Shin, Kye Jung; Koo, Ki Dong; Yoo, Kyung Ho; Kim, Dong Chan; Kim, Dong Jin; Park, Sang Woo Bioorganic and Medicinal Chemistry Letters, 2000, vol. 10, # 13 p. 1421 - 1425 doi: 10.1016/S0960-894X(00)00253-5