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New di(heteroaryl)thioethers 1,3-diarylureas in the thieno[3,2-b]pyridine series as VEGFR2 tyrosine kinase inhibitors: docking, synthesis, enzymatic and cellular assays

Publication . Machado, Vera A.; Costa, Raquel; Peixoto, Daniela; Abreu, Rui M.V.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Soares, Raquel; Queiroz, Maria João R.P.

Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) is a tyrosine kinase receptor, expressed primarily in endothelial cells, and is activated by the specific binding of VEGF, produced and released by the tumor, to the VEGFR2 extracellular regulatory domain, undergoing autophosphorylation, triggering signaling pathways leading to endothelial cell proliferation towards the tumor [!].Small molecules may act as inhibitors by competing for the ATP-binding site of the VEGFR2 intracellular tyrosine kinase domain, thereby preventing the intracellular signaling that leads to angiogenesis [2]. Herein, we report the synthesis using rational design of new 1-aryl-3-[3-thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas (la-c) as VEGFR2 tyrosine kinase inhibitors. The compounds presented, with the arylurea in the meta position to the thioether and with F or a Me group, showed very low !Cso values (11-28 nM) in enzymatic assays as predicted by molecular docking. To examine the activity of compounds 1 in endothelial cells, VEGF-stimulated (60 ng/mL) Human Umbilical Vein Endothelial Cells (HUVECs) were cultured in M199 medium in the absence (C) or presence of each compound at different concentrations. A remarkable reduction in the proliferation of HUVECs using the BrdU incorporation assay was observed for all compounds at I !JM, for compound la being observed a higher antiproliferative effect. Further studies are ongoing to examine whether these molecules affect the expression and activity of VEGFR2 and the signaling pathways, using western blotting assays. Given the established role of VEGFR2 in proliferation and migration of endothelial cells, these molecules are promising anti-angiogenic agents that can be used for therapeutic purposes in pathological conditions where angiogenesis is exacerbated, such as cancer.

2013Conference object

Open access

Synthesis, molecular Docking and biological evaluation of new 1-Aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenylureas as Potent Type II VEGFR-2 Tyrosine Kinase inhibitors

Publication . Machado, Vera A.; Peixoto, Daniela; Costa, Raquel; Calhelha, Ricardo C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Soares, Raquel; Queiroz, Maria João R.P.

The vascular endothelial growth factor receptor 2 (VEGFR-2) is a tyrosine kinase receptor, expressed primarily in endothelial cells, and is activated by the specific binding of VEGF to the VEGFR-2 extracellular regulatory domain. Once activated, VEGFR-2 undergoes autophosphorylation, triggering signaling pathways leading to endothelial cell proliferation and subsequent angiogenesisY1 Small molecules may act as inhibitors by competing for the ATP-binding s'1te of the VEGFR-2 intracellular tyrosine kinase domain, thereby preventing the intracellular signa ling that leads to angiogenesis. [ZJ Here, we present the synthesis of new 1-aryl-3-[3-(thieno[3,2-b]pyridin-7-ylthio)phenyl]ureas la-c, as potent type 11 VEGFR-2 inhibitors based on molecular docking (Figure A) and biological evaluation including enzymatic assays using the VEGFR-2 tyrosine kinase domain (ICso=l0-28 nM) and studies in human umbilical vein endothelial cells (HUVECs). The latter included cell viability (MTS), proliferation (BrdU) and Western blot for total and phosphorylated VEGFR-2 (Figure B). The predicted docked poses were analyzed in detail and a plausible explanation for compounds 1 potency was obtained base9 on the simultaneous presence of a S-linker and the arylurea moiety in the meta position as a new substitution pattern for the type 11 VEGFR-2 inhibitors. These chemical features place the thieno[3,2-b]pyridine and the terminal aryl ring in close superimposition to a pyrrolo[3,2-d]pyrimidine derivative. The presence of hydrofobic substituents (F and Me) in the terminal aryl ring is also important. For these compounds a significant inhibition in HUVECs proliferation upon VEGF stimulation was observed at low concentrations (0.5-1.0 IJ.M) without affecting cell viability. Westernblot analysis demonstrated that compounds 1 significantly the inhibited VEGFR-2 phosphorylation at 1.0 jlM, thus confirming their anti-angiogenic potential.

