A compound represented by the formula (I) or a salt of the compound, and a PPAR-.delta. activator which contains the compound or salt as the active ingredient: ##STR00001## (wherein A represents O or S; B.sup.1 represents N, etc.; B.sup.2 represents O, etc.; each of X.sup.1 and X.sup.2 represents O, S, a bond, etc.; Y represents C.sub.1-8 alkylene chain; z represents O or S; R.sup.1 represents aryl, etc. which can have substituents; R.sup.2 represents C.sub.1-8 alkyl, etc.; R.sup.3 represents C.sub.1-8 alkyl, C.sub.2-8 alkenyl, etc.; each of R.sup.4 and R.sup.5 represents hydrogen, C.sub.1-8 alkyl, etc.; and R.sup.6 represents hydrogen, etc.; provided that each of Z and R.sup.3 is attached to the benzene ring, and X.sup.2 is not attached to the benzene ring).