Lee, Ji Hoon; Lee, Kyung Seok; Kang, Yong Koo; Yoo, Kyung Ho; Shin, Kye Jung; Kim, Dong Chan; Kong, Jae Yang; Lee, Yeonhee; Lee, Sook Ja; Kim, Dong Jin Bioorganic and Medicinal Chemistry Letters, 2003 , vol. 13, # 24 p. 4399 - 4403