Solid-phase synthesis of peptide nucleic acid (PNA) monomers and their oligomerization using disulphide anchoring linkers.
A new simple solid-phase method has been developed for synthesizing Boc-protected peptide nucleic acid (PNA) monomers. An immobilized backbone 3 was built on Expansin resin using an ester disulphide handle: 2-hydroxypropyl-dithio-2'-isobutyric acid (HPDI). The base acetic acids of thymine 5, Z-cytosine 9, Z-adenine 12, and 6-O-benzyl guanine 17 were prepared and coupled to the immobilized backbone. The HPDI handle was cleaved under mild conditions by cyanolysis or assisted hydrolysis with tris(2-carboxyethyl)phosphine (TCEP) to give undamaged PNA monomers. These monomers were coupled to form oligomers by solid-phase method with another disulphide linkage: aminoethyldithio-2-isobutyric acid (AEDI) grafted on an amino-functionalized TentaGel resin, using in situ neutralization and TBTU as activating reagent. Final cleavage of the AEDI linker gave PNA bearing a cysteamide residue that could be useful for optimizing PNA properties. Oligomers of up to 16 residues long were assembled.
Karl-Franzens-Universität, Graz, Austria.
G
G
Aldrian-Herrada
A
A
Rabié
R
R
Wintersteiger
J
J
Brugidou
D004247:DNA / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry*; D015394:Molecular Structure; D009841:Oligonucleotides / Q000737:chemistry*
D004220:Disulfides; D009841:Oligonucleotides; D004247:DNA