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Replicating the entire genome is one of the most complex tasks for all organisms. Research carried out in the last few years has provided us with a clearer picture on how cells preserve genomic information from the numerous insults that may endanger its stability. Different DNA repair pathways, coping with exogenous or endogenous threat, have been dissected at the molecular level. More recently, there has been an increasing interest towards intrinsic obstacles to genome replication, paving the way to a novel view on genomic stability. Indeed, in some cases, the movement of the replication fork can be hindered by the presence of stable DNA: RNA hybrids (R-loops), the folding of G-rich sequences into G-quadruplex structures (G4s) or repetitive elements present at Common Fragile Sites (CFS). Although differing in their nature and in the way they affect the replication fork, all of these obstacles are a source of replication stress. Replication stress is one of the main hallmarks of cancer and its prevention is becoming increasingly important as a target for future chemotherapeutics. Here we will try to summarize how these three obstacles are generated and how the cells handle replication stress upon their encounter. Finally, we will consider their role in cancer and their exploitation in current chemotherapeutic approaches.

The preparation and screening of antipyretic, anti-inflammatory, analgesic, gastroprotective and antiplatelet activities of original non-acidic aminobenzo-pyranopyrimidine derivatives are described. Major and dose-dependent analgesic and antipyretic properties were detected in all the compounds after oral administration (6.25-100 mg kg -1 ) in the mouse writhing test and in the E. coli lipopolysaccharide-induced fever in the rat, respectively. Unlike the reference drug Indometacin (ED 50 ulcer = 9.1 mg kg -1 ), no gastrolesivity was displayed by all the new compounds up to 150 mg kg -1 so that therapeutical indices equal or higher than that of Indometacin were calculated. Furthermore, at 100 mg kg -1 they were able to prevent ethanol-induced gastric mucosal injury in rats. At a 1 mmol/l concentration the compounds under study were as effective as acetylsalicylic acid in inhibiting in vitro platelet aggregation induced by adenosine diphosphate.

Some aliphatic and aromatic esters 2a–l were prepared starting from 5-aryl-1,2,4-triazoline-3-thiones bearing a 2-hydroxyethyl chain in position 2. The title compounds were evaluated for antipyretic and anti-inflammatory activities. Nearly all derivatives and in particular 2f , 2h , 2k exhibited antiphlogistic properties but were lacking in antipyretic activity.

In several non-infectious human diseases, such as ulcerous colitis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), the extravasal recruitment of neutrophils plays a crucial role in the development of tissue damage, which, when persistent, can lead to the irreversible organ dysfunction. The neutrophil activation is controlled by a number of intracellular pathways, particularly by a cAMP-dependent protein kinase A (PKA) which also acts on phosphodiesterase IV (PDE4) gene stimulating the synthesis of this enzyme, able to transform cAMP to inactive AMP. PDE4 inhibitors enhance intracellular cAMP and decrease inflammatory cell activation. Several 3-cyclopentyloxy-4-methoxybenzaldehyde and 3-cyclopentyloxy-4-methoxybenzoic acid derivatives were synthesized and studied by us to evaluate their ability to inhibit the superoxide anion production in human neutrophils. These compounds were found able to inhibit the neutrophil activation and some of them increased the cAMP level on tumor necrosis factor-alpha-stimulated neutrophils. Moreover, they also inhibited selectively the human PDE4 enzyme, although they are less potent than the reference compound Rolipram. We report here synthesis, biological studies and some SAR considerations concerning the above mentioned compounds.

Et3N-mediated condensation of preformed or in situ generated indole iminium salts with active methylene reagents provides stereoselectively Knoevenagel-type indoles in moderate to good yields.

