[1] Ohio State Univ, Dept Neurol Surg, Columbus, OH 43210 USA
[2] Ohio State Univ, Div Med Chem & Pharmacognosy, Coll Pharm, Columbus, OH 43210 USA
[3] Ohio State Univ, James Comprehens Canc Ctr, Columbus, OH 43210 USA
[4] Mayo Clin, Dept Radiat Oncol, Rochester, MN USA
[5] Shemiakin Ovchinnikov Inst Bioorgan Chem, Moscow, Russia
[6] Xi An Jiao Tong Univ, Dept Neurosurg, Affiliated Hosp 1, Sch Med, Xian 710049, Peoples R China