1. Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
2. Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpu, Malaysia
3. Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
4. Department of Pharmacy, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia