Carboline Alkaloids from Trigonostemon lii - Hu, Xu-Jia; Di, Ying-Tong; Wang, Yue-Hu; Kong, Ling-Yi; Gao, Suo; Li, Chun-Shun; Liu, Hai-Yang; He, Hongping; Ding, Jian; Xie, Hua; Hao, Xiaojiang (Planta Medica, 2009)