Jia, Meirong; Yang, Kanghui; Fang, Hao; Xu, Yingying; Sun, Siwei; Su, Li; Xu, Wenfang Bioorganic and Medicinal Chemistry, 2011, vol. 19, # 17 p. 5190 - 5198 doi: 10.1016/j.bmc.2011.07.008