Sakaguchi, Jun; Higashi, Taijiro; Azuma, Takahiro; Suzuki, Tomio; Iwasaki, Nobuhiko; Kondo, Noriyuki; Nagata, Osamu; Kato, Hideo; Hanaoka, Miyoji Chemical and Pharmaceutical Bulletin, 2001 , vol. 49, # 6 p. 788 - 790