1. Department of Chemistry, Faculty of Science and Mathematics , Universiti Pendidikan Sultan Idris (UPSI) , 35900, Tanjong Malim , Perak , Malaysia
2. School of Environmental and Natural Sciences, Faculty of Science and Technology , Universiti Kebangsaan Malaysia , 43600, Bangi , Selangor , Malaysia
3. Natural Products Division , Forest Research Institute Malaysia , 52109, Kepong , Selangor , Malaysia
4. Department of Mathematics, Faculty of Science and Mathematics , Universiti Pendidikan Sultan Idris (UPSI) , 35900, Tanjong Malim , Perak , Malaysia