Affiliation: | 1. Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology (VAST), 18 Hoang Quoc Viet, Nghiado, Caugiay, Hanoi, Viet Nam;2. College of Pharmacy, Chungnam National University, Daejeon 305 764, Republic of Korea;3. Department of Oral Biology, Yonsei University College of Dentistry, Seoul 120 752, Republic of Korea |