Bai, Renren; Wei, Zhen; Liu, Jie; Xie, Weijia; Yao, Hequan; Wu, Xiaoming; Jiang, Jieyun; Wang, Qiujuan; Xu, Jinyi Bioorganic and Medicinal Chemistry, 2012 , vol. 20, # 15 p. 4661 - 4667