engleski

COMPARISON OF THE ANTIOXIDANT ACTIVITY AND COMPOSITION OF THE ESSENTIAL OIL AND HYDROLATE ISOLATED FROM Veronica austriaca ssp. jacquinii (BAUMG.) EB. FISH. AND Veronica saturejoides VIS. ssp. saturejoides

The genus Veronica L. is the largest genus of the Plantaginaceae family and in Croatia about 40 species can be found in various habitats. Some species of this genus, especially V. officinalis have been used in folk medicine for the treatment of colds, respiratory diseases, laryngopharyngitis, cough, hernia, cancer, as a diuretic and in the treatment of wounds [1]. According to previous studies, plants of the genus Veronica are a potential source of nutrients and functional substances with a variety of biological effects [2]. The aim of this study was to investigate differences in the composition of free volatile compounds of essential oils and hydrosols of the species Veronica austriaca ssp. jacquinii (Baumg.) Eb. Fish. and Veronica saturejoides Vis. ssp. saturejoides and to determine the antioxidant activity of the isolated extracts. From the essential oils of selected species, we isolated and identified free volatiles and statistically analyzed the results by using PCA to see which of the isolated extracts were more similar to each other and to relate the results with antioxidant activity. The components of the essential oils and hydrosols were analyzed by gas chromatography (GC-MS and GC-FID instrument) [3]. In both species the major component of the oil is hexahydropharnesyl acetone, while in the hydrosols of Veronica saturejoides Vis. ssp. saturejoidesspecies, the major component wastrans-p-mentha-1 (7), 8-dien-2-ol and in Veronica austriaca ssp. jacquinii, it was methyl eugenol. For each isolate, antioxidant activity was examined using two methods, ORAC (Oxygen Radical Absorbance Capacity Assay) and DPPH (2, 2-diphenyl-1-picrylhydrazyl) solution) [3]. Samples of essential oils isolated from Veronica saturejoides Vis. ssp. saturejoides showed stronger antioxidant activity by both tested methods at concentration of 10 mg of essential oil per mL of acetone. The antioxidant activity of the hydrosols proved to be similar in all tested samples for both tested plants according to both ORAC and DPPH methods. It is expected that the antioxidant activity of the hydrosol is lower than that of the oil, since hydrosols contain less active substances than the essential oils.

antioxidant activity ; DPPH ; ORAC ; Veronica ; volatile compounds

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