Six series of N -acyl- N -phenyl ureas 1 – 6 of piperidine ( 1 ), and 2-ethyl- ( 2 ), 3-methyl- ( 3 ), 4-methyl- ( 4 ), 4-phenyl- ( 5 ), cis -2,6-dimethyl- ( 6 ) piperidine were synthesised and evaluated for their anti-inflammatory, anaesthetic, anti-pyretic properties. Some derivatives of series 1 and 5 were also assayed for anti-proliferative activity. Several compounds showed an anti-inflammatory activity comparable or slighty inferior to that of indomethacin in rats ( 1c , d , 2a , b , g , h , 3b , 4h , 5d , e ). Moreover, an appreciable anti-inflammatory activity was also found in 2c , e , 3e , f , g , 4g , 5a , b , c , f , h , and 6a , b , d . All the compounds were devoid of anti-pyretic activity and only a few of them exhibited a low level of infiltration anaesthesia in mice. Compound 5a showed a broad spectrum anti-cancer activity (at low micromolar concentrations), particulary significant against leukemia subpanel.

The preparation and the pharmacological screening of novel anti-aggregatory/antiphlogistic polycyclic pyrimidine derivatives are described. The compounds were developed starting from bioactive 2-aminobenzopyranopyrimidine derivatives in order to assess the importance of the benzopyrano[4,3-d]pyrimidine structure and the role of an amino basic moiety in position 2. Antiplatelet activity was assessed in vitro against ADP and arachidonic acid-induced aggregation in guinea-pig plasma. Anti-inflammatory/analgesic/antipyretic activities were studied in rat paw oedema, mouse writhing test and E. coli-induced rat fever. Ulcerogenic and gastroprotective effects were also investigated in vivo on rat gastric mucosa. Among the tested compounds, the 5-substituted benzopyranopyrimidine derivatives 3d and 4d proved to be the most active antiplatelet agents as potent as acetylsalicylic acid against arachidonic acid-stimulated aggregation. Furthermore the 2-methylthio derivative 4d was endowed with greater efficacy against ADP aggregation suggesting that additional non-TXA2 dependent mechanisms are involved in its biological activity. Orally administered at 100 mg kg(-1) in rats this latter compound displayed antiphlogistic acitivity comparable to indomethacin (10 mg kg(-1)) coupled with an unusual gastroprotective effect on ethanol-induced ulcers. In conclusion, these findings indicate that the 5-pyrrolidino-2-methylthiobenzopyrano[4,3-d]pyrimidine 4d fulfils the chemical requirements to exhibit antiplatelet activity associated with gastroprotective effect.

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.

A simple one-pot procedure for the stereoselective synthesis of Knoevenagel-type indoles is described. The method is based on the in situ reaction of indole iminium salts (four of them are fully characterized) with acyclic symmetrical and unsymmetrical active methylene reagents in the presence of triethylamine. In general, the overall yields are moderate to good. Some of relevant reaction parameters and steric effects affecting stereoselectivity are discussed.

The potassium salt 2 of 1,3,3-trimethyl-N-nitro-2-oxabicyclo[2.2.2]octan-6-imine 1 reacted with bromine in acetic acid solution to give (1S,4S,5S)-5-bromo-1,3,3-trimethyl-N-nitro-2-oxa-bicyclo[2.2.2]octan-6-imine 3. Bromination of the salt 2 in methanolic potassium hydroxide afforded a mixture of (1S,4S)-5,5-dibromo-1,3,3-trimethyl-N-nitro-2-oxabicyclo[2.2.2]octan-6E-and -6Z-imine 4 and 5, whose X-ray crystal-structure determinations allowed their absolute configurations to be established. Bromination of monobromide 3 under different conditions gave the dibromide 4, which was converted into isomer 5 by storage in chloroform solution. Nitrimine 3 reacted with hydroxylamine hydrochloride and sodium hydroxide or piperidine to give (1S,4S,5S)-5-bromo- and -5-hydroxyamino-N-hydroxy-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-imine or (1S,4S,5S)-N-hydroxy-1,3,3-trimethyl-5-(piperidin-1-yl)-2-oxabicyclo[2.2.2]octan-6-imine. Reaction of compound 3 with aliphatic and aromatic primary amines afforded N-substituted (1S,4S,5S)-5-bromo-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-imines. Reduction of compound 3 with sodium cyanoborohydride gave (1S,4S,5S)-5-bromo-1,3,3-trimethyl-N-mtro-2-oxabicyclo[2.2.2]octan-6-amine, whereas consecutive treatment with potassium hydroxide and aq. hydrochloric acid afforded the less stable isomer (1S,4S)-5-bromo-1,3,3-trimethyl-N-nitro-2-oxabicyclo[2.2.2]oct-5-en-6-amine.

