1
|
Bessières M, Roy V, Abuduani T, Favetta P, Snoeck R, Andrei G, Moffat J, Gallardo F, Agrofoglio LA. Synthesis of LAVR-289, a new [(Z)-3-(acetoxymethyl)-4-(2,4-diaminopyrimidin-6-yl)oxy-but-2-enyl]phosphonic acid prodrug with pronounced antiviral activity against DNA viruses. Eur J Med Chem 2024; 271:116412. [PMID: 38643669 DOI: 10.1016/j.ejmech.2024.116412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 04/11/2024] [Accepted: 04/11/2024] [Indexed: 04/23/2024]
Abstract
New acyclic pyrimidine nucleoside phosphonate prodrugs with a 4-(2,4-diaminopyrimidin-6-yl)oxy-but-2-enyl]phosphonic acid skeleton (O-DAPy nucleobase) were prepared through a convergent synthesis by olefin cross-metathesis as the key step. Several acyclic nucleoside 4-(2,4-diaminopyrimidin-6-yl)oxy-but-2-enyl]phosphonic acid prodrug exhibited in vitro antiviral activity in submicromolar or nanomolar range against varicella zoster virus (VZV), human cytomegalovirus (HCMV), human herpes virus type 1 (HSV-1) and type 2 (HSV-2), and vaccinia virus (VV), with good selective index (SI). Among them, the analogue 9c (LAVR-289) proved markedly inhibitory against VZV wild-type (TK+) (EC50 0.0035 μM, SI 740) and for thymidine kinase VZV deficient strains (EC50 0.018 μM, SI 145), with a low morphological toxicity in cell culture at 100 μM and acceptable cytostatic activity resulting in excellent selectivity. Compound 9c exhibited antiviral activity against HCMV (EC50 0.021 μM) and VV (EC50 0.050 μM), as well as against HSV-1 (TK-) (EC50 0.0085 μM). Finally, LAVR-289 (9c) deserves further (pre)clinical investigations as a potent candidate broad-spectrum anti-herpesvirus drug.
Collapse
Affiliation(s)
- Maximes Bessières
- Institute of Organic and Analytical Chemistry (ICOA UMR 7311), University of Orleans, CNRS, F-45067 Orléans, France
| | - Vincent Roy
- Institute of Organic and Analytical Chemistry (ICOA UMR 7311), University of Orleans, CNRS, F-45067 Orléans, France.
| | - Tuniyazi Abuduani
- Institute of Organic and Analytical Chemistry (ICOA UMR 7311), University of Orleans, CNRS, F-45067 Orléans, France
| | - Patrick Favetta
- Institute of Organic and Analytical Chemistry (ICOA UMR 7311), University of Orleans, CNRS, F-45067 Orléans, France
| | - Robert Snoeck
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium
| | - Graciela Andrei
- Laboratory of Virology and Chemotherapy, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium
| | - Jennifer Moffat
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, NY, 13210 USA
| | | | - Luigi A Agrofoglio
- Institute of Organic and Analytical Chemistry (ICOA UMR 7311), University of Orleans, CNRS, F-45067 Orléans, France.
| |
Collapse
|
2
|
Ford A, Mullins ND, Balzarini J, Maguire AR. Synthesis and Evaluation of Prodrugs of α-Carboxy Nucleoside Phosphonates. J Org Chem 2022; 87:14793-14808. [PMID: 36283025 PMCID: PMC9639015 DOI: 10.1021/acs.joc.2c02135] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A range of lipophilic prodrugs of α-carboxy nucleoside phosphonates, potent inhibitors of HIV-1 reverse transcriptase without requiring prior phosphorylation, were synthesized to evaluate their in vivo potency against HIV in cell culture. A series of prodrug derivatives bearing a free carboxylic acid where the phosphonate was masked with bispivaloyloxymethyl, diisopropyloxycarbonyloxymethyl, bisamidate, aryloxyphosphoramidate, hexadecyloxypropyl, CycloSal, and acycloxybenzyl moieties were synthesized, adapting existing methodologies for phosphonate protection to accommodate the adjacent carboxylic acid moiety. The prodrugs were assayed for anti-HIV activity in CEM cell cultures─the bispivaloyloxymethyl free acid monophosphonate prodrug exhibited some activity (inhibitory concentration-50 (IC50) 59 ± 17 μM), while the other prodrugs were inactive at 100 μM. A racemic bispivaloyloxymethyl methyl ester monophosphonate prodrug was also prepared to assess the suitability of the methyl ester as a carboxylic acid prodrug. This compound exhibited no activity against HIV in cellular assays.
