[A new sesquiterpenoid from Lindera aggregata].

The chemical composition of the aqueous part of the extract from Lindera aggregata was studied, which was separated and purified by the macroporous resin column chromatography, MCI medium pressure column chromatography, semi-preparative high-performance liquid phase and other methods. The structures of the compounds were identified according to physical and chemical properties and spectroscopic data. Thirteen compounds were isolated and identified from the aqueous extracts, which were identified as(1S,3R,5R,6R,8S,10S)-epi-lindenanolide H(1), tachioside(2), lindenanolide H(3), leonuriside A(4), 3,4-dihydroxyphenyl ethyl ß-D-glucopyranoside(5), 3,4,5-trimethoxyphenol-1-O-6-α-L-rhamnose-(1→6)-O-ß-D-glucoside(6), 5-hydroxymethylfurfural(7),(+)-lyoniresin-4-yl-ß-D-glucopyranoside(8), lyoniside(9), norboldine(10), norisopordine(11), boldine(12), reticuline(13). Among them, compound 1 was a new one, and compounds 2, 5, 6, 8, 9 were obtained from L. aggregata for the first time. The inflammatory model was induced by lipopolysaccharide(LPS) in the RAW264.7 cells. The results showed that compounds 1, 8, 10 and 12 had significant anti-inflammatory activity.

Three rare anti-inflammatory sesquiterpene lactones from Magnolia grandiflora.

Four new sesquiterpene lactones (SLs) (1-4), along with a biosynthetically related SL (5), have been isolated from the leaves of Magnolia grandiflora. Magrandate A (1) is notable as the first C18 homogemarane type SL, featuring a unique 1,7-dioxaspiro[4.4]nonan-6-one core. Compounds 2 and 3, representing the first instances of chlorine-substituted gemarane-type SL analogs in natural products, were also identified. The structures of these isolates were elucidated through a combination of spectroscopic data analysis, electronic circular dichroism calculations, and X-ray single-crystal diffraction analysis. All isolates demonstrated anti-inflammatory activity in lipopolysaccharide-stimulated RAW264.7 cells. Notably, 3-5 showed a significant inhibitory effect on nitric oxide production, with IC50 values ranging from 0.79 to 4.73 µmol·L-1. Additionally, 4 and 5 exhibited moderate cytotoxic activities against three cancer cell lines, with IC50 values between 3.09 and 11.23 µmol·L-1.

Phytochemistry and Pharmacology of Sesquiterpenoids from Atractylodes DC. Genus Rhizomes.

The rhizomes of the genus Atractylodes DC. consist of various bioactive components, including sesquiterpenes, which have attracted a great deal of research interest in recent years. In the present study, we reviewed the previously published literatures prior to November 2023 on the chemical structures, biosynthetic pathways, and pharmacological activities of the sesquiterpenoids from this genus via online databases such as Web of Science, Google Scholar, and ScienceDirect. Phytochemical studies have led to the identification of more than 160 sesquiterpenes, notably eudesmane-type sesquiterpenes. Many pharmacological activities have been demonstrated, particularly anticancer, anti-inflammatory, and antibacterial and antiviral activities. This review presents updated, comprehensive and categorized information on the phytochemistry and pharmacology of sesquiterpenes in Atractylodes DC., with the aim of offering guidance for the future exploitation and utilization of active ingredients in this genus.

Sesquiterpene Acids and Lactones from Inula Confertiflora with their Antibacterial Activities.

The phytochemical investigation of the leaves of Inula confertiflora, a medicinal plant endemic to Ethiopia, led to the isolation of 15 terpenoids; 1ß-hydroxy-α-costic acid (1), 3α-hydroxycostic acid (2), isotelekin (3), asperilin (4), carabrone (5), carpesioline (6), graveolide (7), inuviscolide (8), 8-epi-inuviscolide (9), 1ß,4ß-dihydroxy-5α(H)-guaia-10(14),11(13)-dien-8α,12-olide (10), isoinuviscolide (11), 4ß,10ß-dihydroxy-5α(H)-1,11(13)-guaidien-8α,12-olide (12), 4ß,10ß-dihydroxy-1ß(H)-5α(H)-guai-11(13)-en-8α,12-olide (13), 4ß,10α-dihydroxy-1ß(H)-5α(H)-guai-11(13)-en-8α,12-olide (14), 4ß,10α-dihydroxy-1α(H)-5α(H)-guai-11(13)-en-8α,12-olide (15). Herein, structural elucidation and full NMR data for compound 1 are presented for the first time. The structures were elucidated using NMR, HRESIMS, and by comparison with literature data. The relative configurations were defined by NOESY correlations and single-crystal X-ray crystallography. Herein, crystallography data of 6 and 7 were reported for the first time. The antibacterial efficacy of some of the isolated compounds was evaluated against two commonly dispersed environmental strains of Escherichia coli and Staphylococcus aureus. Compounds 1, 3, 6, 7, and 8 exhibited moderate antibacterial activities against the tested organisms. The chemotaxonomic significance of compounds is discussed.

