Phytochemical and Antioxidant Investigation of the Aerial Parts of Dorema glabrum Fisch. & C. A. Mey

Dorema glabrum Fisch. & C.A. Mey. (Apiaceae) is a monocarpic perennial plant distributed in southern Caucasus. In Azerbaijan Republic folk medicine, the gum-resin of this species is used as a diuretic and anti-diarrheal agent. It is also traditionally used for the treatment of bronchitis and catarrh. In the present study, chemical constituents of the essential oil and extract of D. glabrum aerial parts were investigated and their free radical scavenging potentials were assessed. GC-MS and GC-FID analyses of the plant essential oil resulted in identifying twenty compounds, out of which elemicin (38.6%) and myristicin (14.3%) were main compounds. Seven compounds including daucosterol (1), chlorogenic acid (2), a mixture of cynarin (3) and 3,5-di-O-caffeoylquinic acid (4), isorhamnetin-3-O-β-D-glucopyranoside (5), isoquercetin (6) and astragalin (7) were also isolated from the ethyl acetate and methanol fractions of D. glabrum aerial parts using different chromatographic methods on silica gel (normal and reversed-phase) and sephadex LH20. Structures of the isolated compounds were elucidated using UV and 1H, 13C-NMR spectra in comparison with those reported in respective published data. Antioxidant activities of the crude extract, fractions and isolated compounds were evaluated using DPPH free radical scavenging assay method. Among the fractions, methanol fraction (IC50= 53.3 ± 4.7 μg ml-1) and among the isolated compounds, caffeoylquinic acid derivatives exhibited the highest free radical scavenging activity (IC50= 2.2-2.6 μg ml-1).