Cui, Yong-Mei; Huang, Qing-Qing; Xu, Jie; Chen, Ling-Ling; Li, Jing-Ya; Ye, Qi-Zhuang; Li, Jia; Nan, Fa-Jun Bioorganic and Medicinal Chemistry Letters, 2005 , vol. 15, # 18 p. 4130 - 4135