@article{woo_choi_kim_lee_2015,  title={Ursane Saponins from the Stems of <i>Firmiana simplex</i> and their Cytotoxic Activity},  volume={26},  ISSN={0103-5053},  url={https://doi.org/10.5935/0103-5053.20150113},  DOI={10.5935/0103-5053.20150113},  number={7},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Woo, Kyeong Wan and Choi, Sang Un and Kim, Ki Hyun and Lee, Kang Ro},  year={2015},  month={Jul},  pages={1450–1456} }