1. NMR/Biosynthesis Group, Max-Planck-Institute for Chemical Ecology, 07745 Jena, Germany
2. Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen), 210014 Nanjing, China
3. Department of Biochemistry, Max-Planck-Institute for Chemical Ecology, 07745 Jena, Germany