1
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Lo MK, Amblard F, Flint M, Chatterjee P, Kasthuri M, Li C, Russell O, Verma K, Bassit L, Schinazi RF, Nichol ST, Spiropoulou CF. Potent in vitro activity of β-D-4'-chloromethyl-2'-deoxy-2'-fluorocytidine against Nipah virus. Antiviral Res 2020; 175:104712. [PMID: 31935422 PMCID: PMC7054849 DOI: 10.1016/j.antiviral.2020.104712] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 01/06/2020] [Accepted: 01/10/2020] [Indexed: 12/26/2022]
Abstract
Nipah virus (NiV) is a highly pathogenic zoonotic paramyxovirus that continues to cause outbreaks in humans characterized by high mortality and significant clinical sequelae in survivors. Currently, no therapeutics are approved for use in humans against NiV infection. Here, we report that 4'-chloromethyl-2'-deoxy-2'-fluorocytidine (ALS-8112) inhibits NiV. ALS-8112 is the parent nucleoside of lumicitabine, which has been evaluated in phase I and II clinical trials to treat pediatric and adult respiratory syncytial virus infection. In this study, we tested ALS-8112 against NiV and other major human respiratory pneumo- and paramyxoviruses in 2 human lung epithelial cell lines, and demonstrated the ability of ALS-8112 to reduce infectious wild-type NiV yield by over 6 orders of magnitude with no apparent cytotoxicity. However, further cytotoxicity testing in primary cells and bone marrow progenitor cells indicated cytotoxicity at higher concentrations of ALS-8112. Our results warrant the evaluation of lumicitabine against NiV infection in relevant animal models.
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Affiliation(s)
- Michael K Lo
- Viral Special Pathogens Branch, US Centers for Disease Control and Prevention, 1600 Clifton Road, Mailstop G-14, Atlanta, GA, 30329, USA.
| | - Franck Amblard
- Center for AIDS Research, Laboratory of Biochemical Pharmacology Emory University, Department of Pediatrics, 1760 Haygood Drive NE, Atlanta, GA, 30322, USA
| | - Mike Flint
- Viral Special Pathogens Branch, US Centers for Disease Control and Prevention, 1600 Clifton Road, Mailstop G-14, Atlanta, GA, 30329, USA
| | - Payel Chatterjee
- Viral Special Pathogens Branch, US Centers for Disease Control and Prevention, 1600 Clifton Road, Mailstop G-14, Atlanta, GA, 30329, USA
| | - Mahesh Kasthuri
- Center for AIDS Research, Laboratory of Biochemical Pharmacology Emory University, Department of Pediatrics, 1760 Haygood Drive NE, Atlanta, GA, 30322, USA
| | - Chengwei Li
- Center for AIDS Research, Laboratory of Biochemical Pharmacology Emory University, Department of Pediatrics, 1760 Haygood Drive NE, Atlanta, GA, 30322, USA
| | - Olivia Russell
- Center for AIDS Research, Laboratory of Biochemical Pharmacology Emory University, Department of Pediatrics, 1760 Haygood Drive NE, Atlanta, GA, 30322, USA
| | - Kiran Verma
- Center for AIDS Research, Laboratory of Biochemical Pharmacology Emory University, Department of Pediatrics, 1760 Haygood Drive NE, Atlanta, GA, 30322, USA
| | - Leda Bassit
- Center for AIDS Research, Laboratory of Biochemical Pharmacology Emory University, Department of Pediatrics, 1760 Haygood Drive NE, Atlanta, GA, 30322, USA
| | - Raymond F Schinazi
- Center for AIDS Research, Laboratory of Biochemical Pharmacology Emory University, Department of Pediatrics, 1760 Haygood Drive NE, Atlanta, GA, 30322, USA
| | - Stuart T Nichol
- Viral Special Pathogens Branch, US Centers for Disease Control and Prevention, 1600 Clifton Road, Mailstop G-14, Atlanta, GA, 30329, USA
| | - Christina F Spiropoulou
- Viral Special Pathogens Branch, US Centers for Disease Control and Prevention, 1600 Clifton Road, Mailstop G-14, Atlanta, GA, 30329, USA.
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2
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Yoshimura Y, Saito Y, Natori Y, Wakamatsu H. Synthesis of 4'-Thionucleosides as Antitumor and Antiviral Agents. Chem Pharm Bull (Tokyo) 2018; 66:139-146. [PMID: 29386464 DOI: 10.1248/cpb.c17-00636] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Many attempts have been made to synthesize structurally novel nucleoside derivatives in order to identify effective compounds for the treatment of tumors and virus-caused disease. At our laboratories, as part of our efforts to synthesize 4'-thionucleosides, we have identified and characterized biologically active nucleosides. During the course of our synthetic study, we developed the Pummerer-type thioglycosylation reaction. As a result, we synthesized a potent antineoplastic nucleoside, 1-(2-deoxy-2-fluoro-β-D-4-thio-arabino-furanosyl)cytosine (4'-thioFAC), and several novel 4'-thionucleosides that possess antiherpes virus activities.
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Affiliation(s)
- Yuichi Yoshimura
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University
| | - Yukako Saito
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University
| | - Yoshihiro Natori
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University
| | - Hideaki Wakamatsu
- Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University
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3
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Yoshimura Y. Development of a Glycosylation Reaction: A Key to Accessing Structurally Unique Nucleosides. HETEROCYCLES 2017. [DOI: 10.3987/rev-17-865] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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van Roey P, Pangborn WA, Schinazi RF, Painter G, Liotta DC. Absolute Configuration of the Antiviral Agent (−)-cis-5-Fluoro-1-[2-Hydroxymethyl)-1,3-Oxathiolan-5-yl]Cytosine. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029300400609] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The structure and absolute configuration of (−)- cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine (FTC), has been determined by X-ray crystallographic analysis. The results confirm that the L-isomer of the nucleoside analogue is the most active enantiomer and that the correct absolute configuration of (−)-FTC is 5-fluoro-(2′R,5′S)-(−)-1-[2-hydroxymethyl)oxathiolan-5-yl]-fluorocytosine. The two molecules in the asymmetric unit show conformations that combine conformational features of two other classes of potent antiviral nucleosides. Both oxathiolane rings have the 3′-sulphur atom in nearly perfect S3′- exo envelope conformations, similar to what is observed for 3′-azido-3′-deoxythymidine (AZT) and 2′,3′-dideoxycytidine. One of the two molecules has a glycosylic link conformation in which the base is eclipsed with the C5′-O1′ bond. This mimics the high- anti conformation that has been observed in the structures of several 2′,3′-didehydro-2′,3′-dideoxypyrimidine nucleosides but is inaccessible for saturated pyrimidine nucleosides. However, the observed conformations cannot be superimposed adequately with other active antiviral nucleosides to suggest a common ‘active site’ conformation.
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Affiliation(s)
- P. van Roey
- Medical Foundation of Buffalo, Buffalo, NY 14203, USA
| | | | - R. F. Schinazi
- Veterans Affairs Medical Center, Decatur, GA 30033, USA
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - G. Painter
- Division of Virology, Burroughs Wellcome Co., Research Triangle Park, NC 27709, USA
| | - D. C. Liotta
- Departmeni of Chemistry, Emory University, Atlanta, GA 30322, USA
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5
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Furman PA, Wilson JE, Reardon JE, Painter GR. The Effect of Absolute Configuration on the Anti-HIV and Anti-HBV Activity of Nucleoside Analogues. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029500600601] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This review concerns the effect of stereoisomerism on the selective activity of anti-HIV and anti-HBV nucleoside analogues. The synthesis of a number of nucleoside analogues with anti-HIV and anti-HBV activity yields mixtures of 1-β-D and 1-β-L stereoisomers. Anti-HIV and anti-HBV activity is associated primarily with one of the two enantiomers and the more potent activity does not always reside with the 1-β-D configuration characteristic of natural nucleosides. In the case of HIV, the origin of this stereoselectivity appears to be the result of differential metabolism of the analogues and not due to differential inhibition of the target enzyme; the HIV reverse transcriptase. However, mutations at position 184 of the HIV-RT does result in stereoselective inhibition of the enzyme. On the other hand, with HBV, there is also a stereoselective inhibition of the HBV DNA polymerase, where the 5′-triphosphate of the 1-β-L enantiomer is the more potent inhibitor.
