1. Department of Natural Products Chemistry, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang, People's Republic of China 110015, Institute of Drug Research and Development, Northeast Pharmaceutical Corp., 37 Zhonggong Beijie, Shenyang, People's Republic of China 110026, Institute of Molecular & Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, Japan 113, and Department of Medicine, Mount Sinai School of Medicine, Box 1178, One Gustave L. Levy Place, New York, New York 10029