2-amino-2-[2-(3-azido-4-octylphenyl)ethyl]propane-1,3-diol

FTY720 is a derivative of ISP-1 (myriocin), a fungal metabolite of the Chinese herb Iscaria sinclarii as well as a structural analog of sphingosine. It is a novel immune modulator that prolongs allograft transplant survival in numerous models by inhibiting lymphocyte emigration from lymphoid organs.¹ FTY720 is phosphorylated by sphingosine kinase, which then acts as a potent agonist at four of the sphingosine-1-phosphate (S1P) receptors (S1P₁, S1P₃, S1P₄, and S1P₅).² Down-regulation of S1P₁ receptors on T and B lymphocytes by FTY720 results in defective egress of these cells from spleen, lymph nodes, and Peyer’s patch.³ azido-FTY720 is a highly photoreactive analog of FTY720 that can be used to identify receptor binding sites for this ligand.⁴