Composition, Enantiomeric Distribution, and Antibacterial Activity of the Essential Oil of Achillea ligustica All. from Corsica JEAN-JACQUES FILIPPI,* ,²,‡ DON-ANTOINE LANFRANCHI, § SOIZIC PRADO, # NICOLAS BALDOVINI, ² AND UWE J. MEIERHENRICH ² LCMBA, UMR CNRS 6001, Universite ´ de Nice-Sophia Antipolis, Parc Valrose, F-06108 Nice Cedex 2, France; Bioanorganische Chemie 130, Universita ¨t Hohenheim, Garbenstrasse 30, D-70593 Stuttgart, Germany; Laboratoire de Ste ´re ´ochimie, ECPM, 25 rue Becquerel, F-67008 Strasbourg Cedex 2, France; and Unite ´ de Ge ´ne ´tique Mole ´culaire Bacte ´rienne, Unite ´ de Chimie Organique, Institut Pasteur, 28 rue du Docteur Roux, F-75724 Paris Cedex 15, France The essential oil of Achillea ligustica from Corsica was investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 82 compounds representing 94.0% of the oil were tentatively identified. The main constituents were the camphane derivatives, representing >30% (camphor, 21.3%; borneol, 6.2%; bornyl acetate, 3.5%) of the whole oil, and santolina alcohol (19.3%). The enantiomeric distribution of 8 chiral constituents was determined by GC-MS using two enantioselective stationary phases (DIME--CD and Lipodex-E). Racemic santolina alcohol, required for optimization of the enantioselective GC conditions, was prepared by an original two-step synthesis from 2,5-dimethylhexa-2,4-diene. The whole essential oil was tested for its antibacterial activity against a wide range of bacteria using a paper disk method. The results show a promising activity against Streptomyces species. KEYWORDS: Achillea ligustica; essential oil composition; enantioselective analysis; antibacterial properties; santolina alcohol INTRODUCTION Achillea ligustica is an herbaceous Asteraceae widespread in the Mediterranean area. In Corsica, this plant is found under the vernacular name “erba santa” (holy herb), which refers to its role in the Corsican traditions. Hence, it was used in cataplasms to relieve sprains and insect bites and had also a reputation for stopping hemorrhages (1). This is apparently a nontoxic plant as it has been traditionally added to cakes consumed on Good Friday. Three studies have been reported on the composition of the essential oil of A. ligustica: Maffei et al. (2) found that samples prepared from plants collected in Italy were rich in artemisia ketone and 2,7-dimethyl-4,6-octadien-2-ol, whereas Tzakou et al. (3) showed that the hydrodistillation of A. ligustica harvested in Greece furnished essential oils containing linalool and 1,8- cineole as main constituents. Tuberoso et al. (4) recently reported the composition of samples of A. ligustica collected in different sites of Sardinia and showed that the essential oils were rich in santolina alcohol. In the course of our studies on Mediterranean aromatic plants, we report here on the composition of Corsican A. ligustica essential oil, determined by means of gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) tech- niques. Stereochemical configurations of the main components were measured by GC using chiral stationary phases, after oil fractionation. Additionally, the essential oil was also tested for its potential to inhibit in Vitro the growth of various bacterial strains. MATERIALS AND METHODS Plant Material. The aerial parts of wild A. ligustica were collected at blooming stage at U Rugnicone, near Ajaccio (Corsica), in May 2004. A voucher specimen (voucher no. B-5071) was deposited in the herbarium of the Museum d’Histoire Naturelle de la ville de Nice, where the taxonomic identification of the plant material was confirmed. Essential Oil Isolation. Fresh aerial parts (1000 g) were hydro- distilled for 5 h in a Clevenger-type apparatus. The essential oil was obtained as a pale blue liquid with a 0.4% yield (w/w). GC and GC-MS Analyses. GC and GC-MS analyses on apolar columns were carried out using an Agilent 6890 N gas chromatograph apparatus equipped with a flame ionization detector (FID) and coupled to a quadrupole Agilent 5973 network mass selective detector working * Address correspondence to this author at the Universita ¨t Hohenheim, Bioanorganische Chemie 130, D-70593 Stuttgart, Germany (e-mail jfilippi@uni-hohenheim.de or jfilippi@unice.fr). ² Universite ´ de Nice-Sophia Antipolis. ‡ Universita ¨t Hohenheim. § Laboratoire de Ste ´re ´ochimie, ECPM. # Institut Pasteur. 6308 J. Agric. Food Chem. 2006, 54, 6308-6313 10.1021/jf060752y CCC: $33.50 © 2006 American Chemical Society Published on Web 07/27/2006