Percorrer por autor "Peixoto, Daniela"
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- 1-Aryl-3-[ 4-( thieno[3,2-d]pyrimidin-4-yloxy )phenyl]ureas as VEG FR2 inhibitors: synthesis, docking enzymatic and cellular assaysPublication . 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.
- 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR-2 tyrosine kinase inhibitors: Synthesis, biological evaluation, and molecular modelling studiesPublication . Soares, Pedro; Costa, Raquel; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Peixoto, Daniela; 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 involved in the growth and differentiation of endothelial cells that is implicated in tumor-associated angiogenesis. In this study novel 1-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas were synthesized and evaluated for the VEGFR-2 tyrosine kinase inhibition. Three of these compounds showed good VEGFR-2 inhibition presenting low IC50 values (150-199 nM) in enzymatic assays. The latter promoted also significant inhibition of cell proliferation at low concentrations (0.5-1 µM), not affecting cell viability, of VEGF-stimulated Human Umbilical Vein Endothelial Cells (HUVECs) using the BrdU assay. The determination of the total and phosphorylated (active) VEGFR-2 was performed by western-blot, and it was possible to conclude that the compounds significantly inhibit the phosphorylation of the receptor at 1 µM pointing to their antiproliferative mechanism of action in HUVECs. The molecular rationale for inhibiting the tyrosine kinase domain of VEGFR-2 was also done and discussed using molecular docking studies.
- 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR2 tyrosine kinase inhibitors: synthesis, docking studies, enzymatic and cellular assaysPublication . Queiroz, Maria João R.P.; Peixoto, Daniela; Soares, Pedro; Abreu, Rui M.V.; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Costa, Raquel; Soares, RaquelA number of thienopyrimidines derivatives have shown potent vascular endothelial growth factor receptor 2 (VEGFR2) inhibition activity. Here, we present the synthesis of new 1-aryl-3-[4-(thieno[3,2-d) pyrimidin-4-yloxy)phenyl]ureas by promoting t he regioselective attack of the hydroxy group of the 4-aminophenol in the chlorine nucleophilic displacement on two 4-chlorinated thieno[3,2-d]pyrimidines, obtaining compounds la and 1b which were reacted with arylisocyanates to give t he corresponding 1,3-diarylureas 2a-f (see scheme). These compounds were evaluated for inhibition of VEGFR2 tyrosine kinase activity using enzymatic assays, and 2a- c showed good inhibition ability with IC50 values in the range of hundreds of nanomolar. The rationale for the inhibition activity is also discussed using docking. To examine the activity of 2a- c in endothelial cells, human umbilical vein endothelial cells (HUVECs) were cultured in the presence or absence of each compound in different concentrations. A decrease in the proliferation of HUVECs was observed by the incorporation of BrdU quantified by ELISA assay. Given the established role of VEGFR2 in proliferation and migration of endothelial cells, these molecules are promising antiangiogenic agents that can be used for therapeutic purposes in pathological conditions where angiogenesis is exacerbated, such as cancer.
- Aminodi(hetero)arylamines in the thieno[3,2-b]pyridine series: synthesis, effects in human tumor cells growth, cell cycle analysis, apoptosis and evaluation of toxicity using non-tumor cellsPublication . Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Peixoto, Daniela; Abreu, Rui M.V.; Vale-Silva, Luís A.; Pinto, Eugénia; Lima, Raquel T.; Alvelos, M. Inês; Vasconcelos, M. Helena; Queiroz, Maria João R.P.Three aminodi(hetero)arylamines were prepared via a palladium-catalyzed C-N Buchwald-Hartwig coupling of methyl 3-aminothieno[3,2-b]pyridine-2-carboxylate with different bromonitrobenzenes, followed by reduction of the nitro groups of the coupling products to the corresponding amino compounds. The aminodi(hetero)arylamines thus obtained were evaluated for their growth inhibitory effect on four human tumor cell lines MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), NCI-H460 (non-small cell lung cancer) and HepG2 (hepatocellular carcinoma). The toxicity to non-tumor cells was also evaluated using a porcine liver primary cell culture (PLP1), established by us. The aminodi(hetero)arylamine with the NH2 group in the ortho position and an OMe group in the para position to the NH of the di(hetero)arylamine, is the most promising compound giving the lowest GI50 values (1.30–1.63 μM) in all the tested human tumor cell lines, presenting no toxicity to PLP1 at those concentrations. The effect of this compound on the cell cycle and induction of apoptosis was analyzed in the NCI-H460 cell line. It was observed that it altered the cell cycle profile causing a decrease in the percentage of cells in the G0/G1 phase and an increase of the apoptosis levels.
