1. Department of Medicinal Chemistry and Center for Natural Products, Drug Discovery and Development (CNPD3), University of Florida, Gainesville, FL 32610, USA
2. Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait
3. School of Biological Science and Technology, University of Jinan, Jinan 250022, China
4. Smithsonian Marine Station, Fort Pierce, FL 34949, USA