We recently reported on the use of 1,2,4-dithiazolidine-3,5-dione (DtsNH) and 3-ethoxy-1,2,4-dithiazoline-5-one (EDITH) as effective sulfurizing reagents for the preparation of phosphorothioate-containing oligodeoxyribonucleotides. One challenge in automated solid-phase synthesis of phosphorothioate-containing RNA is to develop sulfurization reagents that are effective in the presence of bulky 2'-OH protecting groups. The present study demonstrates that EDITH is exceedingly effective at low concentrations (0.05 M) and short reaction times (2 min) for the automated synthesis of oligoribonucleotides.
Bibliographical noteFunding Information:
We thank Mr Lin Chen for preparing some of the DtsNH and EDITH used in this work. Financial support from NIH grants GM 28934, 42722 and 43552 to GB; GM 49928 to KMF; and grants