Synthesis and Evaluation of Amino-Modified α-GalCer Analogues

α-GalCer analogues featuring a phytoceramide 3- and 4-amino group have been synthesized. A Mitsunobu reaction involving phthalimide was employed for the introduction of the amino groups at the 3- and 4-positions of suitable phytosphingosine-derived precursors. The influence of these modifications on the interaction with the T-cell receptor of NKT cells was investigated, as well as the capacity of the amino-modified analogues to induce a cytokine response after in vivo administration.