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Four new aster saponins (1-4) together with five known analogues (5-9) were isolated from Aster tataricus. The chemical structures of 1-4 were elucidated based on spectrometric and spectroscopic analysis and comparison with reported data. The potential anti-inflammatory activities of aster saponins 1-9 were evaluated subsequently by measuring lipopolysaccharide (LPS)-enhanced nitric oxide (NO) formation in murine macrophages. Among these, aster saponin B (6) exhibited the most potent inhibitory activity (IC 50 : 1.2 μM). Additionally, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein levels were dose-dependently suppressed by 6 in LPS-activated RAW 264.7 cells. Investigation of the anti-inflammatory mechanism indicated that 6 attenuated the phosphorylation and degradation of the inhibitor of NF-κB (IκB), which led to the blocking of NF-κB p65 translocation to the nucleus.

Nine new sesquiterpenoid lactones and 11 known analogues were isolated from the aerial parts of Salvia plebeia R.Br. Their structures were elucidated via HRESIMS and NMR data, and their absolute configurations were defined via electronic circular dichroism data, X-ray crystallographic analysis, and the modified Mosher's ester method. Compounds 1-20 were investigated for their ability to inhibit LPS-stimulated nitric oxide production in murine macrophage cells. Of the isolates, epi-eudebeiolide C (20) showed the highest inhibitory effect (IC 50 of 17.9 μM). mRNA and protein expression of inducible nitric oxide synthase (iNOS), but not that of cyclooxygenase-2 (COX-2), was dose-dependently decreased by 20 in LPS-activated RAW 264.7 cells. Based on a mechanistic study involving the nuclear factor-κB (NF-κB) signaling pathway, the anti-inflammatory effect of 20 was attributed to NF-κB activation blockade via inhibition of NF-κB (IκB) phosphorylation. Therefore, 20 might be a potential candidate for relieving inflammatory diseases.

Five new dammarane-type saponins, gypenosides GD1-GD5 (1-5), along with six known saponins (6-11), were isolated from the aerial parts of Gynostemma pentaphyllum using various chromatographic methods. Their structures were elucidated by a combination of spectroscopic and spectrometric data, including 1D and 2D NMR and HRESIMS. All isolates were tested for their inhibitory effects on IL-6-induced STAT3 promoter activity in Hep3B cells. Compounds 1, 9, and 11 displayed potent inhibitory effects, with IC50 values ranging from 0.27 to 0.59 μM.

Derivatives of bufogenin isolated from the skin of the Chinese toad, Bufo bufo gargarizans Cantor ("Ch'an Su"), and several semisynthetic derivatives of 20beta,21beta-epoxy-resibufogenin (13) have been evaluated for interleukin-6 (IL-6) antagonistic activity due to their growth-inhibitory activities on IL-6-dependent MH-60 cells. Among the naturally derived compounds (1-17), 20S,21-epoxy-resibufogenin formate (1) showed potent inhibitory activity on the IL-6-dependent growth of MH-60 cells. Epoxide groups at both the C-14, C-15 and C-20, C-21 positions are required to exhibit this type of activity. Compounds acetylated at the C-16 position (7 and 9-11) showed a loss of activity. An oxo group at the C-3 position (8, 14, and 15) resulted in cytotoxicity for both cell lines. Stereochemistry is important for selectivity on suppression of IL-6 activity. Among the semisynthetic derivatives (18-25) of 13, compound 19, with an acetyl group introduced at the C-3 position in comparison to 13, demonstrated considerable growth inhibition of IL-6-dependent MH-60 cells.

(2S)-1-O-Palmitoyl-3-O-beta-D-galactopyranosylglycerol, isolated from the marine alga Oscillatoria rosea, inhibited platelet aggregation induced by U46619, a thromboxane A2 analogue. Its structure was elucidated by spectroscopic analysis and chemical evidence.