Nguyen, Jeffrey-Tri; Kato, Keiko; Kumada, Henri-Obadja; Hidaka, Koushi; Kimura, Tooru; Kiso, Yoshiaki Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 6 p. 1832 - 1837 doi: 10.1016/j.bmcl.2011.01.048