National Repository of Grey Literature 115 records found  beginprevious84 - 93nextend  jump to record: Search took 0.00 seconds. 
Synthesis of biaryl-substituted fluorescent nucleosides and nucleoside triphosphates and their incorporation to DNA
Riedl, Jan ; Hocek, Michal
A series of modified nucleosides bearing the fluorescent substituted biaryl labels attached to nucleobase was prepared and their luminescent properties were evaluated. The modified nucleosides show divers fluorescence from 400 to 560 nm when excited at 340 nm in water depending on structural and substitution pattern. The corresponding biaryl-substituted nucleoside triphosphates (dNTPs) were prepared analogously and used for polymerase incorporation to DNA. Applications in hybridization probes were studied.
Hetaryl derivatives of 7-deazapurine ribonucleosides: potent cytostatic agents
Perlíková, Pavla ; Nauš, Petr ; Bourderioux, Aurelie ; Hocek, Michal
A series of novel 7-deazapurine ribonucleosides substituted with aryl and hetaryl groups has been prepared. Suzuki or Stille cross-coupling reactions with 6-chloro-7-deazapurine ribonucleosides substituted with H, F of Cl atom in position 7 were used in the key step of the synthesis. Either cross-coupling of protected ribonucleoside with appropriate (het)arylboronic acid or stannane followed by deprotection, or single-step aqueous-phase Suzuki cross-coupling reaction of unprotected 7-deazapurine ribonucleoside with boronic acid provided target (het)aryl-7-deazapurine ribonucleosides. 6-Furyl- and 6-thienyl-7-deazapurine ribonucleosides showed cytostatic effect in multiple cancer cell lines in nanomolar range. Application of cyclosaligenyl and alanyl-ester phosphoramidate prodrugs did not improved cytostatic activity of parent nucleosides.
Development of a general and modular approach to C-nucleosides
Kubelka, Tomáš ; Štefko, Martin ; Bárta, Jan ; Joubert, Nicolas ; Urban, Milan ; Chapuis, Hubert Jean ; Hocek, Michal
Highly efficient and modular approach was developed for the synthesis of various types of new (het)aryl C-nucleosides. This protocol consists of the synthesis of haloaryl-C-nucleoside intermediates, followed by a functional group transformation to introduce various substituents. Using this approach protected 2′-deoxy-C-nucleosides bearing halogenated benzene, pyridine, thiophene, furane and pyrimidine were prepared. These intermediates were then submitted to a wide range of palladium-catalyzed reactions. The same approach was also used for preparation of C-nucleosides bearing ribofuranose moiety. Functional ribofuranosides bearing diverse substituted pyridine and benzene nucleobases were prepared in this way.
Polymerase construction of base-modified DNA for chemical biology
Hocek, Michal ; Macíčková-Cahová, Hana ; Kielkowski, Pavel ; Raindlová, Veronika ; Kalachová, Lubica ; Riedl, Jan ; Balintová, Jana ; Ménová, Petra
An efficient two-step methodology for construction of base-modified DNA was developed based on aqueous-phase cross-coupling reactions of halogenated nucleoside triphosphates (dNTPs) followed by polymerase incorporation. A number of diverse chemical modifications have been successfully incorporated in this way for the use in chemical biology (modulation of cleavage by restriction enzymes, interactions with diverse DNA-binding proteins and bioconjugations).
Modulární metodika na přípravu 3- a 4- substituovaných benzenových a anilínových C-ribonukleosidů
Štefko, Martin ; Hocek, Michal
A novel modular, efficient and practical methodology for the preparation of 3- and 4-substituted phenyl and aniline C-ribonucleosides was developed. The key intermediates were synthesized in two steps from TBS-protected ribonolactone in 75% and 66% yields, respectively, as pure beta-anomers. The bromophenyl intermediates were subjected to a series of palladium catalyzed cross-coupling, aminations and alkoxylation reactions to give, after deprotection a series of free 1 beta-(3- and 4-alkyl, -aryl, -amino -alkoxyphenyl and -hetaryl substituted phenyl)-C-ribonucleosides (20 examples).
Syntéza modifikovaných fluorescenčních nukleosidů
Riedl, Jan ; Hocek, Michal
A series of modified nucleosides bearing the fluorescent substituted biaryl labels attached to nucleobase was prepared and their luminescent properties were evaluated. The modified nucleosides show strong fluorescence at ca. 400 nm when excited at 310 nm in water depending on substitution pattern.
Syntéza modifikovaných nukleosidů a nukleosid-trifosfátů nesoucích oligopyridinové ligandy
Kalachová, Lubica ; Hocek, Michal
The synthesis of 2'-deoxyuridine and 2'-deoxycytidine derivatives bearing bipyridine, phenantroline or terpyridine ligands via acetylene or phenylene tethers and their corresponding triphosphates was accomplished through Pd-catalyzed cross-coupling.
Syntéza (purin-6-yl)acetátů a jejich transformace
Hasník, Zbyněk ; Hocek, Michal
A novel approach to the synthesis of (purin-6-yl)acetates was developed based on Pd-catalysed cross-coupling reactions of 6-chloropurines with the Reformatsky agent. These intermediates were converted into various products by functional group transformations. Amides were prepared by amidation of ester group with amines, 6-(hydroxyethyl)purines by reduction by NaBH4, and beta-substituted 6-ethylpurines by mesylation of 6-(hydroxyethyl)purines and subsequent nucleophilic substitution.
Přímá C-H arylace purinů a purinových nukleosidů
Čerňa, Igor ; Hocek, Michal
Direct C–H arylation of purines to position 8 by diverse aryl halides was achieved using Pd catalysis in the presence of CuI and Cs2CO3. The methodology was applied in consecutive regioselective synthesis of 2,6,8-trisubstituted purines bearing three different C-substituents in combination with two cross-coupling reaction. In addition, direct arylation of unprotected purine nucleosides with aryl iodides at position 8 was developed to allow straightforward single-step introduction of diverse aryl groups.
Modulární syntéza 5-substituovaných thiofen-2-yl C-2'-deoxyribonukleosidů
Bárta, Jan ; Hocek, Michal
A new modular methodology for the preparation of 5-substituted thiophen-2-yl C-nucleosides was developed. A Friedel–Crafts-type of C-glycosidation of 2-bromothiophene with bis-toluoyl protected methylglycoside gave the desired bis-toluoyl protected 1-beta-(5-bromothiophen-2-yl)-1,2-dideoxyribofuranose in 60%. Deprotection of the protected product gave free bromothiophene C-nucleoside, which was reprotected to bis-TBDMS protected C-nucleoside. The key intermediates were then subjected to a series of palladium catalyzed cross-coupling reactions to afford, after suitable deprotection, a series of free C-nucleosides. Alternatively, other types of C-nucleosides were prepared directly by aqueous-phase Suzuki cross-coupling reactions of free C-nucleosides with boronic acids.

National Repository of Grey Literature : 115 records found   beginprevious84 - 93nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.