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The Scientific World Journal
Volume 2012 (2012), Article ID 489646, 5 pages
Research Article

Antifungal Activity and Composition of Essential Oils of Conyza canadensis Herbs and Roots

1Department of Pharmacognosy, University of Szeged, Eötvös u. 6, 6720 Szeged, Hungary
2Institute of Clinical Microbiology, University of Szeged, Semmelweis u. 6. 6725 Szeged, Hungary

Received 28 October 2011; Accepted 26 December 2011

Academic Editors: V. Cechinel-Filho and P. Kittakoop

Copyright © 2012 Katalin Veres et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Essential oils from herbs and roots of Conyza canadensis (horseweed), collected in Hungary, were obtained by hydrodistillation. The chemical compositions of the oils were analysed by combination of GC and GC/MS. The major constituent of the oil obtained from the aerial parts of horseweed was limonene (78%), while the main component of root oil was 2Z,8Z-matricaria ester. The antimicrobial activities of the oils were tested on Gram-positive (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pyogenes), Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, reference fungal strains, and fungal strains isolated from patients (Candida, Cryptococcus, Trichophyton, Rhodotorula, and Aspergillus) by agar disc diffusion and broth dilution methods. None of the oils showed any activity against the tested bacterial strains, but exhibited moderate-to-strong activity against all fungi with the only exception of A. fumigatus. The highest zone of inhibition was observed in case of Cryptococcus neoformans and Trichophyton interdigitalis