The sweet origin of glycolipids

 Esraa Abu Safi^a,b , Rotem Edri^a , and Moran Frenkel-Pinter^a,c

^a Institute of Chemistry, The Hebrew University of Jerusalem, Israel 9190401

 ^b Azrieli College of Engineering Jerusalem, Israel 9103501

 ^c The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Israel 9190401

Sugars are integral to the genesis of life and the process of chemical evolution, particularly in their incorporation into the RNA structure and in central metabolism. Lipids, a diverse array of organic compounds encompassing fatty acids, phospholipids, glycolipids, and other molecular constituents, serve as crucial components in the formation of biological membranes. While both sugars and lipids were studied individually in the context of origin of life, the abiotic formation of covalently linked glycolipids and their coevolution into present biology has not been established. In this work, we embarked on exploring the chemical interactions between simple and sugars. To that end, we studied condensation reactions of two lipids, decanol (DOH) and decanoic acid (DA), with three monosaccharides: glucose, fructose, and mannose, under dry conditions. We characterized the obtained products using several analytical techniques, including LC-MS, light- and fluorescent- microscopy. Our results revealed prominent chemical specificity of DOH resulting in several glycolipid products. The products of DOH and sugars self assembled into microdroplets. on the other hand, DA did not react with the various tested sugars. These results signify a preferential reactivity between sugars and fatty alcohols over fatty acids. Notably. contemporary glycolipids such as gangliosides contain ether bonds, similarly to products of DOH and sugars. Our findings may shed light on the chemical roots of this biological selection and delineate new routes. into chemical evolution and the exploration of the chemical origins of life.