| abstract |
This invention dicloses compositions of matter that are oligonucleotide analogs containing one or more improvements, where the improvement consists of replacing one or more of the phosphodiester linking units (-O-PO2--O-) by a dimethylene sulfide (-CH2-S-CH2-), sulfoxide (-CH2-SO-CH2-), or sulfone linking unit (-CH2-SO2-CH2-). This linkage is stable to degradation both by enzymes and by alkaline hydrolysis, contains no stereogenic atoms, and confers improved stability and the ability to fold into tertiary structure upon natural oligonucleotides and their analogs. |