1
|
Abstract
Prominent in the current stage of drug development, antiviral compounds can be efficiently prepared through cycloaddition reactions. The chapter reports the use of classical Diels–Alder and their hetero version for the design and synthesis of compounds that were tested for their antiviral activities against a variety of viruses. Furthermore, 1,3-dipolar cycloaddition reactions of selected 1,3-dipoles, such as azides, nitrones, and nitrile oxides, are reviewed in the light of their application in the preparation of key intermediates for antiviral synthesis. A few examples of [2+2] cycloaddition reactions are also presented. The products obtained from these pericyclic reaction approaches were all tested for their activities in terms of blocking the virus replication, and the relevant biological data are highlighted.
Collapse
|
2
|
Hatano A, Wakana H, Terado N, Kojima A, Nishioka C, Iizuka Y, Imaizumi T, Uehara S. Bio-catalytic synthesis of unnatural nucleosides possessing a large functional group such as a fluorescent molecule by purine nucleoside phosphorylase. Catal Sci Technol 2019. [DOI: 10.1039/c9cy01063g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Unnatural nucleosides are attracting interest as potential diagnostic tools, medicines, and functional molecules.
Collapse
Affiliation(s)
- Akihiko Hatano
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| | - Hiroyuki Wakana
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| | - Nanae Terado
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| | - Aoi Kojima
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| | - Chisato Nishioka
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| | - Yu Iizuka
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| | - Takuya Imaizumi
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| | - Sanae Uehara
- Department of Chemistry
- Shibaura Institute of Technology
- Saitama
- Japan
| |
Collapse
|
3
|
Martínez-Casares RM, Pérez Méndez HI, Manjarrez Alvarez N, Solís Oba A, Hernández Vázquez L, López-Luna A. Comparison of the diastereoisomeric excess of uridine, inosine and adenosine cyanohydrins determined by HPLC-DAD and 1H NMR. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2017; 36:652-665. [PMID: 29185863 DOI: 10.1080/15257770.2017.1375516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The separation of the diastereoisomers of the nucleoside derivatives of uridine, inosine and adenosine was performed by HPLC using chiral and no chiral columns, it was observed with the no chiral columns the resolution was good enough to determine diastereoisomeric excess. These methods were compared with 1H NMR, and no significant differences were observed between the three techniques. Diastereoisomeric uridine (3a), inosine (3b) and adenosine (4c) cyanohydrins were resolved by 1H nuclear magnetic resonance (1H NMR), chiral normal phase-high-performance liquid chromatography-diode array detector (NP-HPLC-DAD) and reversed phase (RP-HPLC-DAD); these methods allowed the assesment of the percent diastereoisomeric excess (% de) of the nucleosidic cyanohydrins of 3a (4, 6 and 4), 3b (10, 8 and 6) and 4c (4, 4 and 4). To the best of our knowledge, there are no reports using analytical techniques for the separation of the epimers of 3a, 3b and 4c.
Collapse
Affiliation(s)
- Rubria Marlen Martínez-Casares
- a Doctorado en Ciencias Biológicas y de la Salud , Universidad Autónoma Metropolitana-Unidad Xochimilco , Coyoacán , CDMX , México
| | - Herminia Inés Pérez Méndez
- b Departamento de Sistemas Biológicos , Universidad Autónoma Metropolitana-Unidad Xochimilco , Coyoacán , CDMX , México
| | - Norberto Manjarrez Alvarez
- b Departamento de Sistemas Biológicos , Universidad Autónoma Metropolitana-Unidad Xochimilco , Coyoacán , CDMX , México
| | - Aida Solís Oba
- b Departamento de Sistemas Biológicos , Universidad Autónoma Metropolitana-Unidad Xochimilco , Coyoacán , CDMX , México
| | - Liliana Hernández Vázquez
- b Departamento de Sistemas Biológicos , Universidad Autónoma Metropolitana-Unidad Xochimilco , Coyoacán , CDMX , México
| | - Alberto López-Luna
- b Departamento de Sistemas Biológicos , Universidad Autónoma Metropolitana-Unidad Xochimilco , Coyoacán , CDMX , México
| |
Collapse
|
4
|
Alaoui AE, Faraj A, Pierra C, Boudou V, Johnson R, Mathé C, Gosselin G, Korba B, Imbach JL, Schinazi R, Sommadossi JP. Inhibition of Hepatitis B Virus Replication by Nucleoside Enantiomers of β-2′,3′-Dideoxypurine Analogues. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029600700508] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Various purine β-L-2′,3′-dideoxynucleoside analogues with both sugar and base modifications including β-L-ddG, β-L-ddl, β-L-ddA, 2′-azido-β-L-araddA, 2′-amino-β-L-araddA, 2′,5′-anhydro-β-L-araddA, 2′-azido-β-L-ddA, 2′-amino-β-L-ddA, 2′-fluoro-β-L-ddA, 3′-azido-β-L-ddA, 3′-amino-β-L-ddA, 3′-fluoro-β-L-ddA, 2,6-diamino-β-L-2′,3′-dideoxyfuranosylpurine, 6-cyclopropylamino-β-L-ddA, 2′-azido-6-N-triphenylphosphine-β-L-araddA, 2-amino-6-methylamino-β-L-2′,3′-dideoxyfuranosylpurine, 2-amino-6-cyclopropylamino-β-L-2′,3′-dideoxyfuranosylpurine, 2-amino-6-cyclopentylamino-β-L-2′,3′-dideoxyfuranosylpurine, 2′,3′-didehydro-β-L-ddA and 2′,3′-didehydro-6-N-triphenyl phosphine-β-L-ddA were synthesized and evaluated as potential inhibitors of hepatitis B virus (HBV) replication in HBV DNA-transfected human hepatoblastoma-derived Hep-G2 cells (2.2.15 cells). β-L-ddA, 2′-azido-β-L-ddA, 3′-azido-β-L-ddA, 2″,3′-didehydro-β-L-ddA (β-L-D4A) and a modified base of β-L-D4A, inhibited HBV replication in vitro. β-L-D4A was the more potent and selective antiHBV agent with a 50% effective concentration value of 0.1 μM and a selectivity index of 1800. On the basis of this finding, studies are in progress to synthesize new purine derivatives with the β-L unnatural configuration which hopefully will lead to identifying additional potent and highly selective anti-HBV agents.
Collapse
Affiliation(s)
- A.M. El Alaoui
- Department of Pharmacology and Toxicology, The Liver Center, and the Division of Clinical Pharmacology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - A. Faraj
- Department of Pharmacology and Toxicology, The Liver Center, and the Division of Clinical Pharmacology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - C. Pierra
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université de Montpellier II, 34095 Montpellier, France
| | - V. Boudou
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université de Montpellier II, 34095 Montpellier, France
| | - R. Johnson
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université de Montpellier II, 34095 Montpellier, France
| | - C. Mathé
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université de Montpellier II, 34095 Montpellier, France
| | - G. Gosselin
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université de Montpellier II, 34095 Montpellier, France
| | - B.E. Korba
- Division of Molecular Virology and Immunology, Georgetown University, Rockville, MD 20852, USA
| | - J.-L. Imbach
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université de Montpellier II, 34095 Montpellier, France
| | - R.F. Schinazi
- Georgia Research Center for AIDS and HIV Infections, Veterans Affairs Medical Center, Decatur, GA 30033, USA
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Emory University, School of Medicine, Atlanta, GA 30322, USA
| | - J.-P. Sommadossi
- Department of Pharmacology and Toxicology, The Liver Center, and the Division of Clinical Pharmacology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
5
|
Hurwitz SJ, Otto MJ, Schinazi RF. Comparative Pharmacokinetics of Racivir®, (±)-β-2′,3′-Dideoxy-5-Fluoro-3′-Thiacytidine in Rats, Rabbits, Dogs, Monkeys and HIV-Infected Humans. ACTA ACUST UNITED AC 2016; 16:117-27. [PMID: 15889534 DOI: 10.1177/095632020501600204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Racivir® is a 50:50 racemic mixture of the (–)- and (+)-β-enantiomers of 2′-deoxy-3′-thia-5-fluorocytosine (FTC), which is being developed for the treatment of HIV and hepatitis B virus (HBV). The (+)-enantiomer of FTC is approximately 10–20-fold less potent than (–)-FTC, but it selects for a different HIV mutation in human lymphocytes. Plasma concentrations from a group of 54 rats, 12 pregnant rabbits and 60 dogs enrolled in large toxicity studies using a wide variety of oral doses, were compared using non-compartment pharmacokinetic modelling versus dose, treatment duration, species and gender. The pharmacokinetics of Racivir® were also compared with those of a previously published pharmacokinetic study in rhesus monkeys and with data from HIV-infected human male volunteers. The (+)-FTC, but not the (–)-enantiomer, can be deaminated to the non-toxic inactive metabolite (+)-FTU. Therefore, the plasma exposure to (+)-FTU was also determined. The order of relative plasma exposure to (+)-FTU was rhesus monkeys > humans > pregnant rabbits > dogs > rats. Allometric scaling was performed to relate systemic clearance/fraction of drug absorbed (Cl/F) and terminal phase volume of distribution (Vβ/F) versus species body weights. No individual animal species mimicked the Cl/F values in humans. However, allometric scaling using a combination of rats, pregnant rabbits and monkeys predicted the mean human Cl/F value better than a combination of rats and rabbits only (within 0.24 and SD of mean vs 0.81 SD of the observed mean value). Similarly, human Vβ/F values were best predicted using a combination of rat and monkey data (within 0.64 SD of mean value). Species demonstrating greater deamination to (+)-FTU tended to have greater than predicted Cl/F values. The Cmax values of dogs were the closest to humans, but were statistically different. This study highlights the importance of selecting animal species that demonstrate similar cytidine deaminase activity to humans when performing preclinical dosing studies on Racivir® other antiviral agents that are substrates for mammalian cytidine deaminases.