The specialized sesquiterpenoids produced by the genus Elephantopus L.: Chemistry, biological activities and structure-activity relationship exploration.

The genus Elephantopus L. is a valuable resource rich in sesquiterpenoids with structural diversity and various bioactivities, showing great potential for applications in medicinal field and biological industry. Up to now, over 129 sesquiterpenoids have been isolated and identified from this plant genus, including 114 germacrane-type, 7 guaianolide-type, 5 eudesmane-type, 1 elemanolide-type, and 2 bis-sesquiterpenoids. These sesquiterpenoids were reported to show a diverse range of pharmacological properties, including cytotoxic, anti-tumor, anti-inflammatory, antimicrobial, and antiprotozoal. Consequently, some of them were identified as active scaffolds in the design and development of drugs. Considering that there is currently no overview available that covers the sesquiterpenoids and their biological activities in the Elephantopus genus, this article aims to comprehensively review the chemical structures, biosynthetic pathways, pharmacological properties, and structure-activity relationship of sesquiterpenoids found in the Elephantopus genus, which will establish a theoretical framework that can guide further research and exploration of sesquiterpenoids from Elephantopus plants as promising therapeutic agents.

Guaianolide sesquiterpenes and their activity from Artemisia mongolica.

Seven undescribed sesquiterpenes, including three dimeric guaianolide sesquiterpenes artemongolides G-I (1-3) and four sesquiterpene lactones artemanomalide D-G (16-19), along with seventeen known compounds isoabsinthin (4), absinthin (5), 11-eptabsinthin (6), 11, 11'-bis-epiabsinthin (7), 10', 11'- epiabsinthin (8), anabsinthin (9), isoanabsinthin (10), absinthin D (11), anabsin (12), caruifolin D (13), gnapholide (14), caruifolin C (15), 1ß(R),10ß(S)-dihydroxy-3-oxo-11ß (S)H-4,11(13)-guaien-6α(S),12-olide (20), 1α,6α,8α-trihydroxy-5α,7ßH-guaia-3,10(14),11(13)-trien-12-oic acid (21), 1α,6α,8α-trihydroxy-5α,7ßH-guaia-3,9,11(13)-trien-12-oic acid (22), argyinolide J (23), artabsinolide A (24) were isolated from the plant Artemisia mongolica. The structures were determined by interpreting NMR, HRESIMS and ECD data. The X-ray crystal structure of 4, 7 and 8 were reported for the first time. In the anti-vitiligo activity test, compounds 2, 7, 12, 23 and 24 demonstrated activity in promoting melanogenesis at a concentration of 50 µM in B16 cells, with 8-methoxypsoralan (8-MOP) as a positive control. Further research on the mechanism revealed that artemongolides H (2) enhance the expression of MITF and TRPs by upregulating p-Akt and p-GSK-3ß, leading to an increase in ß-catenin content in the cell cytoplasm. Subsequently, ß-catenin translocates into the nucleus, resulting in melanogenesis. The results supported the regulation of melanogenesis by artemongolide H (2) through the Akt/GSK3ß/ß-catenin signaling pathway. The anti-inflammatory results demonstrated that compounds 4, 5, 6, 9 and 14 can inhibit the upregulation of IL-6 mRNA and CCL2 mRNA expression. Compound 12 specifically inhibited the upregulation of IL-6 mRNA expression. These compounds exhibited significant anti-inflammatory activities. The activity results revealed that these sesquiterpene compounds have the potential to become lead compounds for the treatment of vitiligo and inflammatory diseases.

Dauferulins A-L, daucane-type sesquiterpenes from the roots of Ferula communis: Their structures and biological activities.

Phytochemical study on the roots of a medicinal plant Ferula communis L. (Apiaceae) resulted in the isolation of 20 sesquiterpenes including 12 previously undescribed compounds, dauferulins A-L (1-12). The detailed spectroscopic analysis revealed 1-12 to be daucane-type sesquiterpenes with a p-methoxybenzoyloxy group at C-6. The absolute configurations of 1-12 were deduced by analysis of the ECD spectra. Dauferulins A-L (1-12), known sesquiterpenes (13-20), and analogues (14a-14l) derived from 6-O-p-methoxybenzoyl-10α-angeloyloxy-jeaschkeanadiol (14) were evaluated for their effects on AMPK phosphorylation in human hepatoma HepG2 cells as well as inhibitory activities against erastin-induced ferroptosis on human hepatoma Hep3B cells and IL-1ß production from LPS-treated murine microglial cells.

