The invention relates to compounds of structural formula (I) or (II): ##STR00001## or a pharmaceutically acceptable salt, solvate, clathrate, or prodrug thereof, wherein L, L.sub.1, Y, R.sub.1, R.sub.2, R.sub.9, R.sub.10, ring A, ring B, ring C, and ring D are defined herein. These compounds are useful as immunosuppressive agents and for treating and preventing inflammatory conditions, allergic disorders, and immune disorders.