Cleavage of Oligonucleotides from Solid-Phase Supports Using o-Nitrobenzyl Photochemistry

Abstract

Oligonucleotides are cleaved from modified solid phase supports using the o-nitrobenzyl intramolecular photochemical redox reaction. Oligonucleotides can be cleaved before or after removal of protecting groups. Employment of phosphoramidites containing allyloxy protecting groups that are labile to Pd 0 enables one to deprotect oligonucleotides without the use of base. The yields of isolated oligonucleotides relative to yields obtained using conventional hydrolytic cleavage vary between 59% and 87%. Tritium labeling indicates that small amounts of thymidine-thymidine photodimers are formed during the photolysis time required to obtain good yields of oligonucleotides from the succinate linked photolabile support (4). Photodimer formation is minimized(< 7%) during the prolonged irradiation required when cleaving oligonucleotides from 7 by employing bandpass filtering