Morihira, Koichiro; Nishimori, Toshiyuki; Kusama, Hiroyuki; Horiguchi, Yoshiaki; Kuwajima, Isao; Tsuruo, Takashi Bioorganic and Medicinal Chemistry Letters, 1998, vol. 8, # 21 p. 2973 - 2976 doi: 10.1016/S0960-894X(98)00539-3