Morpholinos and PNAs compared

[Synthesis of 2'-aminometylmorpholino nucleoside analogues containing 4'-carboxymethyl lynker group]

A simple and effective method for the synthesis of 2'-aminomethylmorpholino-4'-carboxymethyl nucleoside analogues and Boc-modified derivatives as synthons for peptide synthesis was developed.

Effect of Steric Constraint at the γ-Backbone Position on the Conformations and Hybridization Properties of PNAs

Conformationally preorganized peptide nucleic acids (PNAs) have been synthesized through backbone modifications at the γ-position, where R = alanine, valine, isoleucine, and phenylalanine side chains. The effects of these side-chains on the conformations and hybridization properties of PNAs were determined using a combination of CD and UV-Vis spectroscopic techniques. Our results show that the γ-position can accommodate varying degrees of sterically hindered side-chains, reaffirming the bimodal function of PNAs as the true hybrids of “peptides” and “nucleic acids.”

Design and synthesis of dinucleotide 5'-triphosphates with expanded functionality

We propose the new approach to the synthesis of 5'-triphosphate derivatives of natural and modified dinucleotides with expanded functionality. Our strategy includes the combination of the solution phase synthesis of necessary dimers using the wide range of nucleic acids chemistry methods and the subsequent introduction of the triphosphate residue. A number of the new potential substrates for the template dependent synthesis of nucleic acids with expanded functionality are obtained, namely, 5'-triphosphates of dinucleotides containing the functionally active groups in heterocyclic bases, in carbohydrate-phosphate backbone, and the groups mimicking the residues of natural amino acids. The abilities of the proposed synthetic route are also demonstrated by the synthesis of 5'-triphosphates of dinucleotides with modified carbohydrate-phosphate backbone.

New oligonucleotide analogues based on morpholine subunits joined by oxalyl diamide tether

We report on the design, synthesis and some of the properties of the new oligonucleotide analogues based on morpholine nucleoside (MorB) subunits joined by an oxalyl diamide tether instead of a phosphate group. The synthetic strategy and oligomer design are optimized to easily obtain target substances without using protective groups. The dimers HOMorU-Ox-NHMorU, HOMorU-Ox-NHMorA, and uracil containing the hexamer HOMorU-(Ox-NHMorU)5 were synthesized. The structures of all substances were confirmed by 1H, 13C, NMR, and mass spectroscopy. Base stacking interactions in dimers were revealed by CD-spectra data.