The synthesis of 5-[[omega-(dialkylamino)alkoxy]methylene]-1,3,3-trimethyl-2- oxabicyclo[2.2.2]octan-6-ones by reaction of (+)-5-(hydroxymethylene)-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan- 6-one with a series of omega-(chloroalkyl)dialkylamines in the presence of potassium carbonate is described. Some compounds showed strong hypotensive, local anesthetic and antiarrhythmic activity in rats and mice, as well as moderate analgesic, antipyretic and in vitro platelet antiaggregating activity.

The synthesis in excellent yields of 2,3-dihydro-6-mercapto-1,3,5-triphenyl-2-thioxo-4(3H)-pyrimidinone 3 and 5-ethoxycarbonyl-2,3-dihydro-6-mercapto-1,3-diphenyl-2-thioxo-4(3H )- pyrimidinone 4 by reaction of methyl phenylacetate or diethyl malonate, respectively, with phenyl isothiocyanate (3 molar equivalents) and sodium hydride (2 molar equivalents) in DMF solution is described. Acylation of 3 and 4 with acyl chlorides gave, generally in satisfactory yields, 6-acylthio derivatives 13 and 14. Some of the above compounds showed a platelet antiaggregating activity in vitro superior or comparable to that of acetylsalicylic acid, as well as remarkable antiinflammatory, antiarrhythmic, local anesthetic and antihyperlipidemic activities in rats and in mice. Weak anticonvulsant and hypoglycemic activities were also detected.

The synthesis of novel 2-aryl-3-phenylamino-4,5-dihydro-2H-benz[g]indazoles 4a-f, starting from N-phenyl-3,4-dihydro-1(2H)-oxonaphthalene-2-carbothioamide and the proper arylhydrazines, is described. Title compounds were evaluated for antiinflammatory, analgesic, antipyretic, antiarrhythmic, hypotensive, local anaesthetic and platelet antiaggregating activities; some of them showed an appreciable antiarrhythmic activity in rats and a good level of infiltration anaesthesia in mice.

The title compounds were synthesized by cyclizing 3-dimethylaminomethylene-4-chromanone with creatine to give the acid 2 that was successively converted into the corresponding amides 3a-f via diphenylphosphorylazide and the relevant amines. The free acid 2 and some of 3a-f showed antiinflammatory, hypotensive and antiarrhythmic properties.

A series of 2-aryl-6-methyl-3-phenylamino-6,7-dihydropyrano[4,3-c]pyrazol-4(2H )-ones were prepared and tested for antiinflammatory, analgesic, antipyretic, antiarrhythmic, antihypertensive and platelet antiaggregating activities. All of them showed an appreciable level of analgesic activity in mice.

