Oleanane-Type Triterpenoid Saponins and Rosmarinic Acid from Clinopodium Umbrosum

Clinopodium umbrosum from Lamiaceae family has been used widely in traditional medicine as an herbal medicine. Due to a lack of phytochemical reports and limited studies on C. umbrosum, this plant species was selected for further phytochemical analysis. The grounded aerial parts of the plant were extracted with petroleum ether, chloroform, and methanol, subsequently. The methanol extract was fractionated via Solid Phase Extraction (SPE), Vacuum Liquid Chromatography (VLC), and reversed Phase High-Performance Liquid Chromatography (HPLC), respectively. 1D and 2D NMR spectral analyses were applied for structure elucidation of the purified compounds. The Gas Chromatography-Mass Spectrometry (GC-MS) technique was used for the analysis of the essential oil of C. umbrosum which was achieved through hydrodistillation. In addition, free radical scavenging activity together with total phenolics and flavonoid content of the methanol extract was assessed. Structure elucidation of the purified compounds revealed the presence of a caffeic acid derivative and two triterpene saponins in C. umbrosum methanol extract. Based on the GC-MS analysis of the essential oil results tolualdehide, palmitic acid, and acetophenone were the main components of the essential oil of this plant. Moreover, a high percentage of phenolic and flavonoid components of the extract seems to be responsible for its antioxidant and free radical trapping activity. Conclusion: Overall, the phytochemical analysis of C. umbrosum showed the presence of rosmarinic acid, buddlejasaponin IVa and buddlejasaponin IV as the main constituents of the methanol extract.