Human N6-Methyl-AMP/DAMP Aminohydrolase (Abacavir 5'-Monophosphate Deaminase) is Capable of Metabolizing N6-Substituted Purine Acyclic Nucleoside Phosphonates

Recombinant human abacavir monophosphate deaminase (hABC-MP deaminase) was compared with the recently described ratN6-methyl-AMP (meAMP) aminohydrolase. hABC-MP deaminase, a 42 kDa polypeptide, exists predominantly as a monomer under non-denaturing conditions. Similar to the rat enzyme, hABC-MP deaminase efficiently catalyzes the hydrolytic deamination of natural substrates meAMP (5),N6,N6-dimethyl-AMP (13) and medAMP (6). Acyclic nucleoside phosphonate (ANP)N6-cyclopropyl-2,6-diamino-9-[2-(phosphonomethoxy)ethyl]purine (cPrPMEDAP) (1), an intermediate intracellular metabolite of antileukemic agent GS-9219, was effectively converted to the corresponding active guanine analog by hABC-MP deaminase. In addition to cPrPMEDAP (1), a number of other biologically activeN6-substituted purine ANPs are alternative substrates for hABC-MP deaminase. The efficiency of their deamination depends on the character ofN6-substitution in the adenine and/or 2,6-diaminopurine ring. ANPs withN6-cyclic substituents are deaminated more readily than corresponding compounds with aliphatic substituents of the same length. The deamination of ANPs is also influenced by modifications at the phosphonoalkyl side chain. Among 9-[2-(phosphonomethoxy)propyl] ANPs, (S)-enantiomers are preferred to (R)-enantiomers. Alternatively, the presence of extended 9-[2-(phosphonoethoxy)ethyl] moiety leads to a moderate increase in the reaction velocity compared to cPrPMEDAP (1). Comparison of hABC-MP deaminase and the rat meAMP aminohydrolase across a broad spectrum ofN6-substituted substrates revealed a strong correlation of their substrate specificities. Similar to the rat meAMP aminohydrolase, hABC-MP deaminase was highly sensitive to deoxycoformycin monophosphate, but not to the guanine product of cPrPMEDAP (1) deamination. Together, these data demonstrate that hABC-MP deaminase is human meAMP aminohydrolase involved in the intracellular activation of biologically activeN6-substituted nucleotide analogs.

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Interaction of Phosphates of the Acyclic Nucleoside Phosphonates with Nucleoside Diphosphate Kinase from Yeast and Bovine Liver

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20060035 ◽

2006 ◽

Vol 71 (1) ◽

pp. 35-43 ◽

Cited By ~ 6

Author(s):

Květoslava Horská ◽

Ivan Votruba ◽

Antonín Holý

Keyword(s):

Nucleoside Diphosphate Kinase ◽

Bovine Liver ◽

Kinetic Constants ◽

Aliphatic Chain ◽

Ndp Kinase ◽

Hydroxymethyl Group ◽

Acyclic Nucleoside Phosphonates ◽

Acyclic Nucleoside ◽

Acyclic Nucleoside Phosphonate

The ability of monophosphates of selected acyclic nucleoside phosphonates to serve as substrates for the title NDP kinases was studied. Comparison of the kinetic constants (KM, Vmax, kcat and kcat/KM) estimates indicates that the yeast enzyme catalyzes the phosphorylation of purine and pyrimidine acyclic nucleoside phosphate phosphonates of the 9-[2-(phosphonomethoxy)ethyl] and/or 9-[2-(phosphonomethoxy)propyl] series more efficiently than bovine liver NDP kinase. Yeast enzyme preferentially phosphorylates phosphates of the (phosphono- methoxyalkyl)guanines rather than their adenine counterparts; both enzymes phosphorylate R-enantiomers of the 9-[2-(phosphonomethoxy)propyl] series more efficiently than the corresponding S-enantiomers. Substitution of the aliphatic chain at the position 3 with hydroxymethyl group considerably increases the substrate activity of phosphate of acyclic nucleoside phosphonate. The resulting substrate activity (kcat/KM ratio) of all acyclic nucleoside phosphonate phosphates studied is three to five orders of magnitude lower than that for natural NDPs.

