Browsing by Author "Borges, Fernanda"
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- 1-aryl-3-(4-(7-methylthieno[3,2-d]pyrimidin-4-yloxy)phenyl)ureas: synthesis and molecular modelling studies using VEGFR-2Publication . Soares, Pedro; Froufe, Hugo J.C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Borges, Fernanda; Queiroz, Maria João R.P.The development of anticancer drugs inhibiting angiogenesis has been an area of extensive research in the past decade. Angiogenesis is a requirement for tumor growth and metastasis and occurs through several signalling pathways. One key pathway that initiates proliferation and migration of endothelial cells is signalling through the vascular endothelial growth factor receptor-2 (VEGFR-2).1 Therefore, small molecules that block this signalling pathway through inhibition of VEGFR-2 tyrosine kinase activity could potentially inhibit angiogenesis and tumor growth. Recently works describing thienopyrimidine2 and thienopyrimidine 1,3-diarylureas3 as VEGFR-2 inhibitors have emerged in the literature. Here we present the synthesis of new 1-aryl-3-(4-(7-methylthieno[3,2-d]pyrimidin-4-yloxy)phenyl)ureas 2 in high yields by reaction of 4-[(7-methylthieno[3,2-d]pyridin-4-yl)oxy]aniline 1 with arylisocyanates. The former was prepared by regioselective nucleophilic substitution of 4-chloro-7-methylthieno[3,2-d]pyrimidine with 4-aminophenol
- 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as potential inhibitors of VEGFR-2: synthesis and molecular modelling studiesPublication . Soares, Pedro; Froufe, Hugo J.C.; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Borges, Fernanda; Queiroz, Maria João R.P.Angiogenesis is a requirement for tumor growth and metastasis and occurs through several signalling pathways. One key pathway that initiates proliferation and migration of endothelial cells is signalling through the vascular endothelial growth factor receptor-2 (VEGFR-2).1 Therefore, small molecules that block this signalling pathway through inhibition of the VEGFR tyrosine kinase activity could potentially inhibit angiogenesis and tumour growth. Recently works describing thienopyrimidines2 and thienopyridine ureas3 as inhibitors of VEGFR-2 have appeared in the literature. Here we present the synthesis of new 1,3-diarylureas 2 starting by regioselective nucleophilic substitution of the 4-chlorothieno[3,2-d]pyrimidine with 4-aminophenol to obtain 4-(thieno[3,2-d]pyridin-4-yloxy)aniline 1 which reacts with different arylisocyanates
- NMR studies on the antiradical mechanism of phenolic compounds towards 2,2-diphenil-1-pycridrazyl radicalPublication . Silva, Artur; Santos, Clementina M.M.; Cavaleiro, José; Tavares, Hilário; Borges, Fernanda; Silva, Francisco A.Phenolic compounds are the most abundant c1ass of natural antioxidants. These types of compounds are ubiquitous in fruits and vegetables and in plant-derived beverages, such tea and wine, being important constituents of human diet. Recent studies have pointed out particular interest on phenolic type compounds (e.g. flavonoids, catechins, cinnamic and benzoic acid derivatives) with respect not on1y to the organoleptic characteristics of foodstuffs (e.g. flavour, bitterness, astringency) but also to their potential benefits in deleterious oxidative radicalar processes related with human disease (e.g. cancer, atherosc1erosis).l,2 The antioxidant activity of phenolic compounds could be related with their antiradicalar activity and/or with the ability to act as metal ions chelators. Although there is general agreement that catecholic compounds possess radical scavenging properties till now its mechanism of action is not fully understood. The. determination of antiradicalar potency of antioxidants is usually performed using "Trap Assays" from which a screening of their scavenging activity towards different radical species could be obtained. The DPPH method is a non-enzymatic assay widely used for this purpose, in which the reactivity of the tested compounds towards a stable free radicaI2,2-diphenyl-l-picrylhydrazyl (DPPHe ) is measured.3 Following our interest on the antioxidant behaviour of phenolic compounds4 ,5 the mechanism of the antiradicalar activity of ortho-dihydroxy cinnamic acids and 2-styry1chromone derivatives towards DPPHe was studied by NMR spectroscopy.