1. Natural Products Research Laboratory
2. School of Science
3. Mae Fah Luang University
4. Chiang Rai
5. Thailand
6. Department of Chemistry
7. Faculty of Science
8. Chulalongkorn University
9. Bangkok
10. 10330 Thailand
11. School of Chemistry
12. University of Wollongong
13. Wollongong
14. 2522 Australia