Cytotoxic guaianolides and seco-guaianolides from Artemisia atrovirens

Artemyriantholidimers A-G, undescribed guaiane-type sesquiterpenoid dimers from Artemisia myriantha and their antihepatoma activities

Artemyriantholidimers A-G (1-7), seven undescribed guaiane-type sesquiterpenoid dimers (GSDs), and 27 known compounds (8-34) were isolated from Artemisia myriantha (Asteraceae). Their structures and relative configurations were elucidated based on the comprehensive analyses of UV, IR, MS, NMR data, quantum chemical NMR calculations with DP4+ probability analyses, and the absolute configurations were elucidated by ECD calculations. The undescribed GSDs (1-7) were presumably formed via Diels-Alder reactions, and compounds 5-7 were rare GSDs with α-configuration of H-6'. Compounds 4-7 showed significant inhibition on HepG2, Huh7, and SK-Hep-1 cells with IC50 values ranging from 6.9 to 13.0 μM by antihepatoma assay. The best active compound 5 was deduced to be targeted on the protein AURKA of the p53 signaling pathway by network pharmacological analysis with a high bind affinity of AURKA (total score: -8.98) by molecular docking, and had a KD value of 62.4 μM by surface plasmon resonance assay.

Germacrane-type sesquiterpenes from Artemisia atrovirens and their anti-inflammatory activity

Artemisia plants are well-known for their abundant sesquiterpene compounds, which encompass various structural types and exhibit a range of biological activities. In this study, a systematic investigation of Artemisia atrovirens revealed the presence of germacrane-type sesquiterpenes for the first time. This included the discovery of 10 new compounds and three known analogues, among which were two rare dimeric germacrane-type compounds. Their structures were fully characterized through a comprehensive analysis involving MS, IR, 1D- and 2D-NMR spectroscopic data, single crystal X-ray diffraction, density functional theory (DFT) NMR calculations, and time-dependent DFT electronic circular dichroism (TDDFT ECD) calculations. Furthermore, all isolated compounds were evaluated for their anti-inflammatory activity in LPS-stimulated RAW 264.7 murine macrophages. Compound 10 demonstrated a potent inhibitory effect on NO production, with an IC50 value of 4.01 ± 0.09 μM. This study highlights the diverse chemical repertoire of Artemisia species and underscores their potential in drug discovery and development.

Anti-inflammatory discovery of sesquiterpenoids and a jasmonic acid derivative from Artemisia stolonifera

Eleven previously undescribed sesquiterpenoids (8-18), one undescribed jasmonic acid derivative (35) and 28 known compounds were isolated from the leaves of Artemisia stolonifera. Undescribed compounds with their absolute configurations were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction and ECD calculation. Compound 8 was identified as a rare sesquiterpenoid featuring a rearranged 5/8 bicyclic ring system, whereas compound 17 was found to be an unprecedented monocyclic sesquiterpenoid with methyl rearrangement. Evaluation of biological activity showed that compounds 1-5 and 7 displayed cytotoxicity against six tumor cells. In the meantime, compounds 11, 12, 18 and 35 exhibited inhibitory effects against LPS-stimulated NO production in RAW 264.7 macrophage cells and reduced the transcription of IL-6 and IL-1β in a dose-dependent manner at 25, 50 and 100 μM. Moreover, the anti-inflammatory-based network pharmacology and molecular docking analyses revealed potential target proteins of 11, 12, 18 and 35.

Six undescribed guaianolide-type sesquiterpenes from the aerial parts of Daphne penicillata

Six undescribed guaianolide sesquiterpenes (1-6) were obtained from the aerial parts of Daphne penicillata. Their structures and absolute configuration were elucidated by HRESIMS, NMR analyses, ECD calculations and single-crystal X-ray diffraction analysis. Structurally, all compounds possess the typical 5,7-fused system of 8,12-guaianolides and this guaianolide-type was first reported to be isolated from Daphne penicillata. All compounds (1-6) were evaluated for anti-inflammatory and cytotoxic activity. Among them, compounds 1 and 5 showed moderate inhibitory effects on LPS-induced NO production in BV2 cells and 4 displayed potential inhibition against Hep3B cells with an IC50 value of 7.33 μM.