The synthesis of 6-thiosubstituted 5-ethoxycarbonyl-1,3-diphenyl-2-thioxo-2,3-dihydropyrimidin- 4(1H)-ones 3, and of 6-substituted 5-hydroxy-1,3-diphenyl-2,3-dihydrothieno[2,3-d]pyrimidin-4(1H)-ones 5 and their esters 6 is described. These derivatives were prepared in order to evaluate the influence on the pharmacological profile of alkyl substituents bearing polar/hydrophilic functionalities at an enethiol substructure as in compounds 3 or to assess the effects arising from the incorporation of the sulfur atom in a thiophene moiety as in thienopyrimidinones 5 and 6 in comparison with a series of 5-substituted 6-acylthio-1,3-diphenyl-2-thioxo-2,3-dihydropyrimidin-4(1H)-ones 1c,d, previously described. Preliminary screenings suggest that all tested compounds maintained or even increased the local anesthetic activity, but failed in the platelet antiaggregating activity; on the other hand, antiarrhythmic and antiinflammatory activity was preserved in some esters 6.

A series of 1,3,4-thiadiazol-2(3H)-ones (2a–j) with a nicotinoyl/isonicotinoyl group in position 3 and an aroylamino substituent in position 5 of the ring was prepared and evaluated for antipyretic and anti-inflammatory activities. All the title compounds and in particular 2e, 2i and 2j exhibited anti-inflammatory activity and were devoid of antipyretic properties.

A series of N -methyl- N -pyrimidin-2-yl glycines 2a–e , having the pyrimidine ring fused with a cyclohexane [ N -methyl- N -(5,6,7,8-tetrahydroquinazolin-2-yl)glycine], cyclohexene [ N -methyl- N -(5,6-dihydroquinazolin-2-yl)glycine], 1,2,3,4-tetrahydronaphthalene [ N -methyl- N -(5,6-dihydrobenzo[e]quinazolin-2-yl)glycine], benzopyrane [ N -methyl- N -(5-phenyl-5 H -[1]benzopyrano[4,3- d ]pyrimidin-2-yl)glycine] and benzothiopyrane [ N -methyl- N -(5 H -[1]benzothiopyrano[4,3- d ]pyrimidin-2-yl)glycine] ring, was prepared and tested for antiinflammatory activity. With the same purpose a number of N -5 H -[1]benzopyrano[4,3- d ]pyrimidin-2-yl substituted amino acids 3a–e , having a different chain length and branching were also synthesized and tested. All the described products 2 and 3 showed an appreciable antiphlogistic activity, particularly 2b and 2c .

A series of new 2,5-cycloamino-5 H -[1]benzopyrano[4,3- d ]pyrimidines 3a – i have been synthesized and tested in vivo for the anti-inflammatory/analgesic/antipyretic effects and in vitro to evaluate the antiplatelet activity on guinea-pig platelet-rich plasma aggregated by collagen, adenosine-5′-diphosphate (ADP) and arachidonic acid (AA). Title compounds were ineffective in vivo; however, the pyrrolidino derivatives 3a and 3c exhibited an antiplatelet activity against all the aggregants differing from that of acetylsalicylic acid (ASA) while the 5-morpholino derivatives 3g – i showed the most potent ASA-like antiplatelet activity.

The synthesis of a new family of A1-adenosine receptor (A1AR) ligands 3a–n has been performed in a straightforward way. Affinity data at A1AR, A2AAR and A3AR in bovine membranes show that these new compounds bind the A1AR in a selective way over A2AAR and A3AR and one of them (3j) presents a very high affinity, probably due to the phenethylamine substituent at C-4.

The structural simplification of the non-nucleoside reverse transcriptase inhibitors (NNRTIs) O-(2-phthalimidoethyl)-N-(hetero)aroyl-N-arylthiocarbamates led us to design (hetero)aroyl esters of 2-(N-phthalimido)ethanol as a potential new class of anti-HIV-1 agents. The setup of a solution-phase parallel synthesis method allowed the rapid preparation of a high number of analogues. In cell-based assays, 20 of 34 esters showed anti-HIV-1 activity ranging from nanomolar to micromolar concentrations. The most potent esters had only a minor effect or were ineffective in enzyme assay against HIV-1 reverse transcriptase. Variations on the O-(2-phthalimidoethyl) moiety led to compounds devoid of antiretroviral activity, but cytotoxic, in particular those bearing the 4-chloro-3-nitrobenzoyl moiety. The most cytotoxic compound displayed a CC50 value of 1.6 μM.

