[1] Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur, 50603, Malaysia
[2] Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universiti Malaya, Kuala Lumpur, 50603, Malaysia
[3] Centre for Natural Products Research and Drug Discovery (CENAR), Universiti Malaya, Kuala Lumpur, 50603, Malaysia
[4] Chemistry Division, Centre for Foundation Studies in Science, Universiti Malaya, Kuala Lumpur, 50603, Malaysia
[5] Natural Products Division, Forest Research Institute Malaysia, Selangor, Kepong,52019, Malaysia
[6] Rubber Research Institute of Malaysia, Malaysian Rubber Board, Selangor, Sungai Buloh,47000, Malaysia
[7] Institute of Advanced Chemistry of Catalonia (IQAC), Consejo Superior de Investigaciones Científicas (CSIC) and Networking Research Center on Bioengineering, Biomaterials and Nanomedicine CIBER-BBN), Jordi Girona, 18-26, Barcelona,08034, Spain
[8] Department of Pharmaceutical Technology, Faculty of Pharmacy, Universiti Malaya, Kuala Lumpur, 50603, Malaysia