C-Sialosides: Synthesis and biological activities

This mini-review focuses on the synthesis and biological activities of sialic acid (SA) derivatives with a C-glycosidic linkage in place of the standard O-glycosidic bond at the C-2 position. We summarize reported synthetic methodologies for monoand di-saccharides in separate sections. Then, we introduce our strategy for the construction of C-sialoside linkages utilizing Ireland-Claisen rearrangement reaction and its application to the synthesis of a ganglioside GM4 analogue. Although C-sialosides are expected to be useful as sialidase-resistant analogues of sialoglycoconjugates (sialoGCs), their biological activities have not yet been investigated in detail. Herein we briefly discuss the potential applications of C-sialosides.