Collapse
Affiliation(s)
- Selwyn J Hurwitz
- Department of Pediatrics, Emory University School of Medicine and Veterans Affairs Medical Center, Decatur, GA, USA
| | | | | |
Collapse
|
6
|
Affiliation(s)
- Jonas J. Forsman
- Laboratory of Organic Chemistry, Åbo Akademi University, FI-20500 Åbo, Finland
| | - Reko Leino
- Laboratory of Organic Chemistry, Åbo Akademi University, FI-20500 Åbo, Finland
| |
Collapse
|
7
|
Khalil NSAM. N- and S-α-l-Arabinopyranosyl[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles. First synthesis and biological evaluation. Eur J Med Chem 2007; 42:1193-9. [PMID: 17408811 DOI: 10.1016/j.ejmech.2007.01.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 01/21/2007] [Accepted: 01/25/2007] [Indexed: 11/20/2022]
Abstract
First synthesis of N- and S-alpha-l-arabinopyranosyl[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles is described. Antimicrobial screening of two selected regioisomeric compounds against Aspergillus fumigatus, Penicillium italicum, Syncephalastrum racemosum, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis and Escherichia coli are compared.
Collapse
Affiliation(s)
- Nasser S A M Khalil
- Regional Center for Food and Feed (RCFF), Agricultural Research Center, 9El Gamaa Street, Giza, Egypt.
| |
Collapse
|
8
|
Khalil NSAM. First synthesis and antimicrobial activity Of N- and S-alpha-L-arabinopyranosyl-1,2,4-triazoles. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2007; 26:361-77. [PMID: 17479432 DOI: 10.1080/15257770701296986] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Arabinosylation of some 4-amino- and 4-arylideneamino-5-(pyridin-3-yl)-2,4-dihydro-[1,2,4]-triazole-3-thiones with 2,3,4-tri-O-acetyl-beta-L-arabinopyranosyl bromide led to an efficient synthetic approach to the corresponding N-and S-alpha-L-arabinopyranosides. Structure assignment of these two regiosiomers was based on chemical and spectroscopic evidences. Antimicrobial activities of two selected regioisomeric N-and S-alpha-L-arabinopyranosides were compared. The N-alpha-L-arabinopyranoside showed higher inhibitory effect than its regioisomeric S-alpha-L-arabinopyranoside against Aspergillus fumigatus, Penicillium italicum, Staphylococcus aureus, and Pseudomonas aeruginosa.
Collapse
Affiliation(s)
- Nasser S A M Khalil
- Regional Center for Food and Feed, Agricultural Research Center, Giza, Egypt.
| |
Collapse
|
9
|
Gosselin G, Boudou V, Griffon JF, Pavia G, Pierra C, Imbach JL, Faraj A, Sommadossi JP. Unnatural β-L-Enantiomers of Nucleoside Analogues as Potent Anti-Hepatitis B Virus Agents. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/07328319808004708] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- G. Gosselin
- a Laboratoire Chimie Bioorganique, UMR CNRS 5625 , Universite Montpellier II , 34095 , Montpellier , Cedex 5, France
| | - V. Boudou
- a Laboratoire Chimie Bioorganique, UMR CNRS 5625 , Universite Montpellier II , 34095 , Montpellier , Cedex 5, France
| | - J-F Griffon
- a Laboratoire Chimie Bioorganique, UMR CNRS 5625 , Universite Montpellier II , 34095 , Montpellier , Cedex 5, France
| | - G. Pavia
- a Laboratoire Chimie Bioorganique, UMR CNRS 5625 , Universite Montpellier II , 34095 , Montpellier , Cedex 5, France
| | - C. Pierra
- a Laboratoire Chimie Bioorganique, UMR CNRS 5625 , Universite Montpellier II , 34095 , Montpellier , Cedex 5, France
| | - J-L Imbach
- a Laboratoire Chimie Bioorganique, UMR CNRS 5625 , Universite Montpellier II , 34095 , Montpellier , Cedex 5, France
| | - A. Faraj
- b University of Alabama, Department of Pharmacology , Birmingham , AL , 35294 , USA
| | - J-P Sommadossi
- b University of Alabama, Department of Pharmacology , Birmingham , AL , 35294 , USA
| |
Collapse
|
10
|
Saag MS. Emtricitabine, a new antiretroviral agent with activity against HIV and hepatitis B virus. Clin Infect Dis 2005; 42:126-31. [PMID: 16323102 DOI: 10.1086/498348] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 08/02/2005] [Indexed: 11/04/2022] Open
Abstract
Emtricitabine (FTC) is a new nucleoside agent that has activity against both human immunodeficiency virus (HIV) and hepatitis B virus. It is very similar to lamivudine (3TC) with respect to its activity, convenience, and safety and resistance profile. Indeed, with the exception of the longer intracellular half-life of triphosphate FTC, there is little to distinguish between the 2 drugs. Clinical trials comparing FTC with 3TC as part of a triple-drug regimen have demonstrated their equivalence, whereas a study comparing activity of FTC with that of stavudine demonstrated FTC's superiority. In clinical practice, the choice of 3TC versus FTC will most likely be made in the context of drugs coformulated with them. Although FTC is not formally approved for use in patients coinfected with HIV and hepatitis B virus, it is often a preferred choice for such patients when combined with tenofovir, which also has anti-hepatitis B virus activity. Recent treatment guidelines for the treatment of HIV infection by both the International AIDS Society-USA and US Department of Health and Human Services have placed FTC in combination with tenofovir, didanosine, or zidovudine in the preferred category of nucleoside backbone regimens for patients receiving antiretroviral therapy.
Collapse
Affiliation(s)
- Michael S Saag
- Division of Infectious Disease, Department of Medicine, University of Alabama, Birmingham, AL 39294-2050, USA.
| |
Collapse
|
11
|
Spadari S, Maga G, Verri A, Focher F. Molecular basis for the antiviral and anticancer activities of unnatural L-beta-nucleosides. Expert Opin Investig Drugs 2005; 7:1285-300. [PMID: 15992031 DOI: 10.1517/13543784.7.8.1285] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
As a general rule, enzymes act on only one enantiomer of a chiral substrate and only one of the enantiomeric forms of a chiral molecule may bind effectively at the catalytic site, displaying biological activity. In recent years, some exceptions have been found among viral and cellular enzymes involved in the synthesis of deoxynucleoside triphosphates and in their polymerisation into DNA. Examples are: herpes virus thymidine kinases, cellular deoxycytidine kinase and deoxynucleotide kinases, human immunodeficiency virus type 1 (HIV-1) reverse transcriptase, hepatitis B virus (HBV) DNA polymerase and, to a lesser extent, some cellular DNA polymerases. The lack of enantioselectivity allows herpes simplex virus (HSV) thymidine kinase and cellular deoxycytidine kinase to phosphorylate the unnatural L-beta-enantiomers of D-thymidine and D-deoxycytidine, respectively, or of their analogues to monophosphate. This phosphorylation represents the first and often the rate-limiting step of their activation to triphosphates. The L-triphosphates can then exert antiviral (anti-HSV, anti-Human cytomegalovirus, anti-HIV-1, anti-HBV) and anticancer activities. Although only one L-nucleoside (3TC) has so far gained United States of America Food and Drug Administration (USA FDA) approval for clinical use against HIV-1, other L-enantiomers of nucleoside analogues, which have shown antiviral or anticancer activity in cell cultures are in clinical trials. Their resistance to enantioselective enzymes, such as thymidine phosphorylase, thymidylate synthase, (deoxy)-cytidine and dCMP deaminases, and their lower affinity for the mitochondrial thymidine kinase can ensure a higher selectivity and lower cytotoxicity with respect to those exerted by their corresponding natural D-enantiomers and might be exploited to solve problems arising during chemotherapy, such as metabolic inactivation, cytotoxicity and drug-resistance.