Collapse
Affiliation(s)
- Alan Ford
- School
of Chemistry, Analytical and Biological Chemistry Research Facility,
Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork T12 K8AF, Ireland
| | - Nicholas D. Mullins
- School
of Chemistry, Analytical and Biological Chemistry Research Facility,
Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork T12 K8AF, Ireland
| | - Jan Balzarini
- Rega
Institute for Medical Research, KU Leuven, Herestraat 49, B-3000 Leuven, Belgium
| | - Anita R. Maguire
- School
of Chemistry, Analytical and Biological Chemistry Research Facility,
Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork T12 K8AF, Ireland,School
of Pharmacy, Analytical and Biological Chemistry Research Facility,
Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork T12 K8AF, Ireland,
| |
Collapse
|
3
|
Abdurakhmanova ER, Brusnakov MY, Golovchenko OV, Pilyo SG, Velychko NV, Harden EA, Prichard MN, James SH, Zhirnov VV, Brovarets VS. Synthesis and in vitro anticytomegalovirus activity of 5-hydroxyalkylamino-1,3-oxazoles derivatives. Med Chem Res 2020. [DOI: 10.1007/s00044-020-02593-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
4
|
Beadle JR, Valiaeva N, Yang G, Yu JH, Broker TR, Aldern KA, Harden EA, Keith KA, Prichard MN, Hartman T, Buckheit RW, Chow LT, Hostetler KY. Synthesis and Antiviral Evaluation of Octadecyloxyethyl Benzyl 9-[(2-Phosphonomethoxy)ethyl]guanine (ODE-Bn-PMEG), a Potent Inhibitor of Transient HPV DNA Amplification. J Med Chem 2016; 59:10470-10478. [PMID: 27933957 DOI: 10.1021/acs.jmedchem.6b00659] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Human papillomavirus (HPV) high-risk genotypes such as HPV-16 and HPV-18 cause the majority of anogenital tract carcinomas, including cervical cancer, the second most common malignancy in women worldwide. Currently there are no approved antiviral agents that reduce or eliminate HPV and reverse virus-associated pathology. We synthesized and evaluated several alkoxyalkyl acyclic nucleoside phosphonate diesters and identified octadecyloxyethyl benzyl 9-[(2-phosphonomethoxy)ethyl]guanine (ODE-Bn-PMEG) as an active compound which strongly inhibited transient amplification of HPV-11, -16, and -18 origin-containing plasmid DNA in transfected cells at concentrations well below its cytotoxic concentrations. ODE-Bn-PMEG demonstrated increased uptake in human foreskin fibroblast cells and was readily converted in vitro to the active antiviral metabolite, PMEG diphosphate. The P-chiral enantiomers of ODE-Bn-PMEG were obtained and appeared to have equivalent antiviral activities against HPV. ODE-Bn-PMEG is a promising candidate for the local treatment of HPV-16 and HPV-18 and other high-risk types, an important unmet medical need.
Collapse
Affiliation(s)
- James R Beadle
- University of California, San Diego , La Jolla, California 92093, United States
| | - Nadejda Valiaeva
- University of California, San Diego , La Jolla, California 92093, United States
| | - Guang Yang
- University of Alabama at Birmingham , Birmingham, Alabama 35233, United States
| | - Jei-Hwa Yu
- University of Alabama at Birmingham , Birmingham, Alabama 35233, United States
| | - Thomas R Broker
- University of Alabama at Birmingham , Birmingham, Alabama 35233, United States
| | - Kathy A Aldern
- University of California, San Diego , La Jolla, California 92093, United States
| | - Emma A Harden
- University of Alabama at Birmingham , Birmingham, Alabama 35233, United States
| | - Kathy A Keith
- University of Alabama at Birmingham , Birmingham, Alabama 35233, United States
| | - Mark N Prichard
- University of Alabama at Birmingham , Birmingham, Alabama 35233, United States
| | - Tracy Hartman
- ImQuest BioSciences , Frederick, Maryland 21704, United States
| | | | - Louise T Chow
- University of Alabama at Birmingham , Birmingham, Alabama 35233, United States
| | - Karl Y Hostetler
- University of California, San Diego , La Jolla, California 92093, United States.,Antiva Biosciences, Inc. , South San Francisco, California 94080, United States
| |
Collapse
|
5
|
