In vitro synthesis of linear α-1,3-glucan and chemical modification to ester derivatives exhibiting outstanding thermal properties

Sci Rep. 2016 Jul 29;6:30479. doi: 10.1038/srep30479.

Abstract

Bio-based polymer is considered as one of potentially renewable materials to reduce the consumption of petroleum resources. We report herein on the one-pot synthesis and development of unnatural-type bio-based polysaccharide, α-1,3-glucan. The synthesis can be achieved by in vitro enzymatic polymerization with GtfJ enzyme, one type of glucosyltransferase, cloned from Streptococcus salivarius ATCC 25975 utilizing sucrose, a renewable feedstock, as a glucose monomer source, via environmentally friendly one-pot water-based reaction. The structure of α-1,3-glucan is completely linear without branches with weight-average molecular weight (Mw) of 700 kDa. Furthermore, acetate and propionate esters of α-1,3-glucan were synthesized and characterized. Interestingly, α-1,3-glucan acetate showed a comparatively high melting temperature at 339 °C, higher than that of commercially available thermoplastics such as PET (265 °C) and Nylon 6 (220 °C). Thus, the discovery of crystalline α-1,3-glucan esters without branches with high thermal stability and melting temperature opens the gate for further researches in the application of thermoplastic materials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon-13 Magnetic Resonance Spectroscopy
  • Esters / chemical synthesis
  • Esters / chemistry*
  • Glucans / chemical synthesis*
  • Glucans / chemistry*
  • Glucosyltransferases / metabolism
  • Molecular Weight
  • Proton Magnetic Resonance Spectroscopy
  • Streptococcus / enzymology
  • Temperature*
  • Transition Temperature

Substances

  • Esters
  • Glucans
  • alpha-1,3-glucan
  • Glucosyltransferases