Characterization of Volatile Constituents of Haplopappus greenei and Studies on the Antifungal Activity against Phytopathogens BETUL DEMIRCI,* ,† KEMAL HUSNU CAN BASER, † NURHAYAT TABANCA, ‡ AND DAVID E. WEDGE ‡ Department of Pharmacognosy, Faculty of Pharmacy, Anadolu University, 26470 Eskisehir, Turkey, and Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture, The University of Mississippi, University, Mississippi 38677 Essential oil of Haplopappus greenei A. Gray was obtained by hydrodistillation of aerial parts, which were subsequently analyzed by gas chromatography and gas chromatography-mass spectrometry. Major components were identified as carvacrol (8.7%), -pinene (7.6%), trans-pinocarveol (6.2%), and caryophyllene oxide (5.8%), respectively. In total, 104 components representing 84.9% of the investigated essential oil were characterized. Furthermore, the essential oil was evaluated for antimalarial, antimicrobial, and antifungal activities. However, only antifungal activity was observed against the strawberry anthracnose-causing fungal plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides using the direct overlay bioautography assay. Major essential oil components were also evaluated for antifungal activity; the carvacrol standard demonstrated nonselective activity against the three Colletotrichum species and the other compounds were inactive. KEYWORDS: Haplopappus greenei; Asteraceae; essential oil; GC-MS; carvacrol; -pinene; strawberry pathogenic fungi; biological activity; antifungal activity INTRODUCTION The genus Haplopappus Cass, which belongs to the family of Asteraceae, is characterized by perennial herbs or shrubs with yellow flowers and is distributed in North and South America. Some Haplopappus species are used in Chilean folk medicine as choleretics and cholagogues (1, 2). Furthermore, the exudates of the various Haplopappus species are used to treat infected wounds and gastrointestinal infections, to promote wound healing, and as digestive stimulants (3). Haplopappus greenei A. Gray [) Ericameria greenei (A. Gray) G.L. Nesom, H. bloomeri (Gray) var. greenei, Macronema greenei (Gray)] is commonly known as “Greene’s goldenweed”. This species produced a significant amount of resinous exudates from the twigs and leaves (1, 2). Previous phytochemical investigations of Haplopappus species have revealed the pres- ence of triterpenes (4, 5), diterpenes (3, 6-14), flavonoids (5, 15-20), coumarins (1, 12, 16, 20, 21), monoterpenes (22, 23), and sesquiterpenes (22-26). In the published literature only a few volatile compounds from Haplopappus species have been reported (23-25). For example, R-pinene, -phellandrene, and phellandral were found as major compounds in the steam-distilled oil of the leaves and stems of H. laricifolius (24). Isocomene, modhelphene, 1,2,3,4-tetrahy- dro-1,1,5,6-tetramethylnaphthalene, -caryophyllene, caryophyl- lene oxide, limonene, borneol, bornyl acetate, and carvone were reported in the H. heterophyllus volatile oil (25). Urzua et al. described the chemical composition of the resinous exudates from H. foliosus and H. uncinatus and identified a number of monoterpenes, sesquiterpenes, hydrocarbons, and phenyl pro- panoids (23). Urzua et al. recently reported the antibacterial diterpenoids of the resinous exudate (3). Several groups investigating the biological activities of Haplopappus species have reported antioxidant, antimicrobial, and antibacterial activities (2, 3, 13, 21, 27, 28). The aim of this study was to evaluate the antimalarial, antimicrobial, and antifungal activities of H. greenei essential oil and its major constituents for activity against various plant and human pathogenic microorganisms. Furthermore, to the best of our knowledge we are reporting for the first time the volatile constituents of H. greenei characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). MATERIALS AND METHODS General. Pure essential oil compounds (-pinene, carvacrol, trans- pinocarveol, and caryophyllene oxide) (>95%, Aldrich-Sigma, St. Louis, MO) and fungicide technical grade standards benomyl, cyprodi- * Corresponding author tel: +90 222 335 05 80-3717; fax: +90 222 335 07 50; e-mail: bdemirca@anadolu.edu.tr or betuldemirci@gmail.com. † Anadolu University. ‡ U.S. Department of Agriculture. 3146 J. Agric. Food Chem. 2006, 54, 3146-3150 10.1021/jf053222v CCC: $33.50 © 2006 American Chemical Society Published on Web 03/23/2006