Poster presented at TIDES 2011.
As with cholesterol modifications, tocopherol has been shown to have potential use in the delivery of oligonucleotides into cells. Vitamins such as tocopherol are not produced by the target cells, but are used by the latter and therefore vitamins are recognised. They are thought to be internalised by cells only after interaction with a binding protein and therefore have the potential for specific targeting of a cell type. We have looked at the use of tocopherol CEP and octyltocopherol CEP in oligonucleotide synthesis with the aim to define the optimum deprotection conditions. The synthesis conditions were not optimised since these are reported elsewhere.
The hydrophobic nature of tocopherol has also been utilised as a means of improving the purification of ribozymes. We have also investigated the use of tocopherol as a means of allowing an initial purification of thiol-modified oligos with a view to improving the efficiency of a second ion-exchange purification.
Thiol-modified oligonucleotides are often used as a means of incorporating labels such as dyes by reaction with maleimides or acetamides. There is often a need to carry out multiple purifications in order to ensure the purity of the thiol-modified oligonucleotide prior to conjugation and a simple, efficient method
of removing DMT-containing N-1 failures would be advantageous.