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ABSTRACT: Inosine monophosphate dehydrogenase (IMPDH), an NAD-dependent enzyme that controls de novo synthesis of guanine nucleotides, has received considerable interest in recent years as an important target enzyme, not only for the discovery of anticancer drugs, but also for antiviral, antiparasitic, and immunosuppressive chemotherapy. The field of IMPDH inhibitor research is highly important for providing potential therapeutics against a validated target for disease intervention. This patent review examines the chemical structures and biological activities of recently reported IMPDH inhibitors. Patent databases SciFinder and Espacenet and Delphion were used to locate patent applications that were published between January 2002 and July 2012, claiming chemical structures for use as IMPDH inhibitors. From 2002 to 2012, around 47 primary patent applications have claimed IMPDH inhibitors, which we analyzed by target and applicant. The level of newly published patent applications covering IMPDH inhibitors remains high and a diverse range of scaffolds has been claimed.
Recent patents on anti-cancer drug discovery. 05/2013; 8(2):103-125.
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Livio Luongo,
Riccardo Petrelli,
Luisa Gatta,
Catia Giordano,
Francesca Guida,
Patrizia Vita, Palmarisa Franchetti,
Mario Grifantini,
Vito de Novellis,
Loredana Cappellacci,
Sabatino Maione
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ABSTRACT: This study was undertaken in order to investigate the effect of chronic treatment with 5′-chloro-5′-deoxy-(±)-ENBA, a potent and highly selective agonist of human adenosine A(1) receptor, on thermal hyperalgesia and mechanical allodynia in a mouse model of neuropathic pain, the Spared Nerve Injury (SNI) of the sciatic nerve. Chronic systemic administration of 5′-chloro-5′-deoxy-(±)-ENBA (0.5 mg/kg, i.p.) reduced both mechanical allodynia and thermal hyperalgesia 3 and 7 days post-SNI, in a way prevented by DPCPX (3 mg/kg, i.p.), a selective A(1) adenosine receptor antagonist, without exerting any significant change on the motor coordination or arterial blood pressure. In addition, a single intraperitoneal injection of 5′-chloro-5′-deoxy-(±)-ENBA (0.5 mg/kg, i.p.) 7 days post-SNI also reduced both symptoms for at least two hours. SNI was associated with spinal changes in microglial activation ipsilaterally to the nerve injury. Activated, hypertrophic microglia were significantly reduced by 5′-chloro-5′-deoxy-(±)-ENBA chronic treatment. Our results demonstrated an involvement of adenosine A(1) receptor in the amplified nociceptive thresholds and in spinal glial and microglial changes occurred in neuropathic pain, without affecting motor coordination or blood pressure. Our data suggest a possible use of adenosine A(1) receptor agonist in neuropathic pain symptoms.
Molecules 01/2012; 17(12):13712-26. · 2.39 Impact Factor
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ABSTRACT: A series of N6-aminopurine-9-β-D-ribonucleosides and ribose-modified 3'-C-methyl analogues substituted at N6-position with a small group like hydroxy, methoxy or amino group or at C2(N6) position have been synthesized and tested against a panel of human leukemia and carcinoma cell lines. N6-Hydrazino-9-β-D-ribofuranosyl-purine (5) displayed the best antiproliferative activity in the low micromolar or submicromolar range against all tested tumor cell lines. The activity of this nucleoside is related in part to ribonucleotide reductase inhibition. C2-modification or 3'-C-methylation in N6-substituted adenosine analogues leads to a decrease or loss in activity.
