1. Higher Education Centre of Excellence (HiCoE), Institute of Tropical Forestry and Forest Products, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
2. Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
3. Chemistry Division, Centre of Foundation Studies for Agricultural Science, University Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia