Triterpenoids from Galbanum of uygur medicine and their anticholinesterase activities

Eight triterpenes were isolated from the methanol extract of Galbanum by various chromatographic methods including silica gel, ODS opening column, recrystallization and semi-preparative HPLC. Their structures were determined by spectroscopic methods and physicochemical properties as 3β,19α,21α-trihydroxyl-12-en-28-oic acid (1), sumaresinolic acid (2), 3β,19α-dihydroxyl-12-en-28-oic acid (3), oleanolic acid (4), 3β,6β,19α-trihydroxyl-12-en-28-oic acid (5), 19α-hydroxy oleanonic acid (6), 6α-hydroxy oleanonic acid (7), and (11R,12R)-3α,6α-dihydroxy-epoxyolean-28α,13α-olide (8). Among them, compound 1 is a new compound, while compounds 2-8 were newly isolated from the Apiaceae family. The ability of compounds 1-8 to inhibit cholinesterase was determined with an improved Ellman method. Compound 1 showed strong inhibitory activity against butyrylcholinesterase. The molecular docking results indicated that Trp82, His438, Phe329 and Ala328 played an important role in the binding of compound 1 to butyrylcholinesterase.