The invention relates to compounds of structural formula (I) :or a pharmaceutically acceptable salt, solvate, clathrate, or prodrug thereof, wherein R’1, X, X’, L and Y are defined herein. These compounds are useful as immunosuppressive agents and for treating and preventing inflammatory conditions, allergic disorders, and immune disorders.本發明係關於具有結構式(I)之化合物或其醫藥上可接受之鹽、溶劑合物、晶籠化合物或前藥:其中R’1、X、X’、L和Y係於本文中定義者。此等化合物可用於作為免疫抑制劑及用以治療和預防發炎症狀、過敏性症狀、和免疫失調症。