Glycolipid biomaterials: synthesis and solid-state properties of a poly(sophorolipid)

Structural complexity inherited from a microbial synthesis of glycolipids was translated into unique poly(sophorolipid) biomaterials. ROMP polymn. of natural diacetylated lactonic sophorolipids gave a high mol. wt. polymer with asym. bola-amphiphilic repeating units. The poly(sophorolipid) chain alternates C18 oleic-like aliph. segments (90% cis-configured double bonds) with bulky diacetylated disaccharide moieties. The poly(sophorolipid) is a solid at room temp. that undergoes the glass transition at 61 °C and melts at 123 °C. The crystal phase is assocd. with ordered packing of the aliph. chain segments. The semicryst. poly(sophorolipid) also displays a long-range order (d = 2.44 nm) involving sophorose groups that persist after crystal phase melting (in high-T diffractograms) with a slightly shortened distance (2.27 nm).