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 0.3-9.7 microM concentration range. Compound 14s exhibited selectivity for melanoma SK-MEL-5 (GI(50)

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. Seventy-six analogues were prepared by parallel solution-phase synthesis. Twenty-two C-TCs displayed nanomolar activity against wild-type HIV-1 and a number of analogues were effective against the Y181C mutant. Compound 56 combined the highest activity so far identified against Y181C (EC 50 = 1.3 μM) with good potency against the K103R mutant (EC 50 = 4.8 μM). Docking simulations helped to rationalize the SARs.

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 μM. In order to perform a structure–activity relationship (SAR) study, we prepared 40 analogues of 1 by an unprecedented one-pot method of solution-phase parallel synthesis. The SAR strategy was focused on the variation of the N -aryl portion (mono-, di- and trisubstitution of the phenyl ring and its replacement with a 1-naphthyl, cyclopropyl or benzyl group) and of the 2-phthalimidoethyl moiety (introduction of a methyl on the phthalimide substructure, replacement of the phthalimide moiety with a phenyl ring and elongation of the ethyl linker). Most DSs proved to inhibit the wild-type HIV-1 replication in cell-based assays and 15 of them were active at nanomolar concentrations. The most potent congeners ( 11 , 15 , 16 , 17 , 18 , 19 , 20 and 32 , EC 50 : 10–70 nM) shared the N - para -substituted phenyl moiety. Compound 17 tested in enzyme assay against recombinant wild-type reverse transcriptase displayed an IC 50 value of 0.74 μM. Compounds 19 and 33 were active at micromolar concentrations against the clinically relevant Y181C and/or K103R resistant mutants.

Among cannabinoid type-1 (CB1) 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. The synthesized compounds were evaluated in vitro for their affinity on human CB1 and CB2 (cannabinoid type-2) receptors. Computational studies, performed both in the design step and after biological assays, contributed to rationalize the obtained results in terms of specific molecular interactions between antagonists and the human CB1 receptor.

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. In spite of the inhibition of COX activity displayed in vitro, the compounds did not cause gastric damage in rats after acute oral administration. A different pharmacological profile was observed for the 2-azido derivatives, particularly in vivo.

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.

A facile stereoselective synthesis of Knoevenagel-type compounds 8 and 9 was accomplished through a one-pot two-step procedure. The reaction of ethylenethiourea ( 1) and ethyleneurea ( 2) with benzoyl chloride- N, N-dimethylformamide complex in N, N-dimethylformamide gave the corresponding isolable ternary N-methyleniminium chlorides 3 and 4, along with benzoic acid ( 5) as a byproduct. Hydrolysis of salts 3 and 4 yielded the N-formyl derivatives 6 and 7, thus confirming the N-methyleniminium structure. Salts 3 and 4 condensed in situ at 120 °C with a variety of acyclic active methylene reagents Y-CH 2 -Z (Y = or ≠ Z), in the presence of 5 (Procedure A) or of 5 and triethylamine (1.5 equiv) (Procedure B), afforded α,β-unsaturated compounds 8 and 9. The overall yields ranged from poor to good. Mechanistic hypotheses concerning the formation of 3 and 4 and the origin of the stereoselectivity are also discussed.

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. J. Med. Chem. 2003, 46, 768-781), two targeted solution-phase TC libraries were prepared by parallel synthesis. The lead optimization strategy led to para-substituted TCs 31, 33, 34, 39, 40, 41, 44, 45, and 50, which were active against wild-type HIV-1 in MT-4-based assays at nanomolar concentrations (EC50 range: 0.04-0.01 microM). The most potent congener 50 (EC50 = 0.01 microM) bears a methyl group at position 4 of the phthalimide moiety and a nitro group at the para position of the N-phenyl ring. Most of the TCs showed good selectivity indices, since no cytotoxic effect was detected at concentrations as high as 100 microM. TCs 31, 37, 39, 40, and 44 significantly reduced the multiplication of the Y181C mutant, but they were inactive against K103R and K103N + Y181C mutants. Nevertheless, the fold increase in resistance of 41 was not greater than that of efavirenz against the K103R mutant in enzyme assays. The docking model predictions were consistent with in vitro biological assays of the anti-HIV-1 activity of the TCs and related compounds synthesized.

