Anti-inflammatory abietanes diterpenoids isolated from Tripterygium hypoglaucum

Tripterygium hypoglaucum (H. Lév.) Hutch. has been used to remedy rheumatoid arthritis , however, it shows frequent toxicity to the body. In this study, liquid chromatograph-mass spectrometer (LC-MS) was guided to characterize abietanes diterpenoids with anti-inflammatory activity from the stem of T. hypoglaucum . Thirteen undescribed abietanes diterpenoids were isolated and purified, and their chemical structure was identified using various spectroscopic methods . These compounds belonged to abietanes with splitting C ring, abietanes with benzenoid rings, diterpene quinoids , diterpene quinoids with lactone rings, and abietanes with benzenoid and lactone rings, respectively. Lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages was used to evaluate anti-inflammatory activity of the compounds. The results indicated that hypoglicin B-G and hypoglicin J-M exhibited inhibitory activity of NO production with the IC 50 values of 6.01, 25.21, 8.29, 3.63, 0.72, 0.89, 36.91, 0.82, 2.85, 11.92 μM, respectively. Among these compounds, compound hypoglicin L showed high anti-inflammatory activity and low toxicity (SI = 5.02 × 10 4 ). Further QPCR analysis revealed that hypoglicin D and hypoglicin L can inhibit the mRNA expression of iNOS in LPS-stimulated RAW264.7 cells at doses of 12.5 and 3.13 μM, respectively. Taken together, ten anti-inflammatory diterpenoids were found from T. hypoglaucum in this study.