Synthesis and application of 2′-fluoro-substituted cap analogs

Design, synthesis, and biological evaluation of 2′-fluoro-substituted cap analogs, i.e., m7,2′FG[5′]ppp[5′]G and m7,2′FG[5′]ppp[5′]m7G are described. Structures were confirmed by 1H, 31P, 19F NMR and MS data. The effects of the 2′-fluoro-substituted moiety from the normal and N7 double methylated mCAP were evaluated with respect to their capping efficiency, in vitro T7 RNA polymerase transcription efficiency, and translation activity using cultured HeLa cells. Luciferase fusion protein production was monitored by measuring the luciferase activity. mRNA poly(A) capped with 2′-fluoro-substituted cap analogs, (m7,2′FG[5′]ppp[5′]G) and (m7,2′FG[5′]ppp[5′]m7G), were translated 2.4- and 2.5-fold more efficiently, respectively, than mRNA capped with conventional m7G[5′]ppp[5′]G.