1. Department
of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, United States
2. Facultad
de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570, Mexico
3. Department
of Medicinal Plants, Agronomy College, Sichuan Agricultural University, 211 Huimin Roadd, Wenjiang Region, Chengdu 611130, PR China