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Affiliation(s)
- P. A. Furman
- Triangle Pharmaceuticals Inc., 1829 East Franklin St., Building 1000, Suite 1005, Chapel Hill, N.C., 27514, USA
| | - J. E. Wilson
- Division of Biochemistry, 3030 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - J. E. Reardon
- Division of Biochemistry, 3030 Cornwallis Road, Research Triangle Park, NC 27709, USA
| | - G. R. Painter
- Virology, Burroughs Wellcome Co., 3030 Cornwallis Road, Research Triangle Park, NC 27709, USA
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6
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Nucleoside Analogue Inhibitors of Human Immunodeficiency Virus Reverse Transcriptase. Antiviral Res 2014. [DOI: 10.1128/9781555815493.ch4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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7
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Inhibition of hepatitis C virus replicon RNA synthesis by PSI-352938, a cyclic phosphate prodrug of β-D-2'-deoxy-2'-α-fluoro-2'-β-C-methylguanosine. Antimicrob Agents Chemother 2011; 55:2566-75. [PMID: 21444700 DOI: 10.1128/aac.00032-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PSI-352938 is a novel cyclic phosphate prodrug of β-D-2'-deoxy-2'-α-fluoro-2'-β-C-methylguanosine 5'-monophosphate that has potent activity against hepatitis C virus (HCV) in vitro. The studies described here characterize the in vitro anti-HCV activity of PSI-352938, alone and in combination with other inhibitors of HCV, and the cross-resistance profile of PSI-352938. The effective concentration required to achieve 50% inhibition for PSI-352938, determined using genotype 1a-, 1b-, and 2a-derived replicons stably expressed in the Lunet cell line, were 0.20, 0.13, and 0.14 μM, respectively. The active 5'-triphosphate metabolite, PSI-352666, inhibited recombinant NS5B polymerase from genotypes 1 to 4 with comparable 50% inhibitory concentrations. In contrast, PSI-352938 did not inhibit the replication of hepatitis B virus or human immunodeficiency virus in vitro. PSI-352666 did not significantly affect the activity of human DNA and RNA polymerases. PSI-352938 and its cyclic phosphate metabolites did not affect the cyclic GMP-mediated activation of protein kinase G. Clearance studies using replicon cells demonstrated that PSI-352938 cleared cells of HCV replicon RNA and prevented replicon rebound. An additive to synergistic effect was observed when PSI-352938 was combined with other classes of HCV inhibitors, including alpha interferon, ribavirin, NS3/4A inhibitors, an NS5A inhibitor, and nucleoside/nucleotide and nonnucleoside inhibitors. Cross-resistance studies showed that PSI-352938 remained fully active against replicons containing the S282T or the S96T/N142T amino acid alteration. Replicons that contain mutations conferring resistance to various classes of nonnucleoside inhibitors also remained sensitive to inhibition by PSI-352938. PSI-352938 is currently being evaluated in a phase I clinical study in genotype 1-infected individuals.
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8
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Strauch S, Jantratid E, Dressman JB, Junginger HE, Kopp S, Midha KK, Shah VP, Stavchansky S, Barends DM. Biowaiver monographs for immediate release solid oral dosage forms: lamivudine. J Pharm Sci 2011; 100:2054-63. [PMID: 21491435 DOI: 10.1002/jps.22449] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 11/25/2010] [Accepted: 11/26/2010] [Indexed: 11/07/2022]
Abstract
Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing lamivudine as the only active pharmaceutical ingredient were reviewed. The solubility and permeability data of lamivudine as well as its therapeutic index, its pharmacokinetic properties, data indicating excipient interactions, and reported BE/bioavailability (BA) studies were taken into consideration. Lamivudine is highly soluble, but its permeability characteristics are not well-defined. Reported BA values in adults ranged from 82% to 88%. Therefore, lamivudine is assigned to the biopharmaceutics classification system (BCS) class III, noting that its permeability characteristics are near the border of BCS class I. Lamivudine is not a narrow therapeutic index drug. Provided that (a) the test product contains only excipients present in lamivudine IR solid oral drug products approved in the International Conference on Harmonization or associated countries in usual amounts and (b) the test product as well as the comparator product fulfills the BCS dissolution criteria for very rapidly dissolving; a biowaiver can be recommended for new lamivudine multisource IR products and major post-approval changes of marketed drug products.
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Affiliation(s)
- S Strauch
- Institute of Pharmaceutical Technology, Goethe University, Frankfurt am Main, Germany
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9
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Sofia MJ, Bao D, Chang W, Du J, Nagarathnam D, Rachakonda S, Reddy PG, Ross BS, Wang P, Zhang HR, Bansal S, Espiritu C, Keilman M, Lam AM, Steuer HMM, Niu C, Otto MJ, Furman PA. Discovery of a β-d-2′-Deoxy-2′-α-fluoro-2′-β-C-methyluridine Nucleotide Prodrug (PSI-7977) for the Treatment of Hepatitis C Virus. J Med Chem 2010; 53:7202-18. [DOI: 10.1021/jm100863x] [Citation(s) in RCA: 481] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Michael J. Sofia
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Donghui Bao
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Wonsuk Chang
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Jinfa Du
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | | | - Suguna Rachakonda
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - P. Ganapati Reddy
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Bruce S. Ross
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Peiyuan Wang
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Hai-Ren Zhang
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Shalini Bansal
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | | | - Meg Keilman
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Angela M. Lam
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | | | - Congrong Niu
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Michael J. Otto
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
| | - Phillip A. Furman
- Pharmasset, Inc., 303A College Road East, Princeton, New Jersey 08540
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10
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PSI-7851, a pronucleotide of beta-D-2'-deoxy-2'-fluoro-2'-C-methyluridine monophosphate, is a potent and pan-genotype inhibitor of hepatitis C virus replication. Antimicrob Agents Chemother 2010; 54:3187-96. [PMID: 20516278 DOI: 10.1128/aac.00399-10] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The hepatitis C virus (HCV) NS5B RNA polymerase facilitates the RNA synthesis step during the HCV replication cycle. Nucleoside analogs targeting the NS5B provide an attractive approach to treating HCV infections because of their high barrier to resistance and pan-genotype activity. PSI-7851, a pronucleotide of beta-D-2'-deoxy-2'-fluoro-2'-C-methyluridine-5'-monophosphate, is a highly active nucleotide analog inhibitor of HCV for which a phase 1b multiple ascending dose study of genotype 1-infected individuals was recently completed (M. Rodriguez-Torres, E. Lawitz, S. Flach, J. M. Denning, E. Albanis, W. T. Symonds, and M. M. Berry, Abstr. 60th Annu. Meet. Am. Assoc. Study Liver Dis., abstr. LB17, 2009). The studies described here characterize the in vitro antiviral activity and cytotoxicity profile of PSI-7851. The 50% effective concentration for PSI-7851 against the genotype 1b replicon was determined to be 0.075+/-0.050 microM (mean+/-standard deviation). PSI-7851 was similarly effective against replicons derived from genotypes 1a, 1b, and 2a and the genotype 1a and 2a infectious virus systems. The active triphosphate, PSI-7409, inhibited recombinant NS5B polymerases from genotypes 1 to 4 with comparable 50% inhibitory concentrations. PSI-7851 is a specific HCV inhibitor, as it lacks antiviral activity against other closely related and unrelated viruses. PSI-7409 also lacked any significant activity against cellular DNA and RNA polymerases. No cytotoxicity, mitochondrial toxicity, or bone marrow toxicity was associated with PSI-7851 at the highest concentration tested (100 microM). Cross-resistance studies using replicon mutants conferring resistance to modified nucleoside analogs showed that PSI-7851 was less active against the S282T replicon mutant, whereas cells expressing a replicon containing the S96T/N142T mutation remained fully susceptible to PSI-7851. Clearance studies using replicon cells demonstrated that PSI-7851 was able to clear cells of HCV replicon RNA and prevent viral rebound.