Klimenko K, Marcou G, Horvath D, Varnek A. Chemical Space Mapping and Structure-Activity Analysis of the ChEMBL Antiviral Compound Set. J Chem Inf Model 2016; 56:1438-54. [PMID: 27410486 DOI: 10.1021/acs.jcim.6b00192] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Curation, standardization and data fusion of the antiviral information present in the ChEMBL public database led to the definition of a robust data set, providing an association of antiviral compounds to seven broadly defined antiviral activity classes. Generative topographic mapping (GTM) subjected to evolutionary tuning was then used to produce maps of the antiviral chemical space, providing an optimal separation of compound families associated with the different antiviral classes. The ability to pinpoint the specific spots occupied (responsibility patterns) on a map by various classes of antiviral compounds opened the way for a GTM-supported search for privileged structural motifs, typical for each antiviral class. The privileged locations of antiviral classes were analyzed in order to highlight underlying privileged common structural motifs. Unlike in classical medicinal chemistry, where privileged structures are, almost always, predefined scaffolds, privileged structural motif detection based on GTM responsibility patterns has the decisive advantage of being able to automatically capture the nature ("resolution detail"-scaffold, detailed substructure, pharmacophore pattern, etc.) of the relevant structural motifs. Responsibility patterns were found to represent underlying structural motifs of various natures-from very fuzzy (groups of various "interchangeable" similar scaffolds), to the classical scenario in medicinal chemistry (underlying motif actually being the scaffold), to very precisely defined motifs (specifically substituted scaffolds).
Collapse
Affiliation(s)
- Kyrylo Klimenko
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France.,Department on Molecular Structure and Chemoinformatics, A.V. Bogatsky Physico-Chemical Institute of NAS of Ukraine , Lyustdorfskaya doroga, 86, Odessa 65080, Ukraine
| | - Gilles Marcou
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France
| | - Dragos Horvath
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France
| | - Alexandre Varnek
- Laboratoire de Chemoinformatique, UMR 7140 CNRS/Université de Strasbourg , 1, rue Blaise Pascal, Strasbourg 67000, France
| |
Collapse
|
6
|
Baszczyňski O, Janeba Z. Medicinal Chemistry of Fluorinated Cyclic and Acyclic Nucleoside Phosphonates. Med Res Rev 2013; 33:1304-44. [DOI: 10.1002/med.21296] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Ondřej Baszczyňski
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; v.v.i. Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Zlatko Janeba
- Institute of Organic Chemistry and Biochemistry; Academy of Sciences of the Czech Republic; v.v.i. Flemingovo nám. 2 16610 Prague 6 Czech Republic
| |
Collapse
|
7
|
Yang K, Wills E, Baines JD. A herpes simplex virus scaffold peptide that binds the portal vertex inhibits early steps in viral replication. J Virol 2013; 87:6876-87. [PMID: 23576509 PMCID: PMC3676109 DOI: 10.1128/jvi.00421-13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 04/03/2013] [Indexed: 12/12/2022] Open
Abstract
Previous experiments identified a 12-amino-acid (aa) peptide that was sufficient to interact with the herpes simplex virus 1 (HSV-1) portal protein and was necessary to incorporate the portal into capsids. In the present study, cells were treated at various times postinfection with peptides consisting of a portion of the Drosophila antennapedia protein, previously shown to enter cells efficiently, fused to either wild-type HSV-1 scaffold peptide (YPYYPGEARGAP) or a control peptide that contained changes at positions 4 and 5. These 4-tyrosine and 5-proline residues are highly conserved in herpesvirus scaffold proteins and were previously shown to be critical for the portal interaction. Treatment early in infection with subtoxic levels of wild-type peptide reduced viral infectivity by over 1,000-fold, while the mutant peptide had little effect on viral yields. In cells infected for 3 h in the presence of wild-type peptide, capsids were observed to transit to the nuclear rim normally, as viewed by fluorescence microscopy. However, observation by electron microscopy in thin sections revealed an aberrant and significant increase of DNA-containing capsids compared to infected cells treated with the mutant peptide. Early treatment with peptide also prevented formation of viral DNA replication compartments. These data suggest that the antiviral peptide stabilizes capsids early in infection, causing retention of DNA within them, and that this activity correlates with peptide binding to the portal protein. The data are consistent with the hypothesis that the portal vertex is the conduit through which DNA is ejected to initiate infection.
