Patent ID: 8680253

Claim:
A peptide nucleic acid derivative of Formula I or a pharmaceutically acceptable salt thereof: wherein, n is an integer equal to or larger than 5; S 1 , S 2 , . . . , S n-1 , S n , T 1 , T 2 , . . . , T n-1 , and T n independently represent hydrido, deuterido, substituted or non-substituted alkyl, or substituted or non-substituted aryl radical; X and Y independently represent hydrido, deuterido, substituted or non-substituted alkyl, substituted or non-substituted acyl, substituted or non-substituted sulfonyl, or substituted or non-substituted aryl radical; Z represents hydroxy, substituted or non-substituted alkyloxy, substituted or non-substituted aryloxy, or substituted or non-substituted amino radical; B 1 , B 2 , . . . , B n-1 , and B n are independently selected from natural nucleobases including adenine, thymine, guanine, cytosine and uracil, and unnatural nucleobases; and, at least one of B 1 , B 2 , . . . , B n-1 , and B n is independently selected from unnatural nucleobases represented by Formula II, Formula III, or Formula IV: wherein, R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are independently selected from substituted or non-substituted alkyl, and hydrido radical; and, L 1 , L 2 and L 3 are a covalent linker represented by Formula V connecting a basic amino group to the moiety responsible for nucleobase pairing properties: wherein, Q 1 and Q m are substituted or non-substituted methylene (—CH 2 —) radical, and Q m is directly linked to the basic amino group; Q 2 , Q 3 , . . . , and Q m-1 are independently selected from substituted or non-substituted methylene, oxygen (—O—), sulfur (—S—), and substituted or non-substituted amino radical [—N(H)—, or —N(substituent)-]; and, m is an integer from 2 to 15.