ABSTRACT
Herein we describe the discovery of IDX21437 35b, a novel RPd-aminoacid-based phosphoramidate prodrug of 2'-α-chloro-2'-ß-C-methyluridine monophosphate. Its corresponding triphosphate 6 is a potent inhibitor of the HCV NS5B RNA-dependent RNA polymerase (RdRp). Despite showing very weak activity in the in vitro Huh-7 cell based HCV replicon assay, 35b demonstrated high levels of active triphosphate 6 in mouse liver and human hepatocytes. A biochemical study revealed that the metabolism of 35b was mainly attributed to carboxyesterase 1 (CES1), an enzyme which is underexpressed in HCV Huh-7-derived replicon cells. Furthermore, due to its metabolic activation, 35b was efficiently processed in liver cells compared to other cell types, including human cardiomyocytes. The selected RP diastereoisomeric configuration of 35b was assigned by X-ray structural determination. 35b is currently in Phase II clinical trials for the treatment of HCV infection.
Subject(s)
Antiviral Agents/pharmacology , DNA-Directed RNA Polymerases/antagonists & inhibitors , Drug Discovery , Enzyme Inhibitors/pharmacology , Hepacivirus/drug effects , Uridine Monophosphate/analogs & derivatives , Uridine/pharmacology , Animals , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , DNA-Directed RNA Polymerases/metabolism , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Hepacivirus/enzymology , Hepatocytes/drug effects , Hepatocytes/virology , Humans , Liver/drug effects , Liver/virology , Mice , Microbial Sensitivity Tests , Molecular Structure , Structure-Activity Relationship , Uridine/chemical synthesis , Uridine/chemistry , Uridine Monophosphate/chemical synthesis , Uridine Monophosphate/chemistry , Uridine Monophosphate/pharmacology , Viral Nonstructural Proteins/antagonists & inhibitors , Viral Nonstructural Proteins/metabolismABSTRACT
BACKGROUND: Ribonucleoside analogs possessing a ß-methyl substituent at the 2'-position of the d-ribose moiety have been previously discovered to be potent and selective inhibitors of hepatitis C virus (HCV) replication, their triphosphates acting as alternative substrate inhibitors of the HCV RdRp NS5B. Results/methodology: In this article, the authors detail the synthesis, anti-HCV evaluation in cell-based replicon assays and structure-activity relationships of several phosphoramidate diester derivatives of 2'-C-methylguanosine (2'-MeG). CONCLUSION: The most promising compound, namely the O-[S-(hydroxyl)pivaloyl-2-thioethyl]{abbreviated as O-[(HO)tBuSATE)]} N-benzylamine phosphoramidate diester derivative (IDX184), was selected for further in vivo studies, and was the first clinical pronucleotide evaluated for the treatment of chronic hepatitis C up to Phase II trials.
Subject(s)
Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Drug Discovery , Guanosine Monophosphate/analogs & derivatives , Hepacivirus/drug effects , Hepatitis C/drug therapy , Guanosine Monophosphate/chemical synthesis , Guanosine Monophosphate/pharmacology , Humans , Structure-Activity RelationshipABSTRACT
A 6-step procedure was developed for the synthesis of a new family of acyclic nucleoside phosphonates (ANPs), "PHEEPA" [(2-pyrimidinyl-2-(2-hydroxyethoxy)ethyl)phosphonic acids] in overall yields ranging from 4.5% to 32%. These compounds, which possess on one side a hydroxy function and on the other side a phosphonate group, can be considered either as potential antiviral agents or as transition state analogues of nucleoside phosphorylases such as thymidine phosphorylase.
Subject(s)
Biomimetic Materials/chemistry , Biomimetic Materials/chemical synthesis , Chemistry Techniques, Synthetic/methods , Nucleosides/chemistry , Organophosphonates/chemistry , Organophosphonates/chemical synthesis , Pyrimidines/chemistry , Pyrimidines/chemical synthesis , Thymidine Phosphorylase/chemistryABSTRACT
Several thieno[3,4-d]pyrimidine derivatives, including four hitherto unknown 2',3'-dideoxy- and 2',3'-dideoxy-2',3'-didehydro-C-nucleoside analogues of adenosine and inosine have been synthesized. When evaluated in cell culture experiments against human immunodeficiency virus, none of the tested compounds exhibited any significant antiviral effect, while two of them showed some cytotoxicity.
