The condensation of a pyrrole and acetone or cyclohexanone that gives the corresponding tetrameric calix[4]pyrrole, catalyzed by HAuCl₄ or Bi(NO₃)₃, was tuned to yield the pentameric macrocycle calix[5]pyrrole as the major product in the presence of the biomolecule DNA obtained from salmon sperm in the reaction mixture. The DNA affected the ratio of the tetrameric to the pentameric macrocycle when present in adequate amounts in the reaction medium.