Efficient diversification of GM3 gangliosides <i>via</i> late-stage sialylation and dynamic glycan structural studies with <sup>19</sup>F solid-state NMR
Maina Takahashi, Junya Shirasaki, Naoko Komura, Katsuaki Sasaki, Hidenori Tanaka, Akihiro Imamura, Hideharu Ishida, Shinya Hanashima, Michio Murata, Hiromune Ando
Abstract
Sialic acid-containing glycoconjugates are involved in important biological processes such as immune response, cancer metastasis, and viral infection. However, their chemical syntheses have been challenging, mainly due to the difficulties in the α-sialylation of oligosaccharides. Very recently, we established a completely stereoselective sialidation method using a macrobicyclic sialyl donor. Herein, we describe a rational and efficient synthesis of sialoglycolipids via direct sialylation of a glycolipid at a late-stage, based on our novel sialidation method. The synthetic method enabled the development of GM3 ganglioside analogs with various C5-modifications of the sialosyl moiety. Furthermore, the synthesized analog was subjected to solid-state 19F NMR analysis on the model membranes and it revealed the influence of cholesterol on glycan dynamics.