Dimethylthiarum Disulfide: New Sulfur Transfer Reagent in Phosphorothioates Oligonucleotide Synthesis

Dimethylthiarum disulfide (DTD) has been developed as a new and efficient sulfur-transfer reagent for automated synthesis of phosphorothioate oligonucleotides using phosphoramidite chemistry. The traditional four-step automated oligonucleotide synthesis has been compressed to three-step protocol using DTD. This improvement allowed an overall 20% reduction in the solvent consumption and reduced the total synthesis time by 25%. The large-scale application of DTD has been successfully demonstrated by synthesis of therapeutically useful 20-mer phosphorothioate antisense oligonucleotides with excellent yield and purity.