Synthesis of very short chain lysophosphatidyloligodeoxynucleotides”

Very short chain 5'-O-lysophosphatidyloligonucleotides [5'-O-(1-O-palmitoyl-sn-glycero-3-phosphoryl)oligode-oxynucleotides, (5'-LyPOdNs)] were synthesized following a two-step chemoenzymatic synthesis. 5'-O-(sn-Glycero-3- phosphoryl)oligodeoxynucleotides (5'-GPOdNs) were first prepared by simply using a phosphoramidite of [(4S)-2,2- dimethyl-1,3-dioxolan-4-yl] methanol (1) in a further coupling step after the solid-phase elongation of each desired oligodeoxynucleotide. Next, the regioselective palmitoylation at the C-1 hydroxyl of the glycerol moiety of 5'-GPOdNs was achieved by a lipase-catalyzed transacylation with trifluoroethyl palmitate in organic solvent. Despite of the molecular bulkiness of 5'-GPOdNs, 2-, 3-, and 4-mer 5'-LyPOdNs were prepared by this procedure. Although in very low yield, 5- and 6-mer 5'-LyPOdNs were also obtained by this way.