Two new polypodane-type bicyclic triterpenoids from mastic

Pistacia lentiscus L. is an evergreen shrub belonging to the Anacardiaceae family, cultivated exclusively in the southern area of Chios Island. Mastic gum as a unique natural resin of the tree Pistacia lentiscus L. has been used extensively in functional foods and traditional medicine. The biological properties of Pistacia resins may be influenced by different chemical constituents. Herein the present work is aimed to further explore the diverse triterpenoids of mastic, and evaluate their anti-inflammatory activity. Two undescribed polypodane-type bicyclic triterpenoids were isolated from the Pistacia resins, their structures were elucidated using ultraviolet, infrared, high resolution electrospray ionization mass spectroscopy (HRESIMS), and nuclear magnetic resonance data. LPS-stimulated RAW264.7 macrophages were incubated with various concentrations of isolated compounds, and results showed that compounds 1 and 2 inhibited nitric oxide production in LPS-induced RAW264.7 cells with IC50 values of 28.1 and 32.6 mu M, respectively.