Further SAR studies on bicyclic basic merbarone analogues as potent antiproliferative agents.

Pyrimidopyrimidine derivatives 1 were prepared as rigid thioanalogues of merbarone (a catalytic topoisomerase II inhibitor) and screened as antiproliferative agents against different tumor cell lines. A number of the synthesized compounds emerged as cytotoxic in cell-based assays (MT-4, HeLa and MCF-7 cells) at low micromolar concentrations. In a National Cancer Institute screening, selected member of the series showed a broad spectrum of antiproliferative activity against various tumours (melanoma, renal, CNS, colon and breast cancers).

Two novel GPER agonists induce gene expression changes and growth effects in cancer cells.

Although the action of estrogens has been traditionally explained by the binding to and transactivation of the nuclear estrogen receptor (ER)α and ERβ, recently the G protein-coupled receptor GPR30/GPER has been involved in the rapid estrogen signaling. We investigated the ability of two original molecules, which were named GPER-L1 and GPERL2, to bind to and activate the GPER transduction pathway in cancer cells. Competition assays, docking simulations, transfection experiments, real-time PCR, immunoblotting, gene silencing technology and growth assays were performed to ascertain the selective action of GPER-L1 and GPER-L2 in activating the GPER-mediated signaling.

Homology modeling in tandem with 3D-QSAR analyses: a computational approach to depict the agonist binding site of the human CB2 receptor.

CB2 receptor belongs to the large family of G-protein coupled receptors (GPCRs) controlling a wide variety of signal transduction. The recent crystallographic determination of human β2 adrenoreceptor and its high sequence similarity with human CB2 receptor (hCB2) prompted us to compute a theoretical model of hCB2 based also on β2 adrenoreceptor coordinates. This model has been employed to perform docking and molecular dynamic simulations on WIN-55,212-2 (CB2 agonist commonly used in binding experiments), in order to identify the putative CB2 receptor agonist binding site, followed by molecular docking studies on a series of indol-3-yl-tetramethylcyclopropyl ketone derivatives, a novel class of potent CB2 agonists.

Parallel synthesis of O-phenoxyethyl and O-adamantyl N-acyl thiocarbamates endowed with antiproliferative activity.

In order to further explore the antiproliferative properties of O-phenoxyethyl and O-adamantyl acylthiocarbamates (ATCs), a series of 14 derivatives was prepared by a parallel adaptation of a highly convergent one-pot three-step procedure. Ten acylthiocarbamates were selected by the National Cancer Institute drug evaluation program and screened against a panel of 55 to 58 cell lines derived from nine different types of human cancers. In general, the tested compounds showed a widespread micromolar activity with some specificity against leukemia, renal UO-31, central nervous system (CNS) SNB-75, and non-small cell lung HOP-92 cancer cell lines.

6-amino-4-oxo-1,3-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonyl derivatives as a new class of potent inhibitors of Interleukin-8-induced neutrophil chemotaxis.

A series of 6-amino-4-oxo-1,3-diphenyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonyl derivatives was synthesized. The compounds demonstrated to be novel, potent and selective inhibitors of Interleukin-8-induced human neutrophil chemotaxis. A SAR study was performed by varying the carbonyl function at position 5 and the chain linked to the amino group at position 6 of the scaffold.

Parallel synthesis, molecular modelling and further structure-activity relationship studies of new acylthiocarbamates as potent non-nucleoside HIV-1 reverse transcriptase inhibitors.

The structure-activity relationships (SARs) of acylthiocarbamates (ATCs), a new class of non-nucleoside HIV-1 reverse transcriptase inhibitors, have been expanded. Sixty-six new analogues were prepared by parallel solution-phase synthesis. In general, the potency of new ATCs was better than that of the first series and O-[2-phthalimidoethyl] 4-chlorophenyl(3-nitrobenzoyl) thiocarbamate turned out to be the most potent ATC so far synthesized (EC(50)=1.

Novel modifications in the series of O-(2-phthalimidoethyl)-N-substituted thiocarbamates and their ring-opened congeners as non-nucleoside HIV-1 reverse transcriptase inhibitors.

The structure-activity relationships (SARs) of N-aryl-O-(2-phthalimidoethyl)thiocarbamates (C-TCs) and their imide ring-opened congeners (O-TCs) as non-nucleoside HIV-1 reverse transcriptase inhibitors were further investigated. The SAR strategy involved modifications of the N-phenyl ring followed by the hybridization of the most promising N-aryl and O-(2-phthalimidoethyl) substructures. The role of stereochemistry and tert-butyl substitution of the phthalimidoethyl moiety on activity was also investigated.

