Sesquiterpene lactones from Inula falconeri, a plant endemic to the Himalayas, as potential anti-inflammatory agents.

A phytochemical investigation of Inula falconeri, a plant endemic to the Himalayas, afforded 10 new sesquiterpenoids and 26 known sesquiterpene lactones, including those bearing guaiane, pseudoguaiane, xanthane, eudesmane, germacrane, rare secocaryophyllane, chromolaevane, and carabrane frameworks. The structures were elucidated via spectroscopic analysis and compared with data from literature. All the isolates were assessed for their inhibitory effects against LPS-induced nitric oxide production in RAW264.7 macrophages. Compounds 4, 11, 24, and 31 showed stronger inhibitory activities than the positive control with IC(50) values of 0.13, 0.07, 0.11, and 0.11 μM, respectively. These studies also led to a better understanding of the structure-activity relationships for the sesquiterpene lactone family of compounds.

Cheng X ，Zeng Q ，Ren J ，Qin J ，Zhang S ，Shen Y ，Zhu J ，Zhang F ，Chang R ，Zhu Y ，Zhang W ，Jin H ... -  《-》

Japonicones E-L, dimeric sesquiterpene lactones from Inula japonica Thunb.

Eight new dimeric sesquiterpene lactones (japonicones E-L, 1- 8), including a novel sesquiterpene dimer bearing a rare hydroperoxide group (japonicone E, 1), were isolated from the aerial part of Inula japonica Thunb. Their structures were determined mainly by the use of 1D and 2D NMR spectroscopic techniques including HSQC, (1)H-(1)H COSY, HMBC, and NOESY. All the isolates were tested for inhibitory effects against LPS-induced NO production in RAW264.7 macrophages. Among the compounds tested, japonicone F (2) showed the strongest activity with the IC(50) value of 4.1 microg/mL.

Qin JJ ，Jin HZ ，Zhu JX ，Fu JJ ，Hu XJ ，Liu XH ，Zhu Y ，Yan SK ，Zhang WD ... -  《-》

Sesquiterpene lactones from Inula hupehensis inhibit nitric oxide production in RAW264.7 macrophages.

Phytochemical investigation of the aerial parts of Inula hupehensis Ling. led to the isolation and identification of 27 sesquiterpene lactones (1-27), including three new eudesmanolides (3-5), three new germacranolides (9-11), one new xanthanolide (16), two new carabrone derivatives (25-26), and 18 known sesquiterpene lactones. The structures were elucidated by extensive spectroscopic methods and comparison to previously reported spectroscopic data. All compounds were evaluated for their inhibitory effects against LPS-induced nitric oxide production in RAW264.7 macrophages, and compound 5 showed the strongest activity with the IC₅₀ value of 3.2 ± 0.4 µM.

Qin JJ ，Zhu JX ，Zeng Q ，Cheng XR ，Zhang SD ，Jin HZ ，Zhang WD ... -  《-》

Sesquiterpenoids from Inula racemosa Hook. f. inhibit nitric oxide production.

A novel trinorsesquiterpene (1), three new (2-4), and 10 known sesquiterpenes were isolated from the roots of Inula racemosa Hook. f. The structures and absolute configurations of the new sesquiterpenes were elucidated by extensive spectroscopic and computational methods. All compounds were evaluated for their inhibition of LPS-induced nitric oxide production in RAW264.7 macrophages, and the results indicated that compounds 9, 12, and 13 moderately inhibited nitric oxide production with IC₅₀ values of 7.39 ± 0.36, 6.35 ± 0.26, and 5.39 ± 0.18 µM, respectively.

Zhang SD ，Qin JJ ，Jin HZ ，Yin YH ，Li HL ，Yang XW ，Li X ，Shan L ，Zhang WD ... -  《-》

Five new sesquiterpene lactones from Inula hupehensis.

Ren J ，Qin JJ ，Cheng XR ，Yan SK ，Jin HZ ，Zhang WD ... -  《-》