Biomedical subjects

W T Markiewicz

Publications and source records attributed to W T Markiewicz.

21 records · Page 2Linked to original sources

PubMed1976

Nucleoside-3'-phosphotriesters as key intermediates for the oligoribonucleotide synthesis. III. An improved preparation of nucleoside 3'-phosphotriesters, their 1H NMR characterization and new conditions for removal of 2-cyanoethyl group.

An improved procedure for the transformation of 5'-O-monomethoxytrityl-2'-O-acetyl-3'-phosphates of uridine la, inosine ib and 6-N-benzoyladenosine lc into corresponding 3'/2,2,2-trichloroethyl, 2-cyanoethyl/-phosphates iiaic is reported. H NMR characterization of nucleoside 3'-phosphotriesters is presented. New conditions i.e. anhydrous triethylamine-pyridine treatment have been found for the selective removal of 2-cyanoethyl group from nucleoside 3'-phosphotriesters in the presence of neighbouring 2'-O-acetyl one.

Adenosine↗

PubMed1975

The modified nucleosides of tRNAs. II. Synthesis of 2'-O-methylcytidylyl (3'-5') cytidine.

The synthesis of 2'-O-methylcytidylyl (3'-5')cytidine by the triester method using as protecting groups, 2,2,2-trichloroethyl for phosphate hydroxyl group, p-chlorophenyoxyacetyl for 5-hydroxyl group, methoxymethylidene for 2',3'-cis-diol system, and benzoyl for the exo-amino group of cytidine is presented. The obtained product was characterised by UV, electrophoresis, chromatography and an enzymatic digestion.

Chromatography, Paper↗

PubMedDate not supplied

Studies on synthesis and structure of O-beta-D-ribofuranosyl(1"-->2')ribonucleosides and oligonucleotides.

Minor nucleosides found in several eukaryotic initiator tRNASiMet, O-beta-D-ribofuranosyl(1"-->2')adenosine and -guanosine (Ar and Gr), as well as their pyrimidine analogues, were obtained from N-protected 3',5'-O-(1,1,3,3-tetraisopropyldisiloxane-1,3-diyl)ribonucle osides and 1-O-acetyl-2,3,5-tri-O-benzoyl-beta-D-ribofuranose in the presence of tin tetrachloride in 1,2-dichloroethane. A crystal structure has been solved for 2'-O-ribosyluridine. The 3'-phosphoramidites of protected 2'-O-ribosylribonucleosides were prepared as the reagents for 2'-O-ribofuranosyloligonucleotides synthesis. O-beta-D-Ribofuranosyl(1"-->2')adenylyl(3'-->5')guanosine (ArpG) was obtained and its structure was analysed by NMR spectroscopy.

Disaccharides↗