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11
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Stuyver LJ, McBrayer TR, Tharnish PM, Clark J, Hollecker L, Lostia S, Nachman T, Grier J, Bennett MA, Xie MY, Schinazi RF, Morrey JD, Julander JL, Furman PA, Otto MJ. Inhibition of hepatitis C replicon RNA synthesis by beta-D-2'-deoxy-2'-fluoro-2'-C-methylcytidine: a specific inhibitor of hepatitis C virus replication. Antivir Chem Chemother 2006; 17:79-87. [PMID: 17042329 DOI: 10.1177/095632020601700203] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
beta-D-2'-Deoxy-2'-fluoro-2'-C-methylcytidine (PSI-6130) is a cytidine analogue with potent and selective anti-hepatitis C virus (HCV) activity in the subgenomic HCV replicon assay, 90% effective concentration (EC90)=4.6 +/- 2.0 microM. The spectrum of activity and cytotoxicity profile of PSI-6130 was evaluated against a diverse panel of viruses and cell types, and against two additional HCV-1b replicons. The S282T mutation, which confers resistance to 2'-C-methyl adenosine and other 2'-methylated nucleosides, showed only a 6.5-fold increase in EC90. When assayed for activity against bovine diarrhoea virus (BVDV), which is typically used as a surrogate assay to identify compounds active against HCV, PSI-6130 showed no anti-BVDV activity. Weak antiviral activity was noted against other flaviviruses, including West Nile virus, Dengue type 2, and yellow fever virus. These results indicate that PSI-6130 is a specific inhibitor of HCV. PSI-6130 showed little or no cytotoxicity against various cell types, including human peripheral blood mononuclear and human bone marrow progenitor cells. No mitochondrial toxicity was observed with PSI-6130. The reduced activity against the RdRp S282T mutant suggests that PSI-6130 is an inhibitor of replicon RNA synthesis. Finally, the no-effect dose for mice treated intraperitoneally with PSI-6130 for six consecutive days was > or =100 mg/kg per day.
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12
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Zhang W, Mauldin JK, Schmiedt CW, Brockus CW, Boudinot FD, McCrackin SMA. Pharmacokinetics of lamivudine in cats. Am J Vet Res 2004; 65:841-6. [PMID: 15198226 DOI: 10.2460/ajvr.2004.65.841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Objective—To characterize the pharmacokinetics of
lamivudine (3TC) in cats.
Animals—6 sexually intact 9-month-old barrier-reared
domestic shorthair cats.
Procedure—Cats were randomly alloted into 3
groups, and lamivudine (25 mg/kg) was administered
IV, intragastrically (IG), and PO in a 3-way crossover
study design with 2-week washout periods between
experiments. Plasma samples were collected for 12
hours after drug administration, and lamivudine concentrations
were determined by high-performance liquid
chromatography. Maximum plasma concentrations
(Cmax), time to reach Cmax (Tmax), and bioavailability
were compared between IG and PO routes.
Area under the curve (AUC) and terminal phase halflife
(t½) among the 3 administration routes were also
compared.
Results—Plasma concentrations of lamivudine
declined rapidly with a t½ of 1.9 ± 0.21 hours, 2.6 ±
0.66 hours, and 2.7 ± 1.50 hours after IV, IG, and PO
administration, respectively. Total body clearance and
steady-state volume of distribution were 0.22 ± 0.09
L/h/kg and 0.60 ± 0.22 L/kg, respectively. Mean Tmax
for IG administration (0.5 hours) was significantly
shorter than Tmax for PO administration (1.1 hours).
The AUC after IV, IG, and PO administration was 130
± 55.2 mg·h/L, 115 ± 97.5 mg·h/L, and 106 ± 94.9
mg·h/L, respectively. Lamivudine was well absorbed
after IG and PO administration with bioavailability values
of 88 ± 45% and 80 ± 52%, respectively.
Conclusions and Clinical Relevance—Cats had a
shorter t½ but slower total clearance of lamivudine,
compared with humans. Plasma concentrations of
lamivudine were maintained above the minimum
effective concentration for inhibiting FIV replication by
50% (0.14µM [0.032 µg/mL] for wild-type FIV clinical
isolate) for at least 12 hours after IV, IG, or PO administration.
(Am J Vet Res 2004;65:841–846)
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Affiliation(s)
- Weijiang Zhang
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, GA 30602-7390, USA
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Sood RK, Bhadti VS, Fattom AI, Naso RB, Korba BE, Kern ER, Chen HM, Hosmane RS. Novel ring-expanded nucleoside analogs exhibit potent and selective inhibition of hepatitis B virus replication in cultured human hepatoblastoma cells. Antiviral Res 2002; 53:159-64. [PMID: 11750942 DOI: 10.1016/s0166-3542(01)00204-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Novel ring-expanded nucleoside (REN) analogs (1-3) containing 5:7 fused ring systems as the heterocyclic base were found to be potent and selective inhibitors of hepatitis B virus (HBV) replication in cultured human hepatoblastoma 2.2.15 cells. The most active compound, 6-amino-4,5-dihydro-8H-1-(beta-D-ribofuranosyl)imidazo[4,5-e][1,3]diazepine-4,8-dione (1), inhibited the synthesis of intracellular HBV replication intermediates and extracellular virion release in 2.2.15 cells with 50% effective concentration (EC50) of 0.604 and 0.131 microM, respectively. All three compounds had no effect on the synthesis of viral ribonucleic acids (RNA) in 2.2.15 cells. These compounds also exhibited low cellular toxicity in stationary and rapidly growing cell systems.
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Affiliation(s)
- Ramesh K Sood
- W.W. Karakawa Microbial Pathogenesis Laboratory, Nabi, Rockville, MD 20852, USA
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14
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Rybak RJ, Hartline CB, Qiu YL, Zemlicka J, Harden E, Marshall G, Sommadossi JP, Kern ER. In vitro activities of methylenecyclopropane analogues of nucleosides and their phosphoralaninate prodrugs against cytomegalovirus and other herpesvirus infections. Antimicrob Agents Chemother 2000; 44:1506-11. [PMID: 10817700 PMCID: PMC89904 DOI: 10.1128/aac.44.6.1506-1511.2000] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human cytomegalovirus (HCMV) infection does not generally cause problems in the immunocompetent adult but can result in severe clinical disease in the fetus, neonate, and immunocompromised host. Ganciclovir (GCV), the agent currently used to treat most HCMV infections, has resulted in much therapeutic success; however, efficacy remains suboptimal. Therefore, there is still a need to develop new compounds for use against HCMV infections. In the present study, several Z- and E-series methylenecyclopropane analogues and their phosphoroalaninate prodrugs were tested initially for activity against HCMV, strain AD169, and murine cytomegalovirus (MCMV) in vitro. Many were found to exhibit efficacy comparable to that of GCV against HCMV in plaque assays and were active against MCMV as well. The compounds were also tested for efficacy against herpes simplex virus types 1 and 2, varicella-zoster virus, and Epstein-Barr virus, and some had levels of activity that were comparable to that of acyclovir. In addition, the compounds synguanol (QYL-438) and 2-amino-6-cyclopropylamino analogue (QYL-769) were chosen for further evaluation and were found to be effective against additional laboratory and clinical isolates of HCMV and GCV-resistant isolates. QYL-438 and QYL-769 were found to be nontoxic in human and mouse fibroblasts and were considerably less toxic than GCV in granulocyte macrophage CFUs and erythroid burst-forming units. These results provide evidence for the high activity of some of these methylenecyclopropane analogues against various herpesviruses, particularly HCMV, in tissue culture and suggest that further evaluation is warranted to determine their potential for use in future clinical studies.
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Affiliation(s)
- R J Rybak
- University of Alabama School of Medicine, Birmingham, Alabama, USA
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15
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Mourier NS, Eleuteri A, Hurwitz SJ, Tharnish PM, Schinazi RF. Enantioselective synthesis and biological evaluation of 5-o-carboranyl pyrimidine nucleosides. Bioorg Med Chem 1999; 7:2759-66. [PMID: 10658581 DOI: 10.1016/s0968-0896(99)00222-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Base-modified carborane-containing nucleosides such as 5-o-carboranyl-2'-deoxyuridine (CDU) when combined with neutrons have potential for the treatment of certain malignancies. Lack of toxicity in various cells, high accumulation in cancer cells and intracellular phosphorylation are desirable characteristics for modified nucleosides used in boron neutron capture therapy (BNCT) for brain tumors and other malignancies. The aim of this work was to synthesize the two beta-enantiomers of several 5-o-carboranyl-containing nucleosides. These derivatives may possess favorable properties such as high lipophilicity, high transportability, the ability to be phosphorylated, and resistance to catabolism. Beta-isomers of 2',3'-dihydroxynucleosides and analogues containing a heteroatom in the sugar moiety were also synthesized. Carboranyl pyrimidine nucleosides were prepared either from the parent beta-D-nucleoside, beta-L-nucleoside, or by a coupling reaction. The dioxolane derivative 7 was prepared by a coupling reaction between protected 5-o-carboranyluracil (8, CU) and the corresponding protected heterocycle. Specific catalysts were used during the N-glycosylation process to favor the formation of the beta-isomer. Biological evaluation of these new chiral 5-o-carboranyl pyrimidine derivatives indicated that most of these compounds have low toxicity in a variety of normal and malignant cells and achieved high cellular levels in a lymphoblastoid cell line. Increasing the number of hydroxyl groups on the sugar moiety decreased the cellular accumulation and serum binding to different extents. Five compounds were identified for further biological evaluation as potential agents for BNCT.