European journal of medicinal chemistry 02/2011; 46(5):1499-504. · 3.27 Impact Factor
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Riccardo Petrelli,
Yuk Yin Sham,
Liqiang Chen,
Krzysztof Felczak,
Eric Bennett,
Daniel Wilson,
Courtney Aldrich,
Jose S Yu,
Loredana Cappellacci, Palmarisa Franchetti,
Mario Grifantini,
Francesca Mazzola,
Michele Di Stefano,
Giulio Magni,
Krzysztof W Pankiewicz
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ABSTRACT: Diadenosine disulfide (5) was reported to inhibit NAD kinase from Listeria monocytogenes and the crystal structure of the enzyme-inhibitor complex has been solved. We have synthesized tiazofurin adenosine disulfide (4) and the disulfide 5, and found that these compounds were moderate inhibitors of human NAD kinase (IC(50)=110 microM and IC(50)=87 microM, respectively) and Mycobacterium tuberculosis NAD kinase (IC(50)=80 microM and IC(50)=45 microM, respectively). We also found that NAD mimics with a short disulfide (-S-S-) moiety were able to bind in the folded (compact) conformation but not in the common extended conformation, which requires the presence of a longer pyrophosphate (-O-P-O-P-O-) linkage. Since majority of NAD-dependent enzymes bind NAD in the extended conformation, selective inhibition of NAD kinases by disulfide analogues has been observed. Introduction of bromine at the C8 of the adenine ring restricted the adenosine moiety of diadenosine disulfides to the syn conformation making it even more compact. The 8-bromoadenosine adenosine disulfide (14) and its di(8-bromoadenosine) analogue (15) were found to be the most potent inhibitors of human (IC(50)=6 microM) and mycobacterium NAD kinase (IC(50)=14-19 microM reported so far. None of the disulfide analogues showed inhibition of lactate-, and inosine monophosphate-dehydrogenase (IMPDH), enzymes that bind NAD in the extended conformation.
Bioorganic & medicinal chemistry 09/2009; 17(15):5656-64. · 2.82 Impact Factor
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Palmarisa Franchetti,
Loredana Cappellacci,
Patrizia Vita,
Riccardo Petrelli,
Antonio Lavecchia,
Sonja Kachler,
Karl-Norbert Klotz,
Ida Marabese,
Livio Luongo,
Sabatino Maione,
Mario Grifantini
Journal of Medicinal Chemistry 05/2009; · 4.80 Impact Factor
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Palmarisa Franchetti,
Loredana Cappellacci,
Patrizia Vita,
Riccardo Petrelli,
Antonio Lavecchia,
Sonja Kachler,
Karl-Norbert Klotz,
Ida Marabese,
Livio Luongo,
Sabatino Maione,
Mario Grifantini
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ABSTRACT: To further investigate new potent and selective human A1 adenosine receptor agonists, we have synthesized a series of 5′-chloro-5′-deoxy- and 5′-(2-fluorophenylthio)-5′-deoxy-N6-cycloalkyl(bicycloalkyl)-substituted adenosine and 2′-C-methyladenosine derivatives. These compounds were evaluated for affinity and efficacy at human A1, A2A, A2B, and A3 adenosine receptors. In the series of N6-cyclopentyl- and N6-(endo-norborn-2-yl)adenosine derivatives, 5′-chloro-5′-deoxy-CPA (1) and 5′-chloro-5′-deoxy-(±)-ENBA (3) displayed the highest affinity in the subnanomolar range and relevant selectivity for hA1 vs the other human receptor subtypes. The higher affinity and selectivity of 5′-chloro-5′-deoxyribonucleoside derivatives 1 and 3 for hA1 AR vs hA3 AR compared to that of the parent 5′-hydroxy compounds CPA and (±)-ENBA was rationalized by a molecular modeling analysis. 5′-Chloro-5′-deoxy-(±)-ENBA, evaluated for analgesic activity in the formalin test in mice, was found to inhibit the first or the second phases of the nocifensive response induced by intrapaw injection of formalin at doses ranging between 1 and 2 mg/kg i.p.
