Triterpenoids from Chios mastic gum of Pistacia lentiscus and their inhibition of LPS-induced NO production in RAW 264.7 cells

Abstract

A phytochemical investigation of mastic, the resinous secretion obtained from the wounds of the trunk and branches of Pistacia lentiscus, led to the isolation of six undescribed triterpenoids (1–6), including two unusual nor-dammarane-type triterpenoids (1 and 2), four tirucallane-type triterpenoids (3–6), together with seven known compounds (7–13). The structures of those undescribed compounds were elucidated by integrating spectroscopic analyses, including NMR, UV, IR, as well as HR-MS data. The absolute configurations of compounds 1 and 2 were confirmed by electronic circular dichroism. Anti-inflammatory evaluation revealed that compounds 5, 8, 9, and 12 exhibited moderate inhibition of the nitric oxide production in RAW264.7 cells with IC50 values ranging from 20.24 to 36.63 μM, compared to that of positive control, dexamethasone (IC50 = 19.85 μM).