1. Medicinal Plants Research Center, Federal University of Piauí, Teresina, Brazil.
2. Department of Chemistry, Federal University of Piauí, Teresina, Brazil.
3. Pathology Laboratory and Forensic Medicine-Favet, State University of Ceará, Fortaleza, Brazil.
4. Department of Pharmacology, Laboratory of Antitumor Substances-LSAT, Federal University of Minas Gerais, Belo Horizonte, Brazil.