Phytochemical composition of elichrysum arenarium (L.) Moench essential oil (aerial parts) from Turkey

Abstract

Introduction. The aim of the present study was to determine the phytochemical composition of Helichrysum arenarium (L.) Moench (aerial parts) essential oil and extracts obtained from Turkey as a source of bioactive components for the food, cosmetics and pharmaceutical industry. Materials and methods. The flower essential oil was obtained by hydrodistillation for 2 h and its composition was analyzed using gas chromatographic analysis (GC/MS). Extracts were obtained from the airdried flowers by treatment with 70 and 90% ethanol (1:5 v/w) in an ultrasonic bath. In the extracts, the total phenolic content was obtained by Folin-Cicalteu method. The total flavonoid content was determined by Al(NO3)3 reagents, measured at wavelength 415 nm against a blank. Antioxidant activity of the extracts was determined using DPPH, ABTS, FRAP, and CUPRAC assay. Results and discussion. The amount of extracted essential oil was 0.07% with the main constituents oleic acid (30.28%), ethyl hexadecanoate (20.19%), linoleic acid (18.89%), and sclareol (4.22%). The composition of the oil predominated by oxygenated hydrocarbons (76.90%), followed by diterpenes (11.50%), hydrocarbons (3.53%)), oxygenated sesquiterpenes (3.30%), phenyl propanoids (2.93%), sesquiterpene hydrocarbons (1.43%), monoterpene hydrocarbons (0.34%), and oxygenated monoterpenes (0.07%). The content of the total polyphenols in the 95% ethanol extracts was 7.56 mg GAE/g dw and the total flavonoids was 3.13 mg GAE/g dw, whereas their content in the 70% ethanol extract were 6.62 mg GAE/g dw and 3.34 mg GAE/g dw, respectively. Among the plant samples, 70% ethanol extract exhibited higher CUPRAC (159.46 mM TE/g dw) followed by ABTS radical action decolourization (47.53 mM TE/g dw). The results for ethanol extracts and their antioxidant activity were in accordance with the total phenolic content and the concentration of flavonoids. The flowers of H. arenarium were dominated by total carotenoid (10.68 μg/g dw), followed by total chlorophyll (51.24 μg/g dw). The content of chlorophyll a (32.67 μg/g dw) was higher than that of chlorophyll b (18.57 μg/g dw). Conclusions. The main compounds of the. arenarium essential oil were oleic acid, ethyl hexadecanoate, linoleic acid, and sclareol. The extracts showed a high level of total phenolic content and antioxidant potential, which make the studied plant species as a potential source of alternative natural antioxidant or a source of biologically active components.