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Affiliation(s)
- N S Mourier
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
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Weitzel T, Plettenberg A, Albrecht D, Lorenzen T, Stoehr A. Severe anemia as a newly recognized side-effect caused by lamivudine. AIDS 1999; 13:2309-11. [PMID: 10563721 DOI: 10.1097/00002030-199911120-00018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Martin LT, Cretton-Scott E, Schinazi RF, Zhou XJ, McClure HM, Mathe C, Gosselin G, Imbach JL, Sommadossi JP. Pharmacokinetics of beta-L-2',3'-dideoxy-5-fluorocytidine in rhesus monkeys. Antimicrob Agents Chemother 1999; 43:920-4. [PMID: 10103200 PMCID: PMC89226 DOI: 10.1128/aac.43.4.920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/1997] [Accepted: 01/02/1999] [Indexed: 11/20/2022] Open
Abstract
beta-L-2',3'-Dideoxy-5-fluorocytidine (beta-L-FddC), a novel cytidine analog with an unnatural beta-L sugar configuration, has been demonstrated by our group and others to exhibit highly selective in vitro activity against human immunodeficiency virus types 1 and 2 and hepatitis B virus. This encouraging in vitro antiviral activity prompted us to assess its pharmacokinetics in rhesus monkeys. Three monkeys were administered an intravenous dose of [3H] beta-L-FddC at 5 mg/kg of body weight. Following a 3-month washout period, an equivalent oral dose was administered. Plasma and urine samples were collected at various times for up to 24 h after dosing, and drug levels were quantitated by high-pressure liquid chromatography. Pharmacokinetic parameters were obtained on the basis of a two-compartment open model with a first-order elimination from the central compartment. After intravenous administration, the mean peak concentration in plasma (Cmax) was 29.8 +/- 10.5 microM. Total clearance, steady-state volume of distribution, terminal-phase plasma half-life (t1/2 beta), and mean residence time were 0.7 +/- 0.1 liters/h/kg, 1.3 +/- 0.1 liters/kg, 1.8 +/- 0.2 h, and 1.9 +/- 0.2 h, respectively. Approximately 47% +/- 16% of the intravenously administered radioactivity was recovered in the urine as the unchanged drug with no apparent metabolites. beta-L-FddC exhibited a Cmax of 3.2 microM after oral administration, with a time to peak drug concentration of approximately 1.5 h and a t1/2 of 2.2 h. One monkey in the oral administration arm of the study had a significant delay in the absorption of the aqueous administered dose. The absolute bioavailability of orally administered beta-L-FddC ranged from 56 to 66%.
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Affiliation(s)
- L T Martin
- Department of Clinical Pharmacology, University of Alabama, Birmingham 35294, USA
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18
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Abstract
Lamivudine (3TC), the negative enantiomer of 2'-deoxy-3'-thiacytidine, is a dideoxynucleoside analogue used in combination with other agents in the treatment of human immunodeficiency virus type 1 (HIV-1) infection and as monotherapy in the treatment of hepatitis B virus (HBV) infection. Lamivudine undergoes anabolic phosphorylation by intracellular kinases to form lamivudine 5'-triphosphate, the active anabolite which prevents HIV-1 and HBV replication by competitively inhibiting viral reverse transcriptase and terminating proviral DNA chain extension. The pharmacokinetics of lamivudine are similar in patients with HIV-1 or HBV infection, and healthy volunteers. The drug is rapidly absorbed after oral administration, with maximum serum concentrations usually attained 0.5 to 1.5 hours after the dose. The absolute bioavailability is approximately 82 and 68% in adults and children, respectively. Lamivudine systemic exposure, as measured by the area under the serum drug concentration-time curve (AUC), is not altered when it is administered with food. Lamivudine is widely distributed into total body fluid, the mean apparent volume of distribution (Vd) being approximately 1.3 L/kg following intravenous administration. In pregnant women, lamivudine concentrations in maternal serum, amniotic fluid, umbilical cord and neonatal serum are comparable, indicating that the drug diffuses freely across the placenta. In postpartum women lamivudine is secreted into breast milk. The concentration of lamivudine in cerebrospinal fluid (CSF) is low to modest, being 4 to 8% of serum concentrations in adults and 9 to 17% of serum concentrations in children measured at 2 to 4 hours after the dose. In patients with normal renal function, about 5% of the parent compound is metabolised to the trans-sulphoxide metabolite, which is pharmacologically inactive. In patients with renal impairment, the amount of trans-sulphoxide metabolite recovered in the urine increases, presumably as a function of the decreased lamivudine elimination. As approximately 70% of an oral dose is eliminated renally as unchanged drug, the dose needs to be reduced in patients with renal insufficiency. Hepatic impairment does not affect the pharmacokinetics of lamivudine. Systemic clearance following single intravenous doses averages 20 to 25 L/h (approximately 0.3 L/h/kg). The dominant elimination half-life of lamivudine is approximately 5 to 7 hours, and the in vitro intracellular half-life of its active 5'-triphosphate anabolite is 10.5 to 15.5 hours and 17 to 19 hours in HIV-1 and HBV cell lines, respectively. Drug interaction studies have shown that trimethoprim increases the AUC and decreases the renal clearance of lamivudine, although lamivudine does not affect the disposition of trimethoprim. Other studies have demonstrated no significant interaction between lamivudine and zidovudine or between lamivudine and interferon-alpha-2b. There is limited potential for drug-drug interactions with compounds that are metabolised and/or highly protein bound.
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Affiliation(s)
- M A Johnson
- Glaxo Wellcome Research and Development, Greenford, England.
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19
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Affiliation(s)
- P Wang
- Center for Drug Discovery, Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, Athens 30602-2352, USA
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20
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Mueller BU, Lewis LL, Yuen GJ, Farley M, Keller A, Church JA, Goldsmith JC, Venzon DJ, Rubin M, Pizzo PA, Balis FM. Serum and cerebrospinal fluid pharmacokinetics of intravenous and oral lamivudine in human immunodeficiency virus-infected children. Antimicrob Agents Chemother 1998; 42:3187-92. [PMID: 9835513 PMCID: PMC106021 DOI: 10.1128/aac.42.12.3187] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We studied the pharmacokinetics of intravenously and orally administered lamivudine at six dose levels ranging from 0.5 to 10 mg/kg of body weight in 52 children with human immunodeficiency virus infection. A two-compartment model with first-order elimination from the central compartment was simultaneously fitted to the serum drug concentration-time data obtained after intravenous and oral administration. The maximal concentration at the end of the 1-h intravenous infusion and the area under the concentration-time curve after oral and intravenous administration increased proportionally with the dose. The mean clearance of lamivudine (+/- standard deviation) in the children was 0.53 +/- 0.19 liter/kg/h (229 +/- 77 ml/min/m2 of body surface area), and the mean half-lives at the distribution and elimination phases were 0.23 +/- 0.18 and 2.2 +/- 2.1 h, respectively. Clearance was age dependent when normalized to body weight but age independent when normalized to body surface area. Lamivudine was rapidly absorbed after oral administration, and 66% +/- 25% of the oral dose was absorbed. Serum lamivudine concentrations were maintained above 1 microM for >/=8 h of 24 h on the twice daily oral dosing schedule with doses of >/=2 mg/kg. The cerebrospinal fluid drug concentration measured 2 to 4 h after the dose was 12% (range, 0 to 46%) of the simultaneously measured serum drug concentration. A limited-sampling strategy was developed to estimate the area under the concentration-time curve for concentrations in serum at 2 and 6 h.
