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Chemiczna synteza oligorybonukleotydów

100%

Milecki J.

Wiadomości Chemiczne

2002

tom [Z] 56, 3-4

255-277

Basic issues and problems of chemical synthesis of oligoribonucleotides are presented. The paper describes three methods for construction of oligonucleotide chains: (1) a triester method which involves activation of nucleoside phosphodiesters with different azole sulfonates, and currently widely used methods employing PIII synthetic intermediates: (2) a phosphoramidite method which makes use of activation of nucleoside phosphoramidites by weakly acidic azoles or azole salts, (3) an H-phosphonate method, which uses nucleoside H-phosphonates activated by acid chlorides, both PIII intermediates are applied mainly in solid-support synthetic methodology. Problems of choosing appropriate protecting group for the synthesis are discussed. The article presents properties of basic types of protecting groups for lactam, exo-amino (base-labile protection), and hydroxyl groups (acid-labile for 5' protection, acid- or specific reagent-labile for 2' protection). The problem of 2'OH protection is described in detail. In this respect acid-labile groups and alkylsilyl groups are compared and their advantages and disadvantages are discussed. More detailed discussion is devoted to the phenomenon of the silyl group migration during the synthesis of monomeric units for oligonucleotide chain assembly. Basing on the NMR study of the isomerisation reaction it was possible to determine limits of safety of the reaction conditions.

Z-RNA. The synthesis of 2'-O-[13C]methyl- and 5-methyl-analogs of ribo-CGCGCG

38%

Biala E. , Milecki J. , Kowalewski A. , Popenda M. , Antkowiak W. Z. , Adamiak R. W.

tom 40

nr 4

Chemical synthesis of 2'-0-[13C methyl-rCGCGCG and 5-methyl-rCGCGCG using support-aided phosphoramidite method is presented. 2'-0-Methyl guanosine derivative was separated from its 3'-0-methyl counterpart using transient 5',3'-0-silylation with l,3-dichloro-l,l,3,3-tetraisopropyldisiloxane (Markiewicz reagent). The hexamers were obtained in a purity suitable for NMR studies.