1. Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Science, and Laboratory of Chemical Genetics, ShenZhen Graduate School, Peking University, Beijing, 100871, China, and VivoQuest, Inc., 711 Executive Boulevard, Valley Cottage, New York 10989 zyang@pku.edu.cn