N-acylated and N,N'-diacylated imidazolidine-2-thione derivatives and N,N'-diacylated tetrahydropyrimidine-2(1H)-thione analogues: synthesis and antiproliferative activity.

Fifty-one acylthioureas (ATUs) incorporating imidazolidine-2-thione or its upper cyclohomologue were prepared by parallel synthesis and evaluated against a high number of human cancer cell lines for antiproliferative activity. ATUs 1o (3,5-dichlorobenzoyl), 1s (2-furoyl), 3s (2-furoyl) and 1t (2-thenoyl) displayed activity against leukemia, melanoma LOX IMVI, non-small cell lung NCI-H522, renal 786-0, CAKI-1, SN12C, UO-31 and breast MCF7, MDA-MB-435, T-47D cancer cell lines in the 0.3-9.

Parallel one-pot synthesis and structure-activity relationship study of symmetric formimidoester disulfides as a novel class of potent non-nucleoside HIV-1 reverse transcriptase inhibitors.

The molecular duplication of non-nucleoside reverse transcriptase inhibitor (NNRTI) O-(2-phthalimidoethyl)-N-arylthiocarbamates (C-TCs) led to the identification of symmetric formimidoester disulfides (DSs) as a novel class of potent NNRTIs. The lead compound 1 [dimer of the isothiocarbamic form of TC O-(2-phthalimidoethyl)-N-phenylthiocarbamate] turned out to prevent the wild-type HIV-1 multiplication in MT-4 cell culture with an EC(50) value of 0.35 microM.

Rational design, synthesis and biological evaluation of new 1,5-diarylpyrazole derivatives as CB1 receptor antagonists, structurally related to rimonabant.

Among cannabinoid type-1 (CB(1)) receptor antagonists, those developed around the 1,5-diarylpyrazole scaffold of rimonabant (Acomplia are the most extensively investigated. In recent years, many SAR and QSAR reports on this topic have been published, focusing on the substitution and orientation of the N1 and C5 aryl functionalities and on the substituents at the 3-carboxamide position. In this context, the purpose of our study was to design and synthesize a set of 1-(2,4-dichlorophenyl)-5-arylpyrazoles strictly related to rimonabant, but with the hydrazide/amide group shifted from position 3 to position 4 of the pyrazole scaffold.

Thiocarbamates as non-nucleoside HIV-1 reverse transcriptase inhibitors. Part 2: Parallel synthesis, molecular modelling and structure-activity relationship studies on analogues of O-(2-phenylethyl)-N-phenylthiocarbamate.

To acquire further insight into the structure-activity relationship (SAR) of the thiocarbamates (TCs) described in the preceding work, 57 analogues of the lead compound O-(2-phenylethyl)-N-phenylthiocarbamate I were prepared by parallel solution-phase synthesis. We varied the 2-phenylethyl moiety (mono-substitution on the phenyl ring and modification of the ethyl linker), keeping constant the N-phenyl ring substitutions which have given the best results in the previous series. Most of the new TCs inhibited wild-type HIV-1 at micro- and nanomolar concentrations in MT-4 cell-based assays.

Thiocarbamates as non-nucleoside HIV-1 reverse transcriptase inhibitors. Part 1: Parallel synthesis, molecular modelling and structure-activity relationship studies on O-[2-(hetero)arylethyl]-N-phenylthiocarbamates.

In order to expand the structure-activity relationship (SAR) studies on Thiocarbamates (TCs), a recently discovered class of potent non-nucleoside HIV-1 reverse transcriptase inhibitors, 38 analogues of the lead O-[2-(2-pyridyl)ethyl]-N-phenylthiocarbamate 1 were prepared by parallel solution-phase synthesis. The SAR strategy was focused on the variation (mono- and disubstitution) of the N-phenyl ring and the replacement of the 2-pyridyl with 4-pyridyl, 2-thienyl and phenyl rings. The majority of the new TCs proved to prevent the wild-type HIV-1 multiplication in MT-4 cell culture and the most potent congeners displayed an EC(50) value of 100 nM.

Crystal structures of HIV-1 reverse transcriptase complexes with thiocarbamate non-nucleoside inhibitors.

