1. Natural
Products Research Group, Department of Chemistry, Faculty of Engineering
and Physical Sciences, University of Surrey, Guildford GU2 7XH, U.K.
2. Department
of Chemistry, Faculty of Science and Technology, Rambhai Barni Rajabhat University, Chanthaburi 22000, Thailand
3. Department
of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
4. Faculty
of Science and Technology, Hatyai University, Songkhla 90110, Thailand
5. School
of Chemistry and Physics, University of KwaZulu-Natal, Durban 4041, South Africa