Chemical synthesis and cytotoxicity of neo-glycolipids; rare sugar-glycerol-lipid compounds.

Rare sugars are defined as monosaccharides and their derivatives, which rarely exist in nature and have various beneficial effects on organisms, biomaterials and foods. Glycolipids are composed of sugars and lipids and have been intensively studied in various fields such as environmental engineering, nanotechnology and molecular biology. Here, we synthesise new types of glycolipids composed of rare sugars, glycerol and lipids (RSGLs), using 6 different types of rare sugars by combining the modified Fischer and lipase reverse reactions. We confirm the production of RSGLs by thin layer chromatography (TLC), Fourier-transform infrared (FT-IR) spectroscopy and matrix assisted laser desorption/ionisation time of flight mass spectroscopy (MALDI-TOF-MS) and investigate the cytotoxicity of RSGLs by lactate dehydrogenase (LDH) and alamar blue assays. We successfully synthesise novel RSGLs; i.e., D-ribose-glycorol-lipid, D-allose-glycorol-lipid, L-rhamnose-glycorol-lipid, L-lyxorse-glycorol-lipid, L-gulose-glycorol-lipid and L-fucose-glycorol-lipid. We finally clarify the effect of the concentration of those RSGLs on cytotoxicity, which is of great importance considering the utilisation of RSGLs particularly in the field of biomedicine.