Novel tricyclic compounds of general formula (I) or pharmacologically acceptable salts thereof, exhibiting leukotriene antagonism, wherein R<1> is halogeno or the like; R<2> is nitro or the like; A is a group derived from a five- or six-membered aromatic heterocycle containing 1 to 3 heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur, or the like; B is -OCH2- or the like; X is sulfur or the like; Y is C1-10 alkylene which may be substituted with halogeno or the like; Z is optionally protected carboxyl or the like; <u>----</u> represents a single or double bond; m is an integer of 1 to 4; and n is an integer of 1 to 3.
