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Modified nucleosides derived from pyrimido[4,5-b]indole
Konč, Juraj ; Hocek, Michal (advisor) ; Jindřich, Jindřich (referee)
Syntheses of two series of 2'-sugar-modified pyrimido[4,5-b]indole nucleosides were developed. The synthetic strategy was based on functional group transformations of the 2'-hydroxy group of the 3',5'-protected ribonucleoside. The key intermediate was prepared via stereoselective nucleobase anion glycosylation of the known 4,6-dichloropyrimido[4,5-b]indole nucleobase with 2,3-O-isopropylidene- 5-O-TBS-protected halogenose, subsequent deprotection under acidic conditions and protection of 3'- and 5'-hydroxy groups with Markiewicz reagent. Pyrimidoindole arabinonucleoside was then synthesized using a sequence of oxidation-reduction reactions of the 2'-hydroxy stereocenter. The synthesis of pyrimidoindole 2'-deoxy- 2'-fluororibonucleoside was achieved by stereoselective SN2 fluorination of the THP-protected arabinoside followed by acidic deprotection. For the biological activity testing, two series of 4-substituted arabinonucleosides and 2'-deoxy- 2'-fluororibonucleosides were synthesized employing nucleophilic substitution or Pd-catalyzed cross-coupling reactions.
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Synthesis of novel C-nucleosides with modified sugar
Havlíček, Vojtěch ; Hocek, Michal (advisor) ; Janeba, Zlatko (referee)
In this bachelor thesis, a new method of preparation of C-nukleosides with 2'-deoxy-2',2'-difluoro modified sugar part was developed. During the research, nucleophilic addition on furanolacton was used and for this modification, the method of modular approach was developed. Using this method, it is possible to prepare a series of structurally similar compounds. We succeeded in preparing two C-nukleosides, potentially biologically active substances.
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Synthesis of novel cytostatic deazapurine nucleosides and pronucleotides
Perlíková, Pavla ; Hocek, Michal (advisor) ; Jindřich, Jindřich (referee) ; Hlaváč, Jan (referee)
The synthetic routes to three types of phosphate prodrugs of 6-hetaryl-7-deazapurine ribonucleosides based on palladium-catalyzed cross-coupling reactions have been developed. CycloSal- and phosphoramidate pronucleotides and octadecyl phosphates derived from 6- hetaryl-7-deazapurine ribonucleosides were screened for their in vitro cytostatic activity. It was shown that cytostatic activity of cycloSal phosphates was similar or slightly lower compared to the parent nucleosides. Significant drop of cytostatic activity was observed in phosphoramidate pronucleotides. Octadecyl phosphates were devoid of any cytostatic activity. 6-Hetaryl-7-deazapurine ribonucleosides with bulky groups in position 6 showed very strong and selective inhibition of adenosine kinase from Mycobacterium tuberculosis. 2'-Modified 6-hetaryl-7-deazapurine nucleosides: 2'-O-methylribonucleosides, arabinonucleosides and 2'- deoxy-2'-fluororibonucleosides, were prepared by multistep functional group transformations from a ribonucleoside. The synthesis of 2'-deoxy-2',2'-difluoro-erythro-pentofuranosyl nucleosides was based on a glycosylation of 6-chloro-7-deazapurine with a sugar synthon followed by palladium-catalyzed cross-coupling reaction and deprotection. Despite the low yields and laborious separation of the anomers,...
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