Synthesis and Characterization of a Novel Glycolipid with Glucosylglycerate as a Hydrophile Showing Protective Effects on Heat-induced Protein Denaturation

A novel glycolipid featuring a glucosylglycerate moiety as a polar head group was synthesized in two steps from sucrose, glycerate, and N-dodecylamine. Glucosylglyceric acid was formed from sucrose and glyceric acid using sucrose synthase as a catalyst, followed by condensation with N-dodecylamine using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) as a condensing agent. A white solid compound was recovered with a yield of 21% after purification by hydrophobic column chromatography. The structure and purity of the isolated compound, identified as N-dodecyl glucosylglyceric acid amide (aGGA), were confirmed by 1H and 13C nuclear magnetic resonance and liquid chromatography-electrospray ionization-mass spectrometry. aGGA was soluble in several polar solvents, including acetone, dimethyl formamide, and short chain alcohols. The dissolution of aGGA in water reduced the surface tension to 27.8 mN m-1 at a critical micellar concentration of 1.57 × 10-4 M. In addition, the presence of aGGA at concentrations as low at 0.68 mM protected egg white from heat-induced denaturation. These results suggest that aGGA could be useful as a protein-protecting surfactant.