Plant Extracts and Phytochemicals from the Asteraceae Family with Antiviral Properties.

Asteraceae (Compositae), commonly known as the sunflower family, is one of the largest plant families in the world and includes several species with pharmacological properties. In the search for new antiviral candidates, an in vitro screening against dengue virus (DENV) was performed on a series of dichloromethane and methanolic extracts prepared from six Asteraceae species, including Acmella bellidioides, Campuloclinium macrocephalum, Grindelia pulchella, Grindelia chiloensis, Helenium radiatum, and Viguiera tuberosa, along with pure phytochemicals isolated from Asteraceae: mikanolide (1), eupatoriopicrin (2), eupahakonenin B (3), minimolide (4), estafietin (5), 2-oxo-8-deoxyligustrin (6), santhemoidin C (7), euparin (8), jaceidin (9), nepetin (10), jaceosidin (11), eryodictiol (12), eupatorin (13), and 5-demethylsinensetin (14). Results showed that the dichloromethane extracts of C. macrocephalum and H. radiatum and the methanolic extracts prepared from C. macrocephalum and G. pulchella were highly active and selective against DENV-2, affording EC50 values of 0.11, 0.15, 1.80, and 3.85 µg/mL, respectively, and SIs of 171.0, 18.8, >17.36, and 64.9, respectively. From the pool of phytochemicals tested, compounds 6, 7, and 8 stand out as the most active (EC50 = 3.7, 3.1, and 6.8 µM, respectively; SI = 5.9, 6.7, and >73.4, respectively). These results demonstrate that Asteraceae species and their chemical constituents represent valuable sources of new antiviral molecules.

Discovery of sesquiterpene from Youngia japonica with antitumor effect.

Fourteen sesquiterpenes, including one undescribed sesquiterpene lactone, were isolated from Youngia japonica, and their structures were identified by NMR, HRESIMS, ECD and calculated ECD. Cytotoxic activities of all isolates against A549, HeLa, and 4 T1 cell lines were detected by CCK8 assay. Among them, 2 showed obvious cytotoxic activity against A549 cells. Subsequently, the production of ROS, and apoptosis of A549 cells treated with 2 were evaluated. The result showed that 2 distinctly increased the ROS level, and induced the apoptosis of A549 cells. Further anticancer mechanism studies showed that 2 increased the expression of cleaved caspase 3. Taken together, our results demonstrated that 2 might become potential leading compounds for the treatment of lung cancer.

Two new 2-(2-phenylethyl)chromone derivatives and two sesquiterpenes from agarwood of Aquilaria sinensis with anti-inflammatory activity.

Two new 2-(2-phenylethyl)chromones (1-2), two new sesquiterpenes (12-13), and twelve known compounds (3-11, 14-16) were isolated from agarwood of Aquilaria sinensis. These structures were confirmed by HRESIMS, 1D and 2D NMR spectra. The absolute configurations of two new sesquiterpenes were determined by comparing the experimental and calculated ECD spectra. Among them, 7,8-dihydroxy-2-[2-(4'-methoxyphenyl)ethyl]chromone (2) was the first time found that the hydroxyl groups at both C-7/C-8 in agarwood. And Aseudesm B (13), the aldehyded methyl group at C-5 of eucalyptane sesquiterpenes was first discovered in natural products. In the bioassays, all compounds were evaluated for their inhibitory activity against lipopolysaccharide-activated nitric oxide (NO) production in RAW264.7 cells. Compounds 2-5, 7, 9-10, and 13-14 revealed notable inhibitory effects against NO production with IC50 values ranging from 4.0 to 13.0 µM.

Eudesmane sesquiterpenoids with inhibitory effects on NO production from Artemisia princeps.

Five undescribed eudesmane methyl esters (1-5), three undescribed eudesmane-12,6-olides (6-8), and 21 known analogues (9-29) were isolated from the aerial part of Artemisia princeps Pamp. Their structures were established by detailed analysis of the NMR and HRESIMS data. The absolute configurations of 1-8 were determined based on single-crystal X-ray diffraction analysis and ECD calculations. Moreover, the inhibitory effects on LPS-induced NO production in BV-2 microglial cells of all the isolated compounds were assessed. Except for compounds 2, 4, 10, and 11, the others showed significant inhibitory activities, with IC50 values of 0.73-18.66 µM, wherein the potential structure-activity relationship was also discussed.

ß-Elemene in zedoary turmeric oil injection induces dyspnea by binding to hemoglobin and upregulating HIF-1α.

