Speaker
Dr
Federica Sebastiani
(Physical Chemistry Department, University of Lund - CR Competence AB, Lund)
Description
The increased effort to preserve the environment has driven extensive research toward the identification of surfactants that are nontoxic, biodegradable, and synthetized from sustainable resources (1). Alkylglycosides, which have a head-group consisting of one or several sugar moieties, promise to meet these demands. Alkylglycoside surfactants with functionalised oligomeric head group (>3 sugars) have recently proved possible to synthetize by enzymatic means (2,3). This novel class of surfactants has been specifically designed to ensure biocompatibility and controlled biodegradability, and hence lend themselves to applications within the area of in vivo controlled release (e.g. food additives).
Our study focused on a surfactant comprising a long alkyl chain, 16 carbons, and a long glucose chain, 8 glucose units, which is referred to as C16G8. Since the functionalities and possible applications of C16G8 can compete with the widely used Polysorbate 80, we investigated thoroughly the self-aggregation mechanism. We characterised the system with several techniques, such as light scattering, both static (SLS) and dynamic (DLS), NMR, SAXS and SANS. The complementary use of neutrons and x-rays was crucial to determine the structure of the aggregates, since the contrast between the glucose chain and the alkyl chain differs when probed with x-rays and neutrons.
We will discuss the effect of temperature and concentration on the size and shape of the aggregates and, furthermore, the effect of different anomeric configurations (4). The combination of these techniques allowed us to reveal the features of this novel sugar surfactant and build a fundamental knowledge required for identification and development of applications.
**Acknowledgements**
This work has received funding from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme FP7/2007-2013/ under REA grant agreement n° 606713. The SANS study was allowed by allocations of beam time at the ILL (Grenoble, France).
1. Holmberg, K. Natural surfactants. Curr. Opin. Colloid Interface Sci. 6, 148–159 (2001).
2. Svensson, D., Ulvenlund, S. & Adlercreutz, P. Enzymatic route to alkyl glycosides having oligomeric head groups. Green Chem. 11, 1222 (2009).
3. Svensson, D., Ulvenlund, S. & Adlercreutz, P. Efficient synthesis of a long carbohydrate chain alkyl glycoside catalyzed by cyclodextrin glycosyltransferase (CGTase). Biotechnol. Bioeng. 104, 854–861 (2009).
4. Lindhorst, T. K. & Schmidt-Lassen, J. Exploring the meaning of sugar configuration in a supramolecular environment: Comparison of six octyl glycoside micelles by ITC and NMR spectroscopy. Medchemcomm 1218–1226 (2014).
| Topic Area / Session | Lipids |
|---|
Primary author
Dr
Federica Sebastiani
(Physical Chemistry Department, University of Lund - CR Competence AB, Lund)
Co-author
Dr
Stefan Ulvenlund
(CR Competence)
