1. Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao Shandong 266003 China
2. National Museum of Natural History 2300 RA Leiden The Netherlands
3. College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao Shandong 266100 China
4. Laboratory of Marine Drugs and Biological Products, National Laboratory for Marine Science and Technology, Qingdao Shandong 266235 China