Enhancement of siRNA silencing activity using universal bases or mismatches in the sense strand was written by Maier, Martin; Addepalli, Haripriya; Manoharan, Muthiah. And the patent was published on January 28,2010.HPLC of Formula: 550-33-4 The following contents are mentioned in the patent:
Double-stranded nucleic acids useful as an siRNAs are provided that have a sense strand and an antisense strand relative to a target nucleic acid, where the sense strand contains one or more modified or non-natural nucleobases, or one or more mismatch base pairings with the antisense strand. A method of gene silencing comprises administering to a mammal in need thereof a therapeutically effective amount of a double-stranded oligonucleotides containing a sense strand and an antisense strand, where the sense strand contains one or more modified nucleobases or one or more mismatch base pairings with the antisense strand. The effect of mismatch base pairing and modified nucleobases on siRNA potency is dependent on the mismatched base pair and its position on the sense strand. Apparently, local destabilization in the central region of the sense strand via mismatched base pairs (position 9-12) are more effective in enhancing potency than those outside of this region. The effect of modified nucleobases (e.g., 2,4-difluorotoluyl-ribonucleotide and -deoxyribonucleotide, 5-nitroindole deoxyribonucleotide and ribonucleotide, deoxyribo- and ribonebularine,, deoxy- and riboinosine, and ribo- or deoxyribo-2-aminopurine) to enhance potency over the parent compound is particularly significant in position 10. While there is no significant correlation between activity and thermal stability at positions 9, 11, and 12, the potency of the siRNAs appears to increase with decreased thermal stability due to modifications in position 10. Further, abasic modifications in position 10 and 12 particularly enhance potency over the parent compound This study involved multiple reactions and reactants, such as (2R,3S,4R,5R)-2-(Hydroxymethyl)-5-(9H-purin-9-yl)tetrahydrofuran-3,4-diol (cas: 550-33-4HPLC of Formula: 550-33-4).
(2R,3S,4R,5R)-2-(Hydroxymethyl)-5-(9H-purin-9-yl)tetrahydrofuran-3,4-diol (cas: 550-33-4) belongs to tetrahydrofuran derivatives. THF (Tetrahydrofuran) is water-miscible and has a low viscosity making it a highly versatile solvent used in a variety of industries. It is more basic than diethyl ether and forms stronger complexes with Li+, Mg2+, and boranes. It is a popular solvent for hydroboration reactions and for organometallic compounds such as organolithium and Grignard reagents.HPLC of Formula: 550-33-4
Referemce:
Tetrahydrofuran – Wikipedia,
Tetrahydrofuran | (CH2)3CH2O – PubChem