Triterpenes from Meliosma oldhamii Miquel Branches and their Elastase Inhibitory Activities

Phytochemical investigation on the ethanol extracts of Meliosma oldhamii Miquel branches led to the isolation of seven triterpene constituents: betulin (1), lupeol (2), oleanolic acid (3), 3-acetoxyolean-12-en-28acid (4), 3-acetoxyolean-12-en-28-aldehyde (5), 3-acetoxy-28-hydroxyolean-12-ene (6) and maslinic acid (7). Their chemical structures were determined based on the spectroscopic studies, as well as by comparison with literature data. Elastase inhibition activities were examined for the isolates using ursolic acid as a positive control. In this test, the compounds 1 and 3 proved to inhibit porcine pancreatic elastase with an IC50 values of 39.3 and 39.5 g/mL, indicating comparable activities to ursolic acid (IC50 = 28.5 g/mL). This study demonstrated that the M. oldhamii extract including triterpenes has potentials applicable as anti-wrinkle ingredient in cosmetic formulations. All of the compounds 1-7 were isolated for the first time from M. oldhamii.