2014Conference object

Open access

Methyl 3-[4-(3-arylureido)phenylamino]thieno[3,2-b]pyridine-2-carboxylates as potential inhibitors of VEGFR-2: synthesis and molecular modelling studies

Publication . Peixoto, Daniela; Calhelha, Ricardo C.; Dias, Sofia; Froufe, Hugo J.C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Queiroz, Maria João R.P.

When over expressed or mutated, protein tyrosine kinases become potent oncoproteins that cause deregulated cell growth angiogenesis and metastasis. Because of these characteristics, they are targets for small molecule inhibitors in the treatment of cancer. Recently some thieno[3,2-c]pyridine 1,3-diarylurea derivatives were prepared as VEGFR-2 (vascular endothelium growth factor receptor-2) inhibitors.1 Here we present the synthesis of methyl 3-[4-(3-arylureido)phenylamino]thieno[3,2-b]pyridine-2-carboxylates 2 in excellent yields, by reaction of the methyl 3-(4-aminophenylamino)thieno[3,2-b]pyridine-2-carboxylate 1, prepared also by us, with different arylisocyanates (Scheme).

2011Conference object

Open access

1-Aryl-3-[ 4-( thieno[3,2-d]pyrimidin-4-yloxy )phenyl]ureas as VEG FR2 inhibitors: synthesis, docking enzymatic and cellular assays

Publication . Peixoto, Daniela; Calhelha, Ricardo C.; Soares, Pedro; Abreu, Rui M.V.; Froufe, Hugo J.C.; Ferreira, Isabel C.F.R.; Costa, Raquel; Soares, Raquel; Queiroz, Maria João R.P.

A number of thienopyrimidines derivatives have shown potent VEGFR2 (Vascular Endothelium Growth Factor Receptor2) tyrosine kinase inhibition activity.[ll VEGF is a sun·ogate marker of angiogenesis that activates VEGFR2 in endothelial cells. Here we present the synthesis of new 1-aryl-3-[ 4-(thieno[3,2-d]pyrimidin-4- yloxy)phenyl]ureas from the aminodi(hetero)arylether 1, also prepared by us, which was reacted with arylisocyanates to give the corresponding 1,3-diarylureas 2a-c.

2012Conference object

Open access

Antioxidant activity of aminodiarylamines in the thieno[3,2-b]pyridine series: radical scavenging activity, lipid peroxidation inhibition and redox profile

Publication . Calhelha, Ricardo C.; Peixoto, Daniela; Vilas-Boas, Miguel; Queiroz, Maria João R.P.; Ferreira, Isabel C.F.R.

The antioxidant activity of the aminodi(hetero)arylamines, prepared by C-N coupling of the methyl 3-aminothieno[3,2-b]pyridine-2-carboxylate with bromonitrobenzenes and further reduction of the obtained nitro compounds, was evaluated by chemical, biochemical and electrochemical assays. The aminodi(hetero) arylamine with the amino group ortho to the NH and a methoxy group in para, was the most efficient in radical scavenging activity (RSA, 63 mu M) and reducing power (RP, 33 mu M), while the aminodiarylamine with the amino group in para to the NH, gave the best results in beta-carotene-linoleate system (41 mu M) and inhibition of formation of thiobarbituric acid reactive substances in porcine brain cells homogenates (7 mu M), with EC50 values even lower than those obtained for the standard trolox. This diarylamine also presented the lowest oxidation potential, lower than the one of trolox, and the highest antioxidant power in the electrochemical assays. The para substitution with an amino group enables higher antioxidant potential.

2014Journal article

Open access