Shirahata, Tatsuya; Sunazuka, Toshiaki; Yoshida, Kiminari; Yamamoto, Daisuke; Harigaya, Yoshihiko; Nagai, Takayuki; Kiyohara, Hiroaki; Yamada, Haruki; Kuwajima, Isao; Omura, Satoshi Bioorganic and Medicinal Chemistry Letters, 2003, vol. 13, # 5 p. 937 - 941 doi: 10.1016/S0960-894X(02)01069-7