A comparative assessment of biological activities of Gundelia dersim Miller and Gundelia glabra Vitek, Yüce & Ergin extracts and their chemical characterization via HPLC-ESI-TOF-MS

Plants from the Gundelia genus have been well appraised as both food and remedies. The members of the Gundelia genus are widely used as foods in several countries including Turkey. This study presents a comparative assessment of two poorly studied Gundelia species (G. glabra Miller and G. dersim Vitek, Yüce & Ergin). The effect of conventional (infusion, maceration, and Soxhlet extraction) and non-conventional (homogeniser and ultrasound assisted extraction) methods of extraction of bioactive secondary metabolites from the selected Gundelia species was also assessed. A total of 68 different compounds were detected by high-performance liquid chromatography coupled to electrospray ionization and time-of-flight mass spectrometry (HPLC-ESI-TOF-MS) technique. Non-conventional extraction techniques do not guarantee higher antioxidant activity. As such, G. dersim (91.27, 138.87, 182.28, and 125.65 mg TE [Trolox equivalent]/g dried extract, for 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC), and ferric reducing antioxidant power (FRAP) assays, respectively).The highest α-glucosidase inhibition was recorded for the extracts obtained by ultrasonication. In the multivariate analysis, the extracts from Gundelia species were separated based on their biological activities. The presented findings could be one methodological starting point for designing novel products from two Gundelia species.