ESR study of enediyne calicheamicin gamma(1)(I) with phenyl tert-butyl nitrone (PBN) gave a significant kinetic isotope effect (k(H)/k(D) = 1.8) for the formation of the phenyl radical PBN monoadducts.
Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan. t-usuki@sophia.ac.jp