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Syntheses of Base and Side-Chain Modified Pyrimidine 1-[2-(Phosphonomethoxy)propyl] Derivatives as Potent Inhibitors of Thymidine Phosphorylase (PD-ECGF) from SD-Lymphoma

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20060595 ◽

2006 ◽

Vol 71 (4) ◽

pp. 595-624 ◽

Cited By ~ 18

Author(s):

Karel Pomeisl ◽

Ivan Votruba ◽

Antonín Holý ◽

Radek Pohl

Keyword(s):

Thymidine Phosphorylase ◽

Cell Lymphoma ◽

Inhibitory Effect ◽

Side Chain ◽

The Novel ◽

Inhibitory Potency ◽

Methyl Group ◽

Acyclic Nucleoside Phosphonates ◽

Acyclic Nucleoside ◽

Trifluoromethyl Groups

In this study we synthesized a series of thymine and 5-ethyluracil acyclic nucleoside phosphonates bearing hydroxymethyl, methoxymethyl, azidomethyl, aminomethyl and (trimethylammonio)methyl group in side chain as potent inhibitors of thymidine phosphorylase. In addition, we investigated in particular the novel syntheses of fluorinated derivatives containing fluoromethyl or trifluoromethyl groups in side chain such as 5-ethyl- 1-[(S)-3-fluoro-2-(phosphonomethoxy)propyl]uracil (8) or 5-ethyl-1-[3,3,3-trifluoro-2-(phosphonomethoxy)propyl]uracil and thymine derivatives 27 and 28. Uracil acyclic nucleoside phosphonates 1-{2-[(diisopropoxyphosphoryl)methoxy]ethyl}uracil (12) and 1-{2-[(diisopropoxyphosphoryl)methoxy]-3,3,3-trifluoropropyl}uracil (19) were fluorinated to corresponding 5-fluorouracil derivatives. While the 5-fluorouracil derivatives exhibit a marginal inhibitory effect, thymine and 5-ethyluracil compound with fluorine in side chains possess considerable inhibitory potency toward thymidine phosphorylase from rat spontaneous T-cell lymphoma.

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Selective Activity of Various Nucleoside and Nucleotide Analogues against Human Herpesvirus 6 and 7

Antiviral Chemistry and Chemotherapy ◽

10.1177/095632029700800102 ◽

1997 ◽

Vol 8 (1) ◽

pp. 24-31 ◽

Cited By ~ 32

Author(s):

K Takahashi ◽

M Suzuki ◽

Y Iwata ◽

S Shigeta ◽

K Yamanishi ◽

...

Keyword(s):

Large Scale ◽

Human Herpesvirus ◽

Tetrazolium Salt ◽

Human Herpesvirus 6 ◽

Phosphonoformic Acid ◽

Highly Sensitive ◽

Acyclic Nucleoside ◽

Herpesvirus 6 ◽

Acyclic Nucleoside Phosphonate ◽

Large Scale Screening

We have developed a new sensitive enzyme immunoassay (EIA) and MTT (tetrazolium salt) assay for screening compounds against two variants of human herpesvirus 6 (HHV-6A, HHV-6B) and human herpesvirus 7 (HHV-7) and evaluated the anti-HHV-6 and HHV-7 activity of a series of anti-herpesvirus compounds and acyclic nucleoside phosphonate analogues. The results indicate that the pattern of activity of these compounds against these betaherpesviruses is similar to that for human cytomegalovirus (HCMV). The highest potency and selectivity against the two variants of HHV-6 and HHV-7 was demonstrated by S2242 (N7-isomer of 6-deoxy-ganciclovir). Also, ganciclovir (GCV), foscarnet, (phosphonoformic acid; PFA) and the acyclic nucleoside phosphonate analogues such as cidofovir (HPMPC) exhibited selective inhibitory activity against these viruses. Thymidine kinase (TK)-dependent drugs (acyclovir, ACV; brivudin, BVDU; and sorivudine, BVaraU) showed little, if any, activity. These results suggest a structural homology of the DNA polymerase and a lack of TK gene among these three betaherpesviruses (HHV-6, HHV-7 and HCMV). The finding that HHV-7 was highly sensitive to GCV also suggests that HHV-7 may have an HCMV-UL97-homologue gene for the phosphorylation of GCV. The present EIA method is more rapid and sensitive than the previously reported procedures and could be useful for the large-scale screening of compounds against HHV-6 and HHV-7.

