Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/2007
Publication Date: 9/26/2007
Citation: Tabanca, N., Demirci, B., Crockett, S.L., Can Baser, K., Wedge, D.E. 2007. Chemical Composition and Antifungal Activity of Arnica longifolia, Aster hesperius and Chrysothamnus nauseosus Essential Oils. Journal of Agricultural and Food Chemistry. 55(21):8430-8435. Interpretive Summary: Asteraceae plants have a long history of use in folk medicine in many cultures. In this study we focused our investigation on the essential oils and their biological activity of three members of the Asteraceae known for their medicinal use collected from Pacific Northwest region of the United States: Arnica longifolia, Aster hesperius and Chrysothamnus nauseosus var. nauseosus. Essential oils showed good antifungal activity against Colletotrichum acutatum, C. fragariae, C. gloesporides. Out of six pure compounds, only carvacrol and a-bisabolol demonstared antifungal activity against important plant pathogens.
Technical Abstract: Essential oils from three different Asteraceae obtained by hydrodistillation of aerial parts were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). Main compounds obtained from each taxon were found as follows: Arnica longifolia: carvacrol 37.3%, a-bisabolol 8.2%; Aster hesperius: hexadecanoic acid 29.6%, carvacrol 15.2%; and Chrysothamnus nauseosus var. nauseosus: B-phellandrene 22.8% and B-pinene 19.8%. Essential oils were also evaluated for their antimalarial, antimicrobial, and antifungal activities. Direct bioautography demonstrated antifungal activity of the essential oils obtained from three Asteraceae taxa and two pure compounds, carvacrol and B-bisabolol to Colletotrichum acutatum, C. fragariae and C. gloeosporioides. Subsequent evaluation of antifungal compounds using a 96-well micro-dilution broth assay indicated that a-bisabolol showed weak growth inhibition of Botrytis cinerea after 72 hrs.