There are provided derivatives having PPAR agonist activity. The derivatives include compounds and/or their pharmaceutically acceptable salts; the compounds having the formula (I) wherein A has the structure (II) or (III); X is chosen from --CH.sub.2--, --O--, --NH--, and --S--; Y is chosen from --O--, --NH--, and --S--; Z, which may be located in any position of substitution, is hydrogen or halogen; R.sup.1 and R.sup.2, which may be the same or different, are independently chosen from hydrogen and C.sub.1-C.sub.8 alkyl, or R.sup.1 and R.sup.2 together form a carbocyclic ring having from 4 to 6 carbon atoms; R.sup.3 is chosen from hydrogen and C.sub.1-C.sub.8 alkyl; R.sup.4, R.sup.5, and R.sup.6, which may be the same or different, are independently chosen from hydrogen and C.sub.1-C.sub.8 alkyl; and n is 1 to 6. Various embodiments and variants are provided. In accordance with other aspects, the invention also provides methods of producing a PPAR.alpha. agonist activity in a mammal, the methods including administering to the mammal an effective amount of certain derivative(s) of the first aspect of the invention, a method of producing a PPAR.alpha. agonist activity and a PPAR.alpha. agonist activity in a mammal, the method including administering to the mammal an effective amount of certain derivative(s); and a pharmaceutical composition that includes the derivative(s) of the first aspect of the invention and one or more pharmaceutically-acceptable excipients. Various embodiments and variants are provided.