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Affiliation(s)
- B U Mueller
- Pediatric Branch and Biostatistics and Data Management Section, National Cancer Institute, Bethesda, Maryland, USA.
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21
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Solas C, Li YF, Xie MY, Sommadossi JP, Zhou XJ. Intracellular nucleotides of (-)-2',3'-deoxy-3'-thiacytidine in peripheral blood mononuclear cells of a patient infected with human immunodeficiency virus. Antimicrob Agents Chemother 1998; 42:2989-95. [PMID: 9797238 PMCID: PMC105978 DOI: 10.1128/aac.42.11.2989] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/1998] [Accepted: 08/12/1998] [Indexed: 11/20/2022] Open
Abstract
An analytical methodology was developed to quantitate the intracellular nucleotides including mono-, di-, and triphosphates and the diphosphocholine derivative of (-)-2', 3'-deoxy-3'-thiacytidine (3TC) in human peripheral blood mononuclear cells (PBMCs). The procedure includes the resolution of 3TC nucleotides by solid-phase extraction (SPE) on an anion-exchange cartridge, with subsequent enzyme digestion of the resulting phosphates to the parent drug that is ultimately quantitated by high-performance liquid chromatography with UV detection (HPLC-UV). Validation was performed with PBMCs from healthy donors exposed to [3H]3TC, leading to the formation of intracellular nucleotides that were quantitated by anion-exchange HPLC with radioactive detection (HPLC-RA). These nucleotide levels served as reference values and were used for cross-validation with data obtained by HPLC-UV. An excellent correlation was established between the results obtained by HPLC-RA and those obtained by HPLC-UV, with a slope of the regression lines close to unity and intercepts near nullity as well as a correlation coefficient close to unity for all 3TC phosphates. The assay was characterized by a limit of quantitation below 1 ng (amount on column) with a precision (percentage of coefficient of variation of repeated measurement) ranging from 0.8 to 18.1% and an accuracy (deviation of the amount determined by HPLC-UV from the nominal reference value) varying from -14.8 to 19.4%. This methodology was successfully applied to determine the quantity of 3TC nucleotides in PBMCs of a patient infected with human immunodeficiency virus after oral administration of 3TC and stavudine.
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Affiliation(s)
- C Solas
- Department of Clinical Pharmacology, The Liver Center, Center for AIDS Research, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA
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22
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Balzarini J, Pelemans H, Riess G, Roesner M, Winkler I, De Clercq E, Kleim JP. Retention of marked sensitivity to (S)-4-isopropoxycarbonyl-6-methoxy-3-(methylthiomethyl)-3,4-di hydroquin oxaline-2(1H)-thione (HBY 097) by an azidothymidine (AZT)-resistant human immunodeficiency virus type 1 (HIV-1) strain subcultured in the combined presence of quinoxaline HBY 097 and 2',3'-dideoxy-3'-thiacytidine (lamivudine). Biochem Pharmacol 1998; 55:617-25. [PMID: 9515572 DOI: 10.1016/s0006-2952(97)00506-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
An azidothymidine (AZT)-resistant virus strain (HIV-1/AZT) (containing the 67 Asp --> Asn, 70 Lys --> Arg, 215 Thr --> Phe and 219 Lys --> Gln mutations into its reverse transcriptase) was grown in the combined presence of 2',3'-dideoxy-3'-thiacytidine (3TC, lamivudine) and the nonnucleoside reverse transcriptase inhibitor (S)-4-isopropoxycarbonyl-6-methoxy-3-(methylthiomethyl)-3,4-dih ydroquinoxaine-2(1H)-thione (quinoxaline HBY 097). Replication of HIV-1/AZT was inhibited to a significantly greater extent by the combination of 3TC and quinoxaline HBY 097 than by either drug alone. Virus breakthrough was markedly delayed in the combined presence of 3TC and HBY 097 at drug concentrations as low as 0.05 microg/mL and 0.0025 microg/mL, respectively. The virus that was recovered after exposure to the compounds (3TC and HBY 097) individually had acquired, in the genetic AZT-resistance background of HIV-1/AZT, 103 Lys --> Glu and 106 Val --> Ala mutations. The 103 Lys --> Glu mutation had not been observed before. However, both virus mutants retained marked sensitivity to HBY 097. In all cases, the genotypic AZT-resistance mutations were maintained in the mutant virus RT genomes, and the viruses also remained phenotypically resistant to AZT. Given the exquisite potency of a concomitant combination of 3TC and HBY 097 in suppressing virus replication, this drug combination should be further pursued in clinical trials in HIV-1-infected individuals.
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Affiliation(s)
- J Balzarini
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium.
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23
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Revankar GR, Ojwang JO, Mustain SD, Rando RF, De Clercq E, Huffman JH, Drach JC, Sommadossi JP, Lewis AF. Thiazolo[4,5-d]pyrimidines. Part II. Synthesis and anti-human cytomegalovirus activity in vitro of certain acyclonucleosides and acyclonucleotides derived from the guanine analogue 5-aminothiazolo[4,5-d]pyrimidine-2,7(3H,6H)-dione. Antivir Chem Chemother 1998; 9:53-63. [PMID: 9875377 DOI: 10.1177/095632029800900102] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The synthesis and in vitro antiviral activity of certain hydroxyalkoxymethyl, hydroxyalkyl, hydroxyalkenyl and phosphonoalkenyl derivatives of the guanine congener 5-aminothiazolo[4,5-d]pyrimidine-2,7(3H,6H)-dione are reported. The compounds of this study were selected for their structural similarity to acyclonucleosides with known anti-herpesvirus activity. 5-Amino-3-[(Z)-4-hydroxy-2-buten-1-yl]thiazolo[4,5-d]pyrimidine-2, 7(3H,6H)- dione was the only member of the series to display significant in vitro activity against human cytomegalovirus (HCMV); however, this compound did not inhibit other herpesviruses, human immunodeficiency virus type 1 or murine cytomegalovirus. It was found to have a cytotoxicity profile similar to that of ganciclovir (DHPG). The antiviral effect was found to be sensitive to the initial viral input and the time of addition during the virus replication cycle. Significantly, the compound was found to have equal anti-HCMV activity, against standard virus strains, to DHPG, but also showed potent activity against DHPG-resistant virus strains, except for a strain mutated in the UL97 (phosphotransferase) gene.
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Affiliation(s)
- G R Revankar
- Aronex Pharmaceuticals, Woodlands, TX 77381-4223, USA
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24
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Rahn JJ, Kieller DM, Tyrrell DL, Gati WP. Modulation of the metabolism of beta-L-(-)-2',3'-dideoxy-3'-thiacytidine by thymidine, fludarabine, and nitrobenzylthioinosine. Antimicrob Agents Chemother 1997; 41:918-23. [PMID: 9145844 PMCID: PMC163825 DOI: 10.1128/aac.41.5.918] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
beta-L-(-)-2',3'-Dideoxy-3'-thiacytidine (3TC) is a cytosine nucleoside analog that potently inhibits the replication of human and duck hepatitis B viruses and human immunodeficiency virus through the activity of its 5'-triphosphate ester metabolite. The present study examined the intracellular decay of 3TC 5'-phosphates and tested strategies for modulating the cellular content of those nucleotides in primary cultures of duck hepatocytes and in human hepatoma 2.2.15 cells and CCRF-CEM T lymphoblasts. Inhibition by deoxycytidine of the 5'-phosphorylation of 3TC in duck hepatocytes confirmed that, as in mammalian cells, deoxycytidine kinase catalyzed 3TC activation. The 5'-mono, 5'-di-, and 5'-triphosphates of 3TC underwent monoexponential elimination from duck hepatocytes and 2.2.15 cells (half-lives, 3.6 to 8.0 h). Thymidine and fludarabine, which are agents that enhance the activity of deoxycytidine kinase, were tested in strategies for increasing the cellular content of 3TC 5'-phosphates. Coordinate treatment of cells with 3TC and thymidine (50 microM) increased the content of 3TC 5'-monophosphate in duck hepatocytes and the content of 3TC 5'-di- and 5'-triphosphates in 2.2.15 cells, but enhancement of 3TC 5'-phosphate levels in CCRF-CEM cells required a higher thymidine concentration (100 microM). Fludarabine (5 microM) did not affect the contents of 3TC 5'-di- and 5'-triphosphates in duck hepatocytes, but modestly increased the contents of those nucleotides in 2.2.15 cells and CCRF-CEM cells. Nitrobenzylthioinosine (NBMPR), an inhibitor of the es facilitated diffusion nucleoside transporter, reduced the level of entry of 3TC into 2.2.15 cells and abolished inward fluxes of thymidine, adenosine, and deoxycytidine. In 2.2.15 cells and CCRF-CEM cells, NBMPR reduced the formation of 3TC 5'-di- and 5'-triphosphates and reversed the thymidine- and fludarabine-induced increases in the formation of those nucleotides. NBMPR protected against the cytotoxicity of 3TC in CCRF-CEM cells, whereas thymidine potentiated that toxicity, apparently by enhancing the formation of 3TC 5'-triphosphate. Taken together, these results indicate that deoxycytidine kinase and the es nucleoside transporter are targets for manipulation of the metabolism and activity of 3TC.
