1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as potential inhibitors of VEGFR-2: synthesis and molecular modelling studies

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 arylisocyanate

1-aryl-3-(4-(7-methylthieno[3,2-d]pyrimidin-4-yloxy)phenyl)ureas: synthesis and molecular modelling studies using VEGFR-2

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-aminopheno

Thieno[3,2-b]pyridine arylethers: synthesis and growth inhibitory activity on human tumor cell lines

Thienopyridine skeleton has been reported as havi ng inte resting biological activity, namely antitumorlll and antiangiogenic121 activities. Herein, we describe the synth esis of thienopyridine arylethers la-f in moderate to good yields by a copper-cata lyzed C- 0 coupling, using N,N-dimethylglycine as a ligand, of the 7-bromothieno[3,2-b]pyridine, also prepared with substituted phenols (see scheme)

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

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

Flocculation onset in Saccharomyces cerevisiae: effect of ethanol, heat and osmotic stress

Aims: To examine the effect of different stress conditions on the onset of flocculation in an ale-brewing strain, Saccharomyces cerevisiae NCYC 1195. Methods and Results: Flocculation was evaluated using the method of Soares, E.V. and Vroman, A. [Journal of Applied Microbiology (2003) 95, 325]; plasma membrane integrity was accessed using propidium iodide and the staining of the yeast cell wall was performed using calcofluor white M2R. Cells in exponential phase of growth were subjected to different stress conditions. The addition of 1%, 3% and 5% (v/v) ethanol, 1% and 3% (v/v) isopropanol or a brief heat shock (52ºC, 5 min), did not induce an early flocculation phenotype when compared with control cells. The addition of 10% (v/v) ethanol, a continuous mild heat-stress (37ºC) or an osmotic stress (0.5 or 1 mol l-1 of NaCl) did not induce a flocculent phenotype. Conclusions: Flocculation seems not to be induced as a response to different chemical (ethanol and isopropanol) and physical (heat and osmotic) stress conditions. Conversely, osmotic and ethanol [10% (v/v)] stress, as well as a continuous mild heat shock (37ºC), have a negative impact on the phenotype expression of flocculation. Significance and Impact of the Study: The findings reported here contribute to the elucidation of the control of yeast flocculation. This information might be useful to the brewing industry, as the time when the onset of flocculation occurs can determine the fermentation performance and the beer quality, as well as in other biotechnological industries where flocculation can be used as a cell separation process.ERASMUS; ISEP (Portugal)

A cost-effective microfluidic device for determination of biodiesel content in diesel blends

The increasing production and extensive use of biodiesel in the latest years call for the development of fast and cost-effective procedures for point-of-care analysis. One of the main quality parameters is the biodiesel content in diesel blends, which needs to conform to regional legislations. In this work, a microfluidic device exploiting chemical derivatization of alkyl esters and detection by smartphone-based digital-image colorimetry was developed. It was designed to ensure proper experimental conditions for chemical derivatization, including re- agent release, and photometric measurements. Analytes reacted with alkaline hydroxylamine yielding the cor- responding alkyl hydroxamates, measured as colored Fe(III) complexes. Analytical response was based on the measurement of the G (green) channel from RGB color system. By taking methyl linoleate as a model compound, a linear response was obtained from 0.1% to 0.6%(v/v) (Analytical signal = 69.6 +2.1 C, r = 0.999), coefficient of variation (n = 10) of 4.0% and limit of detection (99.7% confidence) of 0.04%(v/v). Procedure consumes 1.2 µL of sample, 230 µg of hydroxylamine, 480 µg of NaOH, 14 µg of Fe(III) and equivalent to 1.2 µL of 69%(v/v) HNO3. Accurate results were achieved in relation to the MIR reference method, with agreement at the 95% confidence levelThe authors gratefully acknowledge the financial support from Fundaç˜ao de Amparo `a Pesquisa do Estado de S˜ao Paulo FAPESP (proc. 2021/12242–5 and 2018/07687–5). and the support from the Spanish “Ministerio de Economía y Competitividad” (Project PID2019–103938RB- I00) and Junta de Andalucía (Projects B-FQM-243-UGR18 and P18-RT- 2961)

