Affiliation: | 3. Department of Chemistry, College of Letters and Science University of Wisconsin, Madison, Wisc. 53706, U.S.A.;1. Department of Biochemistry College of Agricultural and Life Sciences University of Wisconsin, Madison, Wisc. 53706, U.S.A.;2. Department of Oncology, School of Medicine University of Wisconsin, Madison, Wisc. 53706, U.S.A. |