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Novel Acyclic Nucleoside Phosphonate Analogues with Potent Anti-Hepatitis B Virus Activities

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.3.1177-1180.2005 ◽

2005 ◽

Vol 49 (3) ◽

pp. 1177-1180 ◽

Cited By ~ 34

Author(s):

C. Ying ◽

A. Holý ◽

D. Hocková ◽

Z. Havlas ◽

E. De Clercq ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Amino Group ◽

Wild Type ◽

Pyrimidine Base ◽

B Virus ◽

Acyclic Nucleoside Phosphonates ◽

Acyclic Nucleoside ◽

Acyclic Nucleoside Phosphonate

ABSTRACT Novel acyclic nucleoside phosphonates with a pyrimidine base preferentially containing an amino group at C-2 and C-4 and a 2-(phosphonomethoxy)ethoxy or (R)-2-(phosphonomethoxy)propoxy group at C-6 selectively inhibit the replication of wild-type and lamivudine-resistant hepatitis B viruses. The activity of the most potent compounds was comparable to that of adefovir.

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Cidofovir and (S)-9-[3-Hydroxy-(2-Phosphonomethoxy)Propyl]Adenine Are Highly Effective Inhibitors of Vaccinia Virus DNA Polymerase When Incorporated into the Template Strand

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01172-07 ◽

2007 ◽

Vol 52 (2) ◽

pp. 586-597 ◽

Cited By ~ 55

Author(s):

Wendy C. Magee ◽

Kathy A. Aldern ◽

Karl Y. Hostetler ◽

David H. Evans

Keyword(s):

Vaccinia Virus ◽

Dna Polymerase ◽

Dna Polymerases ◽

Antiviral Agent ◽

Effective Concentration ◽

Intracellular Metabolite ◽

Template Strand ◽

Acyclic Nucleoside ◽

Acyclic Nucleoside Phosphonate ◽

Viral Enzyme

ABSTRACT The acyclic nucleoside phosphonate drug (S)-9-[3-hydroxy-(2-phosphonomethoxy)propyl]adenine [(S)-HPMPA], is a broad-spectrum antiviral and antiparasitic agent. Previous work has shown that the active intracellular metabolite of this compound, (S)-HPMPA diphosphate [(S)-HPMPApp], is an analog of dATP and targets DNA polymerases. However, the mechanism by which (S)-HPMPA inhibits DNA polymerases remains elusive. Using vaccinia virus as a model system, we have previously shown that cidofovir diphosphate (CDVpp), an analog of dCTP and a related antiviral agent, is a poor substrate for the vaccinia virus DNA polymerase and acts to inhibit primer extension and block 3′-to-5′ proofreading exonuclease activity. Based on structural similarities and the greater antiviral efficacy of (S)-HPMPA, we predicted that (S)-HPMPApp would have a similar, but more pronounced effect on vaccinia polymerase than CDVpp. Interestingly, we found that (S)-HPMPApp is a good substrate for the viral enzyme, exhibiting Km and V max parameters comparable to those of dATP, and certainly not behaving like CDVpp as a functional chain terminator. Metabolic experiments indicated that (S)-HPMPA is converted to (S)-HPMPApp to a much greater extent than CDV is converted to CDVpp, although both drugs cause identical effects on virus DNA replication at their 50% effective concentration. Subsequent studies showed that both compounds can be faithfully incorporated into DNA, but when CDV and (S)-HPMPA are incorporated into the template strand, both strongly inhibit trans-lesion DNA synthesis. It thus appears that nucleoside phosphonate drugs exhibit at least two different effects on DNA polymerases depending upon in what form the enzyme encounters the drug.

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Xanthine-based acyclic nucleoside phosphonates with potent antiviral activity against varicella-zoster virus and human cytomegalovirus

Antiviral Chemistry and Chemotherapy ◽

10.1177/2040206618813050 ◽

2018 ◽

Vol 26 ◽

pp. 204020661881305 ◽

Cited By ~ 1

Author(s):

Ondřej Baszczyňski ◽

Martin Maxmilian Kaiser ◽

Michal Česnek ◽

Petra Břehová ◽

Petr Jansa ◽

...