Collapse
Affiliation(s)
- S Spadari
- Istituto di Genetica Biochimica ed Evoluzionistica, National Research Council, Abbiategrasso 207, 27100 Pavia, Italy.
| | | | | | | |
Collapse
|
12
|
Chaudhuri NC, Moussa A, Stewart A, Wang J, Storer R. Development of a Novel Synthetic Process for 2-Deoxy-3,5-di-O-p-toluoyl-α-l-ribofuranosyl Chloride: A Versatile Intermediate in the Synthesis of 2‘-Deoxy-l-ribonucleosides. Org Process Res Dev 2005. [DOI: 10.1021/op0500436] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Narayan C. Chaudhuri
- Department of Process Chemistry, Idenix Pharmaceuticals, Inc., 60 Hampshire Street, Cambridge, Massachusetts 02139, U.S.A
| | - Adel Moussa
- Department of Process Chemistry, Idenix Pharmaceuticals, Inc., 60 Hampshire Street, Cambridge, Massachusetts 02139, U.S.A
| | - Alistair Stewart
- Department of Process Chemistry, Idenix Pharmaceuticals, Inc., 60 Hampshire Street, Cambridge, Massachusetts 02139, U.S.A
| | - Jingyang Wang
- Department of Process Chemistry, Idenix Pharmaceuticals, Inc., 60 Hampshire Street, Cambridge, Massachusetts 02139, U.S.A
| | - Richard Storer
- Department of Process Chemistry, Idenix Pharmaceuticals, Inc., 60 Hampshire Street, Cambridge, Massachusetts 02139, U.S.A
| |
Collapse
|
13
|
Cho BH, Kim JH, Jeon HB, Kim KS. A new efficient and practical synthesis of 2-deoxy-l-ribose. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
14
|
Asmuth DM, Nguyen HH, Melcher GP, Cohen SH, Pollard RB. Treatments for hepatitis B. Clin Infect Dis 2004; 39:1353-62. [PMID: 15494913 DOI: 10.1086/425010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Accepted: 06/29/2004] [Indexed: 12/13/2022] Open
Abstract
New optimism surrounds treatments for chronic hepatitis B (CHB). Interferon- alpha , lamivudine, and adefovir dipivoxil are currently approved by the United States Food and Drug Administration for the treatment of CHB. All 3 treatments possess unique characteristics with respect to their side effect profiles, potencies, and treatment niches within the spectrum of CHB. New agents, which are in various stages of clinical development, represent potential improvements within existing, as well as novel, classes of antiviral therapy, and they offer significant promise of a cure for the many patients with chronic and progressive hepatitis B. However, there remain many challenges in understanding the implications of drug resistance, the role of combination therapy, and how to define the response to therapy within subsets of patients with hepatitis B.
Collapse
Affiliation(s)
- David M Asmuth
- Division of Infectious Diseases, Dept. of Internal Medicine, UC Davis Medical Center, 4150 V St., PSSB G500, Sacramento, CA 95817 , USA.
| | | | | | | | | |
Collapse
|
15
|
Mansour AK, Eid MM, Khalil NSAM. Synthesis of some new 2-alpha-L-arabinopyranosyl-1,2,4-triazines as potential antitumor chemotherapeutics. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2004; 22:1805-23. [PMID: 14533883 DOI: 10.1081/ncn-120023274] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Synthetic routes towards different 2-alpha-L-arabinopyranosyl-3-thioxo-2,3-dihydro-1,2,4-triazin-5(4H)-/ones or thiones were investigated. Primary human anticancer screening of two selected compounds resulted in an active compound against SF-268 (CNS) cell line.
Collapse
|
16
|
Abstract
Emtricitabine (FTC) is a synthetic nucleoside analogue of cytosine, which is intracellularly phosforylated to form the active form emtricitabine 5'triphosphate (E5TP). E5TP inhibits both HIV and Hepatitis B reverse transcriptase. Clinical trials have shown FTC to be active as part of highly active anti-retroviral therapy in naïve HIV-positive patients. FTC may be dosed once daily and in vitro is less associated with the M184V mutation, which is classically associated with failure of treatment with lamivudine. In clinical practice, toxicity with FTC is unusual. The most common treatment-related adverse events are diarrhoea, headache, nausea, dizziness, abdominal pain, aesthenia and rash. Skin discolouration, which is typically reported as hyperpigmentation and usually affecting either the palms of the hands or the soles of the feet, is reported on under 2% of individuals and is almost exclusive to patients of African origin.
Collapse
Affiliation(s)
- M Nelson
- Chelsea and Westminster Hospital, HIV Medicine, London, UK.
| | | |
Collapse
|
17
|
Ray AS, Schinazi RF, Murakami E, Basavapathruni A, Shi J, Zorca SM, Chu CK, Anderson KS. Probing the mechanistic consequences of 5-fluorine substitution on cytidine nucleotide analogue incorporation by HIV-1 reverse transcriptase. Antivir Chem Chemother 2004; 14:115-25. [PMID: 14521328 DOI: 10.1177/095632020301400301] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Beta-D and beta-L-enantiomers of 2',3'-dideoxycytidine analogues are potent chain-terminators and antimetabolites for viral and cellular replication. Seemingly small modifications markedly alter their antiviral and toxicity patterns. This review discusses previously published and recently obtained data on the effects of 5- and 2'-fluorine substitution on the pre-steady state incorporation of 2'-deoxycytidine-5'-monophosphate analogues by HIV-1 reverse transcriptase (RT) in light of their biological activity. The addition of fluorine at the 5-position of the pyrimidine ring altered the kinetic parameters for all nucleotides tested. Only the 5-fluorine substitution of the clinically relevant nucleosides (-)-beta-L-2',3'-dideoxy-3'-thia-5-fluorocytidine (L-FTC, Emtriva), and (+)-beta-D-2',3'-didehydro-2',3'-dideoxy-5-fluorocytidine (D-D4FC, Reverset), caused a higher overall efficiency of nucleotide incorporation during both DNA- and RNA-directed synthesis. Enhanced incorporation by RT may in part explain the potency of these nucleosides against HIV-1. In other cases, a lack of correlation between RT incorporation in enzymatic assays and antiviral activity in cell culture illustrates the importance of other cellular factors in defining antiviral potency. The substitution of fluorine at the 2' position of the deoxyribose ring negatively affects incorporation by RT indicating the steric gate of RT can detect electrostatic perturbations. Intriguing results pertaining to drug resistance have led to a better understanding of HIV-1 RT resistance mechanisms. These insights serve as a basis for understanding the mechanism of action for nucleoside analogues and, coupled with studies on other key enzymes, may lead to the more effective use of fluorine to enhance the potency and selectivity of antiviral agents.
Collapse
Affiliation(s)
- Adrian S Ray
- Department of Pharmacology, Yale University School of Medicine, New Haven, Conn., USA
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Chen H, Pai SB, Hurwitz SJ, Chu CK, Glazkova Y, McClure HM, Feitelson M, Schinazi RF. Antiviral activity and pharmacokinetics of 1-(2,3-dideoxy-2-fluoro-beta-L-glyceropent-2-enofuranosyl)cytosine. Antimicrob Agents Chemother 2003; 47:1922-8. [PMID: 12760868 PMCID: PMC155827 DOI: 10.1128/aac.47.6.1922-1928.2003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
1-(2,3-Dideoxy-2-fluoro-beta-L-glyceropent-2-enofuranosyl)cytosine (L-2'-Fd4C) is an L-nucleoside analogue with both anti-human immunodeficiency virus (HIV) and anti-hepatitis B virus (HBV) activity with median effective concentrations of 0.12 microM in peripheral blood mononuclear cells and 0.002 microM in HepG2-2.2.15 cells, respectively. The purpose of this study was to examine the antihepadnavirus potency and pharmacokinetics of L-2'-Fd4C in vivo. HBV-transgenic mice treated intraperitoneally with L-2'-Fd4C showed a reduction of HBV levels in their blood comparable to that produced by lamivudine. The pharmacokinetics of L-2'-Fd4C in rhesus monkeys was evaluated after intravenous and oral administration. The concentrations in plasma declined in a biexponential manner after intravenous administration, with a long terminal-phase half-life of 5.02 h. The steady-state volumes of distribution and systemic clearance were 1.09 liter x kg(-1) and 0.25 liter x h(-1) x kg(-1), respectively, with a renal clearance of 0.16 liter x h(-1) x kg(-1). The oral bioavailability was approximately 44%. About 53% of the compound administered intravenously and 19% of that administered orally were recovered unchanged in the urine within the 24-h urine collection period, and no other metabolite was detected. The compound penetrated the central nervous system at concentrations that exceeded the median effective antiviral concentration against HIV in cell cultures. Based upon these observations, further testing to develop this agent for treatment of HIV and HBV infections is warranted.
