Design, Synthesis, and Biological Evaluation of 6-Substituted Thieno[3,2- d]pyrimidine Analogues as Dual Epidermal Growth Factor Receptor Kinase and Microtubule Inhibitors.

The clinical evidence for the success of tyrosine kinase inhibitors in combination with microtubule-targeting agents prompted us to design and develop single agents that possess both epidermal growth factor receptor (EGFR) kinase and tubulin polymerization inhibitory properties. A series of 6-aryl/heteroaryl-4-(3',4',5'-trimethoxyanilino)thieno[3,2- d]pyrimidine derivatives were discovered as novel dual tubulin polymerization and EGFR kinase inhibitors. The 4-(3',4',5'-trimethoxyanilino)-6-( p-tolyl)thieno[3,2- d]pyrimidine derivative 6g was the most potent compound of the series as an antiproliferative agent, with half-maximal inhibitory concentration (IC50) values in the single- or double-digit nanomolar range. Compound 6g bound to tubulin in the colchicine site and inhibited tubulin assembly with an IC50 value of 0.71 µM, and 6g inhibited EGFR activity with an IC50 value of 30 nM. Our data suggested that the excellent in vitro and in vivo profile of 6g may be derived from its dual inhibition of tubulin polymerization and EGFR kinase.

Quinazolinones, Quinazolinthiones, and Quinazolinimines as Nitric Oxide Synthase Inhibitors: Synthetic Study and Biological Evaluation.

The synthesis of different compounds with a quinazolinone, quinazolinthione, or quinazolinimine skeleton and their in vitro biological evaluation as inhibitors of inducible and neuronal nitric oxide synthase (iNOS and nNOS) isoforms are described. These derivatives were obtained from substituted 2-aminobenzylamines, using diverse cyclization procedures. Furthermore, the diamines were synthesized by two routes: A conventional pathway and an efficient one-pot synthesis in a continuous-flow hydrogenator. The structures of these heterocycles were confirmed by (1) H and (13) C nuclear magnetic resonance and high-resolution mass spectroscopy data. The structure-activity relationships of the target molecules are discussed in terms of the effects of both the R radical and the X heteroatom in the 2-position. In general, the assayed compounds behave as better iNOS than nNOS inhibitors, with the quinazolinone 11e being the most active inhibitor of all tested compounds and the most iNOS/nNOS selective one.

(1) H and (13) C NMR spectral assignment of N,N'-disubstituted thiourea and urea derivatives active against nitric oxide synthase.

The (1) H and (13) C NMR resonances of seventeen N-alkyl and aryl-N'-[3-hydroxy-3-(2-nitro-5-substitutedphenyl)propyl]-thioureas and ureas (1-17), and seventeen N-alkyl or aryl-N'-[3-(2-amino-5-substitutedphenyl)-3-hydroxypropyl]-thioureas and ureas (18-34), designed as NOS inhibitors, were assigned completely using the concerted application of one- and two-dimensional experiments (DEPT, HSQC and HMBC). NOESY studies confirm the preferred conformation of these compounds. Copyright © 2016 John Wiley & Sons, Ltd.

Development of urea and thiourea kynurenamine derivatives: synthesis, molecular modeling, and biological evaluation as nitric oxide synthase inhibitors.

Herein we describe the synthesis of a new family of kynurenamine derivatives with a urea or thiourea moiety, together with their in vitro biological evaluation as inhibitors of both neuronal and inducible nitric oxide synthases (nNOS and iNOS, respectively), enzymes responsible for the biogenesis of NO. These compounds were synthesized from a 5-substituted-2-nitrophenyl vinyl ketone scaffold in a five-step procedure with moderate to high chemical yields. In general, the assayed compounds show greater inhibition of iNOS than of nNOS, with 1-[3-(2-amino-5-chlorophenyl)-3-oxopropyl]-3-ethylurea (compound 5 n) being the most potent iNOS inhibitor in the series and the most iNOS/nNOS-selective compound. In this regard, we performed molecular modeling studies to propose a binding mode for this family of compounds to both enzymes and, thereby, to elucidate the differential molecular features that could explain the observed selectivity between iNOS and nNOS.

Design, synthesis and biological evaluation of arylcinnamide hybrid derivatives as novel anticancer agents.

The combination of two pharmacophores into a single molecule represents one of the methods that can be adopted for the synthesis of new anticancer molecules. A series of novel antiproliferative agents designed by a pharmacophore hybridization approach, combining the arylcinnamide skeleton and an α-bromoacryloyl moiety, was synthesized and evaluated for its antiproliferative activity against a panel of seven human cancer cell lines. In addition, the new derivatives were also active on multidrug-resistant cell lines over-expressing P-glycoprotein. The biological effects of various substituents on the N-phenyl ring of the benzamide portion were also described. In order to study the possible mechanism of action, we observed that 4p slightly increased the Reactive Oxygen Species (ROS) production in HeLa cells, but, more importantly, a remarkable decrease of intracellular reduced glutathione content was detected in treated cells compared with controls. These results were confirmed by the observation that only thiol-containing antioxidants were able to significantly protect the cells from induced cell death. Altogether our results indicate that the new derivatives are endowed with good anticancer activity in vitro, and their properties may result in the development of new cancer therapeutic strategies.

Synthesis and biological evaluation of 4,5-dihydro-1H-pyrazole derivatives as potential nNOS/iNOS selective inhibitors. Part 2: Influence of diverse substituents in both the phenyl moiety and the acyl group.

In a preliminary article, we reported a series of 4,5-dihydro-1H-pyrazole derivatives as neuronal nitric oxide synthase (nNOS) inhibitors. Here we present the data about the inhibition of inducible nitric oxide synthase (iNOS) of these compounds. In general, we can confirm that these pyrazoles are nNOS selective inhibitors. In addition, taking these compounds as a reference, we have designed and synthesized a series of new derivatives by modification of the heterocycle in 1-position, and by introduction of electron-donating or electron-withdrawing substituents in the aromatic ring. These derivatives have been evaluated as nNOS and iNOS inhibitors in order to identify new compounds with improved activity and selectivity. Compound 3r, with three methoxy electron-donating groups in the phenyl moiety, is the most potent nNOS inhibitor, showing good selectivity nNOS/iNOS.

NMR spectroscopic characterization of new 2,3-dihydro-1,3,4-thiadiazole derivatives.

The (1) H and (13) C NMR resonances of twenty-seven 2,2-dimethyl-5-(2-nitrophenyl-5-substituted)-2,3-dihydro-1,3,4-thiadiazoles, and twenty-seven 3-acyl-5-(2-amino-5-substituted)-2,2-dimethyl-2,3-dihydro-1,3,4-thiadiazoles were assigned completely using the concerted application of one-dimensional and two-dimensional experiments (DEPT, HMQC and HMBC). NOESY experiments, X-ray crystallography and conformational analysis confirm the preferred conformation of these compounds.

Characterization of 4,5-dihydro-1H-pyrazole derivatives by (13) C NMR spectroscopy.

The (13) C NMR resonances of 19 1-acyl-3-(2-nitro-5-substitutedphenyl)-4,5-dihydro-1H-pyrazoles, and 19 1-acyl-3-(2-amino-5-substituted)-4,5-dihydro-1H-pyrazoles, were completely assigned using the concerted application of one- and two-dimensional NMR experiments (DEPT, gs-HSQC and gs-HMBC).