Bioactivity-guided isolation of anti-inflammatory limonins from .

is an economically important tree and widely cultured in the southeast of China. Its barks, leaves, and fruits are consumed as a traditional medicine and perceived as a valuable source for bioactive limonin compounds. The extracts from root barks of showed significant anti-inflammatory effect. The aim of this research was to explore the material basis of anti-inflammatory activity, and to purify and identify anti-inflammatory active ingredients. By a bioassay-guided isolation of dichloromethane fraction obtained two novel phragmalin limonins, Chukrasitin D and E ( and ), together with 12 known limonins (-). The chemical structure of these compounds is determined on the basis of extensive spectral analysis and chemical reactivity. In addition, the activities of these isolated limonins on the production of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and nuclear factor kappa B (NF-B) in RAW264.7 cells induced by lipopolysaccharide (LPS) were evaluated. Limonins and indicated significant anti-inflammatory activity with IC values of 6.24 and 6.13 M. Compound notably inhibited the production of NF-B, TNF- and interleukin 6 (IL-6) in macrophages The present results suggest that the root barks of exhibited anti-inflammatory effect and the limonins may be responsible for this activity.