| Budget Amount *help |
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1988: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Research Abstract |
1. Various nucleoside-5-phosphorimidazolides were prepared from nucleotides such as adenylic acid uridylic acid, cytidylic acid, guanilic acid and 8-azide-adenylic acid, with imidazole and azole compounds such as benzimidazole and triazoles. 2. Using urany complex catalyst which was formed from uranyl nitrate and nucleoside-5'- phosphporimidazolide, the nucleoside-5'-phosphporimidazolide were polymerized.
3. Analysis of the products by high performance liquid chromatography revealed that oligonucleotides from dimer to hexadecamer were formed in high yields. 4. The selectivity of 2'5'-internucleotide bond was 65 - 98%. The type, yield and the regioselectivity of the resulting oligonucleotides were greatly dependent on the pH of the medium, reaction temperature and the concentration of the catalyst. The polymerization took place most efficiently under neutral conditions. 5. Nucleoside-5'- phosphporimidazolides with any nucleic acid bases were polymerized by uranyl complex catalysts forming the corresponding oligonucleotides, though the type of the resulting oligonucleotides were different depending on the type of nucleic acid base used.
6. Hg2+ or Ag+ ion coordinated to the base part exclusively and altered the selectivity of the oligocytidylate formation by uranyl complex catalyst. Use of azole compounds as a nucleotide activating group in the place of imidazole changed the rate, selectivity and yield of the uranyl-ion complex catalyzed oligonucleotide synthesis. 7. Further we have found that Mn2+ and Cd2+ facilitate the pyrophosphate bond formation of nucleotides through the different type of metal-nucleotide complex. 8. Applying the above reaction, we prepared some biologically active nucleotides such as 2-5A analogues, coenzymes and dinucleoside polyphosphates.
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