Synthesis and bioactivities evaluation of oleanolic acid oxime ester derivatives as α-glucosidase and α-amylase inhibitors oleh Xu-Yang Deng, Jun-Jie Ke, Ying-Ying Zheng, Dong-Li Li, Kun Zhang, Xi Zheng, Jing-Ying Wu, Zhuang Xiong, Pan-Pan Wu, Xue-Tao Xu