Antisense oligonucleotides: efficient synthesis of 2'-O-methoxyethyl phosphorothioate oligonucleotides using 4,5-dicyanoimidazole. Are these oligonucleotides comparable to those synthesized using 1H-tetrazole as coupling activator?
Multiple 2'-O-methoxyethyl modified phosphorothioate oligonucleotides of 18-20-mer in length were synthesized at various scales using 4,5-dicyanoimidazole (DCI) as coupling activator. Extensive synthetic, analytical (using ion-pair LC-MS), and in vivo pharmacological, toxicological studies showed that oligonucleotides made with DCI and 1H-tetrazole are chemically and biologically equivalent. This extensive study will help the oligonucleotide therapeutic industry to move from using a potentially explosive activator (1H-tetrazole) to a safe activator (DCI).
Wang
Zhiwei
Z
Isis Pharmaceuticals, Inc., 2282 Faraday Avenue, Carlsbad, CA 92008, USA.
Siwkowski
Andy
A
Lima
Walt F
WF
Olsen
Phil
P
Ravikumar
Vasulinga T
VT
D000818:Animals; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002853:Chromatography, Liquid; D007093:Imidazoles; D007202:Indicators and Reagents; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D008807:Mice, Inbred BALB C; D016376:Oligonucleotides, Antisense / Q000138:chemical synthesis* / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D012449:Safety; D013777:Tetrazoles; D013810:Therapeutic Equivalency
C110830:4,5-dicyanoimidazole; D007093:Imidazoles; D007202:Indicators and Reagents; D016376:Oligonucleotides, Antisense; D013777:Tetrazoles; C045574:1H-tetrazole