RESUMO
BACKGROUND: Montanoa guatemalensis is a small to medium-sized tree in the Asteraceae that grows in Central America from Mexico south through Costa Rica. There have been no previous investigations on the essential oil of this tree. METHODS: The leaf essential oils of M. guatemalensis were obtained from different individual trees growing in Monteverde, Costa Rica, in two different years, and were analyzed by gas chromatography-mass spectrometry. RESULTS: The leaf oils from 2008 were rich in sesquiterpenoids, dominated by α-selinene, ß-selinene, and cyclocolorenone, with lesser amounts of the monoterpenes α-pinene and limonene. In contrast, the samples from 2009 showed no α- or ß-selinene, but large concentrations of trans-muurola-4(14),5-diene, ß-cadinene, and cyclocolorenone, along with greater concentrations of α-pinene and limonene. The leaf oils were screened for cytotoxic and antimicrobial activities and did show selective cytotoxic activity on MDA-MB-231 breast tumor cells. CONCLUSION: M. guatemalensis leaf oil, rich in cyclocolorenone, α-selinene, and ß-selinene, showed selective in vitro cytotoxic activity to MDA-MB-231 cells. The plant may be a good source of cyclocolorenone.
