@article {5, title = {Natural and unnatural anthraquinones isolated from the ethanol extract of the roots of Knoxia valerianoides}, journal = {Acta Pharmaceutica Sinica B}, volume = {2}, year = {2012}, pages = {260{\textendash}266}, author = {Zhao, Feng and Wang, Sujuan and Lin, Sheng and Zhu, Chenggen and Yue, Zhenggang and Yu, Yang and Liu, Bo and Wu, Xiuli and Yang, Yongchun and Li, Yan and others} }