1. Department of Biological Chemistry and Molecular
Pharmacology, Harvard Medical School, Boston,
Massachusetts 02115, United States
2. Natural Products Laboratory, School of Pharmacy, Sungkyunkwan University, Suwon 440-746, Korea
3. Bio-organic Science Division, Pharmacology Research
Center, Korea Research Institute of Chemical Technology, Teajeon 305-600, Korea
4. Dong-A Pharm Institute, Kiheung, Youngin
449-905, Korea