Collapse
Affiliation(s)
- Huachun Chen
- Department of Pediatrics, Emory University and Veterans Affairs Medical Center, Decatur, Georgia 30033, USA
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Walters KA, Tipples GA, Allen MI, Condreay LD, Addison WR, Tyrrell L. Generation of stable cell lines expressing Lamivudine-resistant hepatitis B virus for antiviral-compound screening. Antimicrob Agents Chemother 2003; 47:1936-42. [PMID: 12760870 PMCID: PMC155849 DOI: 10.1128/aac.47.6.1936-1942.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Lamivudine [beta-L-(-)-2',3'-dideoxy-3'-thiacytidine] is a potent inhibitor of hepadnavirus replication and is used both to treat chronic hepatitis B virus (HBV) infections and to prevent reinfection of transplanted livers. Unfortunately, lamivudine-resistant HBV variants do arise during prolonged therapy, indicating a need for additional antiviral drugs. Replication-competent HBV constructs containing the reverse transcriptase domain L180M/M204V and M204I (rtL180M/M204V and rtM204I) mutations associated with lamivudine resistance were used to produce stable cell lines that express the resistant virus. These cell lines contain stable integrations of HBV sequences and produce both intracellular and extracellular virus. HBV produced by these cell lines was shown to have a marked decrease in sensitivity to lamivudine, with 450- and 3,000-fold shifts in the 50% inhibitory concentrations for the rtM204I and rtL180M/M204V viruses, respectively, compared to that for the wild-type virus. Drug assays indicated that the lamivudine-resistant virus exhibited reduced sensitivity to penciclovir [9-(4-hydroxy-3-hydroxymethyl-but-1-yl) guanine] but was still inhibited by the nucleoside analogues CDG (carbocyclic 2'-deoxyguanosine) and abacavir ([1S,4R]-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclopentene-1-methanol). Screening for antiviral compounds active against the lamivudine-resistant HBV can now be done with relative ease.
Collapse
Affiliation(s)
- Kathie-Anne Walters
- Department of Medical Microbiology and Immunology, Glaxo Wellcome-Heritage Research Institute, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
| | | | | | | | | | | |
Collapse
|
20
|
Preclinical and clinical development of the anti-HIV, anti-HBV oxathiolane nucleoside analog emtricitabine. FRONTIERS IN VIRAL HEPATITIS 2003. [PMCID: PMC7155727 DOI: 10.1016/b978-044450986-4/50088-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three classes of drugs are available to treat patients infected with human immunodeficiency virus (HIV) : the nucleoside reverse transcriptase inhibitors (NRTI), the nonnucleoside reverse transcriptase inhibitors (NNRTI), and the protease inhibitors (PI). Emtricitabine represents one of the most potent anti-HIV agents identified to date, producing two log10 drop in viral load as monotherapy at a 200 mg qd dose as the affected individual became susceptible to opportunistic infections and specific immune deficiency resulting from the depletion of CD4+ lymphocytes. The clinical profile of emtricitabine discussed in this chapter demonstrated (1) a plasma half-life of 8-10 hours with linear kinetics, (2) an intracellular emtricitabine 5’-triphosphate half-life greater than 39 hours that supports daily dosing, (3) no significant drug–drug interactions that limits the use of emtricitabine in combination therapy, (4) comparable safety and efficacy to lamivudine, and (5) low incidence of Ml84V mutations. This important observation suggests that emtricitabine can increase the durability of oxathiolane nucleoside analog-containing drug regimens. Hepatitis B virus (HBV) constitutes a major worldwide health threat, as the clinical development program is just entering the pivotal phase. Emtricitabine can be an extremely important drug for the treatment of patients coinfected with HIV and HBV.
Collapse
|
21
|
Tatti KM, Korba BE, Stang HL, Peek S, Gerin JL, Tennant BC, Schinazi RF. Mutations in the conserved woodchuck hepatitis virus polymerase FLLA and YMDD regions conferring resistance to lamivudine. Antiviral Res 2002; 55:141-50. [PMID: 12076758 DOI: 10.1016/s0166-3542(02)00019-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
During more than 104 weeks of treatment with lamivudine (3TC) in chronic woodchuck hepatitis virus (WHV) carrier woodchucks, viral recrudescence occurred. Analysis of WHV DNA polymerase from woodchuck serum samples by PCR followed by DNA sequencing demonstrated that all samples were wild type at the conserved YMDD motif in domain C. Four of the six 3TC-treated woodchucks showed a mixture of the wild-type Ala (GCT) and the mutant Thr (ACT) at the conserved amino acid residue 566 (FLLA) in domain B of the WHV polymerase region. The appearance of the A566T mutation was temporally associated with viral recrudescence. This change is analogous with the amino acid 181 (FLLA) in HBV where 3TC selects for a change from Ala to Thr in humans. In the woodchuck, the Ala to Thr change in the polymerase gene results in a mutation of the WHV surface protein (amino acid 377) from Trp (TGG) to an opal codon (TGA), which may prematurely terminates the polypeptide. Three WHV molecular infectious clones were constructed to study this mutation in greater detail in vitro: A566T, analogous to A181T in HBV; M589V, analogous to the M204V in HBV; and the double mutant A566T/M589V, analogous to A181T/M204V in HBV. These mutants exhibited drug-sensitivity and replication profiles that paralleled those reported for analogous HBV variants. In transfected Huh7 cells, WHV containing the M589V mutation conferred at least 100-fold increased resistance to 3TC, but replicated approximately 5-fold less efficiently than wild-type virus as judged by both extracellular virus production and intracellular DNA replicative forms. In contrast, A566T mutant was approximately 10-fold more resistant to 3TC, replicated intracellularly as well as wild type, but produced 10-fold lower levels of virions than wild type. These findings are consistent with the observation that the A566T mutation alters the overlapping WHV surface antigen reading frame. WHV carrying mutations in the conserved YMDD motif, while not directly selected during lamivudine therapy in WHV carrier woodchucks, are replication competent in cell culture indicating the potential for their emergence in treated animals. These results further illustrate the utility of the WHV/woodchuck model to studies of HBV-drug resistance.
Collapse
Affiliation(s)
- Kathleen M Tatti
- Laboratory of Biochemical Pharmacology, Department of Pediatrics, Veterans Affairs Medical Center and Emory University, Medical Research 151H, 1670 Clairmont Road, Decatur, GA 30033, USA
| | | | | | | | | | | | | |
Collapse
|
22
|
Hurwitz SJ, Tennant BC, Korba BE, Liberman I, Gerin JL, Schinazi RF. Viral pharmacodynamic model for (-)-beta-2',3'-dideoxy-5-fluoro-3'-thiacytidine (emtricitabine) in chronically infected woodchucks. Antivir Chem Chemother 2002; 13:165-76. [PMID: 12448689 DOI: 10.1177/095632020201300303] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
There is a need for adequate models of virus depletion in animals and humans as a function of drug dose in order to plan starting dose regimens in the clinic for new antiretroviral nucleoside agents. An indirect response pharmacodynamic model was fitted to link the plasma pharmacokinetics from a 28 day treatment with the nucleoside reverse transcription inhibitor emtricitabine [(-)-FTC], with the resulting virus depletion and recovery profiles in woodchucks chronically infected with woodchuck hepatitis B virus. In this approach it is assumed that the virus is eliminated from serum in a first order fashion and that the fraction of serum virus load produced per day is inhibited by the accumulation of nucleoside triphosphate in a manner that could be described using a Hill equation. Nadir virus load values were inversely related to pretreatment virus load levels within each dose group. A median inhibitory concentration value of 1.5 microM for (-)-FTC triphosphate, previously measured against the isolated viral polymerase of woodchuck hepatitis, was used in model fitting. The fitted value for concentration exponent eta of 3.46 indicated a greater than linear sensitivity of virus inhibition with dose. Since the post-treatment virus rebound was much greater than predictions of an initial model, a dose-dependent rebound factor was incorporated in the final model. The rebound factor was maximal at the end of (-)-FTC treatment and decayed mono-exponentially with a rate constant Kreb of 0.11/day. The model inferred decay half-life of (-)-FTC triphosphate in the apparent 'effect compartment' of the model was similar to the half-life value previously estimated for human hepatitis B virus-infected hepatocytes. The model described adequately the virus depletion and recovery profiles for the dose range tested and could be adapted for the selection of starting doses for future animal and human studies with emtricitabine and other nucleoside analogues in development.
Collapse
Affiliation(s)
- Selwyn J Hurwitz
- Department of Pediatrics, Emory University School of Medicine, Veterans Affairs Medical Center, Decatur, Ga., USA
| | | | | | | | | | | |
Collapse
|
23
|
Chong Y, Chu CK. Efficient synthesis of 2-deoxy-L-erythro-pentose (2-deoxy-L-ribose) from L-arabinose. Carbohydr Res 2002; 337:397-402. [PMID: 11861013 DOI: 10.1016/s0008-6215(01)00329-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An efficient and practical route for the large-scale synthesis of 2-deoxy-L-erythro-pentose (2-deoxy-L-ribose) starting from L-arabinose was developed using Barton-type free-radical deoxygenation reaction as a key step. The radical precursor, a phenoxythiocarbonyl ester, was prepared in situ, and the most efficient deoxygenation was achieved by slow addition of tributyltin hydride to the reaction mixture.
