Editorial [ Bioorganic Chemistry Guest Editor: Harri Lonnberg ]

This issue constitutes Part II of the thematic issue of Bioorganic Chemistry. It contains two timely reviews that highlight backbone modifications in oligonucleotides and peptides. The first of them, contributed by Jung and Marx, compiles the synthetic studies of 4'-substituted nucleosides and their incorporation into oligonucleotides. These structural modifications have gained interest for the reason that they may protect the oligonucleotide backbone toward enzymatic degradation and simultaneously allow introduction of conjugate groups in a manner that does not hamper hybridization. Accordingly, the physico-chemical properties of the oligonucleotide may conveniently be tuned by 4'-substitution. The review by Deska and Kazmaier, in turn, concerns backbone modifications of peptides. While human proteins and peptides are composed almost exclusively of 20 common L-amino acids, the amino acid content of peptide-based secondary metabolites of lower organisms is much more versatile, and many of such abnormal peptide structures exhibit pharmacological properties. For this reason, and to obtain appropriate chemical models for structural motives of proteins, synthesis of backbone modified peptide has received wide interest. The results of these synthetic efforts are compiled. I thank the contributors for their thorough work. Hopefully many of the readers of Current Organic Chemistry will find these reviews interesting.