Takeda Chemical Industries, Ltd.
Patent: US6573289 B1, 2003 ;

Matsunaga, Nobuyuki; Kaku, Tomohiro; Ojida, Akio; Tanaka, Toshimasa; Hara, Takahito; Yamaoka, Masuo; Kusaka, Masami; Tasaka, Akihiro
Bioorganic and Medicinal Chemistry, 2004 , vol. 12, # 16 p. 4313 - 4336