Pae, Ae Nim; Kim, Hye Yeon; Joo, Hyun Jin; Kim, Bo Hyung; Cho, Yong Seo; Choi, Kyung Il; Choi, Jung Hoon; Koh, Hun Yeong Bioorganic and Medicinal Chemistry Letters, 1999 , vol. 9, # 18 p. 2679 - 2684