Synthesis of a series of C20 N-acyl chain variants of OCH

ORGN 144

Rachel M Ndonye,, Geetha Velmourougane, and Amy R. Howell, Department of Chemistry, University of Connecticut, Storrs, CT 06269
Glycosphingolipids are found mainly in the external surface of eukaryotic cells and are assumed to participate in immunological activities. OCH is an alpha-galactosylceramide (glycosphingolipid) which has been shown to initiate a CD1-mediated activation of natural killer T-cells (NKT cells) leading to suppression of experimental autoimmune encephalomyelitis (EAE), a prototype autoimmune disease. In order to further elucidate the CD1 mediated NKT-cell activation, effective strategies for the synthesis of glycosphingolipids are critical. We have developed efficient syntheses of OCH analogs containing sphinganines and phytosphingosine sphingoid bases with saturated and unsaturated C20 N-acyl chains. Different methodologies were required to prepare the desired analogs.