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Affiliation(s)
- J J Rahn
- Department of Pharmacology, University of Alberta, Edmonton, Canada
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25
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Zhou XJ, Sommadossi JP. Rapid quantitation of (-)-2'-deoxy-3'-thiacytidine in human serum by high-performance liquid chromatography with ultraviolet detection. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 691:417-24. [PMID: 9174279 DOI: 10.1016/s0378-4347(96)00467-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A rapid, sensitive and specific high-performance liquid chromatographic (HPLC) assay was developed and validated for the measurement of (-)-2'-deoxy-3'-thiacytidine (3TC) in human serum. The method included precipitation of serum proteins by trichloroacetic acid (20%, w/v) treatment followed by centrifugation. The resulting supernatant was directly injected and 3TC was isocratically chromatographed on a reversed-phase C18 column using a mixture of phosphate buffer and methanol (88.3:11.7. v/v) and monitored at 280 nm. The limit of quantitation was 20 ng/ml using 100 microl of serum. The standard curve was linear within the range of 20-10,000 ng/ml. Replicate analysis of three quality control samples (40-1500 ng/ml) led to satisfactory intra- and inter-assay precision (coefficient of variation from 3.0 to 12.9%) and accuracy (deviation from 6.3 to 9.7%). Moreover, sample treatment processes including human immunodeficiency virus (HIV) heat-inactivation, exposure at room temperature and freezing-thawing cycles did not influence the stability of the analyte. This assay was successfully applied to the determination of 3TC serum levels in HIV-infected patients. In addition, preliminary results indicated that this procedure may also be extended to the measurement of 3TC in human plasma and urine.
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Affiliation(s)
- X J Zhou
- Department of Pharmacology and Toxicology, Center for AIDS Research, University of Alabama at Birmingham, 35294-0019, USA
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26
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Martin LT, Faraj A, Schinazi RF, Gosselin G, Mathe C, Imbach JL, Sommadossi JP. Effect of stereoisomerism on the cellular pharmacology of beta-enantiomers of cytidine analogs in Hep-G2 cells. Biochem Pharmacol 1997; 53:75-87. [PMID: 8960066 DOI: 10.1016/s0006-2952(96)00653-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The beta-L enantiomers of 2',3'-dideoxycytidine (beta-L-ddC) and its 5-fuoro derivative, 2',3'-dideoxy-5-fluorocytidine (beta-L-FddC), were demonstrated to be active against human immunodeficiency virus (HIV) and hepatitis B virus (HBV) replication in vitro. In the present study, we investigated the cellular pharmacology of beta-L-ddC and beta-L-FddC and compared it with that of beta-D-2',3'-dideoxy-5-fluorocytidine (beta-D-FddC). Beta-L-FddC (10 microM) was found to be phosphorylated rapidly in Hep-G2 cells to its 5'-mono-, di-, and triphosphate derivatives with intracellular triphosphate levels achieving 26.6 +/- 10.9 pmol/10(6) cells after 72 hr. In contrast, the active 5'-phosphorylated derivative of beta-D-FddC achieved lower levels with triphosphate levels of only 2.3 +/- 0.5 pmol/ (10(6) cells under the same conditions. Beta-L-ddC was also phosphorylated rapidly. A 5'-diphosphocholine (18 +/- 5.8 pmol/10(6) cells) and a 5'-diphosphoethanolamine (13.6 +/- 0.9 pmol/10(6) cells) derivative were detected in beta-D-FddC-treated cells after 72 hr, whereas in beta-L-FddC- and beta-L-ddC-treated cells, only the 5'-diphosphocholine derivative (10.9 +/- 2.8 and 60.4 +/- 5.7 pmol/10(6) cells, respectively) was detected. Beta-L-FddC-5'-triphosphate (beta-L-FddCTP), beta-D-FddC-5'-triphosphate (beta-D-FddCTP), and beta-L-ddC-5'-triphosphate (beta-L-ddCTP) followed a single phase elimination process with an intracellular half-life (T1/2) of 10.5, 5.7, and 12.3 hr, respectively. Furth ermore, beta-L-FddCTP, beta-D-FddCTP, and beta-L-ddCTP levels of 6.7 +/- 2.3, 0.3 +/- 0.1, and 12.0 pmol/10(6) cells, respectively, were still detectable 24 hr following drug removal. The higher intracellular 5'-triphosphate levels of beta-L-FddC and the extended T1/2 of its 5'-triphosphate are consistent with the more potent in vitro antiviral activity of beta-L-FddC in Hep-G2 cells when compared with its beta-D enantiomer, beta-D-FddC.
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Affiliation(s)
- L T Martin
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham 35294, USA
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27
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Cui L, Schinazi RF, Gosselin G, Imbach JL, Chu CK, Rando RF, Revankar GR, Sommadossi JP. Effect of beta-enantiomeric and racemic nucleoside analogues on mitochondrial functions in HepG2 cells. Implications for predicting drug hepatotoxicity. Biochem Pharmacol 1996; 52:1577-84. [PMID: 8937473 DOI: 10.1016/s0006-2952(96)00562-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A group of enantiomeric nucleoside analogues with beta-D or beta-L configuration, which represent potential candidates for the treatment of hepatitis B virus (HBV) infection, were incubated in human hepatoblastoma HepG2 cells at concentrations between 0.1 and 10 microM for 4-14 days. Then the effect on mitochondrial DNA (mtDNA) content, lactic acid production, lipid droplet formation, and mitochondrial morphology were evaluated. No effect on lactic acid production was detected in cells treated with beta-L-2',3'-dideoxy-3'-thiacytidine (3TC), beta-L-2',3'-dideoxy-5-fluoro-3'-thiacytidine (beta-L-FTC), beta-D-2',3'-dideoxy-5-fluoro-3'-thiacytidine (beta-D-FTC), racemic cis 2',3'-dideoxy-5-fluoro-3'thiacytidine [(+/-)-FTC], and 2,4-diamino-7-(2,3-dideoxy-2-fluoro-beta-D-arabinofuranosyl) pyrrolo[2',3'-d]pyrimidine (T70178), whereas a slight increase was associated with beta-D-2-hydroxymethyl-5-(2,6-diaminopurin-9-yl)-1,3-dixolane++ + (beta-D-DAPD) and 4-amino-7-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)pyrrolo[2,3-d]pyrimi dine -5-thiocarboxamide (T70182) at 10 microM. A concentration-dependent increase in lactic acid production was observed in cells exposed to beta-D-2',3'-dideoxy-3'-thiacytidine [(+)-BCH-189], racemic cis 2',3'-dideoxy-3'-thiacytidine [(+/-)-BCH-189], beta-D-2',3'-dideoxy-5-fluorocytidine (beta-D-FddC), beta-L-2',3'-dideoxy-5-fluorocytidine (beta-L-FddC), beta-D-2-hydroxymethyl-5-(5-fluorocytosin-I-yl)-1,3,-dioxolane (beta-D-FDOC), 2,4-diamino-7-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl) pyrrolo[2,3-d]pyrimidine (T70080), and 4-amino-7-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)pyrrolo [2,3-d]pyrimidine (T70179). Inhibition on mtDNA content was demonstrated to be concentration-dependent with (+)-BCH-189, beta-D-FddC, and T70080, whereas 3TC, (+/-)-BCH-189, beta-L-FTC, beta-D-FTC, (+/-)-FTC, beta-L-FddC, beta-D-DAPD, T70178, T70179, and T70182 had no effect. beta-D-FDOC resulted in a marked inhibition of mtDNA synthesis at 10 microM but not at lower concentrations. Cells treated with 3TC, (+/-)-BCH-189, beta-L-FTC, beta-D-FTC, (+/-)-FTC, beta-L-FddC, beta-D-DAPD, T70178, T70179, and T70182 did not show morphological changes compared with the control. In contrast, increased cytoplasmic lipid droplets associated with a loss of cristae in mitochondria were detected in cells treated with either beta-D-FDOC, beta-D-FddC, or T70080, (+)-BCH-189 treatment resulted in loss of cristae in mitochondria. In summary, 3TC, beta-L-FTC, beta-D-FTC, (+/-)-FTC, beta-D-DAPD, T70178, and T70182 exhibited a relatively safe profile, supporting their further development.
