1. Natural Products Laboratory, School of Pharmacy, Sungkyunkwan University, 2066 Seobu-Ro, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
2. Gachon Institute of Pharmaceutical Science, Gachon University, 191 Hambakmoero, Yeonsu-gu, Incheon 21936, Republic of Korea.