National Repository of Grey Literature 16 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Carbocyclic analogues of nucleosides and nonnucleoside inhibitors of thymidine phosphorylase
Nencka, Radim ; Hřebabecký, Hubert (advisor) ; Černý, Miloslav (referee) ; Ledvina, Miroslav (referee) ; Kefurt, Karel (referee)
!ntroduction Analogues ofnucleic acid components belong to the most successful classes oftherapeutics. Extensive modifications ofnucreobases, nucreosides and nucleotides led to the discovery ofa huge group of compounds with remarkable biological activity. The most important are perhaps the effects on various severe diseases such as cancer, leukemia or viral infectrons. The essential aim ofthis Thesis was the preparation ofbiologically active compounds related to the nucleic acid components. Since the carbocyclic anďogues ofnucleosides have been a long-time interest of our group, the first part of this work was devoted to the development of practical synthetic routes towards their new derivatives and to the synthesis of the novel analogues for further biological activity screening. However, the preliminary biological tests of the prepared compounds uncovered very promising lead to the compretely different field than it was expected. During the primer studies, I synthesized several 5,6-disubstituted uracils, initially prepared just as moder compounds for development of nover synthetic approaches towards carbocyclic nucleosides, that showed to posses outstanding inhibitory activity against thymidine phosphorylase. Therefore, the development of novel derivatives based on these findings was estabrished as a new...
Synthesis of Prolinol-Based Phosphonate Nucleotide Analogues
Vaněk, Václav ; Rosenberg, Ivan (advisor) ; Černý, Miloslav (referee) ; Moravcová, Jitka (referee) ; Pour, Milan (referee)
4. Conclusion A series ofnovel isosteric 3'-nucleotide analogues (9a-e and l0a-e) was synthesized, cr-t-- and B-t--prolinol nucleoside N-methylphosphonic acids distinguished for the loss of unambiguously defined configuration at the nitrogen atom in 3'-position of prolinol nng. Remarkable conformational differences between cr-L- and B-l-prolinol nucleotides determined by NMR study suggest some similarity with the natural 5'-o-nucleotide. The same conformational changes in o-series of prolinol nucleotides fit even better the 3'- and 5'-o- nucleotides. In addition, a series of four diastereoisomeric synthons 5-8 was prepared from the commercially available lrans-4-hydroxy-l-proline, giving access to a complete set of prolinol-derived nucleotide analogues bearing cr.L-, B-t--, o.o- and p-o-conÍiguration. In order to constrain the conformational flexibility of the N-phosphonomethyl moiety, seveÍal protected compounds were subjected to N-oxidation or N-methylation which gave chiral N-oxides or quatemary ammonium salts. However, the synthesis of the respective unprotected phosphonic acids was unsuccessful, probably due to their fast decomposition. Acylation ofthe pyrrolidine ring nitrogen atom by several acylphosphonic acid derivatives led to the novel N.phosphonoformyl, /y'.phosphonoacetyl and...
Carbocyclic analogues of nucleosides containing substituted bicyclic systems.
Šála, Michal ; Hřebabecký, Hubert (advisor) ; Černý, Miloslav (referee) ; Moravcová, Jitka (referee)
Charles University in Prague Faculty of Science Department of Organic and Nuclear Chemistry Carbocyclic analogues of nucleosides containing substituted bicyclic systems Michal Šála Ph.D. Thesis Abstract Prague 2010 Introduction Nucleoside and nucleotide analogues are of fundamental importance for all organisms. Therefore, nucleoside analogues are interesting target for drug discovery and development, mainly as potential antiviral and antitumor agents. A crucial disadvantage of natural nucleosides analogues is cleavage of the N-glycosidic bond by phosphorylases. Modification which increases resistance against enzymatic degradation is substitution of the sugar moiety furanose ring by a hydrocarbon ring. Many of such modified analogues - carbocyclic nucleosides1 - exhibit interesting antiviral activity. Several analogues containing conformationally locked bicyclic systems were also synthesized. Well known are carbocylic nucleosides with a fused cyclopropane moiety2 (bicyclo[3.1.0]hexane). Recently, novel conformationally locked carbocyclic nucleosides based on 2-oxabicyclo[2.2.1]heptane ring system were described3 (as precursors for carbocyclic locked nucleic acids). This thesis concerns the synthesis of biologically active compounds related to the carbocyclic nucleoside analogues. First part of the work is...
