A number of modified nucleosides are disclosed composed of modified sugar moieties which contain substituents at C1 and C4 positions, or branched substituents at C3 and C5 positions of deoxyribose or ribose. Each nucleoside is converted to or properly protected and then converted to the corresponding phosphoramidites. These phosphoramidites are used to assemble oligonucleotides in which there is at least one of the forenoted nucleosides. These sugar modified oligonucleotides have the potential to be used as antisense therapies since they are expected to enhance nuclease resistance and cellular uptake while they maintain sequence-specificity and affinity to nucleic acid targets in vitro or in vivo.
本文披露了一些改性核苷酸,由改性糖基组成,其中包含在脱氧
核糖或
核糖的C1和C4位置具有取代基,或在C3和C5位置具有支链取代基。每个核苷酸被转化或适当保护,然后转化为相应的
磷酰胺酯。这些
磷酰胺酯用于组装寡核苷酸,在其中至少有一个前述的核苷酸。这些糖基改性的寡核苷酸具有作为反义疗法的潜力,因为它们预计能够增强
核酸酶抵抗力和细胞摄取能力,同时在体外或体内保持序列特异性和亲和力与核酸靶标。