1. State Key Laboratory of Bioactive Substance and Function of Natural Medicines; NHC Key Laboratory of Biosynthesis of Natural Products, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P. R. China;
2. Biotechnology Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, U.S.A;
3. Chinese Academy of Medical Sciences & Peking Union Medical College, Institute of Medicinal Biotechnology, Beijing, P. R. China;
4. Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA