Identification of natural compounds of Jurinea species by LC-HRMS and GC-FID and their bioactivities

Abstract

The Jurinea Cass. is one of the most important genera within Asteraceae and it comprises about 250 species in total. This genus is known for its numerous biological activities such as antioxidant, antimicrobial, antilipid peroxidation, anticholinesterase, antileishmanial activities. The aim of this study was to determine chemical composition and biological activities of ethanol and n-hexane extracts of three different Jurinea species. For this purpose, different parts of J. mollis, J. cadmea and J. pontica were extracted and totally six n-hexane and six ethanol extracts were obtained. Fatty acid content of n-hexane extracts was determined by GC-FID whereas phenolic and flavonoid content of ethanol extracts by LC-HRMS. Palmitic acid (16:0) was detected as the most abundant fatty acid in all n-hexane extracts with the rates ranging from 42.16%-55.08%, except flowers of J. mollis (JMF) and J. cadmea (JCF). LC-HRMS analysis showed the rutin content of all extracts was higher than other flavonoids, except of J. cadmea flowers, whereas apigenin-7-glucoside was found the most abundant in JCF. Cytotoxic effects of the extracts on HeLa and HEK-293 cells were determined by MTT method, and antioxidant activities were evaluated by DPPH and CUPRAC assays. Ethanol extract of J. mollis flowers significantly inhibited cancerous HeLa cells, with the IC₅₀ value of 9.683 μg/mL while it was more less toxic on healthy HEK-293 cells. Ethanol extracts of J. mollis flowers and J. mollis steams-leaves (JMSL) showed the highest antioxidant activity by a DPPH inhibition % of 45.516 ± 2.497 and 56.671 ± 1.496, respectively. JMF and JMSL have also the highest CUPRAC values (0.880 ± 0.067 and 1.085 ± 0.152 mmol TR/g DWE, respectively). Total flavonoid content was determined using aluminum chloride colorimetric assay while total tannin and phenolic content by Folin Chiocalteu's reagent. Results showed that JMSL has the highest total phenolic (108.359 ± 6.241 mg GAE/ G DWE) and flavonoid (32.080 ± 4.385 mg QE/ g DWE) contents whereas JMF has the highest tannin content (121.333 ± 17.889 mg TAE/ g DWE). In the light of these results, various parts of Jurinea species may be regarded as alternative sources for cytotoxic and/or antioxidant flavonoids, phenolics and unsaturated fatty acids that can arouse the interest of pharmaceutical, food and cosmetic industries.

Keywords: Antioxidant activity; Asteraceae; Cytotoxic activity; GC-FID; Jurinea; LC-HRMS; Total flavonoid content; Total phenolic content; Total tannin content.