Liu, Anqiu; Huang, Ling; Wang, Zhiren; Luo, Zonghua; Mao, Fei; Shan, Wenjun; Xie, Jiaxing; Lai, Kefang; Li, Xingshu Bioorganic and Medicinal Chemistry Letters, 2013 , vol. 23, # 5 p. 1548 - 1552