Tetracyclic compounds

摘要

PCT No. PCT/JP93/00527 Sec. 371 Date Dec. 22, 1993 Sec. 102(e) Date Dec. 22, 1993 PCT Filed Apr. 23, 1993 PCT Pub. No. WO93/22286 PCT Pub. Date Nov. 11, 1993.The present invention relates to novel tetracyclic compounds represented by formula (I) <IMAGE> (I) (wherein each of X1 and X2 independently represents hydrogen or lower alkyl; n represents an integer of 1 to 4), or a pharmaceutically acceptable salt thereof, which are useful as immunosuppressive agents.