Subject(s)
Adenosine/analogs & derivatives , Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Inosine/analogs & derivatives , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , Antiviral Agents/chemistry , HIV/drug effects , Magnetic Resonance Spectroscopy , Pyrimidines/chemistry , Spectrometry, Mass, Electrospray IonizationABSTRACT
The first example of a nucleoside analogue bearing a 5'-deoxy-beta-D-allo-septanose as a seven-membered ring sugar moiety, namely 9-(5-deoxy-beta-D-allo-septanosyl)-adenine, is reported. This compound was synthesized in 14 steps from the commercially available D-glycero-D-gulo-1,4-lactone. When evaluated in cell culture experiments against a broad range of viruses, it did not exhibit any significant antiviral effect or cytotoxicity.
Subject(s)
Nucleosides/chemistry , Nucleosides/chemical synthesis , Oligosaccharides/chemistry , Oligosaccharides/chemical synthesis , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Flavivirus/drug effects , Hepacivirus/drug effects , Models, Chemical , Molecular Structure , Nucleosides/pharmacology , Pestivirus/drug effectsABSTRACT
In the search for inhibitors of the replication of RNA viruses, including hepatitis C virus (HCV), the hitherto unknown 4'-C-azidomethyl-beta-D-ribofuranosyl nucleosides of the five naturally occurring nucleic acid bases have been synthesized and their antiviral properties examined. These 4'-C-branched nucleosides were stereospecifically prepared by glycosylation of purine and pyrimidine aglycons with a suitable peracylated 4-C-azidomethyl-D-pentofuranose sugar, followed by removal of the protecting groups. The prepared compounds were tested for their activity against several viruses, but they did not show an antiviral effect.
Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Purine Nucleosides/chemistry , Purine Nucleosides/pharmacology , Pyrimidine Nucleosides/chemistry , Pyrimidine Nucleosides/pharmacology , RNA Viruses/drug effects , Antiviral Agents/chemical synthesis , Purine Nucleosides/chemical synthesis , Pyrimidine Nucleosides/chemical synthesisABSTRACT
Three 7-fluoro-7-deaza-2-aminopurine nucleoside derivatives were synthesized and evaluated as potential inhibitors of RNA virus replication, including hepatitis C virus (HCV).
Subject(s)
Antiviral Agents/chemical synthesis , Purine Nucleosides/chemical synthesis , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Hepacivirus/drug effects , Purine Nucleosides/chemistry , Purine Nucleosides/pharmacologyABSTRACT
9-Deazaguanosine and the alpha and beta anomers of its 2'-C-methyl counter part, have been synthesized and evaluated against a broad range of RNA viruses, including hepatitis C virus.
Subject(s)
Antiviral Agents/chemical synthesis , Guanosine/analogs & derivatives , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Flavivirus/drug effects , Guanosine/chemical synthesis , Guanosine/chemistry , Guanosine/pharmacology , Hepacivirus/drug effects , Virus Replication/drug effectsABSTRACT
The first example of a nucleoside analogue bearing a 5'-deoxy-beta-D-allo-septanose as the sugar moiety was synthesized and evaluated as a potential inhibitor of several virus replication.
Subject(s)
Adenosine/analogs & derivatives , Antiviral Agents/chemical synthesis , Adenosine/chemical synthesis , Adenosine/chemistry , Adenosine/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacologyABSTRACT
A series of novel 4-fluoro-1H-pyrazole-3-carboxamide nucleoside analogues were synthesized and evaluated as potential inhibitors of RNA virus replication, including hepatitis C virus (HCV).
Subject(s)
Antiviral Agents/chemical synthesis , Ribavirin/analogs & derivatives , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Hepacivirus/drug effectsABSTRACT
Synthesis, in vitro anti-HIV activity, stability studies as well as potential for oral absorption of some novel phenyl S-acyl-2-thioethyl (SATE) phosphotriester derivatives of AZT (zidovudine; 3'-azido-2',3'-dideoxythymidine) are described herein. These pronucleotides are characterized by the presence of polar functions on the SATE biolabile phosphate protections. Whereas derivatives incorporating an amino residue in the vicinity of the thioester functionality display low chemical stability, the introduction of one or two hydroxyl groups on the SATE moieties confers high resistance of the resulting prodrugs towards esterase hydrolysis. Thus, one of these pronucleotides, the monohydroxylated SATE derivative of AZT 2, is able to cross a Caco-2 cell monolayer mainly in intact form, probing that further development is warranted as a possible HIV-pronucleotide candidate.
