1. Atta-ur-Rahman Institute for Natural Products Discovery, Universiti Teknologi MARA, 42300 Bandar Puncak Alam, Selangor, Malaysia
2. Department of Chemistry, Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300 Kota Semarahan, Sarawak, Malaysia
3. School of Pharmacy, International Medical University, Kuala Lumpur 57000, Malaysia
4. Herbal Product Development Programme, Natural Products Division, Forest Research Institute Malaysia, 52109 Kepong, Selangor, Malaysia
5. Faculty of Science, University of Malaya, Pantai Valley, 50603 Kuala Lumpur, Malaysia