| abstract |
A composition for use in medicine, in which the composition comprises a compound of formula (III): ** Formula ** or a salt, racemate, enantiomer, diastereomer, geometric isomer or tautomer thereof, in which X is absent or is O, NH, NR, S; X1 is absent or is O, NH; A is absent or is aryl, aralkyl; n is 0, 1, 2, 3, 4, 5; R is alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, aralkyl, heterocyclic, O-alkyl, O-heteroaryl, steroidal; R3 is selected from hydrogen, alkyl, substituted alkyl, C (O) -alkyl, C (O) O-alkyl, C (O) -aryl, C (O) O-aryl, C (O) NH-alkyl and C (O) NH-aryl; and B1 and B2 are, independently, adenine, guanine, thymine, cytosine, uracil or a modified nucleobase. |