In several non-infectious human diseases, such as ulcerous colitis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), the extravasal recruitment of neutrophils plays a crucial role in the development of tissue damage, which, when persistent, can lead to the irreversible organ dysfunction. The neutrophil activation is controlled by a number of intracellular pathways, particularly by a cAMP-dependent protein kinase A (PKA) which also acts on phosphodiesterase IV (PDE4) gene stimulating the synthesis of this enzyme, able to transform cAMP to inactive AMP. PDE4 inhibitors enhance intracellular cAMP and decrease inflammatory cell activation. Several 3-cyclopentyloxy-4-methoxybenzaldehyde and 3-cyclopentyloxy-4-methoxybenzoic acid derivatives were synthesized and studied by us to evaluate their ability to inhibit the superoxide anion production in human neutrophils. These compounds were found able to inhibit the neutrophil activation and some of them increased the cAMP level on tumor necrosis factor-alpha-stimulated neutrophils. Moreover, they also inhibited selectively the human PDE4 enzyme, although they are less potent than the reference compound Rolipram. We report here synthesis, biological studies and some SAR considerations concerning the above mentioned compounds.

Synthesis and pharmacological screening of new 2-methylthio/2-methanesulfonyl/2-methoxy-5H-[1]benzopyrano[4,3-d]pyrimidines were planned in order to study the effects of the 5-substitution with alkoxy/phenoxy/alkylthio and phenylthio groups both on in vitro antiplatelet and in vivo antinociceptive activities. Antiplatelet activity was assessed in vitro against ADP, Arachidonic acid and U46619 induced aggregation, in rabbit plasma. Anti-inflammatory, analgesic and antipyretic activities were tested in rat paw edema, mouse writhing test and LPS induced rat fever, respectively. Amongst test compounds, 2-methylthio derivatives displayed an ASA-like antiplatelet activity whereas 2-methoxy and, particularly, 2-methanesulfonyl derivatives showed a broad spectrum of antiplatelet action, inhibiting both the ADP- and the AA- and U46619-induced aggregation. With regard to the in vivo pharmacological activities, mainly the 2-methoxy derivatives showed a significant analgesic effect comparable to that of indomethacin. SAR considerations, also in comparison with a number of previously described compounds, were performed.

A new series of 4-amino-6-methylthio-1H-pyrazolo[3,4-d]pyrimidines (2a–m) bearing the 2-chloro-2-phenylethyl chain at the N1 position, has been synthesized. The affinity of these compounds for A1 adenosine receptor (A1AR) was measured. The compounds showed poor affinity. A more interesting result was obtained by 2a, 2d, 2g, which demonstrated inhibitory activity on cell proliferation of the A-431 cell line stimulated by epithelial growth factor (EGF) and on EGF receptor tyrosine kinase (EGFR-TK) phosphorylation.

Novel 1,4,6-trisubstituted pyrazolo[3,4-d]pyrimidines are reported with preliminary in vitro activity data indicating that several of them are potent inhibitors (better than the reference compound) of Src phosphorylation of the breast cancer cells 8701-BC, known to overexpress Src. The ability of such compounds to significantly reduce 8701-BC cell proliferation suggests that this scaffold could be a promising lead for the development of antitumoral agents able to block Src phosphorylation of breast cancer cells.

