Národní úložiště šedé literatury Nalezeno 28 záznamů.  předchozí11 - 20další  přejít na záznam: Hledání trvalo 0.01 vteřin. 
Pyrrolidine nucleotides conformationally constrained via hydrogen bonding
Pohl, Radek ; Poštová Slavětínská, Lenka ; Rejman, Dominik
Conformation of pyrroPME nucleotide analogues was studied by means of NMR at different pD values in D2O solutions. Surprisingly, two stable conformers were found at pD > 9 for both cis and trans configurations and their ratio depended on the acid-base properties of nucleobase attached to pyrrolidine ring. The results of conformational analysis suggest that the conformation of the pyrrolidine ring is locked via intramolecular hydrogen bond between negatively charged phosphonate oxygen atom and protonized pyrrolidine nitrogen.
Activation of human RNase L by 5’-C-phosphonate-modified oligoadenylates
Petrová, Magdalena ; Buděšínský, Miloš ; Zborníková, Eva ; Panova, Natalya ; Novák, Pavel ; Rosenberg, Ivan
Adeno’sine 5’-(S)-C-phosphonate (pCOHX) was prepared as monomer suitable for oligonucleotide synthesis. Modified tetramers pCOHXAAA and pCOHXAApCOHX were assembled on solid phase and evaluated for their ability to activate human RNase L.
5-(Pyren-1-yl)uracil UNA monomers: Synthesis, hybridization studies and i-motif stability
Perlíková, Pavla ; Pedersen, E. B. ; Wengel, J.
We have used direct conjugation of a pyrene moiety to a uracil base in synthesis of novel pyrene-modified UNA building blocks. Oligonucleotides with bulge-incorporated pyrene-modified UNA monomers showed increased duplex thermal stability, whereas destabilizing effect was observed in fully matched duplexes and in i-motifs.
Phosphanucleosides containing 1-hydroxymethylphospholane 1-oxide ring
Páv, Ondřej ; Zborníková, Eva ; Buděšínský, Miloš ; Rosenberg, Ivan
Novel phosphanucleosides containing 1-hydroxymethylphospholane 1-oxide ring were synthesized as compounds with potential biological activity. A ring-closing metathesis was employed to prepare a phospholene precursor, which was then converted into either 4-azido-3-hydroxy-1-hydroxymethylphospholane 1-oxide or 3-azido-1- hydroxymethylphospholane 1-oxide derivatives. Subsequently, nucleobase was introduced using a nucleobase construction. The biological activity of prepared compounds was evaluated.
Preparation of modified oligonucleotides by nicking enzyme amplification reaction
Ménová, Petra ; Hocek, Michal
A method for the enzymatic synthesis of short (10-22 nt) base-modified oligonucleotides was developed, based on the nicking enzyme amplification reaction. The methodology, including product isolation and purification, was scaled up to nanomolar amounts. The modified oligonucleotides were successfully used as primers in primer extension and PCR, affording primer-modified oligonucleotides and DNA. Two simple and efficient methods for fluorescent labelling of the PCR products were also developed.
Vinyl-modified DNA and its cleavage by restriction endonucleases
Mačková, Michaela ; Hocek, Michal
Three types of vinyl modified nucleoside triphosphates (dNVTPs) were prepared by single step aqueous Suzuki- Miyaura cross-coupling reaction of halogenated 2’-deoxynucleotides with vinyltrifluoroborate. These dNVTPs were enzymatically incorporated into DNA in Primer extension experiments and Polymerase chain reaction. Primer extension products were then tested for cleavage by series of type II restriction enzymes and the results were compared with a cleavage of ethynyl-modified DNA.
Sulfur-containing phosphonate monomers for oligonucleotide synthesis
Kostov, Ondřej ; Zborníková, Eva ; Buděšínský, Miloš ; Novák, Pavel ; Rosenberg, Ivan
A series of novel compounds, protected S-MOP nucleoside-5’-O-methylphosphonothioates, was prepared as monomers for solid phase synthesis of phosphonothioate oligonucleotides. In addition we have examined the synthetic potential of nucleoside-5’-O-methyl-(H)-phosphinates for phosphonate oligonucleotide assembly.
Competitive incorporations of modified versus natural nucleotides by DNA polymerases
Kielkowski, Pavel ; Hocek, Michal
A series of 7-substituted 7-deazaadenosine and 5-substituted cytosine triphosphates were tested in competitive incorporations with different DNA polymerases with their natural analogs and analyzed using restriction endonucleases and compared with steady state kinetics of the modified and natural dNTPs. Data sets correlation is up to 99 % and gave us to find modified dATPs with high incorporation ratios.
Oligonucleotides modified with acyclic nucleoside phosphonate (HPEP) units
Kaiser, Martin Maxmilian ; Novák, Pavel ; Rosenbergová, Šárka ; Poštová Slavětínská, Lenka ; Rosenberg, Ivan ; Janeba, Zlatko
Two acyclic nucleoside phosphonates bearing 9-[3-hydroxy-2-(phosphonoethoxy)propyl] (HPEP) moiety and either adenine and thymine as nucleobase were synthetically converted into a suitable building blocks for the subsequent automated solid phase synthesis of modified oligonucleotides. Phosphoramidite chemistry was used for the synthesis of a series of complementary nonamers where the modified acyclic monomers were incorporated using the phosphotriester method. Determination of thermal characteristics of the complexes of the modified nonamers with the complementary strands revealed a destabilizing effect of the introduced acyclic modifications.
Synthesis and biological properties of polysubstituted 5-nitrosopyrimidines
Janeba, Zlatko ; Čechová, Lucie ; Žurek, Jiří ; Procházková, Eliška ; Dračínský, Martin
2,4,6-Triamino-5-nitrosopyrimidines have been reported to contain a strong intramolecular hydrogen bond between the 5-nitroso and 4- or 6-amino groups, thus forming an additional pseudoring. Such analogues were speculated to be good mimics of fused bicyclic derivatives, e.g. purines. A series of novel polysubstituted 2-amino-5-nitrosopyrimidines, as potential structural mimics of modifi ed purine nucleos(t)ides well-known for their important biological properties, has been designed and synthesized. The physicochemical and biological properties of the prepared polysubstituted 2-amino-5-nitrosopyrimidines are being evaluated.

Národní úložiště šedé literatury : Nalezeno 28 záznamů.   předchozí11 - 20další  přejít na záznam:
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