Extraction and Essential Oils Profiling of Different Dorema ammoniacum D. Don. Organs and Evaluation of Antioxidant Capacity

Dorema ammoniacum D. Don. is a perennial medicinal plant from Apiaceae family. There is some evidence in Iranian traditional medicine about the anticonvulsant and anthelmintic properties of D. ammoniacum gum resin exudating from its root and stem. In this study, D. ammoniacum was collected from southwestern part of Iran and their Essential Oils (EOs) content and compositions were investigated by gas chromatography techniques. The EO yield of D. ammoniacum root, stem, leaves, flower and gum were 0.4, 0.2, 0.24, 0.46, and 1.0 v/w%, respectively. Although there were some variations among different organs EOs, some similarities could be easily observed. The major compounds in the gum EO were (2E, 6E)-farnesol (12.2%), cuparene (11.5%), (2Z,6Z)-farnesol (8.7%), β-bisabolene (6.1%). The root oil had thymol (14.7%), heptacosane (12.8%), tridecanol (12.7%) and 4-methylene-5-hexenal (6.8 %) as the major compounds. Endo-Fenchyl acetate (13.1%), elemicin (10.5%), p-cymen-8-ol (6.8%) and thymol (5.6%) were identified in the stem oil. The major constituents of the leaves oil were n-hexadecanol (9.1%), cuparene (8.2%), Di-n-butyl phthalate (6.6%), n-eicosane (6.6%), bicyclogermacrene (5.4%) and β-bisabolene (5.2%). The major compounds in flower oil were tridecanol (13.2%), δ-elemene (11.2%), n-eicosane (8.2%), and heptadecanoic acid (7.8%). According to different applications, nine different extracts were also prepared from all organs and their Antioxidant Activity (AA), Total Phenol Content (TPC) and Total Flavonoid Content (TFC) were evaluated. Analysis of variance showed that there was a significant difference among all extracts of D. ammoniacum in AA, TPC and TFC (P≤ 0.01). Results showed that the highest radical scavenging activity was observed in M2F (second Methanolic extract of Flower) and M2L (second Methanolic extract of Leaves) samples with IC50 of 40.3 μg mL-1 and 43.6 μg mL-1 compared to BHT (26.0 μg mL-1). The highest TPC in M2F and M2R (second Methanolic extract of Root) samples were 36.4 and 35.7 mg GAE g-1 DW of extracts, respectively. The highest TFC belonged to M2L with 26.4 mg QE g-1 DW of extract. Results also showed that D. ammoniacum organs extracts contained moderate to high amounts of AA and TPC.