8 オリゴヌクレオチド合成における保護基を利用した新しい単離法の研究

抄録

Attempts to prepare of oligonucleotides by means of Merrifield method have been investigated in several laboratories. But pure oligonucleotides have only been achieved by using of DEAE-cellulose column which is usual separating method in oligonucleotide synthesis. Because, the purity of oligonucleotides obtained by Merrifield method are depended on the yields of condensation reactions. Based on the above mentioned problem, a new method for the preparation of pure oligonucleotides was investigated in our laboratory. The principle of this method is shown in Fig 1. When a mixture of 2 and 3 was treated with TPS in dry pyridine, 5 was obtained along with 4. An ion exchange resin, having sulfonic acid group, was added to the mixture. Only a desired dinucleotide 5 was adsorbed in the resin. After washing the resin with water, 5 was eluted by means of aqueous solution of triethylamine and concentrated to dryness. The residue was treated with 80% of acetic acid for removal of N,N-dimethyl p-phenylenediamino group to affored 6. When the dinucleotide 6 was further allowed to react with 2 in the presence of TPS, 7 was obtained. After treatment with 80% of acetic acid, 8 was obtained as a pure sample. This method has two advantageous points, namely, (1) pure oligonucleotides can be prepared and confirmed in every separation step, (2) the oligonucleotides can be obtained on a relatively large scale without using of column chromatography.