Collapse
Affiliation(s)
- Youhoon Chong
- Department of Pharmaceutical and Biomedical Sciences, Center for Drug Discovery, College of Pharmacy, The University of Georgia, Athens, GA 30602, USA
| | | |
Collapse
|
24
|
Staschke KA, Colacino JM. Drug discovery and development of antiviral agents for the treatment of chronic hepatitis B virus infection. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2001; Spec No:111-83. [PMID: 11548207 DOI: 10.1007/978-3-0348-7784-8_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A safe and effective vaccine for hepatitis B virus (HBV) has been available for nearly twenty years and currently campaigns to provide universal vaccination in developing countries are underway. Nevertheless, chronic HBV infection remains a leading cause of chronic hepatitis worldwide and there is a strong need for safe and effective antiviral therapies. Attempts to identify and develop antiviral agents to treat chronic HBV infection remains focused on nucleoside analogs such as 3TC (lamivudine), adefovir dipivoxil, (bis-POMPMEA), and others. However, advances in our understanding of the molecular biology of HBV and the development of new assays for HBV polymerase activity, such as the reconstitution of active HBV polymerase in vitro, should facilitate large screening efforts for non-nucleoside reverse transcriptase inhibitors. Recent advances have furthered our understanding of clinical resistance to lamivudine, have provided new approaches to treatment, and have offered new perspectives on the major challenges to the identification and development of antiviral agents for chronic HBV infection. Here, in an update to our previous review article that appeared in this series [59a], we focus on recent advances that have occurred in the areas of virus structure and replication, in vitro viral polymerase assays, cell culture systems, and animal models.
Collapse
Affiliation(s)
- K A Staschke
- Infectious Diseases Research, Lilly Research Laboratories, Indianapolis, IN, USA
| | | |
Collapse
|
25
|
Jeeninga RE, Keulen W, Boucher C, Sanders RW, Berkhout B. Evolution of AZT resistance in HIV-1: the 41-70 intermediate that is not observed in vivo has a replication defect. Virology 2001; 283:294-305. [PMID: 11336554 DOI: 10.1006/viro.2001.0888] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The human immunodeficiency virus type 1 (HIV-1) is notorious for its ability to evolve drug-resistance in patients treated with potent antivirals. Resistance to inhibitors of the viral reverse transcriptase (RT) enzyme is frequently mediated by a single amino acid substitution within RT. Resistance against the nucleoside analogue AZT is remarkable in that multiple amino acid changes accumulate over time to yield virus variants with high-level drug resistance. We now report that in addition to drug-resistance properties, the relative replication capacity of the virus variants affects the evolution of AZT resistance. Some of the typical AZT-resistance mutations have a negative impact on virus replication, and the 41-70 double mutant was found to represent a particularly poor virus. Furthermore, introduction of additional AZT-resistance mutations (41-70-215) leads to nearly complete restoration of virus replication. These results may explain the absence of the 41-70 double mutant in clinical samples and indicate that the evolution of AZT resistance is also influenced by virus replication parameters. Prolonged passage of the replication-impaired 41-70 virus in the absence of AZT yielded several fast-replicating variants. These revertants have compensatory changes in the RT polymerase, some of which have been observed previously in AZT-treated patients. Because we could select for these changes without drug pressure, these changes are likely to improve the RT enzyme function and the HIV-1 replication capacity.
Collapse
Affiliation(s)
- R E Jeeninga
- Department of Human Retrovirology, Academic Medical Center, University of Amsterdam, The Netherlands
| | | | | | | | | |
Collapse
|
26
|
Griffon JF, Mathé C, Faraj A, Aubertin AM, De Clercq E, Balzarini J, Sommadossi JP, Gosselin G. Stereospecific synthesis and biological evaluations of beta-L-pentofuranonucleoside derivatives of 5-fluorouracil and 5-fluorocytosine. Eur J Med Chem 2001; 36:447-60. [PMID: 11451533 DOI: 10.1016/s0223-5234(01)01238-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the search for new chemotherapeutic agents, we have focused our work on the synthesis and the study of several unnatural beta-L-nucleoside analogues. In this paper, we report on the synthesis of beta-L-pentofuranonucleosides (and their 2'-deoxy derivatives) of 5-fluorouracil and their inhibitory effects on the proliferation of several murine and human tumor cells. The corresponding 5-fluorocytosine derivatives were also synthesized and their anti-HIV and anti-HBV activities have been evaluated.
Collapse
Affiliation(s)
- J F Griffon
- Laboratoire de Chimie Organique Biomoléculaire de Synthèse, UMR 5625 CNRS-UM II, Université Montpellier II, case courrier 008, Place Eugène Bataillon, F-34095 Montpellier, France
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Fischer KP, Gutfreund KS, Tyrrell DL. Lamivudine resistance in hepatitis B: mechanisms and clinical implications. Drug Resist Updat 2001; 4:118-28. [PMID: 11512520 DOI: 10.1054/drup.2001.0190] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lamivudine (beta-L-(-)-2',3'-dideoxy-3'-thiacytidine) has been a major breakthrough in the care of patients with hepatitis B. With prolonged monotherapy the development of resistance is an increasingly recognized problem that limits the long term efficacy of this nucleoside analogue. The most common mutations associated with lamivudine resistance occur within the highly conserved YMDD motif in the C domain of the viral polymerase and are often associated with a compensatory mutation in the proximal B domain. The structural and functional relationship of resistance mutations is reflected in different in vitro sensitivities to lamivudine and changes in replication capacities. During prolonged lamivudine treatment there can be successive changes of different resistant mutants (genotypic succession) or a single mutant can remain the dominant viral species. In patients treated for chronic hepatitis B infection the cumulative incidence of viral resistance reaches over 50% after 3 years. Most patients will have lower serum HBV DNA levels after the emergence of resistance which is ascribed to the decreased replication capacity of these mutants. Although severe flares and ongoing HBe antigen seroconversion can occur in these patients with lamivudine-resistant HBV, the impact of continued therapy on the long-term outcome is still insufficiently studied. In the setting of liver transplantation for HBV-associated disease the clinical course after the emergence of viral resistance is variable but still may lead to disease progression and graft failure. Analogous to the success of combination therapies to delay the emergence of antiviral-resistant HIV, it will be important to combine anti-HBV agents with additive or synergistic antiviral properties and different resistance profiles for future de novo combination therapies for hepatitis B infection.
Collapse
Affiliation(s)
- K P Fischer
- Departments of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
| | | | | |
Collapse
|
28
|
Placidi L, Faraj A, Loi AG, Pierra C, Egron D, Cretton-Scott E, Gosseli G, Périgaud C, Martin LT, Schinazi RF, Imbach JL, el Kouni MH, Bryant ML, Sommadossi JP. Antiviral activity and intracellular metabolism of bis(tButylSATE) phosphotriester of beta-L-2',3'dideoxyadenosine, a potent inhibitor of HIV and HBV replication. Antivir Chem Chemother 2001; 12:99-108. [PMID: 11527047 DOI: 10.1177/095632020101200203] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The beta-L-nucleoside analogue beta-L-2',3'-dideoxy adenosine (beta-L-ddA) has been shown to exhibit limited antiviral activities. This was attributed to its rapid catabolism through cleavage of the glycosidic bond and poor phosphorylation to the nucleotide beta-L-2',3'-dideoxyadenosine-5'-mono phosphate (beta-L-ddAMP) (Placidi et al., 2000). However, the nucleotide beta-L-2',3'-dideoxyadenosine-5'-triphosphate (beta-L-ddATP) inhibited the activity of both HIV-1 reverse transcriptase (RT) and viral DNA polymerase isolated from woodchuck hepatitis virus-infected serum (a model of hepatitis B) with an inhibitory concentration (IC50) of 2.0 microM without inhibiting human DNA polymerases alpha, beta, or gamma up to a concentration of 100 microM. These results suggested that prodrugs of beta-L-ddAMP may bypass the poor metabolic activation of beta-L-ddA and lead to more potent and selective antiviral activity. Therefore, the mononucleoside phosphotriester derivative of beta-L-ddAMP incorporating the S-pivaloyl-2-thioethyl (tButylSATE) groups, beta-L-ddAMP-bis(tButylSATE) was synthesized. Beta-L-ddAMP-bis(tButylSATE) inhibited HIV replication in human peripheral blood mononuclear cells (PBMCs) and HBV replication in 2.2.15 cells with effective concentrations (EC50s) of 2 and 80 nM, respectively. Intracellular metabolism of beta-L-ddAMP-bis(tButylSATE) demonstrated that beta-L-ddATP was the predominant intracellular metabolite in PBMC and liver cells. The intracellular half-life of beta-L-ddATP was 5.4 and 9.2 h in HepG2 and PBMCs, respectively. The intracellular concentrations of beta-L-ddATP were maintained above the EC50 for the inhibition of HIV RT and hepatitis B virus (HBV) for as long as 24 h after removal of the drug.