04/2009;
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ABSTRACT: A series of cycloalkyl, bicycloalkyl, aryl, and heteroaryl N (6)-substituted derivatives of the antitumor agent 3'- C-methyladenosine (3'-Me-Ado), an inhibitor of the alpha Rnr1 subunit of mammalian ribonucleotide reductase (RR), were synthesized. The cytotoxicity of these compounds was evaluated against a panel of human leukemia and carcinoma cell lines and compared to that of some corresponding N (6)-substituted adenosine analogues. N (6)-cycloalkyl-3'- C-methylribonucleosides 2- 7 and N (6)-phenyl analogue 8 were found to inhibit the proliferation of K562 leukemia cells. N (6)-(+/-)- endo-2-norbornyl-3'- C-methyladenosine ( 7) was found to be the most cytotoxic compound, with GI 50 values slightly higher than that of 3'-Me-Ado against K562 and carcinoma cell lines and 2.7 fold higher cytotoxicity against human promyelocytic leukemia HL-60 cells. The SAR study confirms that an unsubstituted N (6)-amino group is essential for optimal cytotoxicity of 3'-Me-Ado against both K562 and carcinoma cell lines. Computational studies, carried out on the eukaryotic alpha subunit (Rnr1) of RR from Saccharomyces cerevisiae were performed to rationalize the observed structure-activity relationships.
Journal of Medicinal Chemistry 08/2008; 51(14):4260-9. · 4.80 Impact Factor
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Hyojin Ko,
Rhonda L Carter,
Liesbet Cosyn,
Riccardo Petrelli,
Sonia de Castro,
Pedro Besada,
Yixing Zhou,
Loredana Cappellacci, Palmarisa Franchetti,
Mario Grifantini,
Serge Van Calenbergh,
T Kendall Harden,
Kenneth A Jacobson
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ABSTRACT: The phosphate, uracil, and ribose moieties of uracil nucleotides were varied structurally for evaluation of agonist activity at the human P2Y(2), P2Y(4), and P2Y(6) receptors. The 2-thio modification, found previously to enhance P2Y(2) receptor potency, could be combined with other favorable modifications to produce novel molecules that exhibit high potencies and receptor selectivities. Phosphonomethylene bridges introduced for stability in analogues of UDP, UTP, and uracil dinucleotides markedly reduced potency. Truncation of dinucleotide agonists of the P2Y(2) receptor, in the form of Up(4)-sugars, indicated that a terminal uracil ring is not essential for moderate potency at this receptor and that specific SAR patterns are observed at this distal end of the molecule. Key compounds reported in this study include 9, alpha,beta-methylene-UDP, a P2Y(6) receptor agonist; 30, Up(4)-phenyl ester and 34, Up(4)-[1]glucose, selective P2Y(2) receptor agonists; dihalomethylene phosphonate analogues 16 and 41, selective P2Y(2) receptor agonists; 43, the 2-thio analogue of INS37217 (P(1)-(uridine-5')-P(4)-(2'-deoxycytidine-5')tetraphosphate), a potent and selective P2Y(2) receptor agonist.
Bioorganic & medicinal chemistry 07/2008; 16(12):6319-32. · 2.82 Impact Factor
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ABSTRACT: A series of 5'-carbamoyl and 5'-thionocarbamoyl derivatives of 2'-C-methyl analogues of the A(1) adenosine receptor (A(1)AR) full agonists N(6)-cyclopentyladenosine (CPA), 2-chloro-N(6)-cyclopentyladenosine (CCPA), N(6)-[3-(R)-tetrahydrofuranyl]adenosine (tecadenoson), and 2-chloro analogue (2-Cl-tecadenoson) was synthesized and evaluated for their affinity for adenosine receptor subtypes from bovine, porcine, and human species. In the N(6)-cyclopentylamino series, the 5'-substituted derivatives showed a reduced affinity at the bovine A(1)AR compared to the parent compounds; however, the selectivity for A(1) versus A(2A) receptor was retained or increased. The corresponding N(6)-3-(R)-tetrahydrofuranylamino analogues displayed a very low affinity toward the bovine A(1)AR. The 5'-methylthionocarbamoyl derivative of 2'-Me-CCPA showed the best affinity at porcine A(1)AR with a K(i) value of 13 nM. At human AR subtypes tecadenoson derivatives showed 2.3- to 5-fold lower affinity at A(1)AR and very low affinity at the other subtypes (A(2A), A(2B), and A(3)) compared to the corresponding N(6)-cyclopentyl analogues. The 5'-carbamoyl and 5'-thionocarbamoyl derivatives of 2'-Me-CCPA 3, 4, 7 and tecadenoson derivative 12 were found to be partial A(1) agonists at the porcine receptor. Docking studies explained the lower affinity of N(6)-3-(R)-tetrahydrofuranyl-substituted compounds at bovine A(1)AR compared to that of N(6)-cyclopentyl analogues, showing that the oxygen of the tetrahydrofuranyl ring establishes unfavorable electrostatic interactions with the CO oxygen of Asn254. The low binding affinity of the 2'-C-methyl-N(6)-3-(R)-tetrahydrofuranyl adenosine analogues at human A(1)AR may be ascribed to the presence of unfavorable interactions between the hydrophilic tetrahydrofuranyl ring and the surrounding hydrophobic residues Leu250 (TM6) and Ile274 (TM7).
