[1] Purdue Univ, Dept Med Chem & Mol Pharmacol, Sch Pharm & Pharmaceut Sci, W Lafayette, IN 47907 USA
[2] Purdue Univ, Purdue Canc Ctr, Sch Pharm & Pharmaceut Sci, W Lafayette, IN 47907 USA
[3] Tech Univ Munich, Lehrstuhl Organ Chem & Biochem, D-8046 Garching, Germany