A compound represented by the following general formula (I): (wherein R.sup.1 represents phenyl, etc. which can have substituents selected from the group consisting of C.sub.1-8 alkyl, C.sub.1-8 alkyl having halogen, halogen, hydroxyl, etc.; R.sup.2 represents C.sub.1-8 alkyl, etc.; A represents oxygen, sulfur, etc.; X represents C.sub.1-8 alkylene chain, etc.; Y represents C(.dbd.O), CH.dbd.CH, etc.; R.sup.3, R.sup.4, and R.sup.5 each represents hydrogen, C.sub.1-8 alkyl, etc.; B represents CH or nitrogen; Z represents oxygen or sulfur; R.sup.6 and R.sup.7 each represents hydrogen, C.sub.1-8 alkyl, etc.; and R.sup.8 represents hydrogen or C.sub.1-8 alkyl; provided that at least one of R.sup.3, R.sup.4, and R.sup.5 is not hydrogen) or a salt of the compound; and a PPAR-.delta. activator which contains the compound or salt as the active ingredient.