Abstract
A water-distilled essential oil (EO) from the aerial parts of Pimpinella cypria Boiss. (Apiaceae), an endemic species in northern Cyprus, was analyzed by GC-FID and GC-MS. Forty-five compounds were identified in the oil, which comprised 81.7% of the total composition. The compound classes in the oil were oxygenated sesquiterpenes (33.9%), sesquiterpenes (22.0%), monoterpenes (11.4%), oxygenated monoterpenes (2.6%), and phenylpropanoids (7.5%). The main components of the oil were (Z)-β-farnesene (6.0%), spathulenol (5.9%), ar-curcumene (4.3%), and 1,5-epoxy-salvial(4)14-ene (3.8%). The P. cypria EO deterred yellow fever mosquitoes (Aedes aegypti) from biting at a concentration of 10 μg/cm2 in in vitro bioassays. The oil was tested for repellency in assays using human volunteers. The oil had a minimum effective dosage (MED) for repellency of 47 ± 41 μg/cm2 against Ae. aegypti, which was less efficacious than the positive control N,N-diethyl-3-methylbenzamide (DEET). In larval bioassays, P. cypria EO showed an LC50 value of 28.3 ppm against 1st instar Ae. aegypti larvae. P. cypria EO demonstrated dose dependent repellency against nymphs of the lone star tick, Amblyomma americanum. Between 45.0% and 85.0% repellency was observed at concentrations ranging from 26 to 208 μg/cm2. However, P. cypria EO was less effective compared with DEET in the tick bioassays. Cytotoxicity assays showed that the P. cypria EO did not exhibit significant effects up to the maximum treatment concentration of 50 μg/mL on HEK293, PC3, U87MG, and MCF cells. P. cypria EO also demonstrated moderate antimicrobial activity against Gram-negative and -positive bacteria with MICs ranging from 15.6 to 62.5 μg/mL, except for Candida albicans, which showed the same MIC value of 7.8 μg/mL as the positive control, flucytosine. This is the first report on the chemical composition of P. cypria EO and its insecticidal, toxicant, cytotoxic, and antimicrobial activity.