| abstract |
The present invention provides a novel bicyclic or tricyclic heterocyclic compound represented by the formula (I) n n n n n n n n n n wherein ring A is an optionally substituted aromatic group,n one of X 1 and X 2 is a carbon atom, and the other is a nitrogen atom, X 3 is a nitrogen atom, or CR 2 , X 4 is a nitrogen atom, or CR 3 , X 5 is a sulfur atom, or —CH═CH—, Z 1 is an oxygen atom, —C(R 6 )(R 7 )—, —NH—, —C(R 6 )(R 7 )—NH—, —NH—C(R 6 )(R 7 )—, —C(R 6 )(R 7 )—O—, —O—C(R 6 )(R 7 )—, or a single bond, one of Z 2 and Z 3 is CH and the other is a nitrogen atom, or both are nitrogen atoms, and other symbols are as defined in the DESCRIPTION, or a pharmacologically acceptable salt thereof. |