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Affiliation(s)
- L Cui
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham 35294, USA
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Dornsife RE, Averett DR. In vitro potency of inhibition by antiviral drugs of hematopoietic progenitor colony formation correlates with exposure at hemotoxic levels in human immunodeficiency virus-positive humans. Antimicrob Agents Chemother 1996; 40:514-9. [PMID: 8834914 PMCID: PMC163150 DOI: 10.1128/aac.40.2.514] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Inhibition of in vitro colony formation of human hematopoietic progenitors (CFU-granulocyte-macrophage, burst-forming unit-erythroid) by the antiviral nucleoside drugs alovudine, zalcitabine, zidovudine, ganciclovir, stavudine, didanosine, lamivudine, and acyclovir was measured. Significant correlations between in vitro 50% inhibitory concentrations and the daily human exposures (area under the concentration-time curve from 0 to 24 h; in micromolar.hour) of these chronically administered drugs in human immunodeficiency virus-positive patients that induced neutropenia or anemia were demonstrated by both linear regression and Spearman rank-order analyses. These quantitative correlations allow estimation of the exposure at which bone marrow toxicity may occur with candidate compounds.
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Affiliation(s)
- R E Dornsife
- Division of Experimental Therapy, Burroughs Wellcome Co., Research Triangle Park, North Carolina 27709, USA
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29
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Fowler DA, Xie MY, Sommadossi JP. Protection and rescue from 2',3'-dideoxypyrimidine nucleoside analog toxicity by hemin in human bone marrow progenitor cells. Antimicrob Agents Chemother 1996; 40:191-5. [PMID: 8787904 PMCID: PMC163081 DOI: 10.1128/aac.40.1.191] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Long-term therapy of AIDS patients with 3'-azido-3'-deoxythymidine (AZT) remains of concern because of resulting hematopoietic toxicity. While the mechanism(s) of this toxicity remains elusive, alternative strategies are being developed to reduce these toxic effects, including combination therapy with nonmyelotoxic antihuman immunodeficiency virus drugs and/or administration of protective or rescue agents, including cytokines and growth factors. By using a particularly relevant human CD34+ liquid culture system, the unique profiles of dideoxynucleoside (ddN) toxicities to both proliferation and differentiation were demonstrated, with decreased potencies in the order of 3'-fluoro-3'-deoxythymidine (FLT) = 3'-amino-3'-deoxythymidine (AMT) = 2',3'-dideoxycytidine > AZT for inhibition of proliferation and in the order of FLT = AMT > AZT >> 2',3'-dideoxycytidine for inhibition of hemoglobin synthesis. Hemin selectively protected erythroid-lineage human burst-forming unit-erythroid cells from AZT- and AMT-induced inhibition but had no effect on FLT toxicity under similar conditions. Myeloid-lineage human CFU-granulocyte-macrophages were also not protected by hemin against all three ddN analogs. The simultaneous exposure of cells to hemin and AZT resulted in a complete protection of both cell proliferation and hemoglobin synthesis. In contrast, in reversal studies only the inhibition of the percentage of hemoglobin-synthesizing cells returned to control levels, but the inhibition of proliferation of cells previously exposed to AZT was not reversed by hemin. These studies further define the unique and multifactorial mechanism(s) of ddN-induced toxic effects during hematopoietic development of pluripotent stem cells and suggest that the use of hemin could be beneficial in alleviating the toxicity of certain ddN analogs.
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Affiliation(s)
- D A Fowler
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham 35294, USA
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Affiliation(s)
- J Saunders
- Department of Medicinal Chemistry II, Glaxo Research and Development Limited, Stevenage, Herts, UK
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31
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Chu CK, Ma T, Shanmuganathan K, Wang C, Xiang Y, Pai SB, Yao GQ, Sommadossi JP, Cheng YC. Use of 2'-fluoro-5-methyl-beta-L-arabinofuranosyluracil as a novel antiviral agent for hepatitis B virus and Epstein-Barr virus. Antimicrob Agents Chemother 1995; 39:979-81. [PMID: 7786007 PMCID: PMC162665 DOI: 10.1128/aac.39.4.979] [Citation(s) in RCA: 211] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A novel anti-hepatitis B virus (anti-HBV) agent, 2'-fluoro-5-methyl-beta-L-arabinofuranosyluracil (L-FMAU), was synthesized and found to be a potent anti-HBV and anti-Epstein-Barr virus agent. Its in vitro potency was evaluated in 2.2.15 and H1 cells for anti-HBV and anti-Epstein-Barr virus activities, respectively. In vitro cytotoxicity in MT2, CEM, 2.2.15, and H1 cells was also assessed, and the results indicated high antiviral selectivities of L-FMAU in these cells.
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Affiliation(s)
- C K Chu
- Department of Medicinal Chemistry, College of Pharmacy, University of Georgia, Athens 30602, USA
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Lewis AF, Drach JC, Fennewald SM, Huffman JH, Ptak RG, Sommadossi JP, Revankar GR, Rando RF. Inhibition of human cytomegalovirus in culture by alkenyl guanine analogs of the thiazolo[4,5-d]pyrimidine ring system. Antimicrob Agents Chemother 1994; 38:2889-95. [PMID: 7695278 PMCID: PMC188302 DOI: 10.1128/aac.38.12.2889] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A series of alkyl and alkenyl guanine analogs containing a thiazolo[4,5-d]pyrimidine ring system were prepared by reaction of the appropriate alkyl halide with the sodium salt of the heterocycle. In preliminary antiviral efficacy evaluations against laboratory strains of both human cytomegalovirus (HCMV) and herpes simplex virus types 1 and 2, it was determined that two of the compounds (T70072 and T01132) were more active and less toxic in stationary-phase cell monolayers than were the other derivatives tested. T01132 and T70072, which have 2-pentenyl and 3-methyl-2-butenyl moieties attached to position 3 of the 5-aminothiazolo[4,5-d]pyrimidine-2,7-dione, respectively, were then more extensively evaluated for anti-HCMV activity. The concentrations of T01132 and T70072 required to inhibit HCMV by 50% in plaque reduction assays were approximately 0.5 and 6.8 microM, respectively. These two compounds inhibited the growth of KB, MRC-5, or Vero cells at concentrations of 75 to 150 microM, depending upon the cell line. In bone marrow progenitor cells T01132 was slightly less toxic than ganciclovir (DHPG). The 50% inhibitory concentrations of T01132 against clinical isolates and DHPG-resistant strains of HCMV were approximately the same as those obtained for laboratory strains of HCMV (approximately 0.5 microM). When tested in combination with DHPG, the resultant antiviral activity was determined to be additive but not synergistic. Experiments performed using variations of the viral multiplicity of infection (MOI) demonstrated that T01132 was more active than DHPG at a low MOI (0.002 or 0.02). However, when a higher MOI (0.2 or 2.0) was used, DHPG was more efficacious than T01132. In experiments in which drug was added at various times post-viral infection, T01132 was most effective when added within the first 24 h post-HCMV infection while DHPG was able to protect cells in this assay system when added up to 48 h postinfection, indicating that T01132 is exerting its antiviral effect on events leading up to and possibly including viral DNA synthesis. The data presented in this report suggest that the antiviral activity of alkenyl-substituted thiazolopyrimidine derivatives may represent a mechanism of action against herpesviruses alternative to that of classical nucleoside analogs such as acyclovir or DHPG.