Collapse
Affiliation(s)
- L Placidi
- Department of Pharmacology, University of Alabama at Birmingham, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Bryant ML, Bridges EG, Placidi L, Faraj A, Loi AG, Pierra C, Dukhan D, Gosselin G, Imbach JL, Hernandez B, Juodawlkis A, Tennant B, Korba B, Cote P, Marion P, Cretton-Scott E, Schinazi RF, Sommadossi JP. Antiviral L-nucleosides specific for hepatitis B virus infection. Antimicrob Agents Chemother 2001; 45:229-35. [PMID: 11120971 PMCID: PMC90266 DOI: 10.1128/aac.45.1.229-235.2001] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2000] [Accepted: 10/10/2000] [Indexed: 12/17/2022] Open
Abstract
A unique series of simple "unnatural" nucleosides has been discovered to inhibit hepatitis B virus (HBV) replication. Through structure-activity analysis it was found that the 3'-OH group of the beta-L-2'-deoxyribose of the beta-L-2'-deoxynucleoside confers specific antihepadnavirus activity. The unsubstituted nucleosides beta-L-2'-deoxycytidine, beta-L-thymidine, and beta-L-2'-deoxyadenosine had the most potent, selective, and specific antiviral activity against HBV replication. Human DNA polymerases (alpha, beta, and gamma) and mitochondrial function were not affected. In the woodchuck model of chronic HBV infection, viral load was reduced by as much as 10(8) genome equivalents/ml of serum and there was no drug-related toxicity. In addition, the decline in woodchuck hepatitis virus surface antigen paralleled the decrease in viral load. These investigational drugs, used alone or in combination, are expected to offer new therapeutic options for patients with chronic HBV infection.
Collapse
Affiliation(s)
- M L Bryant
- Novirio Pharmaceuticals, Inc., Cambridge, Massachusetts 02140, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Mathé C, Gosselin G. Synthesis and antiviral evaluation of the beta-L-enantiomers of some thymine 3'-deoxypentofuranonucleoside derivatives. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2000; 19:1517-30. [PMID: 11200256 DOI: 10.1080/15257770008045443] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
3'-Deoxy-beta-L-erythro- (3), 3'-deoxy-beta-L-threo- (6), 2'-fluoro- (7) and 2'-azido-2',3'-dideoxy-beta-L-erythro- (10) pentofuranonucleoside derivatives of thymine have been synthesized and their antiviral properties examined. All these derivatives were stereospecifically prepared by glycosylation of thymine with a suitable peracylated 3-deoxy-L-erythro-pentofuranose sugar (1), followed by appropriate chemical modifications. The prepared compounds were tested for their activity against HIV, but they did not show an antiviral effect.
Collapse
Affiliation(s)
- C Mathé
- Laboratoire de Chimie Organique Biomoléculaire de Synthèse, UMR 5625 CNRS-UM-II, Université Montpellier II, Sciences et Techniques du Languedoc, France
| | | |
Collapse
|
31
|
Korba BE, Schinazi RF, Cote P, Tennant BC, Gerin JL. Effect of oral administration of emtricitabine on woodchuck hepatitis virus replication in chronically infected woodchucks. Antimicrob Agents Chemother 2000; 44:1757-60. [PMID: 10817750 PMCID: PMC89954 DOI: 10.1128/aac.44.6.1757-1760.2000] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Emtricitabine [(-)FTC] [(-)-beta-2', 3'-dideoxy-5-fluoro-3'-thiacytidine] has been shown to be an effective inhibitor of hepatitis B virus (HBV) in cell culture, with a potency and selectivity that are essentially identical to those of lamivudine. The antiviral activity of oral administration of (-)FTC against WHV replication in chronically infected woodchucks, an established and predictive model for antiviral therapy against HBV, was examined in a placebo-controlled study. (-)FTC significantly reduced viremia and intrahepatic WHV replication in a dose-dependent manner that was comparable to the antiviral activity of lamivudine observed in previous studies conducted by our laboratories. No effect on the levels of hepatic WHV RNA or the levels of woodchuck hepatitis surface antigen or anti-woodchuck hepatitis surface and core antibodies in the serum of the treated animals was observed. No evidence of drug-related toxicity was observed in any of the animals treated.
Collapse
Affiliation(s)
- B E Korba
- Division of Molecular Virology and Immunology, Georgetown University Medical Center, Rockville, Maryland 20850, USA.
| | | | | | | | | |
Collapse
|
32
|
Maury G. The enantioselectivity of enzymes involved in current antiviral therapy using nucleoside analogues: a new strategy? Antivir Chem Chemother 2000; 11:165-89. [PMID: 10901289 DOI: 10.1177/095632020001100301] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This review is primarily intended for synthetic bio-organic chemists and enzymologists who are interested in new strategies in the design of virus inhibitors. It is an attempt to assess the importance of the enzymatic properties of L-nucleosides and their analogues, particularly those that are active against viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), herpes simplex virus (HSV), etc. Only data obtained with purified enzymes have been considered and discussed. The examined enzymes include nucleoside- or nucleotide-phosphorylating enzymes, catabolic enzymes, viral target enzymes and cellular polymerases. The enantioselectivities of these enzymes were determined from existing data and are significant only when a sufficient number of enantiomeric pairs of substrates could be examined. The reported data emphasize the weak enantioselectivities of cellular or viral nucleoside kinases and some viral DNA polymerases. Thus, cellular deoxycytidine kinase has a considerably relaxed enantioselectivity with respect to a large number of nucleosides or their analogues, and it occupies a strategic position in the intracellular activation of the compounds. Similarly, HIV-1 reverse transcriptase often has a relatively weak enantioselectivity and can be inhibited by the 5-triphosphates of a large series of L-nucleosides and analogues. In contrast, degradation enzymes, such as adenosine or cytidine deaminases, generally demonstrate strict enantioselectivities favouring D-enantiomers and are used by chemists in asymmetric syntheses. The weak enantioselectivities of some enzymes involved in nucleoside metabolism are more or less pronounced, and one enantiomer or the other is favoured depending on the substrate. This suggests that the low enantioselectivity is fortuitous and does not result from evolutionary pressure, since these enzymes do not create or modify asymmetric centres in substrates. The combined enantioselectivities of the enzymes examined in this review strongly suggest that the field of L-nucleosides and their analogues should be systematically explored in the search for new virus inhibitors.
Collapse
Affiliation(s)
- G Maury
- UMR 5625 du CNRS, Université Montpellier II, France.
| |
Collapse
|
33
|
Placidi L, Cretton-Scott E, Gosselin G, Pierra C, Schinazi RF, Imbach JL, el Kouni MH, Sommadossi JP. Intracellular metabolism of beta-L-2',3'-dideoxyadenosine: relevance to its limited antiviral activity. Antimicrob Agents Chemother 2000; 44:853-8. [PMID: 10722481 PMCID: PMC89782 DOI: 10.1128/aac.44.4.853-858.2000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular metabolism of the beta-L- enantiomer of 2', 3'-dideoxyadenosine (beta-L-ddA) was investigated in HepG2 cells, human peripheral blood mononuclear cells (PBMC), and primary cultured human hepatocytes in an effort to understand the metabolic basis of its limited activity on the replication of human immunodeficiency virus and hepatitis B virus. Incubation of cells with 10 microM [2',3',8-(3)H]-beta-L-ddA resulted in an increased intracellular concentration of beta-L-ddA with time, demonstrating that these cells were able to transport beta-L-ddA. However, it did not result in the phosphorylation of beta-L-ddA to its pharmacologically active 5'-triphosphate (beta-L-ddATP). Five other intracellular metabolites were detected and identified as beta-L-2', 3'-dideoxyribonolactone, hypoxanthine, inosine, ADP, and ATP, with the last being the predominant metabolite, reaching levels as high as 5.14 +/- 0.95, 8.15 +/- 2.64, and 15.60 +/- 1.74 pmol/10(6) cells at 8, 4, and 2 h in HepG2 cells, PBMC, and hepatocytes, respectively. In addition, a beta-glucuronic derivative of beta-L-ddA was detected in cultured hepatocytes, accounting for 12.5% of the total metabolite pool. Coincubation of hepatocytes in primary culture with beta-L-ddA in the presence of increasing concentrations of 5'-methylthioadenosine resulted in decreased phosphorolysis of beta-L-ddA and formation of associated metabolites. These results indicate that the limited antiviral activity of beta-L-ddA is the result of its inadequate phosphorylation to the nucleotide level due to phosphorolysis and catabolism of beta-L-ddA by methylthioadenosine phosphorylase (EC 2.4.2.28).
