Ono, Masahiro; Ikeoka, Ryoichi; Watanabe, Hiroyuki; Kimura, Hiroyuki; Fuchigami, Takeshi; Haratake, Mamoru; Saji, Hideo; Nakayama, Morio Bioorganic and Medicinal Chemistry Letters, 2010 , vol. 20, # 19 p. 5743 - 5748