Ren, Yulin; Matthew, Susan; Lantvit, Daniel D.; Ninh, Tran Ngoc; Chai, Heebyung; Fuchs, James R.; Soejarto, Djaja D.; De Blanco, Esperanza J. Carcache; Swanson, Steven M.; Kinghorn, A. Douglas Journal of Natural Products, 2011 , vol. 74, # 5 p. 1117 - 1125