1. Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
2. Faculty of Pharmacy, Sanata Dharma University, Campus III, Yogyakarta, Indonesia
3. Centre for Natural Products and Drug Discovery (CENAR), University of Malaya, Kuala Lumpur, Malaysia
4. Chemistry Division, Centre for Foundation Studies in Science, University of Malaya, Kuala Lumpur, Malaysia
5. School of Pharmaceutical Sciences, Universiti Sains Malaysia (USM), Penang, Malaysia
6. Department of Pharmacy, Faculty of Health Sciences, Université d՛Angers, France