A series of 2-aryl-3-phenylamino-4,5-dihydro-2H-benz[g]indazoles was synthesized and tested for antiarrhythmic, local anaesthetic and analgesic activity. The title compounds showed a good antinociceptive activity.

A series of 2-methoxy-5H[1]benzopyrano[4,3-d]pyrimidin-5-amines were prepared and screened for their in vitro antiplatelet activity inducing the aggregation by ADP, arachidonic acid (AA) and collagen. In vivo experiments were performed in order to evaluate their antiphlogistic, analgesic and antipyretic activities. Title compounds showed antiplatelet activity in aggregation AA or collagen-induced, and a good analgesic activity without any gastric toxicity. Comparison with a number of analogue benzopyrano[4,3-d]pyrimidine derivatives and some SAR consideration were reported.

A novel series of O-[2-hydroxy-3-(dialkylamino)propyl]ethers of (+)-camphor oxime was prepared and tested for its cardiovascular, analgesic and anti-inflammatory properties. No significant anti-inflammatory and hypotensive activities were displayed by any of the compounds, whereas several of them are reasonably active as antiarrhythmic and analgesic agents.

A novel series of O-[2-hydroxy-3-(dialkylamino)propyl]ethers of (+)-camphor oxime was prepared and tested for its cardiovascular, analgesic and anti-inflammatory properties. No significant anti-inflammatory and hypotensive activities were displayed by any of the compounds, whereas several of them are reasonably active as antiarrhythmic and analgesic agents.

A series of new 2,5-cycloamino-5 H -[1]benzopyrano[4,3- d ]pyrimidines 3a – i have been synthesized and tested in vivo for the anti-inflammatory/analgesic/antipyretic effects and in vitro to evaluate the antiplatelet activity on guinea-pig platelet-rich plasma aggregated by collagen, adenosine-5′-diphosphate (ADP) and arachidonic acid (AA). Title compounds were ineffective in vivo; however, the pyrrolidino derivatives 3a and 3c exhibited an antiplatelet activity against all the aggregants differing from that of acetylsalicylic acid (ASA) while the 5-morpholino derivatives 3g – i showed the most potent ASA-like antiplatelet activity.

The synthesis of a new family of A1-adenosine receptor (A1AR) ligands 3a–n has been performed in a straightforward way. Affinity data at A1AR, A2AAR and A3AR in bovine membranes show that these new compounds bind the A1AR in a selective way over A2AAR and A3AR and one of them (3j) presents a very high affinity, probably due to the phenethylamine substituent at C-4.

A series of substituted 3-(arylamino)-4,5-dihydro-2H-benz[g]indazol-2-yl acetamides was synthesized and tested in comparison with former analogues. The title compounds showed only weak antiarrhythmic properties but good anti-inflammatory and antinociceptive activity, particularly evident in the morpholino derivative.

A series of N -methyl- N -pyrimidin-2-yl glycines 2a–e , having the pyrimidine ring fused with a cyclohexane [ N -methyl- N -(5,6,7,8-tetrahydroquinazolin-2-yl)glycine], cyclohexene [ N -methyl- N -(5,6-dihydroquinazolin-2-yl)glycine], 1,2,3,4-tetrahydronaphthalene [ N -methyl- N -(5,6-dihydrobenzo[e]quinazolin-2-yl)glycine], benzopyrane [ N -methyl- N -(5-phenyl-5 H -[1]benzopyrano[4,3- d ]pyrimidin-2-yl)glycine] and benzothiopyrane [ N -methyl- N -(5 H -[1]benzothiopyrano[4,3- d ]pyrimidin-2-yl)glycine] ring, was prepared and tested for antiinflammatory activity. With the same purpose a number of N -5 H -[1]benzopyrano[4,3- d ]pyrimidin-2-yl substituted amino acids 3a–e , having a different chain length and branching were also synthesized and tested. All the described products 2 and 3 showed an appreciable antiphlogistic activity, particularly 2b and 2c .