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Affiliation(s)
- A F Lewis
- Triplex Pharmaceutical Corporation, The Woodlands, Texas 77380
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Frick LW, Lambe CU, St John L, Taylor LC, Nelson DJ. Pharmacokinetics, oral bioavailability, and metabolism in mice and cynomolgus monkeys of (2'R,5'S-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine, an agent active against human immunodeficiency virus and human hepatitis B virus. Antimicrob Agents Chemother 1994; 38:2722-9. [PMID: 7695253 PMCID: PMC188276 DOI: 10.1128/aac.38.12.2722] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
(2'R,5'S-)-cis-5-Fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine (524W91) is a nucleoside analog with potent anti-human immunodeficiency virus and anti-human hepatitis B virus activities in vitro. The pharmacokinetics and bioavailability of 524W91 after oral dosing were studied in mice dosed with 10, 100, and 600 mg of 524W91 per kg of body weight by the oral and intravenous routes. Cynomolgus monkeys were dosed with 10 and 80 mg of 524W91 per kg. In both species, the clearance of 524W91 was rapid, via the kidney, and was independent of dose. In monkeys, the total body clearance of 10 mg of 524W91 per kg was 0.7 +/- 0.1 liter/h/kg, and the volume of distribution at steady state was 0.8 +/- 0.02 liter/kg. The terminal elimination half-life was 1.0 +/- 0.2 h. The absolute bioavailability after oral dosing was 63% +/- 4% at 10 mg/kg. Concentrations of 524W91 in the cerebrospinal fluid were 4% +/- 0.7% of the corresponding levels in plasma. In mice, the total clearance of 10 mg of 524W91 per kg was 2.3 liters/kg/h, and the volume of distribution at steady state was 0.9 liter/kg. Absolute bioavailability in mice after oral dosing was 96% at a dose of 10 mg/kg. The metabolism of orally administered [6-3H]524W91 was studied in cynomolgus monkeys at a dose of 80 mg/kg and in mice at a dose of 120 mg/kg. Monkeys excreted 41% +/- 6% of the radioactive dose in the 0- to 72-h urine, 33% +/- 10% in the feces, and 10% +/- 7% in the cage wash. Unchanged 524W91 was 64% of the total radiolabeled drug recovered in the urine. The glucuronide was a minor urinary metabolite. 5-Fluorouracil was not detected (less than 0.02% of the dose). Mice dosed orally with 120 mg of [6-3H]524W91 per kg excreted 67% +/- 7% of the radiolable in the )- to 48-h urine. Small amounts of the 3' -sulfoxide and glucuronide metabolites were observed in the urine, but 5-fluorouracil was not detected. Good bioavailability after oral dosing and resistance to metabolism recommend 524W91 for further preclinical evaluation.
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Affiliation(s)
- L W Frick
- Division of Experimental Therapy, Burroughs Wellcome Co., Research Triangle Park, North Carolina 27709, USA
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Faraj A, Fowler DA, Bridges EG, Sommadossi JP. Effects of 2',3'-dideoxynucleosides on proliferation and differentiation of human pluripotent progenitors in liquid culture and their effects on mitochondrial DNA synthesis. Antimicrob Agents Chemother 1994; 38:924-30. [PMID: 7520683 PMCID: PMC188128 DOI: 10.1128/aac.38.5.924] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
2',3'-Dideoxynucleosides (ddNs) including 3'-azido-3'-deoxythymidine (AZT), 3'-fluoro-3'-deoxythymidine (FLT), 3'-amino-3'-deoxythymidine (AMT), 2',3'-dideoxycytidine (ddC), and 2',3'-didehydro-3'-deoxythymidine (D4T) were tested for their effects on proliferation and differentiation of pluripotent progenitor cells (CD34+) purified from human bone marrow cells grown in liquid cultures. These highly purified progenitor cells undergo extensive proliferation during 14 days, with a marked differentiation during the last 7 days. These differentiated cells exhibit normal morphological features in response to specific hematopoietic growth factors of both erythroid and granulocyte-macrophage lineages, as demonstrated by flow cytometry cell phenotyping. The potencies of these ddNs in inhibiting proliferation of granulocyte-macrophage lineage cells were in the order FLT > AMT = ddC > AZT >> D4T, and the potencies in inhibiting proliferation of erythroid lineage cultures were in the order FLT > AMT > AZT > ddC >> D4T. The toxic effects of ddNs assessed in these liquid cultures were in agreement with data obtained by using semisolid cultures, demonstrating the consistency of these two in vitro hematopoietic systems toward ddN toxicity. ddC was toxic to CD34+ progenitor cells and/or cells in the early stages of differentiation, whereas the inhibitory effect of AZT on the erythroid lineage was predominantly observed on a more mature population of erythroid progenitors during the differentiation process. Slot blot analysis of granulocyte-macrophage cultures demonstrated that exposure to ddC and FLT was associated with a decrease in total mitochondrial DNA (mtDNA) content, suggesting that these two ddNs inhibit mtDNA synthesis. In contrast, no difference in the ratio of nuclear DNA to mtDNA was observed in cells exposed to toxic concentrations of AZT and AMT is not associated with an inhibition of mtDNA synthesis. This human pluripotent progenitor liquid culture system should permit detailed investigations of the cellular and molecular events involved in ddN-induced hematological toxicity.
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Affiliation(s)
- A Faraj
- Department of Pharmacology, University of Alabama at Birmingham 35294
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Balzarini J. Metabolism and mechanism of antiretroviral action of purine and pyrimidine derivatives. PHARMACY WORLD & SCIENCE : PWS 1994; 16:113-26. [PMID: 8032337 DOI: 10.1007/bf01880662] [Citation(s) in RCA: 144] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Unlike herpes viruses, human immunodeficiency virus and other retroviruses do not encode specific enzymes required for the metabolism of the purine or pyrimidine nucleotides to their corresponding 5'-triphosphates. Therefore, 2',3'-dideoxynucleosides and acyclic nucleoside phosphonates must be phosphorylated and metabolized by host cell kinases and other enzymes of purine and/or pyrimidine metabolism. Different animal species (or even different cell types within one animal species) may differ in the efficiency of conversion of these drugs to their antivirally active metabolite(s). Three 2',3'-dideoxynucleosides are officially licensed for clinical use [i.e., zidovudine (3'-azido-2',3'-dideoxythymidine, AZT), didanosine (2',3'-dideoxyinosine, DDI) and zalcitabine (2',3'-dideoxycytidine, DDC)]. A number of other 2',3'-dideoxynucleoside analogues [among them stavudine (2',3'-didehydro-2',3'-dideoxythymidine, D4T), 2',3'-dideoxy-3'-thiacytidine (3TC), 2',3'-dideoxy-5-fluoro-3'-thiacytidine (FTC) and the acyclic nucleoside phosphonate 9-(2-phosphonylmethoxyethyl)adenine (PMEA)] are currently under clinical investigation and are candidate compounds for eventual licensing as anti-AIDS drugs. The metabolic pathways, antimetabolic effects and mechanism of antiviral action of these nucleoside analogues will be discussed.
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Affiliation(s)
- J Balzarini
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium
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Schinazi RF. Competitive inhibitors of human immunodeficiency virus reverse transcriptase. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf02171660] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Shewach DS, Liotta DC, Schinazi RF. Affinity of the antiviral enantiomers of oxathiolane cytosine nucleosides for human 2'-deoxycytidine kinase. Biochem Pharmacol 1993; 45:1540-3. [PMID: 8385948 DOI: 10.1016/0006-2952(93)90058-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The two enantiomers of 2',3'-dideoxy-3'-thiacytidine (BCH-189) and their 5-fluoro analogs (FTC) were found to be good substrates for human 2'-deoxycytidine kinase with Km values in the 5.7 to 42.1 microM range. The affinity of the (-)-enantiomers was greater than that of the (+)-compounds. These results may explain the greater in vitro antiviral potency against human immunodeficiency virus and hepatitis B virus of the (-)-enantiomers when compared to their (+)-counterparts. The (+)- and (-)-enantiomers of FTC and BCH-189 are the first nucleoside analogs for which we have observed lower apparent kinetic constants for this enzyme in the presence of ATP compared to UTP.
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Affiliation(s)
- D S Shewach
- Department of Pharmacology, University of Michigan, Ann Arbor 48109
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