| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for reinforcing the mismatch-recognizing ability of a specific antisense nucleic acid by introducing a polyamine to the C-5 position of the pyrimidine base of the antisense nucleic acid, capable of giving nucleic acid medicines having high double strand-forming abilities with perfectly complementary chains and useful for treating infectious diseases such as HIV, etc. SOLUTION: This method for reinforcing the mismatch-recognizing ability of an antisense nucleic acid comprises introducing a polyamine to the C-5 position of the pyrimidine base (preferably expressed by formula I) of an antisense nucleic acid comprising a phosphorothioate oligomer DNA. The polyamine is preferably introduced by treating a phosphorothioate oligomer DNA having a pyrimidine base having a methoxycarbonylmethyl group at the C-5 position as a constituent with an excessive amount of tris(2-aminoethyl)amine, and a polyamine-modified phosphorothioate oligomer DNA of formula II or III (Acr is a compound of formula-IV; U* is a compound of formula V) is used for anti-HIV preparations. |
