Kurume, Ai; Kamata, Yasuhiro; Yamashita, Masayuki; Wang, Qilong; Matsuda, Hisashi; Yoshikawa, Masayuki; Kawasaki, Ikuo; Ohta, Shunsaku Chemical and Pharmaceutical Bulletin, 2008 , vol. 56, # 9 p. 1264 - 1269