Nucleic acid complex, method for forming nucleic acid hybridization, pharmaceutical composition, nucleic acid probe, and complementary-strand nucleic acid complex

Abstract

A nucleic acid complex includes a single-stranded nucleic acid and a cross-linked double-stranded nucleic acid including the first nucleic acid strand linked to at least one of the 5′ end and the 3′ end of the single-stranded nucleic acid and the second nucleic acid strand including a base sequence that is completely or sufficiently complementary to the first nucleic acid strand.

1 . A nucleic acid complex comprising:
 a single-stranded nucleic acid; and   a cross-linked double-stranded nucleic acid comprising a first nucleic acid strand linked to at least one of a 5′ end and a 3′ end of the single-stranded nucleic acid and a second nucleic acid strand comprising a base sequence that is completely or sufficiently complementary to the first nucleic acid strand,   wherein the cross-linked double-stranded nucleic acid is cross-linked by a bond between sugars of the first nucleic acid strand and the second nucleic acid strand,   wherein the sugars of the first nucleic acid strand and the second nucleic acid strand are linked by a cross-linking reagent having an aminooxy group or an amino group,   wherein the cross-linking reagent is a compound represented by
   general formula 1: 
   R 1 —NH—O-L 1 -D-L 2 -A  (1)
 
   
       (wherein
 R 1  is a protective group of a hydrogen atom, an alkyl group, or an amino group, 
 D is an aromatic group selected from a substituted or unsubstituted phenylene group, a substituted or unsubstituted anthrylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted phenanthrylene group, a substituted or unsubstituted anthraquinolylene group, and a substituted or unsubstituted acridinylene group, or a C 2-10  alkyl group, 
 a substituent of the aromatic group is selected from the group consisting of a halogen atom, a C 1-6  alkyl group, a nitro group, a cyano group, a C 2-6  alkenyl group, a C 3-10  cycloalkyl group, a C 1-10  alkoxy group, and a C 1-10  acyl group, 
 L 1  is a direct bond or a divalent group represented by the following general formula 3 or 4; 
 
       
         
           
           
               
               
           
         
       
       (wherein R 3  is a C 1-9  alkylene group or —(CH 2 ) o —(OCH 2 CH 2 ) p —(CH 2 ) q —, o to q are each independently an integer of 0 to 15, o+p+q is 1 to 15), 
       L 2  is a direct bond or a divalent group represented by the following general formula 5 or 6: 
       
         
           
           
               
               
           
         
       
       (wherein R 4  is a C 1-9  alkylene group or —(CH 2 ) r (OCH 2 CH 2 ) s —(CH 2 ) t —, r to t are each independently an integer of 0 to 15, r+s+t is 1 to 15), and
 A is an aminooxy group or a protected aminooxy group) 
 
       or a salt thereof. 
     
     
         2 . The nucleic acid complex according to  claim 1 , wherein the cross-linked double-stranded nucleic acid is linked to the 5′ end of the single-stranded nucleic acid. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . The nucleic acid complex according to  claim 1 ,
 wherein the cross-linking reagent has/comprises the aminooxy group, and   wherein aldehyde groups in the sugar of the first nucleic acid strand and the second nucleic acid strand are linked via the aminooxy group of the cross-linking reagent in the cross-linked double-stranded nucleic acid.   
     
     
         9 . A method of nucleic acid hybridization comprising:
 the step of hybridizing the nucleic acid complex according to  claim 1  with a target nucleic acid comprising a base sequence that is completely or sufficiently complementary to a base sequence of a single-stranded nucleic acid that forms the nucleic acid complex.   
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled)