QSAR model for predicting radical scavenging activity of di(hetero)arylamines derivatives of benzo[b]thiophenes

A QSAR study was developed in order to model the antioxidant activity, specifically the radical scavenger activity (RSA), of 26 di(hetero)arylamines’ derivatives of benzo[b]thiophenes. The QSAR model was constructed, using the partial least squares projection of latent structures (PLS) method, and its robustness and predictability were verified by internal and external cross-validation methods. A total of 4 molecular descriptors, belonging to RDF (Radial Distribution Function) descriptors (RDF020e and RDF045e) and 2D-autocorrelation descriptors (GATS8p and MATS5e) were selected to build the QSAR model. RDF descriptors seem to relate the presence of electronegative atoms at the inner atmosphere of the compounds to increase RSA. 2D-Autocorrelation descriptors associate the presence of polarizable and electronegative pairs of atoms, at specific topological distance, with the RSA of the compounds. Finally this QSAR model proved to be a useful tool in the prediction of radical scavenger activity of congeneric compounds and will be used to guide the synthesis of new diarylamines in our laboratory

QSAR studies on di(hetero)arylamines derivatives of benzo[b]thiophenes as free radical scavengers

Synthetic antioxidants are widely used in food industry y, but because of toxic and carcinogenic effects revealed by some compounds such as BHA and BHT, their use is being restricted. The pursuit for novel compounds with antioxidant properties gained higher significance, since these compounds may contribute for the prevention of diseases in which free radicals are implicated

Endophytic fungi from the genus Colletotrichum are abundant in the Phaseolus vulgaris and have high genetic diversity

To evaluate the diversity of endophytic fungi from the leaves of the common bean and the genetic diversity of endophytic fungi from the genus Colletotrichum using IRAP (inter-retrotransposon amplified polymorphism) and REMAP (retrotransposon-microsatellite amplified polymorphism) analyses. The fungi were isolated by tissue fragmentation and identified by analysing the morphological features and sequencing the internal transcribed spacer (ITS) regions and the rDNA large subunit (LSU). Twenty-seven different taxa were identified. Colletotrichum was the most commonly isolated genera from the common bean (32.69% and 24.29% of the total isolates from the Ouro Negro and Talismã varieties, respectively). The IRAP and REMAP analyses revealed a high genetic diversity in the Colletotrichum endophytic isolates and were able to discriminate these isolates from the phytopathogen Colletotrichum lindemuthianum. Fungi from the genus Colletotrichum are abundant in the Phaseolus vulgaris endophytic community, and the IRAP and REMAP markers can be used to rapidly distinguish between C. lindemuthianum and other Colletotrichum members that are frequently found as endophytes. This is the first report of the diversity of endophytic fungi present in the common bean and the use of IRAP and REMAP markers to assess the genetic diversity of endophytic fungi from the genus Colletotrichum

MOLA: a tool for automation of parallel virtual docking using AutoDock Vina in a heterogeneous set of computer clusters

The use of molecular docking lo search large databases of compounds for possible ligands of a protein receptor is usually termed virtual screening and has been successfully applied in several therapeutic programs at the lead discovery stage. However, large scale virtual screening is lime demanding and usually requires dedicated High Performance Computing (H PC) systems

Insights in the antioxidant activity of diarylamines from the 2,3-dimethylbenzo[b]thiophene through the redox profile

Cyclic voltammetry was used to evaluate the antioxidant activity of 7-aryl or 7-heteroarylamino-2,3-dimethylbenzo[b]thiophenes previously synthesized by some of us, comparing their oxidation potentials with those of the well-known synthetic standards (BHA, BHT). Compounds with electron-donating groups on the arylamine moiety have lower Ep/2 than compounds with electron-withdrawing groups or electron-deficient rings (pyridines). The position of the methoxy group on the arylamine moiety also changes the oxidation potential: lower Ep/2 for the diarylamines with methoxy groups in the para position. Comparing the first peak potential with the ones of BHA and BHT, the diarylamine compounds show lower oxidation potential, and therefore higher reducing power. A reasonable inverse correlation was also observed between the Ep/2 values and the pEC50 values obtained in antioxidant activity chemical assays. It can be generalized that compounds with lower Ep/2 values have better antioxidant activity (DPPH assay) and higher reducing power

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

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

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-2

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 arylisocyanate

New potential anti-hepatocellular carcinoma (HCC) agents: in vitro evaluation of anti-HCC activity and hepatotoxicity of 6-substituted methyl 3-aminothieno[3,2-b]pyridine-2-carboxylates and QSAR studies

Hepatocellular carcinoma (HCC) is a major health problem with more than 660,000 new cases per year worldwide [1]. HCC is resistant to commonly used treatments like chemotherapy and radiotherapy and new anti-HCC therapies are urgently needed. Sorafenib was the first approved small molecule against HCC and underlines the importance of identifying potential new anti-HCC drugs [2]. Thirty-two 6-substituted methyl 3-aminothieno[3,2-b]pyridine-2-carboxylates, previously prepared by some of us [3,4], were evaluated as potential new anti-HCC agents by studying their in vitro cell growth inhibition on human HepG2 cells, generally regarded as a good HCC model, and hepatotoxicity using a porcine liver primary cell culture (PLP1). The presence of amino groups linked to a benzene moiety on the substituent of the 6-position emerged as the key element for the anti-HCC activity

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)