Tricyclic fused heterocycle compounds, process for preparing the same and use thereof

摘要

Compounds represented by formula (1), wherein X is, for example, CH, CH₂, CHR (wherein R is a lower alkyl group or a substituted lower alkyl group) or CRR' (wherein R and R' are the same as the above defined R); Y is, for example, CH, CH₂ or C-O; Z is, for example, O, S, S-O or SO₂; U is C or N; R₁ to R₄ are each independently, for example, a hydrogen atom, OR, SR (wherein R is the same as defined above), or an aromatic ring, a substituted aromatic ring or a heterocycle; at least one of R₅ and R₈ is, for example, OH and the remaining of R₅ and R₈ are each independently, for example, a hydrogen atom or OH, optical isomers thereof, conjugates thereof or pharmaceutically acceptable salts thereof are provided. These compounds are characterized in having a wide range of pharmacological actions such as an excellent relaxing action of tracheal smooth muscles, an inhibition of airway hypersensitivity and an inhibition of infiltration of inflammatory cells into the airway and, in addition, high safety.