Sesquiterpene lactones from Artemisia verlotorum and their anti-inflammatory activities

Seven new sesquiterpenoids (1-7) and 19 known analogues were isolated from the whole plant of Artemisia verlotorum. Their structures were determined by extensive analysis of 1D and 2D NMR and HRESIMS data, electronic circular dichroism (ECD) spectra, density functional theory (DFT) NMR calculations, and time dependent density functional theory (TDDFT) ECD calculations. The absolute configurations of 1, 3, 5 and 7 were confirmed by single crystal X-ray diffraction experiments. Compounds 1 and 2 possess a rarely reported 5/8-bicyclic skeleton, while both compounds 3 and 4 were uncommon iphionane-type sesquiterpenoids. Eudesmane sesquiterpenoids (5-17) reported in this study are all 7,8-cis-lactones, of which, compound 7 represents the first eudesmane sesquiterpene with an oxygen bridge connecting C-5 and C-11. All the compounds were tested in vitro for their anti-inflammatory activities in LPS-stimulated RAW 264.7 murine macrophages. Compound 18 showed a potent inhibitory effect on NO production, with IC50 values of 3.08 ± 0.61 μM.

Chlorine-containing guaianolide sesquiterpenoids from Achillea millefolium L. with inhibitory effects against LPS-induced NO release in BV-2 microglial cells

Chlorine-containing guaianolide sesquiterpenoids are rare natural compounds that are mainly derived from plants of the Asteraceae family. Our previous investigations on the whole plant of Achillea millefolium L. resulted in the discovery of two chlorine-containing guaianolide sesquiterpenoids. In the present study, a LC‒MS tracking strategy based on the characteristic isotropic peak of atomic chlorine was employed to isolate nine undescribed chlorine-containing guaianolide sesquiterpenoids, Millefolactons B1-B9, from A. millefolium L.. The structures of these compounds were elucidated by spectroscopic data analysis, and the corresponding absolute configurations were determined by single-crystal X-ray crystallography and ECD data analysis. Millefolactons B2-B7 displayed inhibitory activities against LPS-induced NO release in BV-2 microglial cells.

Artemleucolides A-L, eudesmane-type sesquiterpenoids from Artemisia leucophylla and their antihepatoma cytotoxicity

Twelve undescribed and 13 known eudesmane-type sesquiterpenoids were obtained from Artemisia leucophylla, and structurally elucidated based on comprehensive analyses of spectral data, including HRESIMS, IR, 1D and 2D NMR, and ECD calculation. The absolute configuration of compound 1 was determined by a single X-ray single crystal diffraction. Chemically, compounds 1-5 featured unprecedented 1,2-seco-1-nor-eudesmane-type skeleton with a cis-fused 6/5 bicyclic system. Antihepatoma evaluation against three human hepatoma cell lines (HepG2, Huh7, and SK-Hep-1) for all compounds demonstrated that compound 7 displayed the most active cytotoxicity with IC₅₀ values of 35.1, 35.0, and 32.7 μΜ.

Anti-inflammatory sesquiterpenoid dimers from Artemisia atrovirens

Eight new sesquiterpenoid dimers, artatrovirenolides A-H (1-8), along with three known analogues (9-11), were isolated from Artemisia atrovirens by using the LC-MS guided isolation. Compound 1 was a compound dimerized from a guaianolide and a 1,10-seco-guaianolide unit while others were from two guaianolide units. Their structures were established by comprehensive analysis of spectroscopic data, and their absolute configurations were determined by the aid of time-dependent density functional theory electronic circular dichroism (TDDFT ECD) calculation. Compound 8 showed anti-inflammatory effect in LPS-stimulated BV-2 microglial cells at 1 μM, while compounds 1, 2, 5, and 6 inhibited microglial inflammation at 10 μM.