- Antioxidant activity of aminodiarylamines in the thieno[3,2-b]pyridine series: radical scavenging activity, lipid peroxidation inhibition and redox profilePublication . 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.
- Epidermal growth factor receptor inhibitory activity of new potential antitumor di(hetero)arylethers and di(hetero)arylamines in the thieno[3,2-b]pyridine seriesPublication . Calhelha, Ricardo C.; Peixoto, Daniela; Soares, Pedro; Ferreira, Isabel C.F.R.; Abreu, Rui M.V.; Queiroz, Maria João R.P.Thienopyridine skeleton has been reported as having interesting biological activity, namely as antitumorals [1] and antiangiogenics [2]. The Epidermal Growth Factor Receptor (EGFR) exists in the cell surface and is activated by binding its specific ligands. The inhibition of its intracellular tyrosine kinase domain prevents the signaling pathways of cellular proliferation [3]. In our research group we have prepared the di(hetero)arylethers 1a-f and the di(hetero)arylamines 2a-f functionalizing the 7-position of the thieno[3,2-b]pyridine in good to high yields, using copper (C-O) or palladium (C-N) catalyzed couplings, like presented below.The di(hetero)arylethers 1a-f and di(hetero)arylamines 2a-f series were evaluated for EGFR tyrosine kinase inhibition activity. Compounds for series 1 presented practically no or very weak inhibition activity while compounds 2 presented good inhibition activity, with the most potent compounds 2e presenting a IC50 value of 40 nM. These compounds can be view as good starting points for the synthesis of even more potent EGFR inhibitors.
- Heteroarylether 1,3-diarylureas in the thieno[3,2-d]pyrimidine series as VEGFR2 tyrosine Kinase inhibitors: synthesis, docking studies, enzymatic and cellular assaysPublication . Queiroz, Maria João R.P.; Peixoto, Daniela; Soares, Pedro; Abreu, Rui M.V.; Froufe, Hugo J.C.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; Costa, Raquel; Soares, RaquelA number of thienopyrimidines derivatives have shown potent YEGFR2 (Vascular Endothelium Growth Factor Receptor2) inhibition activity [ 1]. YEGF is a surrogate marker of angiogenesis that activates VEGFR2 in endothelial cells. VEGF induces proliferation, migration and anastomosis of these cells. Here we present the synthesis of new l-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas, by reaction of 4-aminophenol with 4-chlorothieno[3,2-d]pyrimidine giving compound 1, which was reacted with arylisocyanates to give the corresponding I ,3-diarylureas 2a-c (Scheme).
- Methyl 3-[4-(3-arylureido)phenylamino]thieno[3,2-b]pyridine-2-carboxylates as potential inhibitors of VEGFR-2: synthesis and molecular modelling studiesPublication . 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).
- Methyl 3-amino-6-[4 or 3 or 2-(3-arylureido)phenyl]thieno[3,2-b]pyridine-2-carboxylates: synthesis and molecular modelling studies using VEGFR-2Publication . Peixoto, Daniela; Dias, Sofia; Froufe, Hugo J.C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Queiroz, Maria João R.P.The membrane receptor tyrosine kinases (RTKs), possess both extracellular and intracellular domains and selectively catalyze the phosphorylation of tyrosine hydroxyl groups in response to binding of certain extracellular growth factors. RTK signalling pathways are normally highly regulated, yet their over-activation has been shown to promote the growth, survival, and metastasis of cancer cells, and has been associated with the progression of various human cancers. 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-amino-6-[4 or 3 or 2-(3-arylureido)phenyl]thieno[3,2-b]pyridine-2-carboxylates 2 by reaction of the methyl 3-amino-6-(4 or 3 or 2-aminophenyl)thieno[3,2-b]pyridine-2-carboxylates 1, synthesized earlier by our group,2 with arylisocyanates
- New di(hetero)aryl)ethers and Di(hetero)arylamines in the thieno[3,2-b]pyridine series: synthesis, growth inhibitory activity on tumor cell lines and non tumor cells, effects on cell cycle and on apoptosisPublication . Queiroz, Maria João R.P.; Peixoto, Daniela; Calhelha, Ricardo C.; Soares, Pedro; Santos, Tiago; Lima, Raquel T.; Campos, Joana F.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Vasconcelos, M. HelenaThe thienopyridine skeleton has been reported as having interesting biological activities namely antitumor[1,2] antiangiogenic.[3A] New fluorinated and methoxylated di(hetero)arylethers and di(hetero)arylamines were prepared functionalizing 7-position of the thieno[3,2-bJpyridine, using copper (C-O) or palladium (C-N) catalyzed couplings, respectively, of the 7-t>rolmo: thieno[3,2-bJpyridine (1) with ortho, meta and para fluoro or methoxy phenols and anilines.
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