Collapse
Affiliation(s)
- Kui Yang
- Department of Microbiology and Immunology, Cornell University, Ithaca, New York, USA
| | | | | |
Collapse
|
8
|
Valiaeva N, Wyles DL, Schooley RT, Hwu JB, Beadle JR, Prichard MN, Hostetler KY. Synthesis and antiviral evaluation of 9-(S)-[3-alkoxy-2-(phosphonomethoxy)propyl]nucleoside alkoxyalkyl esters: inhibitors of hepatitis C virus and HIV-1 replication. Bioorg Med Chem 2011; 19:4616-25. [PMID: 21719300 DOI: 10.1016/j.bmc.2011.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 05/27/2011] [Accepted: 06/02/2011] [Indexed: 12/19/2022]
Abstract
We reported previously that octadecyloxyethyl 9-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]adenine (ODE-(S)-HPMPA) was active against genotype 1b and 2a hepatitis C virus (HCV) replicons. This is surprising because acyclic nucleoside phosphonates have been regarded as having antiviral activity only against double stranded DNA viruses, HIV and HBV. We synthesized octadecyloxyethyl 9-(S)-[3-methoxy-2-(phosphonomethoxy)propyl]-adenine and found it to be active in genotype 1b and 2a HCV replicons with EC₅₀ values of 1-2 μM and a CC₅₀ of > 150 μM. Analogs with substitutions at the 3'-hydroxyl larger than methyl or ethyl, or with other purine bases were less active but most compounds had significant antiviral activity against HIV-1 in vitro. The most active anti-HIV compound was octadecyloxyethyl 9-(R)-[3-methoxy-2-(phosphonomethoxy)propyl]guanine with an EC₅₀ < 0.01 nanomolar and a selectivity index of > 4.4 million.
Collapse
Affiliation(s)
- Nadejda Valiaeva
- Division of Infectious Diseases, University of California, San Diego, USA
| | | | | | | | | | | | | |
Collapse
|
9
|
Prichard MN, Kern ER. The search for new therapies for human cytomegalovirus infections. Virus Res 2010; 157:212-21. [PMID: 21095209 DOI: 10.1016/j.virusres.2010.11.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 11/11/2010] [Accepted: 11/12/2010] [Indexed: 12/19/2022]
Abstract
Ganciclovir (GCV), the therapy of choice for human cytomegalovirus (CMV) infections and foscarnet, a drug used to treat GCV-resistant CMV infections was approved more than twenty years ago. Although cidofovir and a prodrug of GCV have since been added to the armamentarium, a highly effective drug without significant toxicities has yet to be approved. Such a therapeutic agent is required for treatment of immunocompromised hosts and infants, which bear the greatest burden of disease. The modest antiviral activity of existing drugs is insufficient to completely suppress viral replication, which results in the selection of drug-resistant variants that remain pathogenic, continue to replicate, and contribute to disease. Sustained efforts, largely in the biotech industry and academia, have identified highly active lead compounds that have progressed into clinical studies with varying levels of success. A few of these compounds inhibit new molecular targets, remain effective against isolates that have developed resistance to existing therapies, and promise to augment existing therapies. Some of the more promising drugs will be discussed with an emphasis on those progressing to clinical studies. Their antiviral activity both in vitro and in vivo, spectrum of antiviral activity, and mechanism of action will be reviewed to provide an update on the progress of potential new therapies for CMV infections.
Collapse
Affiliation(s)
- Mark N Prichard
- Department of Pediatrics, University of Alabama School of Medicine, Birmingham, AL 35233-1711, USA.
| | | |
Collapse
|
10
|
Müller CE. Prodrug approaches for enhancing the bioavailability of drugs with low solubility. Chem Biodivers 2010; 6:2071-83. [PMID: 19937841 DOI: 10.1002/cbdv.200900114] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Low water solubility and low bioavailability are frequent problems in drug development, particularly in the area of central nervous system (CNS) drugs. This short review describes selected prodrug approaches which have been developed to enhance the bioavailability of drugs, especially that of poorly soluble drugs. Some of the most successful drugs on the market are prodrugs. With a better understanding of active-transport processes at cell membranes in the gut as well as at the blood-brain barrier, the importance of prodrug approaches will further increase in the future. Prodrug approaches will already be considered in the early phase of drug discovery.
