Improved antiviral activity of the aryloxymethoxyalaninyl phosphoramidate (APA) prodrug of abacavir (ABC) is due to the formation of markedly increased carbovir 5'- … (original) (raw)
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Febs Letters, 2004
The anti-human immunodeficiency virus (HIV) activity of abacavir (ABC; 1-(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclopentene-1-methanol) could be markedly enhanced by administering the aryloxymethoxyalaninyl phosphoramidate prodrug derivative of ABC (pro-ABC-MP) to virus-infected cell cultures. Metabolic studies with radiolabeled ABC and pro-ABC-MP in human T-lymphocyte and primary macrophage cell cultures revealed a significantly increased delivery of the activated (phosphorylated) metabolite of ABC (ABC-MP) by pro-ABC-MP, and the concomittant appearance of markedly higher intracellular levels of carbovir 5 0triphosphate (CBV-TP), which represents the eventual antivirally active metabolite of ABC. The intracellular amounts of ABC-MP and appearance of CBV-TP closely correlated with the extracellular pro-ABC-MP concentrations that were administered to the cell cultures within a concentration range between 0.5 and 100 lM. The highest amounts of CBV-TP were observed within 6-24 h after drug administration. The improved delivery of ABC-MP and metabolic conversion to CBV-TP explain the markedly enhanced antiviral activity of the prodrug of ABC, and warrant further exploration of this prodrug technology on ABC and related compounds to further enhance and optimize their antiviral efficacy.
The application of phosphoramidate protide technology to acyclovir confers anti-HIV inhibition
Journal of medicinal …, 2009
Recently it has been reported that phosphorylated acyclovir (ACVa) inhibits human immunodeficiency virus type 1 (HIV-1) reverse transcriptase in a cell free system. To deliver phosphorylated ACV inside cells we designed ACV monophosphorylated derivatives using ProTide technology. We found that the L-alanine derivatived ProTides show anti-HIV activity at non-cytotoxic concentrations; ester and aryl variation was tolerated. ACV ProTides with other amino acids, other than L-phenylalanine, showed no detectable activity against HIV in cell culture. The inhibitory activity of the prodrugs against herpes simplex virus (HSV) type -1, -2 and thymidine kinase-deficient HSV-1 revealed different structure-activity relationships, but was again consistent with successful nucleoside kinase bypass. Enzymatic and molecular modelling studies have been performed in order to better understand the antiviral behaviour of these compounds. ProTides showing diminished carboxypeptidase lability translated to poor anti-HIV agents and vice versa, so the assay became predictive.
Medicinal Chemistry Research, 2012
Abacavir (ABC) is clinically associated with hypersensitivity reactions, risk for cardiovascular disease, etc. A possible way to minimize side effects is by modifying chemical structure. Three esters of ABC containing amino acid (glycine) and dipeptide esters (glycyl-glycine) were synthesized and their activity on HIV-1 III B replication in MT-4 cells was evaluated. One of the newly synthesized esters-Gly-ABC-demonstrates low-cytotoxicity and high-anti-HIV-1 activity in MT-4 cells, as well as lowmitochondrial toxicity and high-genetic barrier to resistance.
Antiviral Research, 1997
Lipophilic esters of 3′-azido-3′-deoxy-5′-O-(carboxyphosphinyl)thymidine (PFA-AZT) were synthesized and tested for antiretroviral activity in CD4 + HT4-6C cells infected with either wild-type HIV-1 LAI , a PFA-resistant strain encoding a single-point mutation in reverse transcriptase (E89K), or an AZT-resistant clinical isolate (A018-post). Arbuzov condensation of 1-octadecyl, 1-eicosanyl, and 1-docosanyl chloroformate with trimethyl phosphite yielded the corresponding dimethyl long-chain alkyl triesters of PFA. Selective removal of one methyl group from the triesters with sodium iodide yielded monosodium salts, whereas treatment with bromotrimethylsilane cleaved both methyl groups while leaving the long-chain alkyl group intact. Neutralization of the resulting [(alkyloxy)carbonyl]phosphonic acids with 2 equiv of sodium methoxide afforded disodium salts of the phosphonic acid moiety. Similar chemistry was used to obtain the mono-and disodium salts of the cholesterol ester of PFA. Reaction of the triesters with phosphorous pentachloride, followed by coupling with AZT and O-demeth-
Mechanism of the Antiviral Activity of New Aurintricarboxylic Acid Analogues
Antiviral Chemistry and Chemotherapy, 1996
Various new aurintricarboxylic acid (ATA) polymer analogues have been evaluated for their antiviral activity against a wide array of DNA and RNA viruses, and their mechanism of action against human cytomegalovirus (HCMV) and human immunodeficiency virus type 1 (HIV-1). Most of the polymers exhibited marked antiviral activity against a variety of enveloped viruses, but not against non-enveloped viruses. The ATA polymers displayed the most pronounced activity against HIV-1, HCMV and human herpesvirus type 6 (HHV-6). Their action against HCMV and HIV could be ascribed to inhibition of the initial attachment of virus particles to the cells. Using radiolabelled virus, we proved that the polymers inhibit the binding of HCMV to HEL fibroblasts. By flow cytometric analysis, we demonstrated that these new polymers interfere with (i) the binding of OKT4A monoclonal antibody (mAb) to the cellular CD4 receptor, (ii) the binding of anti-gp120 mAb to HIV-1 glycoprotein (gp) 120, and (iii) the ads...
The synthesis and antiviral screening of the first reported series of pyridine-and pyrimidine-based thioglycoside phosphoramidates are herein reported. They were prepared through two synthetic steps: The first step is via coupling of mercapto-derivatized heterocyclic bases with the appropriate α-bromo per-acetylated sugars. The second one is the hydrolysis of the acetate esters under basic conditions that were consequently conjugated with the phosphoramidating reagent to afford the desired thioglycoside protides. Eight compounds were evaluated for their antiviral activities against different viral cell lines, namely, adenovirus 7, HAV (hepatitis A) HM175, Coxsackievirus B4, and HSV-1 (herpes simplex virus type 1), in addition to the antiviral bioassay against ED-43/SG-Feo (VYG) replicon of HCV (hepatitis C virus) genotype 4a. Both compounds 5b and 11 showed notable antiviral activity against Coxsackie virus B4, reflected from the CC 50 values of 17 and 20 μg/100 μL and IC 50 values of 4.5 and 6.0 μg/100 μL, respectively. Same two compounds elicited remarkable activities toward herpes simplex virus type 1, represented by CC 50 values of 17 and 16 μg/100 μL and IC 50 values of 6.3 and 6.6 μg/100 μL, respectively. Combination of 11 with acyclovir elicited a notable synergistic activity in comparison with acyclovir alone, as inferred from herpes simplex polymerase enzyme inhibitory assay values of 2.64 and 4.78 μg/100 mL, respectively. Only compound 11 elicited a remarkable activity against HCV. Potential promising activities of compound 11 have been shown with respect to CC 50 , IC 50 , and enzyme assay inhibitory activities.