Subject(s)
Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Zidovudine/chemistry , Zidovudine/pharmacology , Caco-2 Cells , Humans , Molecular Structure , Structure-Activity RelationshipABSTRACT
The synthesis of some 3'-deoxy-3'-C-methylnucleoside analogues bearing naturally occuring nucleic acid bases was achieved from the preparation of a suitable peracylated 3-deoxy-3-C-methyl sugar using a stereoselective pathway. In addition, examples of chemical modifications at the 2' position are presented.
Subject(s)
Deoxyribonucleosides/chemistry , Deoxyribonucleosides/chemical synthesis , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Drug Design , Glycosylation , Methylation , StereoisomerismABSTRACT
In search for new antiviral agents, we have been interested in 1'-C-fluoromethyl branched ribonucleosides. In this paper, we describe the synthesis of 1'-C-fluoromethyladenosine via electrophilic fluorination of exo-glycal.
Subject(s)
Adenosine/analogs & derivatives , Antiviral Agents/chemical synthesis , Adenosine/chemical synthesis , Adenosine/chemistryABSTRACT
RNA viruses are the agents of numerous widespread and often severe diseases. Their unique RNA-dependent RNA polymerase (RDRP) is essential for replication and, thus, constitutes a valid target for the development of selective chemotherapeutic agents. In this regard, we have investigated sugar-modified ribonucleoside analogues as potential inhibitors of the RDRP. Title compounds retain 'natural' pyrimidine bases, but possess a beta-methyl substituent at the 2'-position of the D- or L-ribose moiety. Evaluation against a broad range of RNA viruses, either single-stranded positive (ssRNA+), single-stranded negative (ssRNA-) or double-stranded (dsRNA), revealed potent activities for D-2'-C-methyl-cytidine and -uridine against ssRNA+, and dsRNA viruses. None of the L-enantiomers were active. Moreover, the 5'-triphosphates of the active D-enantiomers were found to inhibit the bovine virus diarrhoea virus polymerase. Thus, the 2'-methyl branching of natural pyrimidine ribonucleosides transforms physiological molecules into potent, broad-spectrum antiviral agents that merit further development.
Subject(s)
Antiviral Agents/pharmacology , Pyrimidine Nucleosides/pharmacology , RNA Viruses/drug effects , RNA Viruses/physiology , Virus Replication/drug effects , Animals , Antiviral Agents/chemistry , Cell Line , Cricetinae , Dogs , Haplorhini , Humans , Molecular Structure , Pyrimidine Nucleosides/chemistry , Structure-Activity RelationshipABSTRACT
In our search for new therapeutic agents against chronic hepatitis C, a ribonucleoside analogue, 2'-C-methylcytidine, was discovered to be a potent and selective inhibitor in cell culture of a number of RNA viruses, including the pestivirus bovine viral diarrhea virus, a surrogate model for hepatitis C virus (HCV), and three flaviviruses, namely, yellow fever virus, West Nile virus, and dengue-2 virus. However, pharmacokinetic studies revealed that 2'-C-methylcytidine suffers from a low oral bioavailability. To overcome this limitation, we have synthesized the 3'-O-l-valinyl ester derivative (dihydrochloride form, valopicitabine, NM283) of 2'-C-methylcytidine. We detail herein for the first time the chemical synthesis and physicochemical characteristics of this anti-HCV prodrug candidate, as well as a comparative study of its pharmacokinetic parameters with those of its parent nucleoside analogue, 2'-C-methylcytidine.
Subject(s)
Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacokinetics , Cytidine/analogs & derivatives , Hepacivirus/drug effects , Prodrugs/chemical synthesis , Prodrugs/pharmacokinetics , Pyrimidine Nucleosides/chemical synthesis , Pyrimidine Nucleosides/pharmacokinetics , Animals , Biological Availability , Chemical Phenomena , Chemistry, Physical , Chromatography, High Pressure Liquid , Cytidine/chemistry , Cytosol/metabolism , Humans , Liver/metabolism , Magnetic Resonance Spectroscopy , Protein Binding , Rats , Rats, Sprague-Dawley , SolubilityABSTRACT
The structure-activity relationships and molecular modeling of the uracil nucleotide activated P2Y6 receptor have been studied. Uridine 5'-diphosphate (UDP) analogues bearing substitutions of the ribose moiety, the uracil ring, and the diphosphate group were synthesized and assayed for activity at the human P2Y6 receptor. The uracil ring was modified at the 4 position, with the synthesis of 4-substituted-thiouridine 5'-diphosphate analogues, as well as at positions 2, 3, and 5. The effect of modifications at the level of the phosphate chain was studied by preparing a cyclic 3',5'-diphosphate analogue, a 3'-diphosphate analogue, and several dinucleotide diphosphates. 5-Iodo-UDP 32 (EC50 = 0.15 microM) was equipotent to UDP, while substitutions of the 2'-hydroxyl (amino, azido) greatly reduce potency. The 2- and 4-thio analogues, 20 and 21, respectively, were also relatively potent in comparison to UDP. However, most other modifications greatly reduced potency. Molecular modeling indicates that the beta-phosphate of 5'-UDP and analogues is essential for the establishment of electrostatic interactions with two of the three conserved cationic residues of the receptor. Among 4-thioether derivatives, a 4-ethylthio analogue 23 displayed an EC50 of 0.28 microM, indicative of favorable interactions predicted for a small 4-alkylthio moiety with the aromatic ring of Y33 in TM1. The activity of analogue 19 in which the ribose was substituted with a 2-oxabicyclohexane ring in a rigid (S)-conformation (P = 126 degrees , 1'-exo) was consistent with molecular modeling. These results provide a better understanding of molecular recognition at the P2Y6 receptor and will be helpful in designing selective and potent P2Y6 receptor ligands.