Collapse
Affiliation(s)
- Christa E Müller
- PharmaCenter Bonn, University of Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry I, An der Immenburg 4, D-53121 Bonn.
| |
Collapse
|
11
|
Valiaeva N, Prichard MN, Buller RM, Beadle JR, Hartline CB, Keith KA, Schriewer J, Trahan J, Hostetler KY. Antiviral evaluation of octadecyloxyethyl esters of (S)-3-hydroxy-2-(phosphonomethoxy)propyl nucleosides against herpesviruses and orthopoxviruses. Antiviral Res 2009; 84:254-9. [PMID: 19800369 DOI: 10.1016/j.antiviral.2009.09.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 09/22/2009] [Accepted: 09/23/2009] [Indexed: 11/27/2022]
Abstract
Our previous studies showed that esterification of 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]adenine (HPMPA) or 1-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]cytosine (HPMPC) with alkoxyalkyl groups such as hexadecyloxypropyl (HDP) or octadecyloxyethyl (ODE) resulted in large increases in antiviral activity and oral bioavailability. The HDP and ODE esters of HPMPA were shown to be active in cells infected with human immunodeficiency virus, type 1 (HIV-1), while HPMPA itself was virtually inactive. To explore this approach in greater detail, we synthesized four new compounds in this series, the ODE esters of 9-(S)-[3-hydroxy-2-(phosphonomethoxy)-propyl]guanine (HPMPG), 1-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]thymine (HPMPT), 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-2,6-diaminopurine (HPMPDAP) and 9-(S)-[3-hydroxy-2-(phosphonomethoxy)propyl]-2-amino-6-cyclopropylaminopurine (HPMP-cPrDAP) and evaluated their antiviral activity against herpes simplex virus, type 1 (HSV-1), human cytomegalovirus (HCMV), and vaccinia, cowpox and ectromelia. Against HSV-1, subnanomolar EC(50) values were observed with ODE-HPMPA and ODE-HPMPC while ODE-HPMPG had intermediate antiviral activity with an EC(50) of 40 nM. In HFF cells infected with HCMV, the lowest EC(50) values were observed with ODE-HPMPC, 0.9 nM. ODE-HPMPA was highly active with an EC(50) of 3 nM, while ODE-HPMPG and ODE-HPMPDAP were also highly active with EC(50)s of 22 and 77 nM, respectively. Against vaccinia and cowpox viruses, ODE-HPMPG and ODE-HPMPDAP were the most active and selective compounds with EC(50) values of 20-60 nM and selectivity index values of 600-3500. ODE-HPMPG was also active against ectromelia virus with an EC(50) value of 410 nM and a selectivity index value of 166. ODE-HPMPG and ODE-HPMPDAP are proposed for further preclinical evaluation as possible candidates for treatment of HSV, HCMV or orthopoxvirus diseases.
Collapse
Affiliation(s)
- Nadejda Valiaeva
- Department of Medicine, Division of Infectious Disease, University of California, San Diego, La Jolla, CA 92093-0676, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Alkoxyalkyl prodrugs of acyclic nucleoside phosphonates enhance oral antiviral activity and reduce toxicity: current state of the art. Antiviral Res 2009; 82:A84-98. [PMID: 19425198 DOI: 10.1016/j.antiviral.2009.01.005] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Although the acyclic nucleoside phosphonates cidofovir, adefovir and tenofovir are approved for treating human cytomegalovirus, hepatitis B and HIV infections, respectively, their utility is limited by low oral bioavailability, renal toxicity and poor cell penetration. Research over the past decade has shown that these undesirable features can be eliminated by esterifying the compounds with an alkoxyalkyl group, in effect disguising them as lysophospholipids. In this modified form, the drugs are readily taken up in the gastrointestinal tract and have a prolonged circulation time in plasma. The active metabolite also has a long half life within cells, permitting infrequent dosing. Because these modified drugs are not recognized by the transport mechanisms that cause the accumulation of acyclic nucleoside phosphonates in renal tubular cells, they lack nephrotoxicity. Alkoxyalkyl esterification also markedly increases the in vitro antiviral activity of acyclic nucleoside phosphonates by improving their delivery into cells. For example, an alkoxyalkyl ester of cyclic-cidofovir, a less soluble compound, retains anti-CMV activity for 3 months following a single intravitreal injection. Two of these novel compounds, hexadecyloxypropyl-cidofovir (CMX001) and hexadecyloxypropyl-tenofovir (CMX157) are now in clinical development. This article focuses on the hexadecyloxypropyl and octadecyloxyethyl esters of cidofovir and (S)-HPMPA, describing their synthesis and the evaluation of their in vitro and in vivo activity against a range of orthopoxviruses, herpesviruses, adenoviruses and other double-stranded DNA viruses. The extension to other nucleoside phosphonate antivirals is highlighted, demonstrating that this novel approach can markedly improve the medicinal properties of these drugs.
Collapse
|