1. Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Padjadjaran, Jatinangor, West Java, Indonesia
2. Pharmacy Faculty, Universitas Mulawarman, Samarinda 75242, East Kalimantan, Indonesia
3. Central Laboratory, Universitas Padjadjaran, Jalan Raya Bandung-Sumedang KM 21, Jatinangor 45363, West Java, Indonesia