Synthesis and immunosuppressant activity of pyrazole carboxamides

Probing binding and cellular activity of pyrrolidinone and piperidinone small molecules targeting the urokinase receptor

The urokinase receptor (uPAR) is a cell-surface protein that is part of an intricate web of transient and tight protein interactions that promote cancer cell invasion and metastasis. Here, we evaluate the binding and biological activity of a new class of pyrrolidinone and piperidinone compounds, along with derivatives of previously-identified pyrazole and propylamine compounds. Competition assays revealed that the compounds displace a fluorescently labeled peptide (AE147-FAM) with inhibition constant (Ki ) values ranging from 6 to 63 μM. Structure-based computational pharmacophore analysis followed by extensive explicit-solvent molecular dynamics (MD) simulations and free energy calculations suggested the pyrazole-based and piperidinone-based compounds adopt different binding modes, despite their similar two-dimensional structures. In cells, pyrazole-based compounds showed significant inhibition of breast adenocarcinoma (MDA-MB-231) and pancreatic ductal adenocarcinoma (PDAC) cell proliferation, but piperidinone-containing compounds exhibited no cytotoxicity even at concentrations of 100 μM. One pyrazole-based compound impaired MDA-MB-231 invasion, adhesion, and migration in a concentration-dependent manner, while the piperidinone inhibited only invasion. The pyrazole derivative inhibited matrix metalloprotease-9 (gelatinase) activity in a concentration-dependent manner, while the piperidinone showed no effect suggesting different mechanisms for inhibition of cell invasion. Signaling studies further highlighted these differences, showing that pyrazole compounds completely inhibited ERK phosphorylation and impaired HIF1α and NF-κB signaling, while pyrrolidinones and piperidinones had no effect. Annexin V staining suggested that the effect of the pyrazole-based compound on proliferation was due to cell killing through an apoptotic mechanism. The compounds identified represent valuable leads in the design of further derivatives with higher affinities and potential probes to unravel the protein-protein interactions of uPAR.

Virtual screening targeting the urokinase receptor, biochemical and cell-based studies, synthesis, pharmacokinetic characterization, and effect on breast tumor metastasis

Virtual screening targeting the urokinase receptor (uPAR) led to (±)-3-(benzo[d][1,3]dioxol-5-yl)-N-(benzo[d][1,3]dioxol-5-ylmethyl)-4-phenylbutan-1-amine 1 (IPR-1) and N-(3,5-dimethylphenyl)-1-(4-isopropylphenyl)-5-(piperidin-4-yl)-1H-pyrazole-4-carboxamide 3 (IPR-69). Synthesis of an analogue of 1, namely, 2 (IPR-9), and 3 led to breast MDA-MB-231 invasion, migration and adhesion assays with IC(50) near 30 μM. Both compounds blocked angiogenesis with IC(50) of 3 μM. Compounds 2 and 3 inhibited cell growth with IC(50) of 6 and 18 μM and induced apoptosis. Biochemical assays revealed leadlike properties for 3, but not 2. Compound 3 administered orally reached peak concentration of nearly 40 μM with a half-life of about 2 h. In NOD-SCID mice inoculated with breast TMD-231 cells in their mammary fat pads, compound 3 showed a 20% reduction in tumor volumes and less extensive metastasis was observed for the treated mice. The suitable pharmacokinetic properties of 3 and the encouraging preliminary results in metastasis make it an ideal starting point for next generation compounds.

Antileishmanial and Antibacterial Activity of a New Pyrazole Derivative Designated 4-[2-(1-(Ethylamino)-2-methyl- propyl)phenyl]-3-(4-methyphenyl)-1-phenylpyrazole

Here, we report for the first time the synthesis and the antileishmanial activity of a new pyrazole derivative, namely 4-[2-(1-(ethylamino)-2-methylpropyl)phenyl]-3-(4-methyphenyl)-1-phenylpyrazole). Micromolar concentrations of this compound were found to inhibit the in vitro multiplication of Leishmania tropica, Leishmania major, and Leishmania infantum, three species causing different forms of leishmaniasis. Furthermore, the 50% inhibitory concentration (IC50) values for the compound are only slightly higher than those of amphotericin B, one of the most active antileishmanial agents used as a satisfactory substitute in cases not responding to pentostam. The IC50 values after 48 h for L. tropica, L. major, and L. infantum promastigote growth were 0.48 microg/mL, 0.63 microg/mL and 0.40 microg/mL, respectively for the compound, while they were 0.23 microg/mL, 0.29 microg/mL and 0.24 microg/mL, respectively for amphotericin B. We also tested this compound for its antibacterial activity against several bacteria. The strongest antibacterial activity was observed against Entrococcus feacalis and Staphylococcus aureus with a minimal inhibitory concentration (MIC) of 60 microg/mL.

Amidrazones as Precursors of Biologically Active Compounds - Synthesis of Diaminopyrazoles for Evaluation of Anticancer Activity

The regioselectivity of coupling phenyl isocyanate to 3-(2-acylhydrazino)-3-aminopropenenitriles and ethyl 3-(2-acylhydrazino)-3-aminopropenoates as simple access to aminopyrazole derivatives, endowed with potential antitumoral activity, is reported. 3-(2-Acylhydrazino)-3-aminopropenenitriles react with phenyl isocyanate to afford 3-amino-3-(2-acylhydrazino)-2-phenylaminocarbonyl-2-propenenitriles. These key intermediates were cyclized into 3,5-diaminopyrazole-4-carboxamide derivatives. Preliminary results of poor antiproliferative activities of these compounds are also reported.

Effect of Pyrazoloquinoline Derivatives on the Growth ofLeishmania donovani Promastigotes

A screening study was conducted to examine the effect of a series of synthesized pyrazoloquinoline derivatives on the growth of Leishmania donovani promastigotes. Sixteen compounds were tested, ten of which showed an inhibitory effect on the growth of promastigotes. Compound 1 demonstrated potent antileishmanial activity, followed by compounds 3 and 7. Some compounds showed less significant activities, while others exhibited little or no activity. Some of these compounds may be potential candidates for future treatment of leishmaniasis.

1-Phenyl-3-toluyl-4-[ortho-1′-(N-ethyl-2′-methylpropylamine)]phenylpyrazole, synthesis and evaluation of the in vitro antifungal activity against Botrytis cinerea and Fusarium oxysporum

A novel antifungal pyrazole derivative was synthesized. Designated 1-phenyl-3-toluyl-4-[ortho-1'-(N-ethyl-2'-methylpropylamine)]phenylpyrazole, the compound exerted an antifungal effect toward Botrytis cinerea and Fusarium oxysporum. In fact, our results clearly show that mycelial growth and conidial germination of both fungi were blocked by the compound. Indeed, a 96-well microbioassay procedure was used for fast and easy evaluation of minimal inhibitory concentration (MIC). The MIC values for B. cinerea and F. oxysporum were 25 and 36 microg/ml, respectively.