Synthesis of sugar-based polypeptides

Abstract

Synthetic polypeptides containing sugar moieties can find interesting applications as drug-delivery systems or as hydrogels. Only a few studies report on the successful synthesis of sugar-based polypeptides. The aim of this study is to access a range of well-defined polypeptides carrying linear gluconoyl moieties as side-groups, including homo-polypeptides and co-polypeptides with hydrophilic and hydrophobic sequences. The strategy consisted in first preparing the polypeptide via ring-opening polymerization of N-carboxyanhydrides using either an Al-Schiff's base metal complex or a primary amine. The free amino side-groups of the polylysine units are then reacted with gluconolactone, thus leading to a main polypeptide backbone and linear sugar moieties as pendant groups. Sugar moieties have also been attached to statistical and block co-polypeptides bearing hydrophilic and hydrophobic units such as L-lysine and L-leucine, respectively. The anchoring of linear gluconoyl moieties onto poly(L-lysine) and onto statistical and block co-polypeptides with lysine and leucine sequences is here reported for the first time. © 2008 VSP.