1. Faculty of Science, Natural Products Research Unit, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Khon Kaen University, Khon Kaen, Thailand
2. Faculty of Medicine, Department of Pharmacology, Khon Kaen University, Khon Kaen, Thailand
3. Faculty of Science, Integrated Nanotechnology Research Centre, Department of Physics, Khon Kaen University, Khon Kaen, Thailand