Ishikawa, Minoru; Hiraiwa, Yukiko; Kubota, Dai; Tsushima, Masaki; Watanabe, Takashi; Murakami, Shoichi; Ouchi, Shokichi; Ajito, Keiichi Bioorganic and Medicinal Chemistry, 2006 , vol. 14, # 7 p. 2131 - 2150