Collapse
Affiliation(s)
- L Placidi
- Department of Pharmacology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Pierra C, Imbach JL, De Clercq E, Balzarini J, Van Aerschot A, Herdewijn P, Faraj A, Loi AG, Sommadossi JP, Gosselin G. Synthesis and antiviral evaluation of some beta-L-2', 3'-dideoxy-5-chloropyrimidine nucleosides and pronucleotides. Antiviral Res 2000; 45:169-83. [PMID: 10771081 DOI: 10.1016/s0166-3542(00)00069-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The synthesis and in vitro anti human immunodeficiency virus (HIV) and anti-hepatitis B virus (HBV) activities of some unnatural beta-L-nucleoside enantiomers related to the anti-HIV compound 2', 3'-dideoxy-3'-fluoro-5-chlorouridine (beta-D-3'Fdd5ClU) are reported. In contrast to beta-D-3'Fdd5ClU, beta-L-3'Fdd5ClU and the other L-congeners were devoid of significant anti-HIV effects, but beta-L-2',3'-dideoxy-5-chlorocytidine (beta-L-dd5ClC) and beta-L-2', 3'-dideoxy-3'-fluoro-cytidine (beta-L-3'FddC) showed a distinct anti-HBV activity. Three mononucleoside phosphotriester derivatives with S-pivaloyl-2-thioethyl (t-BuSATE) groups as biolabile phosphate protective groups were also synthesized. The bis(t-BuSATE) derivative of beta-D-3'Fdd5ClU retained anti-HIV activity in thymidine kinase deficient (TK(-)) CEM cells.
Collapse
Affiliation(s)
- C Pierra
- Laboratoire de Chimie Organique Biomoléculaire de Synthèse, UMR CNRS 5625, Case Courrier 008, Université Montpellier II, Place Eugène Bataillon, 34095, Montpellier, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Mathé C, Imbach JL, Gosselin G. 1,2-di-O-acetyl-5-O-benzoyl-3-deoxy-L-erythro-pentofuran ose, a convenient precursor for the stereospecific synthesis of nucleoside analogues with the unnatural beta-L-configuration. Carbohydr Res 2000; 323:226-9. [PMID: 10782306 DOI: 10.1016/s0008-6215(99)00267-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The title compound 1,2-di-O-acetyl-5-O-benzoyl-3-deoxy-L-erythro-pentofuranose (5), a useful precursor for the stereospecific synthesis of beta-L-nucleoside analogues as potential antiviral agents, has been synthesised by a multi-step reaction sequence from L-xylose with a 38% overall yield. The preparation involved conversion of L-xylose to 1,2-O-isopropylidene-alpha-L-xylofuranose which, upon selective 5-O-benzoylation and subsequent radical deoxygenation, provided the protected 3-deoxy sugar derivative. Finally, cleavage of the acetonide group gave the resulting 5-O-benzoyl-3-deoxy-L-erythro-pentose which was acetylated to afford crystalline alpha,beta-5.
Collapse
Affiliation(s)
- C Mathé
- Laboratoire de Chimie Organique Biomoléculaire de Synthèse, UMR CNRS-UM II 5625, Université Montpellier II, France.
| | | | | |
Collapse
|
36
|
Martin LT, Cretton-Scott E, Placidi L, Faraj A, Loi AG, Schinazi RF, McClure HM, Gosselin G, Imbach JL, Sommadossi JP. In vitro and in vivo metabolism and pharmacokinetics of bis [(t-butyl)-S-acyl-2-thioethyl]-beta-L-2',3'-dideoxy-5-fluorocytidine monophosphate. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2000; 19:481-99. [PMID: 10772729 DOI: 10.1080/15257770008033023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Exposure to 10 &M L-FddCMP-bisSATE led to formation of intracellular L-FddCTP levels of 410.1(+/-) +/- 46.2 and 242.1 +/- 13.2 pmol/10(6) cells in unstimulated and PHAstimulated PBM cells, respectively; whereas, exposure of cells to the parent nucleoside, L-FddC, generated 5-10-fold less L-FddCTP. In Hep-G2 cells and EGF/HGF stimulated and unstimulated primary cultured hepatocytes, the active metabolite reached 113 +/- 29, 23.9 +/- 15.6, and 20.6 +/- 10.5 pmol/10(6) cells. Three other metabolites, L-FddCMP-monoSATE, L-FddCMP-SH, and M I, were detected intracellularly and extracellularly in all cell types examined. Intravenous administered dose of 3 mg/kg L-FddCMP-bisSATE to rhesus monkeys resulted in plasma concentration levels of 2.06 +/- 1.00 and 0.39 +/- 0.15 &M of L-FddCMP-monoSATE and L-FddC, respectively, while the prodrug was completely cleared metabolically within 15 min. Following oral administration of an equivalent dose, the absolute oral bioavailability of L-FddC derived from L-FddCMP-bisSATE administration was 65%.
Collapse
Affiliation(s)
- L T Martin
- Department of Clinical Pharmacology, University of Alabama at Birmingham, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Marchand A, Mathé C, Imbach JL, Gosselin G. Synthesis and antiviral evaluation of unnatural beta-L-enantiomers of 3'-fluoro- and 3'-azido-2',3'-dideoxyguanosine derivatives. NUCLEOSIDES, NUCLEOTIDES & NUCLEIC ACIDS 2000; 19:205-17. [PMID: 10772710 DOI: 10.1080/15257770008033004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
3'-fluoro-2',3'-dideoxy- (3) and 3'-azido-2',3'-dideoxy- (4) beta-L-ribofuranonucleoside derivatives of guanine have been synthesized and their antiviral properties examined. All these derivatives were regioselectively and stereospecifically prepared by glycosylation of 2-N-acetyl-6-O-(diphenylcarbamoyl)guanine 5 with a suitable peracylated L-xylo-furanose sugar 6, followed by appropriate chemical modifications. The prepared compounds were tested for their activity against HIV and HBV viruses, but they did not show significant activity.
Collapse
Affiliation(s)
- A Marchand
- Laboratoire de Chimie Organique Biomoléculaire de Synthèse, U.M.R. CNRS 5625, Université de Montpellier II, France
| | | | | | | |
Collapse
|
38
|
Boudou V, Imbach JL, Gosselin G. Synthesis and biological evaluation of 9-(beta-L-arabinofuranosyl)adenine. NUCLEOSIDES & NUCLEOTIDES 1999; 18:2463-73. [PMID: 10639749 DOI: 10.1080/07328319908044620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
For the first time, the stereospecific synthesis of 9-(beta-L-arabinofuranosyl) adenine was carried out. Unfortunately, and unlike its "natural" D-counterpart Vidarabine, this L-enantiomer did not show significant activity when evaluated against a broad range of viruses.
Collapse
Affiliation(s)
- V Boudou
- Laboratoire de Chimie Bioorganique, UMR C.N.R.S. 5625, Université de Montpellier II, Sciences et Techniques du Languedoc, France
| | | | | |
Collapse
|
39
|
Varaprasad CV, Averett D, Ramasamy KS, Wu J. Synthesis and structural studies of monocyclic 4′-Aza-L-Nucleosides. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00837-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
40
|
Development and optimization of anti-HIV nucleoside analogs and prodrugs: A review of their cellular pharmacology, structure-activity relationships and pharmacokinetics. Adv Drug Deliv Rev 1999; 39:117-151. [PMID: 10837771 DOI: 10.1016/s0169-409x(99)00023-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Significant improvements in antiviral therapy have been realized over the past 10 years. Numerous nucleoside analogs, as well as prodrugs of active compounds, have been synthesized and tested for anti-HIV activity. In addition to the five nucleoside analogs currently used clinically for the treatment of HIV infection, a broad spectrum of anti-HIV nucleoside analogs (including 2',3'-dideoxynucleoside analogs, oxathiolanyl 2',3'-dideoxynucleoside analogs, dioxolanyl 2',3'-dideoxynucleoside analogs, carbocyclic 2',3'-dideoxynucleoside analogs and acyclic nucleoside analogs) and their prodrugs (including ester prodrugs, phospholipid prodrugs, dihydropyridine prodrugs, pronucleotides and dinucleotide analogs), targeted at HIV reverse transcriptase, are reviewed with focus on structure-activity relationships, cellular pharmacology and pharmacokinetics. Several of these anti-viral agents show promise in the treatment of AIDS.
Collapse
|
41
|
Cavalcanti SC, Xiang Y, Newton MG, Schinazi RF, Cheng YC, Chu CK. Synthesis of 2',3'-dideoxy-2'-fluoro-L-threo-pentofuranosyl nucleosides as potential antiviral agents. NUCLEOSIDES & NUCLEOTIDES 1999; 18:2233-52. [PMID: 10616728 DOI: 10.1080/07328319908044878] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A series of 2',3'-dideoxy-2'-fluoro-L-threo-pentofuranosyl nucleosides has been synthesized as potential antiviral agents. The synthesized compounds were evaluated against HIV-1, HBV, HSV-1, and HSV-2. Among the synthesized analogues, only the cytosine derivative showed moderate antiviral activity against HIV and HBV.
