The invention relates to compounds of formula (I): or a pharmaceutically acceptable salt, solvate, clathrate, or prodrug thereof wherein X, Y, A, Z, L and n are defined herein. These compounds are useful as immunosuppressive agents and for treating and preventing inflammatory conditions and immune disorders.本發明係有關一種式(I)化合物:;(I);或其醫藥上可接受之鹽、溶劑合物、包合物(clathrate)或前藥,其中X、Y、A、Z、L與n如本文中定義。此等化合物可用為免疫壓抑劑及供治療與預防炎症與免疫病變。