Bioactive secondary metabolites isolated from the branches and leaves of Pittosporum pulchrum Gagnep.

Five new compounds, including two sesquiterpenoid glycosides (1 and 2), two monoterpenoid glycosides (3 and 4), and a quinovose ester (5), together with four known compounds (6-9) were isolated from branches and leaves of Pittosporum pulchrum Gagnep. Their structures were established by 1D and 2D NMR, HR-ESI-MS, IR and UV spectral analyses. This is the first time to investigate the chemical constituents of P. pulchrum. Subsequently, the anti-inflammatory and antioxidant activities of different solvent fractions of ethanol extract and isolated compounds were evaluated. Dichloromethane and ethyl acetate fractions dramatically inhibited the production of NO in a concentration-dependent manner in LPS-induced RAW264.7 cells. Ethyl acetate and n-butanol fractions showed excellent DPPH radical scavenging activities with IC50 values of 24.31 μg/mL and 27.81 μg/mL, respectively. Compounds 7 and 8 might be potential natural antioxidants with IC50 values of 16.13 μM and 24.81 μM, respectively.