Collapse
Affiliation(s)
- S C Cavalcanti
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens 30602, USA
| | | | | | | | | | | |
Collapse
|
42
|
Schinazi RF, Ilan E, Black PL, Yao X, Dagan S. Cell-based and animal models for hepatitis B and C viruses. Antivir Chem Chemother 1999; 10:99-114. [PMID: 10431609 DOI: 10.1177/095632029901000301] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Reliable cell-based assays and animal models have been developed for evaluating agents against hepatitis B virus. Although much progress has been made, in vitro and in vivo assays for hepatitis C virus are still on the horizon. Advances towards establishing inexpensive and reliable experimental models have accelerated the development of therapeutic modalities for these life-threatening viral infections. The characterization of well-defined viral targets coupled with improved molecular diagnostic technologies have illuminated this field.
Collapse
Affiliation(s)
- R F Schinazi
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA.
| | | | | | | | | |
Collapse
|
43
|
Loi AG, Faraj A, Pierra C, Gosselin G, Imbach JL, Locarnini SA, Groman EV, Schinazi RF, Sommadossi JP. Comparison of anti-HBV activity of beta-D- and beta-L-DDA-5'monophosphate prodrugs and effectiveness in combination with lamivudine. NUCLEOSIDES & NUCLEOTIDES 1999; 18:1005-6. [PMID: 10432731 DOI: 10.1080/15257779908041630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
We have investigated the effects of several beta-D-ddA 5'-monophospate (beta-D-ddAMP), and their corresponding beta-L-enantiomers prodrugs against HBV replication. All ddAMP prodrugs inhibited HBV replication in a dose-dependent manner.
Collapse
Affiliation(s)
- A G Loi
- Department of Pharmacology, Univ. of Alabama at Birmingham, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Pierra C, Gosselin G, Sommadossi JP, Faraj A, De Clercq E, Balzarini J, Imbach JL. Stereospecific synthesis and antiviral activities of beta-L-2',3'-dideoxy-5-chloropyrimidine nucleoside derivatives. NUCLEOSIDES & NUCLEOTIDES 1999; 18:643-4. [PMID: 10432657 DOI: 10.1080/15257779908041526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Several 5-chlorouracil and 5-chlorocytosine beta-L-dideoxynucleosides were stereospecifically synthesized and their activities against human immunodeficiency virus (HIV) and hepatitis B virus (HBV) were examined in cell culture.
Collapse
Affiliation(s)
- C Pierra
- Laboratoire de Chimie Bioorganique, UMR CNRS 5625, Université de Montpellier II, France
| | | | | | | | | | | | | |
Collapse
|
45
|
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%.
Collapse
Affiliation(s)
- L T Martin
- Department of Clinical Pharmacology, University of Alabama, Birmingham 35294, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
46
|
From d-to l-nucleoside analogs as antiviral agents. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1075-8593(99)80003-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
|
47
|
Shafiee M, Griffon JF, Gosselin G, Cambi A, Vincenzetti S, Vita A, Eriksson S, Imbach JL, Maury G. A comparison of the enantioselectivities of human deoxycytidine kinase and human cytidine deaminase. Biochem Pharmacol 1998; 56:1237-42. [PMID: 9802336 DOI: 10.1016/s0006-2952(98)00165-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The stereoselectivities of recombinant human deoxycytidine kinase (EC 2.7.1.74) (dCK) and of recombinant human cytidine deaminase (EC 3.5.4.5) (CDA) were investigated with respect to a series of cytidine analogs, most of them having the unnatural L-stereochemistry. The enantioselectivity of dCK was always low and generally favored the L-enantiomers in the case of beta-2',3'-dideoxycytidine (beta-ddC), 5-fluoro-beta-2',3'-dideoxycytidine (beta-FddC) and beta-cytidine (beta-riboC). Concerning beta-2'-deoxycytidine, dCK showed a preference for the D-enantiomer. All other examined beta-L-cytidine analogs, [1-beta-L-lyxofuranosyl cytosine (beta-L-lyxoC), l-beta-L-xylofuranosyl cytosine (beta-L-xyloC), and 5-fluoro-1-beta-L-xylofuranosyl cytosine (beta-L-Fxylo C)], were substrates of dCK regardless of the nature of the pentose. None of the studied alpha-L-anomers (alpha-L-riboC, alpha-L-araC, alpha-L-lyxoC, or alpha-L-xyloC) was a substrate of dCK. Contrasting with the relaxed enantioselectivity of dCK, CDA had a strict requirement for D-cytidine analogs since none of the already listed beta-L- or alpha-L analogs was a substrate or an inhibitor of the enzyme. The conjunction of the preceding stereochemical properties of dCK and CDA confers to L-cytidine analogs important potentialities in antiviral and anticancer therapies.
Collapse
Affiliation(s)
- M Shafiee
- Laboratoire de Chimie Bioorganique, UMR 5625 du CNRS, Université Montpellier II, France
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Delaney WE, Isom HC. Hepatitis B virus replication in human HepG2 cells mediated by hepatitis B virus recombinant baculovirus. Hepatology 1998; 28:1134-46. [PMID: 9755254 DOI: 10.1002/hep.510280432] [Citation(s) in RCA: 120] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A novel transient mechanism for studying hepatitis B virus (HBV) gene expression and replication using recombinant HBV baculovirus to deliver the HBV genome to HepG2 cells was generated. In HBV baculovirus infected HepG2 cells, HBV transcripts, and intracellular and secreted HBV antigens are produced; replication occurs as evidenced by the presence of high levels of intracellular replicative intermediates and protected HBV DNA in the medium. Density-gradient analysis of extracellular HBV DNA indicated that the DNA was contained predominantly in enveloped HBV virions. Covalently closed circular (CCC) DNA is present indicating that, in this system, HBV core particles are capable of delivering newly synthesized HBV genomes back into the nuclei of infected cells. HBV gene expression is driven exclusively from endogenous promoters. Levels of HBV gene expression and replication can be achieved in HBV baculovirus-infected HepG2 cells which far exceed levels found in HepG2 2.2.15 cells. HBV baculovirus infection of HepG2 cells lends itself readily to experimental manipulation as follows: 1) HBV expression can be initiated any time relative to seeding of HepG2 cells; 2) levels of HBV replication can be regulated over a wide range simply by changing the baculovirus multiplicity of infection; 3) HBV replication is readily detectable by one day post infection with HBV baculovirus and persists at least through day eleven post infection; and (4) the transient nature of the infection can be extended and/or enhanced by superinfecting the cultures. We conclude that infection of HepG2 cells by HBV recombinant baculovirus represents a simple to use and highly flexible system for studying the effects of antivirals and/or cytokines on HBV production and for understanding HBV replication and pathogenesis at the molecular level.
Collapse
Affiliation(s)
- W E Delaney
- Department of Microbiology and Immunology, Milton S. Hershey Medical Center, The Pennsylvania State University, Hershey, PA 17033, USA
| | | |
Collapse
|
49
|
Colacino JM, Staschke KA. The identification and development of antiviral agents for the treatment of chronic hepatitis B virus infection. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 1998; 50:259-322. [PMID: 9670781 DOI: 10.1007/978-3-0348-8833-2_6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Hepatitis B virus (HBV) is the leading cause of chronic hepatitis throughout the world. Notwithstanding the availability of a safe and effective vaccine, the world prevalence of HBV has not declined significantly, thus resulting in the need for a selective antiviral agent. HBV is a small, partially double-stranded DNA virus which replicates through an RNA intermediate. Most efforts to develop anti-HBV agents have been targeted to the viral DNA polymerase which possesses reverse transcriptase activity. Currently, the most promising anti-HBV agents are nucleoside analogs which interfere with viral DNA replication. Although earlier nucleoside analogs such as vidarabine (ara-A) and fialuridine (FIAU) have displayed unacceptable toxicities, newer analogs such as lamivudine (3TC), bis-POM PMEA (GS-840), lobucavir, and BMS-200,475 have demonstrated clinical utility. In particular, the use of lamivudine has generated considerable interest in the development of other L-enantiomeric nucleoside analogs for use against HBV. Here, we provide an overview of HBV structure and replication strategy and discuss the use of cell culture systems, in vitro viral polymerase systems, and animal models to identify and evaluate anti-HBV agents. We also discuss the various classes of nucleoside analogs in terms of structure, mechanism of action, status in clinical development, ability to select for resistant HBV variants, and use in combination therapies. Finally, we present a discussion of novel antiviral approaches, including antisense and gene therapy, and address the various challenges to successful anti-HBV chemotherapeutic intervention.
Collapse
Affiliation(s)
- J M Colacino
- Infectious Diseases Research, Lilly Research Laboratories, Indianapolis, IN, USA
| | | |
Collapse
|
50
|
|