1. Laboratory for Synthetic Chemistry and Chemical Biology Limited, Units 1503-1511, 15/F., Building 17W, Hong Kong Science Park, Shatin, Hong Kong SAR 999077, P. R. China
2. Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR 999077, P. R. China
3. AIDS Institute and Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Sassoon Road, Hong Kong SAR 999077, P. R. China
4. Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Tat Chee Avenue, Hong Kong SAR 999077, PR. China
5. Department of Food Science and Nutrition, Faculty of Science, The Hong Kong Polytechnic University, Yuk Choi Road, Hong Kong SAR 999077, P. R. China