Pharmaceutical composition for inflammatory diseases, allergic diseases and autoimmune diseases

A pharmaceutical composition for immunosuppression which comprises as an active ingredient a fatty acid derivative represented by formula (I):

• wherein L, M and N are hydrogen, hydroxy, halogen, lower alkyl, hydroxy(lower)alkyl, lower alkanoyloxy or oxo, wherein at least one of L and M is a group other than hydrogen, and the five-membered ring may have at least one double bond;
• A is —CH3, or —CH2OH, —COCH2OH, —COOH or a functional derivative thereof;
• B is a single bond, —CH2—CH2—, —CH═CH—, —C≡C—, —CH2—CH2—CH2—, —CH═CH—CH2—, —CH2—CH═CH—, —C≡C—CH2— or —CH2—C≡C—;
• Z1 and Z2 are oxygen, nitrogen or sulfur,
• R2 and R3 are lower alkyl, or R2 and R3 are optionally linked together to form lower alkylene,
• R1 is a saturated or unsaturated bivalent lower or medium aliphatic hydrocarbon residue, which is unsubstituted or substituted with halogen, alkyl, hydroxy, oxo, aryl or heterocyclic group, and at least one of carbon atoms in the aliphatic hydrocarbon is optionally replaced by oxygen, nitrogen or sulfur;
• and
• Ra is a saturated or unsaturated lower or medium aliphatic hydrocarbon residue, which is unsubstituted or substituted with halogen, oxo, hydroxy, lower alkyl, lower alkoxy, lower alkanoyloxy, cyclo(lower)alkyl, cyclo(lower)alkyloxy, aryl, aryloxy, heterocyclic group or hetrocyclic-oxy group;
• lower alkoxy;
• lower alkanoyloxy;
• cyclo(lower)alkyl;
• cyclo(lower)alkyloxy;
• aryl;
• aryloxy;
• heterocyclic group;
• heterocyclic-oxy group.