1. School of Chemical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
2. Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
3. Biological Section, School of Distance Education, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
4. Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, 45363 Jatinangor, Indonesia
5. School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia