Abietane-type diterpenoids from the roots of Salvia tebesana

Abstract

Background and objectives: The genus Salvia is one of the largest genera in the family Lamiaceae and represents approximately 1000 species displaying a remarkable diversity.Salvia tebesana Bunge(Lamiaceae) is an endemic medicinal species that grows wild in center of Iran which is locally named “Maryamgoli Tabasi”. Methods: The dried roots (2 kg) were perculated with MeOH at room temperature. Methanol extract was further fractionated to give four different fractions [n-hexane, dichloromethane (CH2Cl2), ethyl acetate (EtOAc) and water (H2O)]. In the next step, to afford the major bioactive compound(s) of the plant, the EtOAC extract was further sub-fractionated by silica gel column chromatography using a mixture of petroleum ether/ethyl acetate with increasing polarity. The different fractions were purified by reversed-phase semi-preparative HPLC. Results: From the ethyl acetate extract, two diterpene quinones with rearranged abietane skeletons, aegyptinones A and B were isolated and their structures were mainly elucidated by 1D and 2D NMR and mass spectroscopy. Conclusion: These compounds have been reported for the first time from this plant.

Keywords

• abietane diterpenoid
• mass spectroscopy
• NMR
• Salvia tebesana