Synthesis of axially chiral pyridin N-oxides and their application in organocatalysis
Hrdina, Radim ; Kotora, Martin (advisor) ; Černý, Miloslav (referee) ; Dvořák, Dalimil (referee) ; Starý, Ivo (referee)
o\ =Í Ě=Eíš$;*e.s Ei3E'1a?i l=;iěa ÉiE.Eé gžiž|; E=ž:g 7ElĚ.; zĚi;i žÉÉiĚě:-'7i,ž 1.!:;s .iÉeEi,Éři{É -;E'-žEš;1;;ítEšÉ .Ě=-Ě!:, ?:íiťŠš:;Ě;'b'jÉ3Ěi.í=-íš;EašÉ€ ={=.á .1 ==ž,+ai g=*ŤÉ É E'! : ::Ě,'!žiE Éí; g := : 9 ?EE =N:jÉ i;i,PE' ii;eÚÉs2 É.e.t sš:áE7 €šÉ-;:ň'ÉÉ |i. ":;šiÉ"EEÉ';Eč=;=.sz;==iaú - !Á..-= "i eať= 'É ď., -'á'.š L >q) N =t ú\r EÉiF T2yEĚ "?*;;> á ''j Ě .| : |, ? - a ^ l p Á ž 2 z: i i i i : i -, Ž .i, É? E=-,+; i Ě siiEĚ Éi;ž4i lEEř:Eí5iř iEE?5:E Ě;tžEizE== l;7;": :;ee-_?Ezii i;+ir+? -ž3;š: zďii; EiUÍEE =.=E=? "€:ž= š:ž=FE,?;EE= iěi;i í! 3,:- .'|:€ F1E.= a o3;Ezi _ =. l'z 'Ú ž ii.- Ě:c5-i= '=2E;šl +:É?49 1i;,í.i ÉE3E;E-€šls*iŤ+z\ ^EE E-oŤ ž.E:š.=ts €šrš EÉEii L EĚIE:Í;E5 oi BaEEE c.,B*Bcá (, I Q Ý
Acyclic nucleoside phosphonates with expanded purine bases
Čapková, Kateřina ; Holý, Antonín (advisor) ; Černý, Miloslav (referee) ; Kefurt, Karel (referee) ; Hocek, Michal (referee)
Univerzita Karlova Příro dovědecká fakulta Katedra organické a jaderné chemie Akademie věd Ceské Republiky Ústav organické chemie a biochemie S tirrltrffi[n Acyklické nukleo sidfo sfon áty rozšířenoupurinovou bazí Kateřina Čapková Shrnutí disertačnípráce Praha 2006 -tt ai-''- ffi-'.--.-/ /{ía' s Acyklické nukleosid fosfonáty předstalují velice zajimavou skupinu nukleotidových analogů s protivirovými, cýostatickj.rni a antiprotozoá|ními účinky.Jsou aktivní nejen proti širokému spektru DNA viru (herpesviry, poxviry, adenoviry, papillomaviry), ale i proti retrovirům (virus hepatitidy B, HIV). Nejvýznamnějšími představiteli celé skupiny jsou PMEA (adefovir, v klinické praxi ve formě adefovir dipivoxil), schválený pro léčbuhepatitidy B (HepseraTM), dále (fi).PMPA (teno-Qvir. v klinické praxi jako tenofovir disoproxil fumarát), schválený pro léčbuAIDS (Viread.'u') a (S)-HPMPC (cidofovir),-schválený pro léčbucýomegalovirové retinitidy u imunosuprimovaných pacientů (VistideTM). 1 V rámci hledání nových potenciálních virostatik a cýostatik bylo mým úkolem připravit série několika nových typůmodifikovaných acyklických nukleosid fosfonátů, konkrétně s tricyklickou bazi odvozenou od původnípurinové baze. Tricyk|ické baze23 ;so., zajímavé předevšímkvůli své fluorescencí,která umoŽňuje snadnou detekci a sledování osudu...
Synthesis of oligosaccharides of Dhexosamine type-potential ligands of activating receptors of NK cells
Kovalová, Anna ; Ledvina, Miroslav (advisor) ; Černý, Miloslav (referee) ; Kefurt, Karel (referee) ; Holý, Antonín (referee)
stu(trd oÍgaŮáůr' ďthercce#*' lsťÍees€pd-e fuandffig sibs.. CoNcLusroN In the course of this work, we prepared oligosaccharides containing 2-acetamido-2- deoxyglucopyranose and 2-acetamido-2-deoxygalactopyranose units and tested them for binding to NK cell receptors NKR-p1 and CD69. Branched oligosaccharides are first effective mimetics of natural ligands of CD69. We successfully completed the synthesis despite some challenging problems (multiple glycosylations, H-bonds), and we also obtained results, which contribute to the understanding of a relevant biological question. APLICABILITY AND PERSPECTIVES Although the synthesized o|igosaccharides were speciÍica||y designed as |igands for lectin receptors of NK cells, they may have other uses too. We intend to introduce linkers to the reducing position of the oligosaccharides to enable their presentation on dendrimeric structures. These multiple glycodendrimers can substitute natural multiantenar ligands. Moreover, oligosaccharides of this type might be used as a part of vector systems of new generation targeted combined chemo- and immunotheraoeutics. This Work was suppofted by grants No. 241/2013/B-CH/PřF and 416/2004/B-CH/PřF of GAUK' No. QF31 1 5/2003 of Ministry of Agricutture of cR, 203/00/0071 of Grant Agency of cR, by research project No 24 055 05O6.and...
Conformationally locked carbocyclic nucleoside analogues.
Dejmek, Milan ; Hřebabecký, Hubert (advisor) ; Černý, Miloslav (referee) ; Moravcová, Jitka (referee)
Three novel series of conformationally locked carbocyclic nucleoside analogues based on the bridgehead substituted norbornane bicyclic skeleton were prepared - analogues with the pseudosugar locked in the North, East or South conformation. These compounds were synthesized as structurally related substances to a commercially successful antiviral drug abacavir, which is used in the therapy of HIV. One of the goals was the exploration of the dependence of antiviral activities of prepared compounds on the conformation of their pseudosugar part. The key intermediates in the syntheses of the North and South analogues, amine precursors suitable for nucleobase construction, were prepared in several steps from easily accessible 5-carboxymethyl norbornene. Introduction of a carboxylic function into the bridgehead position, a key transformation mutual to both syntheses, was accomplished via the Hell-Volhard-Zelinsky bromination of norbornane-2- carboxylic acid, which affords rearranged 2-exo-bromo-1-carboxynorbornane. Approach to the derivatives locked in the East conformation is based on radical cyclization of substituted 4-(bromomethyl)cyclohexanone oxime, which affords norbornane intermediate substituted in both bridgehead positions. Thymine, 6-chloropurine and 2-amino-6-chloropurine nucleobases were used...

National Repository of Grey Literature : 16 records found   1 - 10next  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.