Bioorganic & medicinal chemistry 02/2008; 16(1):336-53. · 2.82 Impact Factor
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ABSTRACT: (i) To generate a new heterodinucleotide (3TCpPMPA) comprising the drugs lamivudine and tenofovir which have been shown to act synergistically and (ii) to protect macrophages from 'de novo' HIV-1-infection through its administration.
3TCpPMPA was obtained by coupling the morpholidate derivative of tenofovir with the mono n-tri-butylammonium salt of lamivudine 5'-monophosphate. Stability and metabolism were evaluated in vitro and in vivo in mice. 3TCpPMPA was encapsulated into autologous erythrocytes by a procedure of hypotonic dialysis, isotonic resealing and reannealing. 3TCpPMPA-loaded erythrocytes were modified to increase their phagocytosis by human macrophages. Macrophages were infected by HIV-1(Ba-L) and inhibition of HIV-1 replication was assessed by HIV p24(gag) quantification.
Pharmacokinetic studies in mice revealed a rapid disappearance of the heterodinucleotide from circulation (t(1/2)=15 min) without any advantage compared with the administration of single drugs. Adding free 3TCpPMPA to macrophages (18 h), a 90% inhibition of viral replication up to 35 days post-treatment was achieved, while only a 60% inhibition was obtained by the combined treatment 3TC and (R)PMPA. When 3TCpPMPA was selectively targeted to the macrophage compartment by a single addition of loaded erythrocytes, the protection of macrophages from 'de novo' infection (99% protection 3 weeks post-treatment) was nearly complete.
Erythrocytes loaded with 3TCpPMPA and modified to increase their phagocytosis are able to protect macrophages from 'de novo' HIV-1 infection. 3TCpPMPA acts as an efficient antiviral pro-drug that, once inside macrophages, can be slowly converted into 3TCMP and (R)PMPA protecting these cells for a longer period of time.
Journal of Antimicrobial Chemotherapy 05/2007; 59(4):666-75. · 5.07 Impact Factor
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ABSTRACT: Initial-rate and product inhibition studies revealed distinctive ordered ternary complex kinetic mechanisms, substrate specificities, and metal ion preferences for the three isozymes of human nicotinamide mononucleotide adenylyl-transferase (NMNAT, EC 2.7.7.1). ATP binds before NMN with nuclear isozyme NMNAT1 and Golgi apparatus NMNAT2, but the opposite order is observed with the mitochondrial isozyme NMNAT3. Only the latter utilizes ITP efficiently in place of ATP, and while NMNH conversion to NADH by NMNAT1 and NMNAT3 occurs at similar rates, conversion by NMNAT2 is much slower. These isozymes can also be discriminated by their action on tiazofurin monophosphate (TrMP), a metabolite of the antineoplastic prodrug tiazofurin. Our finding that TrMP is only a substrate with NMNAT1 and NMNAT3 reveals for the first time an organelle selectivity in the metabolism of this important drug. In search of additional ways to discriminate these isozymes, we synthesized and tested the P1-(nicotinamide/nicotinate-riboside-5')-Pn-(adenosine-5') dinucleotides Np3AD, Np4AD, and Nap4AD. In addition to being highly effective inhibitors, these multisubstrate geometric inhibitors gave inhibition patterns that are consistent with the aforementioned isozyme differences in substrate binding order. Distinctive differences in their substrate specificity and metal ion selectivity also permitted us to quantify individual isozyme contributions to NAD+ formation in human cell extracts.
