1. Division of Life and Pharmaceutical Sciences; Ewha Womans University; Seoul 120-750 Korea
2. Department of Pharmacology, School of Medicine; Ajou University; Suwon 442-749 Korea
3. Microbial Resources Research Center; Ewha Womans University; Seoul 120-750 Korea
4. School of Life Sciences and Biotechnology; Korea University; Seoul 136-713 Korea