O-Phthalimidoethyl-N-arylthiocarbamates (TCs) have been recently identified as a new class of potent HIV-1 reverse transcriptase (RT) non-nucleoside inhibitors (NNRTIs), by means of computer-aided drug design techniques [Ranise A. Spallarossa, S. Cesarini, F.

Identification of a novel pyrazolo[3,4-d]pyrimidine able to inhibit cell proliferation of a human osteogenic sarcoma in vitro and in a xenograft model in mice.

New pyrazolo[3,4-d]pyrimidines were synthesized and found to inhibit Src phosphorylation in a cell-free assay. Some of them significantly reduced the growth of human osteogenic sarcoma (SaOS-2) cells. The best compound, in terms of inhibitory properties toward both Src and SaOS-2 cells, was further investigated and found to reduce bone resorption when used to treat mouse osteoclasts, without interfering with normal osteoblast growth.

Synthesis and biological evaluation of N-pyrazolyl-N'-alkyl/benzyl/phenylureas: a new class of potent inhibitors of interleukin 8-induced neutrophil chemotaxis.

Neutrophils chemotaxis is a complex multistep process that, if upregulated, causes acute inflammation and a number of autoimmune diseases. We report here the synthesis of a new N-(4-substituted)pyrazolyl-N'-alkyl/benzyl/phenylureas that are potent inhibitors of interleukin-8 (IL8)-induced neutrophil chemotaxis. The first series of compounds, obtained by functionalization with a urea moiety of the 5-amino-1-(2-hydroxy-2-phenylethyl)-1H-pyrazole-4-carboxylic acid ethyl ester 3, blocked the IL8-induced neutrophil chemotaxis, while they did not block N-formylmethionylleucylphenylalanine-mediated chemotaxis.

2-Phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole derivatives: new potent inhibitors of fMLP-induced neutrophil chemotaxis.

It is well known that both acute and chronic autoimmune inflammatory disorders arise following a breakdown in control of neutrophil activation and recruitment. In the search for new anti-inflammatory agents, we synthesized some new 2-phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole derivatives and tested them in vitro in order to evaluate their ability to interfere with human neutrophil functions. All tested compounds showed strong inhibition of fMLP-OMe-induced chemotaxis, although they appeared unable to block degranulation and the fMLP-OMe-induced respiratory burst, and were inactive in binding experiments.

2-Amino/azido/hydrazino-5-alkoxy-5H-[1]benzopyrano[4,3-d]pyrimidines: synthesis and pharmacological evaluation.

New series of 5-alkoxy-benzopyranopyrimidine derivatives were developed from the chemical modulation of the substituent in position 2 of the scaffold, with the aim to produce analgesic/antiphlogistic agents more potent than analogues previously reported. The 2-hydrazino derivatives exhibited a good analgesic activity in writhing test; the analgesic doses of the compounds did not affect mice spontaneous locomotor activity thus any confounding sedative effect could be excluded. These derivatives revealed an aspirin-like profile with a strong inhibition of AA-induced platelet aggregation, probably due to a strong, non selective, inhibition of cyclooxygenases.

Pyrazolo[3,4-d]pyrimidines as potent antiproliferative and proapoptotic agents toward A431 and 8701-BC cells in culture via inhibition of c-Src phosphorylation.

We report here the synthesis of new pyrazolo[3,4-d]pyrimidine derivatives along with their biological properties as inhibitors of isolated Src and cell line proliferation (A431 and 8701-BC cells). Such compounds block the growth of cancer cells by interfering with the phosphorylation of Src, and they act as proapoptotic agents through the inhibition of the anti apoptotic gene BCL2. Several of them were found to be more active than the reference compound (1-(tert-butyl)-3-(4-chlorophenyl)-4-aminopyrazolo[3,4-d]pyrimidine, PP2) in inhibiting cell proliferation and in inducing apoptosis, and as active as PP2 in the inhibition of the phosphorylation of isolated Src.

New 1,3,4-thiadiazole derivatives endowed with analgesic and anti-inflammatory activities.

Two series of N-[5-oxo-4-(arylsulfonyl)-4,5-dihydro-1,3,4-thiadiazol-2-yl]-amides were synthesized and tested in vivo for their analgesic and anti-inflammatory activities. All the new compounds possess good antalgic action in the acetic acid writhing test and some terms of the series showed also fair anti-inflammatory activity in the carrageenan rat paw edema test. Ulcerogenic and irritative action on the gastrointestinal mucose, in comparison with indomethacin is low.

