National Repository of Grey Literature 25 records found  previous6 - 15next  jump to record: Search took 0.01 seconds. 
The influence of acyclic nucleotide phosphonates PMEG and PMEDAP on p38 kinase signaling in human leukemic cells
Nejedlá, Michaela ; Entlicher, Gustav (advisor) ; Slaninová, Jiřina (referee)
PMEG [9-(2-phosphonomethoxyethyl)guanine] and PMEDAP [9-phosphonomethoxy- ethyl)-2,6-diaminopurine] are acyclic nucleoside phosphonates possessing cytotoxic properties. Antiproliferative effect of PMEG was demonstrated in various tumor cell lines in vitro. PMEG also represents an active component of some experimental prodrugs with enhanced selectivity and efficacy (such as GS-9219). PMEDAP seems to have weaker effect in vitro compared to PMEG, however it exhibited pronounced antitumor effect in SD-rats with spontaneous lymphoma. Therefore it was included in the present study as well. The aim of this study was to describe the interactions of PMEG and PMEDAP with p38 MAP kinase signaling and its relationship to the apoptosis. We investigated the influence of these compounds on the expression of four genes encoding p38 MAPK isoforms and whether this change is translated into the protein. It was found that PMEG up-regulates p38β and γ mRNA in CCRF-CEM cells and p38 β and δ in HL-60 cells. The effect of PMEDAP was less pronounced than that of PMEG. However, total p38 protein level remained unaffected by PMEG and PMEDAP. Activation of p38 MAPK cascade was also measured in the cells exposed to these agents using phospho-specific antibodies. We found that neither PMEG nor PMEDAP activated p38 kinase...
Determination of enantiopurity of new types of acyclic nucleoside phosphonates by capillary electrophoresis with cyclodextrins-based chiral selectors
Šolínová, Veronika ; Kaiser, Martin Maxmilian ; Lukáč, Miloš ; Janeba, Zlatko ; Kašička, Václav
Capillary electrophoresis with neutral and cationic cyclodextrins as chiral selectors was applied for determination of enantiopurity analysis of new types of six acyclic nucleoside phosphonates, nucleotide analogues bearing ((3-hydroxypropan-2-yl)-1H-1,2,3-triazol-4-yl)phosphonic acid, 2-((diisopropoxyphosphonyl)methoxy)propanoic acid or 2 (phosphonomethoxy)propanoic acid moieties attached to adenine, guanine, 2,6-diaminopurine, uracil and 5-bromouracil nucleobases. All these compounds were found to be synthesized in pure enantiomeric forms. Employing the UV-absorption detection at 206 nm, their detection limits were in the low micromolar level.
Tyrosine-based prodrugs of acyclic nucleoside phosphonates
Tichý, Tomáš ; Pomeisl, Karel ; Krečmerová, Marcela ; McKenna, Ch. E.
Prodrug approach based on masking of a phosphonate function by ester linkage to a tyrosine promoiety has been developed. Results demonstrate that tyrosine is a promoiety providing drug conjugates with good chemical stability, bioavailability and efficient activation to active drug species. Another properties like metabolic stability and antiviral activity can be tuned by modification of the carboxyl function of the promoiety. Phosphonate monoester prodrugs were prepared by PyBOP coupling of a protected tyrosine promoiety with suitably derivatized phosphonate function of the parent drug. Phosphonate diester prodrugs were prepared by "synthon" approach, emloying alkylation of purine nucleobase with pre-prepared PME synthons bearing two protected tyrosine promoieties.
Cytotoxicity screen of the acyclic nucleoside phosphonates against bloodstream stage of \kur{Trypanosoma brucei} and validation of their putative target hypoxanthine/xanthine/guanine phosphoribosyltransferase
MITTERMAYR, Martina
The aim of this study was to test several compounds of acyclic nucleoside phosphonates (ANPs), which are thought to inhibit the purine salvage pathway enzyme hypoxanthine/xanthine/guanine phosphoribosyltransferase (HGXPRT) of the bloodstream stage of Trypanosoma brucei. Further we intended to elucidate if HGXPRT enzymes are essential for the survival of the bloodstream T.brucei.
Acyclic Nucleoside Phosphonates as Inhibitors of Hypoxanthine-Guanine-Xanthine Phosphoribosyltransferase: New Anti-Malarial Chemotherapy Leads
Hocková, Dana ; Holý, Antonín ; Česnek, Michal ; Baszczyňski, Ondřej ; Tichý, Tomáš ; Krečmerová, Marcela ; Janeba, Zlatko ; Skinner-Adams, T. S. ; Naesens, L. ; Keough, D. T. ; de Jersey, J. ; Guddat, L. W.
Hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRTase) is a widely recognized target for the discovery of new anti-malarial drugs. Specific acyclic nucleoside phosphonates (ANPs) inhibit HGXPRTase and possess anti-plasmodial activity. Within the framework of a SAR-study, the classical ANPs (e.g. PME-, PMP- and HPMP-derivatives) as well as novel series of compounds were tested to investigate their efficiency and selectivity on the inhibition of P. falciparum, P. vivax and human enzyme.
3-Fluoro-2-(phosphonomethoxy)propyl hypoxanthine and guanine derivatives as inhibitors of plasmodial hypoxanthine-guanine-xanthine phosphoribosyltransferases
Baszczyňski, Ondřej ; Jansa, Petr ; Hocková, Dana ; Janeba, Zlatko ; Dračínský, Martin ; Holý, Antonín ; Keough, D. T. ; de Jersey, J. ; Guddat, L. W.
A new methodology for the synthesis of ANPs containing 9-[2-(phosphonoethoxy)ethyl] (PEE) moiety has been developed. FPEP compound containing guanine moiety exhibited inhibition activity against the enzyme in micromolar range without any signs of toxicity.
The efficient synthesis of 2-aryl substituted pyrimidine acyclic nucleoside phosphonates using Liebeskind-Srogl cross-coupling
Česnek, Michal ; Břehová, Petra ; Dračínský, Martin ; Holý, Antonín ; Janeba, Zlatko
A series of novel acyclic nucleoside phosphonates with a built-in 2-arylsubstituted pyrimidine moiety has been prepared using the Liebeskind-Srogl cross-coupling protocol. The reactions of highly functionalised 2-methylsulfanylpyrimidines with various arylboronic acids were studied and optimised.
Biological properties of the C-8 substituted analogues of 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA)
Janeba, Zlatko ; Holý, Antonín ; Zídek, Zdeněk
The 9-[2-(phosphonomethoxy)ethyl]adenine (PMEA) derivatives substituted at the C-8 position of the purine moiety did not exhibited any pronounced antiviral or antimalarial activity, but both 8-hydroxy and 8-sulfanyl derivatives of PMEA possess significant immunostimulatory activities.
Synthesis and biological properties of the 2’-trifluoromethyl analogues of tenofovir
Jansa, Petr ; Kolman, Viktor ; Janeba, Zlatko
A series of acyclic nucleoside phosphonates substituted at the aliphatic part of the molecule by the trifluoromethyl group was prepared but none of the compounds exhibits any anti-HIV or anti-HCV activities.

National Repository of Grey Literature : 25 records found   previous6 - 15next  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.