Antibacterial activity of Euterpe oieracea Mart. seeds against clinical isolates

Introduction: The use of antibiotics – including the over- and misuse – in human and veterinary practices selected for resistant pathogens led to their emergence and dissemination along with the transmission of resistant bacteria [1]. Due to this problem, there is a need to investigate new strategies to reverse this tendency in order to achieve the appropriate and effective treatment against infections. Aims: The present work aimed to evaluate the antibacterial activity of an aqueous extract prepared from Euterpe Oleracea Mart. (açai) seeds (originated from Brazil [2]), against clinical isolates from “Centro Hospitalar de Trás-os-Montes e Alto Douro- Unidade de Vila Real”, with high resistance profiles to different antibiotics. Material and Methods: The minimal inhibitory concentrations (MIC) of the growth of Gram-positive and Gram-negative bacteria were determined by the colorimetric assay based on the use of p-iodonitrotetrazolium chloride (INT) dye, after application of the microdilution method. Results and discussion: The açaí aqueous extract showed antimicrobial activity against all the tested Gram-positive bacteria. The lowest MICs (0.25 mg/ml) were obtained against Methicillin Susceptible Staphylococcus aureus (MSSA) and Methicillin Resistant S. aureus (MRSA), followed by the MIC 0.5 mg/ml correspondent to Streptococcus agalactiae and Enterococcus faecalis. Regarding the inhibition of the growth of Gram-negative bacteria, the extract was active against Morganella morganii, Pseudomonas aeruginosa and Acinetobacter baumannii with MICs 1 mg/ml e 2 mg/ml, respectively. The results were better for Gram-positive bacteria in comparison with Gram-negative bacteria. Conclusion: However, even at low concentration (2 mg/ml) the results are very promising for Gram-negative bacteria with high resistance profiles and commonly related with health care-associated infections, namely Pseudomonas aeruginosa and Acinetobacter baumannii

New di(hetero)arylethers and di(hetero)arylamines in the thieno[3,2-b]pyridine series: Synthesis, growth inhibitory activity on human tumor cell lines and non-tumor cells, effects on cell cycle and on programmed cell death

New fluorinated and methoxylated di(hetero)arylethers and di(hetero)arylamines were prepared functionalizing the 7-position of the thieno[3,2-blpyridine, using copper (C-O) or palladium (C N) catalyzed couplings, respectively, of the 7-bromothieno[3,2-blpyridine, also prepared, with ortho, meta and para fluoro or methoxy phenols and anilines. The compounds obtained were evaluated for their growth inhibitory activity on the human tumor cell lines MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer), HCI15 (colon carcinoma), HepG2 (hepatocellular carcinoma) and HeLa (cervical carcinoma). The most active compounds, a di(hetero)arylether with a methoxy group in the meta position relative to the ether function and two di(hetero)arylamines with a methoxy group either in the ortho or in the meta position relative to the NH, were further tested at their GI(50) concentrations on NCI-H460 cells causing pronounced alterations in the cell cycle profile and a strong and significant increase in the programmed death of these cells. The fluorinated and the other methoxylated compounds did not show important activity, presenting high GI(50) values in all the cell lines tested. Furthermore, the hepatotoxicity of the compounds was assessed using porcine liver primary cells (PLP2), established by some of us. Results showed that one of the most active compounds was not toxic to the non-tumor cells at their GI(50) concentrations showing to be the most promising as antitumoral.The authors would like to thank to the Foundation for the Science and Technology (PCT Portugal) for financial support through the NMR Portuguese network (Bruker 400 Avance III-Univ Minho); to FCT and FEDER-COMPETE/QREN/EU for financial support through the research unities PEst-C/QUI/UI686/2011 and PEst-OE/AGR/UI0690/2011, the research project PTDC/QUI-QUI/111060/2009 and the post-Doctoral grants attributed to R.C.C. (SFRH/BPD/68344/2010) and R.T.L. (SRH/BPD/68787/2010). IPATIMUP is an Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher Education and is partially supported by FCT

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

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