Biochemistry 04/2007; 46(16):4912-22. · 3.42 Impact Factor
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ABSTRACT: New effective cytotoxic agents and combinations are urgently needed in cancer treatment. The enzyme inosine monophosphate dehydrogenase is a potentially useful target for drug development, since its activity has been shown to be amplified in malignant cells. Thiophenfurin, an inhibitor of the enzyme synthesized by us, is endowed with a significant apoptotic activity in promyelocytic leukaemia HL60 cells. Since retinoids were successfully employed in the treatment of patients with leukaemia, demonstrating significant differentiation-inducing and apoptotic effects, we carried out this study to evaluate the effects of the combination of thiophenfurin and several retinoid molecules, acting in different phases of the cell cycle in vitro. The results show that thiophenfurin is capable of eliciting significant S phase-specific antiproliferative effects in different sensitive and resistant cell lines with the IC50s ranging from 6.7 to 26 microM. When HL60 cells were treated with thiophenfurin in combination with retinoids, the effects on cell growth were additive or synergistic, depending on the kind of retinoid used and the sequence of treatment. In particular, we observed additive effects when the cells were exposed to thiophenfurin and all-transretinoic acid either simultaneously or sequentially. Instead, when the new heterocyclic retinoid isoxazole benzoic acid was used, synergism was obtained in the cells treated sequentially. The combination of thiophenfurin and isoxazole benzoic acid determined synergistic apoptotic effects through a mitochondrion-dependent mechanism, suggesting the possible usefulness of this combination in the treatment of leukaemia.
Oncology Reports 02/2007; 17(1):185-92. · 1.84 Impact Factor
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ABSTRACT: A series of adenosine derivatives substituted at the 1'-, 2'-, or 3'-position of the ribose ring with a methyl group was synthesized and evaluated for antitumor activity. From this study 3'-C-methyladenosine (3'-Me-Ado) emerged as the most active compound, showing activity against human myelogenous leukemia K562, multidrug resistant human leukemia K562IU, human promyelocytic leukemia HL-60, human colon carcinoma HT-29, and human breast carcinoma MCF-7 cell lines with IC(50) values ranging from 11 to 38 muM. Structure-activity relationship studies showed that the structure of 3'-Me-Ado is crucial for the activity. Substitution of a hydrogen atom of the N(6)-amino group with a small alkyl or cycloalkyl group, the introduction of a chlorine atom in the 2-position of the purine ring, or the moving of the methyl group from the 3'-position to other ribose positions brought about a decrease or loss of antitumor activity. The antiproliferative activity of 3'-Me-Ado appears to be related to its ability to deplete both intracellular purine and pyrimidine deoxynucleotides through ribonucleotide reductase inhibition.
