Xiao, Chuan; Sun, Chao; Han, Weiwei; Pan, Feng; Dan, Zhu; Li, Yu; Song, Zhi-Guang; Jin, Ying-Hua Bioorganic and Medicinal Chemistry, 2011, vol. 19, # 23 p. 7100 - 7110 doi: 10.1016/j.bmc.2011.10.003