Weifeng Dai

Highly oxidized sesquiterpenes from Artemisia austro-yunnanensis

Eight new sesquiterpenes, including four guaianolides (1-4), one guaian sesquiterpene (5), one norguaianolide (6), one 1, 10-secoguaianolides (7), and one eudesmane sesquiterpene (8), along with fourteen known sesquiterpenes (9-22) were isolated from the whole plants of Artemisia austro-yunnanensis. Their structures were elucidated on the basis of spectroscopic date and HRESIMS analysis. All isolated sesquiterpenes (1-22) were evaluated their activities by the assay of LPS-induced NO production on RAW264.7, of which compounds 2-4, 9, 10 and 17 produced significant inhibition of NO production with IC50 values ranging from 2.38 to 10.67μM.

1,10-Secoguaianolides from Artemisia austro-yunnanensis and Their Anti-Inflammatory Effects

Seven 1,10-secoguaianolides 1–7, including a new one (compound 1), were isolated from Artemisia austro-yunnanensis and identified by HRESIMS and other spectroscopic methods. Their anti-inflammatory effects were evaluated by the model of LPS-induced RAW264.7 cells in vitro. Bioassay results showed that six of them (1–4, 6 and 7), with the exception of 5, produce some cytotoxicity on RAW264.7 cells at its high dosage, can significantly decrease the release of NO, TNF-α, IL-1β, IL-6 and PGE2 in a dose dependent manner, and down-regulate the expression of proteins iNOS and COX-2. The mechanism study indicated they regulated the NF-κB dependent transcriptional activity through decreasing the phosphorylation of NF-κB. Further, the relationship between their structures and cytokines to anti-inflammatory were studied by PCA and discussed.

Sesqui- and Diterpenoids from the Radix of Curcuma aromatica

Eight new sesquiterpenoids (1-8), two new diterpenoids (9 and 10), and 17 known sesqui- and diterpenoids (11-27) were isolated from the radix of Curcuma aromatica. Among these compounds, 1 is an unprecedented guaiane with unique cyclopropane and furan functionalities, and 9 is the first atisane diterpenoid isolated from a Curcuma species. Their 2D and 3D structures were established using HRESIMS and spectroscopic methods, including ECD and IECD data. The antioxidant activities of compounds 1-27 were evaluated based on their ability to protect PC12 cells against H2O2-induced damage, with 1, 2, 5-8, 11, 12, 14, 16, 18, and 19 exhibiting notable antioxidant effects on oxidative injury induced by H2O2.