Journal of Medicinal Chemistry 08/2005; 48(15):4983-9. · 5.25 Impact Factor
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Loredana Cappellacci, Palmarisa Franchetti,
Michela Pasqualini,
Riccardo Petrelli,
Patrizia Vita,
Antonio Lavecchia,
Ettore Novellino,
Barbara Costa,
Claudia Martini,
Karl-Norbert Klotz,
Mario Grifantini
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ABSTRACT: A number of 3'-C-methyl analogues of selective adenosine receptor agonists such as CPA, CHA, CCPA, 2'-Me-CCPA, NECA, and IB-MECA was synthesized to further investigate the subdomain of the receptor that binds the ribose moiety of the ligands. Affinity data at A(1), A(2A), and A(3) receptors in bovine brain membranes showed that the 3'-C-modification in adenosine resulted in a decrease of the affinity at all three receptor subtypes. When this modification was combined with N(6)-substitution with groups that induce high potency and selectivity at A(1) receptor, the affinity and selectivity were increased. However, all 3'-C-methyl derivatives proved to be very less active than the corresponding 2'-C-methyl analogues. The most active compound was found to be 3'-Me-CPA which displayed a K(i) value of 0.35 microM at A(1) receptor and a selectivity for A(1) vs A(2A) and A(3) receptors higher than 28-fold. 2'-Me-CCPA was confirmed to be the most selective, high affinity agonist so far known also at human A(1) receptor with a K(i) value of 3.3 nM and 2903- and 341-fold selective vs human A(2A) and A(3) receptors, respectively. In functional assay, 3'-Me-CPA, 3'-Me-CCPA, and 2-Cl-3'-Me-IB-MECA inhibited forskolin-stimulated adenylyl cyclase activity with IC(50) values ranging from 0.3 to 4.9 microM, acting as full agonists. A rhodopsin-based model of the bovine A(1)AR was built to rationalize the higher affinity and selectivity of 2'-C-methyl derivatives of N(6)-substituted-adenosine compared to that of 3'-C-methyl analogues. In the docking exploration, it was found that 2'-Me-CCPA was able to form a number of interactions with several polar residues in the transmembrane helices TM-3, TM-6, and TM-7 of bA(1)AR which were not preserved in the molecular dynamics simulation of 3'-Me-CCPA/bA(1)AR complex.
Journal of Medicinal Chemistry 04/2005; 48(5):1550-62. · 5.25 Impact Factor
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ABSTRACT: Thiazole-4-carboxamide adenine dinucleotide (TAD) analogues T-2'-MeAD (1) and T-3'-MeAD (2) containing, respectively, a methyl group at the ribose 2'-C-, and 3'-C-position of the adenosine moiety, were prepared as potential selective human inosine monophosphate dehydrogenase (IMPDH) type II inhibitors. The synthesis of heterodinucleotides was carried out by CDI-catalyzed coupling reaction of unprotected 2'-C-methyl- or 3'-C-methyl-adenosine 5'-monophosphate with 2',3'-O-isopropylidene-tiazofurin 5'-monophosphate, and then deisopropylidenation. Biological evaluation of dinucleotides 1 and 2 as inhibitors of recombinant human IMPDH type I and type II resulted in a good activity. Inhibition of both isoenzymes by T-2'-MeAD and T-3'-MeAD was noncompetitive with respect to NAD substrate. Binding of T-3'-MeAD was comparable to that of parent compound TAD, while T-2'-MeAD proved to be a weaker inhibitor. However, no significant difference was found in inhibition of the IMPDH isoenzymes. T-2'-MeAD and T-3'-MeAD were found to inhibit the growth of K562 cells (IC(50) 30.7 and 65.0muM, respectively).
Bioorganic & Medicinal Chemistry 04/2005; 13(6):2045-53. · 2.92 Impact Factor
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ABSTRACT: Synthesis, conformational analysis and antitumor evaluation of 2'- and 3'-C-methyl analogues of mizoribine (bredinine, 4-carbamoyl-1-beta-D-ribofuranosylimidazole-5-olate) are reported.
Nucleosides Nucleotides & Nucleic Acids 02/2005; 24(10-12):2023-7. · 0.90 Impact Factor
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ABSTRACT: NAD analogs modified at the ribose adenylyl moiety, named N-2'-MeAD and Na-2'-MeAD, were synthesized as ligands of pyridine nucleotide (NMN/NaMN) adenylyltransferase (NMNAT). Both dinucleotides resulted selective inhibitors against human NMNAT-3 isoenzyme.
