Synthesis of 2′,4′-Propylene-Bridged (Carba-ENA) Thymidine and Its Analogues: The Engineering of Electrostatic and Steric Effects at the Bottom of the Minor Groove for Nuclease and Thermodynamic Stabilities and Elicitation of RNase H
any, effect on nucleaseresistance but 8′S-OH resulted in significantly decreased nucleolytic stability; and (3) 8′-NH2 substituted carba-ENA leads to obvious loss in the nucleaseresistance. The RNA strand in all of the carba-ENA derivatives modified AON:RNA hybrid duplexes can be digested by RNase H1 with high efficiency, even at twice the rate of those of the native and ENA modified counterpart.