* Corresponding authors

^a Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng, China
E-mail: wcjsxq@henu.edu.cn
Fax: +86-378-2864665

^b School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
E-mail: pharmgao@tju.edu.cn
Fax: +86-22-87401895
Tel: +86-22-87401895

^c College of Pharmacy, Henan University, Kaifeng, China

^d Chemistry Department, Henan University, Kaifeng, China