1. Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences; Prince of Songkla University; Hat Yai Songkhla 90112 Thailand
2. Excellent Research laboratory, Phytomedicine and Pharmaceutical Biotechnology Excellence Center, Faculty of Pharmaceutical Sciences; Prince of Songkla University; Hat Yai Songkhla 90112 Thailand
3. Department of Pharmacognosy, Division of Medicinal Chemical Sciences; Kyoto Pharmaceutical University; Misasagi, Yamashina-ku Kyoto 607-8412 Japan