1. College of Pharmacy, Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 426-791, Republic of Korea
2. Collge of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 151-742, Republic of Korea
3. College of Pharmacy, Chung-Ang University, Seoul 156-756, Republic of Korea
4. College of Pharmacy, Yeungnam University, Gyeongsan, 712-749, Republic of Korea