Subject(s)
Receptors, Purinergic P2/drug effects , Uridine Diphosphate/analogs & derivatives , Uridine Diphosphate/chemical synthesis , Cell Line, Tumor , Humans , Models, Molecular , Purinergic P2 Receptor Agonists , Stereoisomerism , Structure-Activity Relationship , Uridine Diphosphate/pharmacologyABSTRACT
The discovery that some nucleoside analogues endowed with the unnatural L-configuration can possess biological activities has been a significant breakthrough in antiviral chemotherapy. In this regard, lamivudine (3TC) was the first L-nucleoside enantiomer approved against HIV and HBV, and several other L-nucleosides are currently under clinical development as antiviral agents.
Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Nucleosides/chemistry , Nucleosides/pharmacology , Cytomegalovirus/drug effects , Hepatitis B virus/drug effects , Humans , Stereoisomerism , Virus Diseases/virology , Viruses/drug effectsABSTRACT
The "unnatural" l-nucleoside beta-l-2'-deoxythymidine (L-dT) is a potent, specific, and selective inhibitor of the replication of hepatitis B virus (HBV), which is currently in Phase III clinical trials. This unit describes, in detail, a semi-large-scale synthesis of l-dT. This convenient methodology produces l-dT in six steps starting with l-ribose and ending with a satisfactory overall yield of l-dT, and may be applied to other 2'-deoxynucleosides, incorporating different heterocyclic bases.
Subject(s)
Antiviral Agents/chemical synthesis , Thymidine/chemical synthesis , Antiviral Agents/pharmacology , Hepatitis B virus/drug effects , Hepatitis B virus/physiology , Thymidine/pharmacology , Virus Replication/drug effectsABSTRACT
Hitherto unknown restricted 3'-deoxy-3',4'-exo-methylene nucleoside derivatives bearing the nucleic acid naturally occurring pyrimidine bases have been synthesized. The compounds were tested for their activity against HIV, HBV, and several RNA viruses, but they did not show significant antiviral effect.
Subject(s)
Antiviral Agents/chemical synthesis , Methane/analogs & derivatives , Nucleic Acid Conformation , Nucleosides/chemical synthesis , Anti-HIV Agents/pharmacology , Antiviral Agents/pharmacology , HIV/metabolism , HIV Infections/drug therapy , Hepatitis B/drug therapy , Hepatitis B virus/metabolism , Hydrocarbons/chemical synthesis , Hydrocarbons/chemistry , In Vitro Techniques , Methane/chemical synthesis , Methane/chemistry , Models, Chemical , Nucleosides/chemistry , RNA Viruses/metabolism , Virus Replication/drug effectsABSTRACT
Hitherto unknown nucleoside analogues incorporating the five naturally occurring nucleic acid bases built on a 2-oxabicyclo[3.1.0]hexane template were synthesized. The synthesis of these new conformationally restricted nucleoside analogues involved the preparation of a suitable sugar precursor bearing the 2-oxabicyclo[3.1.0]hexane scaffold. This sugar was readily obtained from [(3aS,6aS)-2,2-dimethyl-3a,6a-dihydrofuro[2,3-d][1,3]dioxol-5-yl]methyl benzyl ether (4) following a Simons-Smith-type cyclopropanation reaction. Finally, glycosylation reactions and deprotection provided the nucleoside analogues. Using nucleoside 14 bearing thymine base as a model, we found that the conformation of such nucleoside analogue was restricted toward a (0)T(1) conformation.