenyl)-5-methylbenzo [1,2,4]triazin-3-yl]-[4-(2-pyrrolidin-1-ylethoxy)phenyl]amine--a potent, orally active Src kinase inhibitor with anti-tumor activity in preclinical assays

We describe the identification of [7-(2,6-dichlorophenyl)-5-methylbenzo [1,2,4]triazin-3-yl]-[4-(2-pyrrolidin-1-ylethoxy)phenyl]amine (3), a potent, orally active Src inhibitor with desirable PK properties, demonstrated activity in human tumor cell lines and in animal models of tumor growth.     

New broad-spectrum parenteral cephalosporins exhibiting potent activity against both methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Part 3: 7beta-[2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido] cephalosporins bearing 4-[3-(aminoalkyl)-ureido]-1-pyridinium at C-3'

Among the prepared C-3' substituted-pyridinium cephalosporins, a series of 7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido] cephalosporins bearing 4-[3-(aminoalkyl)-ureido]-1-pyridinium at C-3' showed highly potent antibacterial activity against MRSA and Pseudomonas aeruginosa.     

Identification and characterization of 4-[4-(3-phenyl-2-propen-1-yl)-1-piperazinyl]-5H-pyrimido[5,4-b]indole derivatives as Salmonella biofilm inhibitors

A screening of a small-molecule library was conducted, in search of Salmonella biofilm inhibitors active in a broad temperature range, both in prevention and in eradication of biofilms. Moreover, the inhibitors were selected not to influence the planktonic growth of Salmonella to diminish the selective pressure and to prevent or slow down resistance development. Out of the 20,014 compounds screened at 16 and 37 °C, 140 hits were identified. After characterization of the most promising hits at a broader set of temperatures (16, 25, 30 and 37 °C), we identified 7-methoxy-4-[4-(3-phenyl-2-propen-1-yl)-1-piperazinyl]-5H-pyrimido[5,4-b]indole as an interesting preventive anti-biofilm compound. A first structure-activity relationship of this compound was delineated, revealing 8-fluoro-4-[4-(3-phenyl-2-propen-1-yl)-1-piperazinyl]-5H-pyrimido[5,4-b]indole as a promising analogue in the prevention of Salmonella biofilms.     

3-[3-Fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)phenyl]-4-methylpyridine: a highly potent and orally bioavailable metabotropic glutamate subtype 5 (mGlu5) receptor antagonist

Structure-activity relationship studies performed around 3-fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)benzonitrile for the purpose of developing novel mGlu5 receptor antagonists are described. Synthesis of a series of four-ring tetrazoles led to the discovery of 3-[3-fluoro-5-(5-pyridin-2-yl-2H-tetrazol-2-yl)phenyl]-4-methylpyridine, a highly potent, brain penetrant, azole-based mGlu5 receptor antagonist.     

Designing,synthesis and bioactivities of 4-[3-(4-hydroxyphenyl)-5-aryl-4,5-dihydro-pyrazol-1-yl]benzenesulfonamides

In this study, 4-[3-(4-hydroxyphenyl)-5-aryl-4,5-dihydro-pyrazol-1-yl]benzenesulfonamide (1–9) types compounds were synthesized and their chemical structures were confirmed by ¹H NMR, ¹³C NMR and HRMS spectra. Cytotoxic and carbonic anhydrase (CA) inhibitory effects of the compounds were investigated. Cytotoxicity experiments pointed out that compound 4, (4-[5-(4-chlorophenyl)-3-(4-hydroxyphenyl)-4,5-dihydro-pyrazol-1-yl]benzenesulfonamide), exerting the highest tumor selectivity (TS) and potency selectivity expression (PSE) values, can be considered as a lead compound of this study in terms of development of novel anticancer agents. All synthesized sulfonamides showed a good inhibition profile on hCA IX and XII in the range of 53.5–923?nM and 6.2–95?nM, respectively. These compounds were 2.5–13.4 times more selective for the inhibition of hCA XII versus hCA IX, except compound 2 which had similar inhibitory action towards both isoenzymes.     

5-[(2-Methyl-1,3-thiazol-4-yl)ethynyl]-2,3'-bipyridine: a highly potent, orally active metabotropic glutamate subtype 5 (mGlu5) receptor antagonist with anxiolytic activity

Structure-activity relationship studies leading to the discovery of a new, orally active mGlu5 receptor antagonist are described. The title compound, 5-[(2-methyl-1,3-thiazol-4-yl)ethynyl]-2,3'-bipyridine, is highly potent in vitro, has good in vivo receptor occupancy, and is efficacious in the rat fear-potentiated startle model of anxiety following oral dosing.