Synthesis of oligonucleotides with glucosamine at the 3′-position and evaluation of their biological activity

Short interfering RNA (siRNA) has been proven to be an utilizable tool for post-transcriptional gene silencing research. In this study, we designed and synthesized two glucosamine analogues and tried to modify the siRNA using these two glucosamine analogues at the 3′-overhang region of siRNAs to improve the nuclease resistance and to overcome some other weak points. The siRNAs modified with glucosamine analogues had almost no effect of the thermal stability and showed strong resistance to nuclease degradation. Some of them kept the same gene silencing activity level as unmodified siRNA.