The invention relates to compounds of structural formula (I) and structural formula (VI):or a pharmaceutically acceptable salt, solvate, clathrate, or prodrug thereof, wherein R, R1, R2, Z, L, and n are defined herein. These compounds are useful as immunosuppressive agents and for treating and preventing inflammatory conditions, allergic disorders, and immune disorders.本發明係關於結構式(I)與結構式(VI)的化合物或其醫藥上可接受的鹽、溶劑合物、晶籠化合物(clathrate)或前驅藥:式中,R、R1、R2、Z、L與n係於本說明書中定義。該些化合物可作為免疫抑制劑,用於治療與預防炎症、過敏病症及免疫病症。