Shin, Kye Jung; Yoo, Kyung Ho; Kim, Dong Jin; Park, Sang Woo; Ko, Bong Suck; Lee, Sang Joo; Huh, Jae Doo; Park, Seung Yong Bioorganic and Medicinal Chemistry Letters, 1998, vol. 8, # 13 p. 1607 - 1612 doi: 10.1016/S0960-894X(98)00270-4