@article{maciel_martins_pinto_kaiser_esteves-souza_echevarria_2007,  title={Natural and semi-synthetic clerodanes of Croton cajucara and their cytotoxic effects against ehrlich carcinoma and human K562 leukemia cells},  volume={18},  ISSN={0103-5053},  url={https://doi.org/10.1590/S0103-50532007000200022},  DOI={10.1590/S0103-50532007000200022},  number={2},  journal={Journal of the Brazilian Chemical Society},  publisher={Sociedade Brasileira de Química},  author={Maciel, Maria Aparecida M. and Martins, Jenilce R. and Pinto, Angelo C. and Kaiser, Carlos R. and Esteves-Souza, Andressa and Echevarria, Aurea},  year={2007},  month={Mar},  pages={391–396} }