[1] Department of Chemistry, University of Hong Kong, Pokfulam, Hong Kong, Hong Kong
[2] Department of Biochemistry, University of Hong Kong, Pokfulam, Hong Kong, Hong Kong
[3] Open Laboratory of Chemical Biology, University of Hong Kong, Pokfulam, Hong Kong, Hong Kong
[4] Department of Chemistry, Dartmouth College, Hanover, NH 03755-3564, United States