Keyword(s):

Purine Nucleotide ◽

Viral Dna ◽

Single Digit ◽

Varicella Zoster ◽

Dna And Rna ◽

Wide Range ◽

Acyclic Nucleoside Phosphonates ◽

Acyclic Nucleoside ◽

Human Herpesviruses ◽

Acyclic Nucleoside Phosphonate

While noncanonic xanthine nucleotides XMP/dXMP play an important role in balancing and maintaining intracellular purine nucleotide pool as well as in potential mutagenesis, surprisingly, acyclic nucleoside phosphonates bearing a xanthine nucleobase have not been studied so far for their antiviral properties. Herein, we report the synthesis of a series of xanthine-based acyclic nucleoside phosphonates and evaluation of their activity against a wide range of DNA and RNA viruses. Two acyclic nucleoside phosphonates within the series, namely 9-[2-(phosphonomethoxy)ethyl]xanthine (PMEX) and 9-[3-hydroxy-2-(phosphonomethoxy)propyl]xanthine (HPMPX), were shown to possess activity against several human herpesviruses. The most potent compound was PMEX, a xanthine analogue of adefovir (PMEA). PMEX exhibited a single digit µM activity against VZV (EC50 = 2.6 µM, TK+ Oka strain) and HCMV (EC50 = 8.5 µM, Davis strain), while its hexadecyloxypropyl monoester derivative was active against HSV-1 and HSV-2 (EC50 values between 1.8 and 4.0 µM). In contrast to acyclovir, PMEX remained active against the TK– VZV 07–1 strain with EC50 = 4.58 µM. PMEX was suggested to act as an inhibitor of viral DNA polymerase and represents the first reported xanthine-based acyclic nucleoside phosphonate with potent antiviral properties.

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Palladium-catalyzed allylic amination: a powerful tool for the enantioselective synthesis of acyclic nucleoside phosphonates

Organic & Biomolecular Chemistry ◽

10.1039/c7ob01478c ◽

2017 ◽

Vol 15 (34) ◽

pp. 7227-7234 ◽

Cited By ~ 4

Author(s):

Mariam Azzouz ◽

Sébastien Soriano ◽

Margarita Escudero-Casao ◽

M. Isabel Matheu ◽

Sergio Castillón ◽

...

Keyword(s):

Enantioselective Synthesis ◽

High Yield ◽

Allylic Substitution ◽

Allylic Amination ◽

Palladium Catalyzed ◽

Acyclic Nucleoside Phosphonates ◽

Acyclic Nucleoside ◽

Acyclic Nucleoside Phosphonate

Acyclic nucleoside phosphonate were prepared in high yield and up to 92% ee using an enantioselective palladium-catalyzed allylic substitution.

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Analogues of the cholecystokinin octapeptide modified in the central part of the molecule

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19911963 ◽

1991 ◽

Vol 56 (9) ◽

pp. 1963-1970 ◽

Cited By ~ 3

Author(s):

Jan Hlaváček ◽

Václav Čeřovský ◽

Jana Pírková ◽

Pavel Majer ◽

Lenka Maletínská ◽

...

Keyword(s):

Amino Acid ◽

Biological Activities ◽

Point Of View ◽

Biologically Active ◽

Side Chain ◽

Amino Acid Residues ◽

Cholecystokinin Octapeptide ◽

Biological Tests ◽

Biological Potency ◽

Biologically Active Conformation

In a series of analogues of the cholecystokinin octapeptide (CCK-8) the amino acid residues were gradually modified by substituting Gly by Pro in position 4, Trp by His in position 5, Met by Cle in position 6, or the Gly residue was inserted between Tyr and Met in positions 2 and 3 of the peptide chain, and in the case of the cholecystokinin heptapeptide (CCK-7) the Met residues were substituted by Nle or Aib. These peptides were investigated from the point of view of their biological potency in the peripheral and central region. From the results of the biological tests it follows that the modifications carried out in these analogues and in their Nα-Boc derivatives mean a suppression of the investigated biological activities by 2-3 orders of magnitude (at a maximum dose of the tested substance of 2 . 10-2 mg per animal).This means that a disturbance of the assumed biologically active conformation of CCK-8, connected with a considerable decrease of the biological potency of the molecule, takes place not only after introduction of the side chain into its centre (substitution of Gly4), but also after the modification of the side chains of the amino acids or by extension of the backbone in further positions around this central amino acid.

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