Nucleosides Nucleotides & Nucleic Acids 02/2005; 24(5-7):477-9. · 0.90 Impact Factor
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ABSTRACT: The beta-anomers of N-ribofuranosylnicotine-3-carboxamide (beta-NAR) and its nicotinic acid analog (beta-NaR) were obtained by stereoselective synthesis via glycosylation of the presilylated bases under Vorbruggen's protocol. A NAR analog, methylated in position 3 of the ribosylic moiety, is also reported.
Bioorganic & Medicinal Chemistry Letters 10/2004; 14(18):4655-8. · 2.55 Impact Factor
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ABSTRACT: Tenofovir [9-(R)-2-(phosphonomethoxypropyl)adenine (PMPA)] and zidovudine [azidothymidine (AZT)] are potent anti-HIV agents that have shown a strong synergy in in vitro studies. In this paper we have investigated both the potentiality of this synergy in vivo and the possibility to administer AZT and PMPA simultaneously as a single drug AZTpPMPA. The pharmacokinetic studies reported here have shown that AZTpPMPA administered intraperitoneally in mice performs as a prodrug, providing a slow delivery of AZT and PMPA in circulation. C57BL/6 mice infected with the retroviral complex LP-BM5 were used to evaluate the efficacy of AZTpPMPA in inhibiting disease progression. Furthermore, the effectiveness of the heterodinucleotide was compared with that of AZT and PMPA, administered as single drugs, or as a combination (AZT plus PMPA). The results obtained showed that AZTpPMPA is able to reduce lymphoadenopathy (88%), splenomegaly (64%), lymph node BM5 proviral DNA content (49%) and hypergammaglobulinaemia (40%). However, upon AZT plus PMPA administration, similar (splenomegaly and lymphoadenopathy reduction) or better results (64% hypergammaglobulinaemia reduction and 75% lymph node BM5 proviral DNA content inhibition) were obtained. Furthermore, these results overlapped those obtained upon PMPA administration. Thus, no synergy between PMPA and AZT was observed in murine AIDS and administration of AZT does not improve the antiviral results obtained by PMPA administration.
Journal of Antimicrobial Chemotherapy 12/2002; 50(5):639-47. · 5.07 Impact Factor
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Luigia Rossi,
Sabrina Dominici,
Sonja Serafini,
Anna Casabianca,
Aurora Cerasi,
Laura Chiarantini,
Angela Gabriela Celeste,
Loredana Cappellacci, Palmarisa Franchetti,
Mario Grifantini,
Mauro Magnani
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ABSTRACT: 9-(2-Phosphonylmethoxyethyl)adenine (PMEA) is an antiviral drug with activity against herpes viruses, Epstein-Barr virus and retroviruses, including the human immunodeficiency virus. Unfortunately, oral PMEA administration, as required for long-term therapy, is hindered by its low bioavailability. In the present study, the synthesis, oral bioavailability and antiretroviral activity of a new prodrug of PMEA, consisting of two molecules of PMEA bound together by a P-O-P bond (Bis-PMEA), are reported. Pharmacokinetic experiments in mice showed that the oral bioavailabilities of PMEA following oral gavage of Bis-PMEA or PMEA (at a dose equivalent to 28 mg of PMEA/kg) were 50.8 and 13.5%, respectively. These results correlate with the antiviral efficacy of Bis-PMEA administered orally at a dose equivalent to 50 mg/kg of PMEA in C57 BL/6 mice infected with the retroviral complex LP-BM5. Oral treatment with Bis-PMEA proved to be more effective than oral treatment with PMEA given at equimolar doses. Moreover, oral Bis-PMEA was more effective than intraperitoneal PMEA (50 mg/kg) in reducing lymphoadenopathy, hypergammaglobulinaemia and lymph node proviral DNA content, overall in the first weeks post virus inoculation. Bis-PMEA thus appears to be an efficient oral prodrug of PMEA without significant toxicity, at least in this mouse model.
Journal of Antimicrobial Chemotherapy 10/2002; 50(3):365-74. · 5.07 Impact Factor
