1. Department of Chemistry, Faculty of Science, Mahidol University, Thailand, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Thailand Science Park, 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani, 12120, Thailand, and Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Thailand