Composition of the essentialoOil of coristospermum cuneifolium and antimicrobial activity evaluation

For the first time, the chemical composition and antimicrobial evaluation of Coristospermum cuneifolium (previously named Ligusticum lucidum subsp. cuneifolium) essential oil obtained from the aerial parts are reported in this work. Approximately 85 % of the total constituents were identified by GC-MS analysis, evidencing the presence of 12 chemical components which belong to several classes of natural compounds. Most of them are reported for the first time in the Ligusticum genus (s.l.) and in the Apiaceae family. Their presence was able to provide a rationale for essential oil use in the field similar to those obtained from other species of the Ligusticum genus (s.l.). Moreover, the huge presence of aromatizing and flavoring components, accounting for 44.4 % of the essential oil composition, might make C. cuneifolium a useful natural source of aromatic components for the food and cosmetic fields. In addition to this, a deep comparison of the essential oil of this species with that of other entities within the Ligusticum genus (s.l.) was performed and discussed on a chemotaxonomic basis. The essential oil was tested for its antimicrobial activity at both high and low inoculum (~5 × 105 and ~ 5 × 103 cfu/mL, respectively) against several bacterial and fungal strains, including methicillin-susceptible Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Candida albicans (ATCC 14053), methicillin-resistant S. aureus (clinical strain), carbapenemsusceptible Klebsiella pneumoniae (clinical strain), carbapenemresistant K. pneumoniae (clinical strain), and carbapenem-resistant Acinetobacter baumannii (clinical strain). A high potency against C. albicans was shown, with an absence of growth at the concentration of 3.01 mg/mL; similarly, for methicillin-susceptible S. aureus and methicillin-resistant S.aureus, a reduction of 1.73 and 2 log10 cfu/mL at the concentration of 3.01 mg/mL was observed. With regard to gramnegative microorganisms, only slight potency against A. baumannii was shown, whereas no activity was found against E. coli and K. pneumoniae.