1. Dipartimento di Chimica Organica e Biochimica, Università Federico II, Complesso Universitario Monte Sant’Angelo, Via Cinthia 4, I-80126, Napoli, Italy
2. United States Department of Agriculture, Agricultural Research Service, Natural Products Utilization Research Unit, Thad Cochran National Center for Natural Products Research, Post Office Box 8048, University, Mississippi 38677-8048
3. Research Institute of Pharmaceutical Sciences, Thad Cochran National Center for Natural Products Research, University, Mississippi 38677-8048