Polyphenolics and triterpenoids from the whole herbs of Melastoma dodecandrum Lour. and their anti-inflammatory activity.

Melastoma dodecandrum Lour. is a creeping shrub belonging to the Melastomataceae family. It has been widely used as a medicine and food in South China and is recognized as a safe and effective anti-inflammatory agent. 35 compounds (1-35) were isolated from the whole herbs of M. dodecandrum, including two undescribed polyphenolics (1 and 2), two undescribed triterpenoids (3 and 4), twenty-eight known polyphenolics (5-32) and three known triterpenoids (33-35). Based on chemical evidence and spectral data analysis (UV, Optical rotation data, 1D and 2D-NMR, and HR-ESI-MS), the structures of undescribed compounds were elucidated. Compounds 1-35 were tested for their inhibitory activity on NO production in LPS-induced RAW264.7 cells. Among them, compound 8 exhibited the most excellent inhibitory activity with IC50 value of 14.50 ± 4.69 μM.