Essential oil compositions and antifungal activity of sunflower (Helianthus) species growing in north Alabama

Abstract

Helianthus species are North American members of the Asteraceae, several of which have been used as traditional medicines by Native Americans. The aerial parts of two cultivars of Helianthus annuus, "Chianti" and "Mammoth", and wild-growing H. strumosus, were collected from locations in north Alabama. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The Helianthus essential oils were dominated by monoterpene hydrocarbons, in particular α-pinene (50.65%, 48.91%, and 58.65%, respectively), sabinene (6.81%, 17.01%, and 1.91%, respectively), β-pinene (5.79%, 3.27%, and 4.52%, respectively), and limonene (7.2%, 7.1%, and 3.8%, respectively). The essential oils were screened against three opportunistic pathogenic fungal species, Aspergillus niger, Candida albicans, and Cryptococcus neoformans. The most sensitive fungus was C. neoformans with minimum inhibitory concentration (MIC) values of 78, 156, and 78 μg/mL, respectively.