Synthesis and 3D QSAR of new pyrazolo[3,4-b]pyridines: potent and selective inhibitors of A1 adenosine receptors.

A number of 4-aminopyrazolo[3,4-b]pyridines 5-carboxylic acid esters (2-8) were synthesized and evaluated for their binding affinity at the A1, A2A, and A3 adenosine receptors (AR), in bovine cortical membranes, as well as for their affinity toward human A1AR (hA1AR). Some of the new compounds were characterized by a high affinity and selectivity toward the A1 receptor subtype, showing a significant improvement in comparison with other pyrazolo-pyridines previously reported in the literature. In particular the methyl ester 2h as well as the isopropyl ester 5h, both of them bearing a p-methoxyphenylethylamino side chain at the position 4, presented Ki values of 6 and 7 nM, respectively.

Affinity prediction on A1 adenosine receptor agonists: the chemometric approach.

In this paper, we are presenting a quantitative-structure-activity relationship (QSAR) study performed on 21 selective A(1) adenosine receptor agonists plus the endogenous substrate, adenosine, so as to identify those predictors which play a key role in describing the binding of the ligand with the A(1) receptor. A large number of molecular descriptors plus a calculated receptor-agonist binding energy and atomic charges were taken into account to derive different QSAR models, using different regression techniques. The results obtained both with linear and nonlinear approaches converge to the selection of the same informative parameters, highlighting the correlation of these descriptors with the biological Response.

Synthesis, antiplatelet and antithrombotic activities of new 2-substituted benzopyrano[4,3-d]pyrimidin-4-cycloamines and 4-amino/cycloamino-benzopyrano[4,3-d]pyrimidin-5-ones.

Atherothrombotic coronary artery disease, associated with deep vein thrombosis, is one of the most common causes of death worldwide. Recently, antiplatelet combination therapy using agents with different mechanisms of action, such as aspirin, dipyridamole, and thienopyridines, seems to be an attractive preventive approach. Moreover, several large, randomized clinical trials support combination therapy with aspirin plus warfarin in high-risk patients with atherosclerotic heart disease.

New pyrazolo[3,4-b]pyridones as selective A(1) adenosine receptor antagonists: synthesis, biological evaluation and molecular modelling studies.

A series of ethyl 4-amino-1-(2-chloro-2-phenylethyl)-6-oxo-6,7-dihydro-1H-pyrazolo[3,4-b]pyridine-5-carboxylates () has been synthesized as potential A(1) adenosine receptor (A(1) AR) ligands. Binding affinities of the new compounds were determined for adenosine A(1), A(2A) and A(3) receptors. Compounds and showed good affinity (K(i)= 299 nM and 517 nM, respectively) and selectivity towards A(1) AR, whereas showed good affinity for A(2A) AR (K(i)= 290 nM), higher than towards A(1) AR (K(i)= 1000 nM).

Structure-based design, parallel synthesis, structure-activity relationship, and molecular modeling studies of thiocarbamates, new potent non-nucleoside HIV-1 reverse transcriptase inhibitor isosteres of phenethylthiazolylthiourea derivatives.

In this paper we describe our structure-based ligand design, synthetic strategy, and structure-activity relationship (SAR) studies that led to the identification of thiocarbamates (TCs), a novel class of non-nucleoside reverse transcriptase inhibitors (NNRTIs), isosteres of phenethylthiazolylthiourea (PETT) derivatives. Assuming as a lead compound O-[2-(phthalimido)ethyl]phenylthiocarbamate 12, one of the precursors of the previously described acylthiocarbamates (Ranise, A.; et al.

Antiproliferative activity of new 1-aryl-4-amino-1H-pyrazolo[3,4-d]pyrimidine derivatives toward the human epidermoid carcinoma A431 cell line.

Synthesis and biological evaluation of a new class of 1-aryl-4-amino-1H-pyrazolo[3,4-d]pyrimidine derivatives are reported. A preliminary cellular assay system using the tumor cell line A431 responding to epidermal growth factor (EGF) for its growth, shows that the new compounds are potent inhibitors of cell growth. The inhibition of tumor cell proliferation is not associated with blockage of EGF receptor (EGFR), but substantially due to the interference with the signalling pathway at the level of Src tyrosine kinase and at the level of the downstream effector signal mitogen activated protein kinases (MAPKs), ERK1-2.