ETHNOPHARMACOLOGICAL RELEVANCE: Zedoary turmeric oil injection (ZTOI) extracted from the rhizome extract of Curcuma phaeocaulis Valeton, Curcuma wenyujin Y. H. Chen et C. Ling or Curcuma kwangsiensis S. G. Lee et C. F. Liang, is widely used for the treatment of virus-induced upper respiratory tract infections, peptic ulcers, viral pneumonia, etc. However, it has attracted widespread attention because it often causes adverse drug reactions (ADRs), including dyspnea. However, little is known about the mechanism underlying dyspnea caused by ZTOI, which limits its clinical application. AIM OF THE STUDY: To investigate the major pathophysiologic signatures and underlying mechanism of ZTOI-related dyspnea. METHODS: Respiratory function detection was used to explore the pathophysiologic signature of dyspnea induced by ZTOI. UV-vis absorption spectroscopy and isothermal titration calorimetry were applied to test the interaction between ZTOI and hemoglobin (Hb). GC‒MS was used to identify the main components in ZTOI. Molecular docking, surface plasmon resonance, and circular dichroism spectroscopy were employed to test the reaction between ß-elemene and Hb. Western blot was performed to investigate the effect of ß-elemene on the hypoxia signaling pathway. RESULTS: The results showed that ZTOI-induced dyspnea was related to a decreased oxygen carrying capacity of Hb. The molecular interaction between ZTOI and Hb was proven. Notably, ß-elemene in ZTOI exhibited high binding affinity to Hb and altered its secondary structure. Furthermore, it was found that ß-elemene downregulated the expression of prolyl hydroxylase-domain protein 2 and upregulated the expression of hypoxia-inducible factor-1α. CONCLUSIONS: Our study is valuable for better understanding the pathophysiological characteristics and underlying mechanism of ZTOI to ensure its safe clinical application. We also provided a strategy to elucidate the underlying mechanism based on inspiration from clinical ADR phenotypes for investigating other medical products with ADRs in the clinic.

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.

Sesquiterpenes from Chloranthus holostegius with anti-inflammatory activities.

The phytoconstituents of the whole plants of Chloranthus holostegius were investigated. As a result, thirteen undescribed sesquiterpenes (chloranholosins A-M, 1-13), including ten acorane-type sesquiterpenes (1-10), one germacrene-type sesquiterpene (11), and two lindenane-type sesquiterpenes (12-13), together with fifteen known sesquiterpenes were isolated. Their structures and absolute configurations were elucidated by a comprehensive method including the spectroscopic data, electronic circular dichroism (ECD) calculations, and single-crystal X-ray diffraction. Chloranholosin L (12) was elucidated as a rare lindenane-type sesquiterpene featuring 14α-Me and 5-OH moieties. And chloranholosin M (13) was the first lindenane-type sesquiterpene possessing ß-cyclopropane, 14α-Me, and 5ß-H configuration from the family Chloranthaceae. Furthermore, twelve new isolates and some known sesquiterpenes were evaluated for their inhibitory activity against LPS-induced nitric oxide (NO) production in RAW 264.7 macrophage cells. Among them, compounds 12, 16, and 23 showed comparable inhibitory activity to that of the positive control, with IC50 values of 47.9, 41.5, and 48.3 µM, respectively.

Phytochemical study of Seriphidium khorassanicum (syn. Artemisia khorassanica) aerial parts: sesquiterpene lactones with anti-protozoal activity.

Two new eudesmane-type sesquiterpene lactones, 1ß,3α,8α-trihydroxy-11ß,13-dihydroeudesma-4(15)-en-12,6α-olide (1) and 1ß,4α,8α-trihydroxy-11ß,13-dihydroeudesma-12,6α-olide (2), and an unprecedented elemane-type sesquiterpene lactone, 1ß,2ß,8α-trihydroxy-11ß,13-dihydroelema-12,6α-olide (3) along with a known eudesmanolide artapshin (4) were isolated from Seriphidium khorassanicum. Structures were elucidated by NMR, HR-ESI-MS, and ECD spectral data analysis. The anti-protozoal activity was evaluated against Leishmania major promastigotes and amastigote-infected macrophages. They showed dose- and time-dependent activity against L. major amastigotes with IC50 values in the range of 4.9 to 25.3 µM being favourably far below their toxicity against normal murine macrophages with CC50 values ranging from 432.5 to 620.7 µM after 48 h of treatment. Compound 3 exhibited the strongest activity and the highest selectivity index (SI) with IC50 of 4.9 ± 0.6 µM and SI of 88.2 comparable with the standard drug, meglumine antimoniate (Glucantime), with IC50 and SI values of 15.5 ± 2.1 µM and 40.0, respectively.

Highly oxygenated guaiane-type sesquiterpene lactones from Artemisia sacrorum and their antihepatoma activity.

The ethanol and EtOAc extracts of Artemisia sacrorum exhibited inhibitory effect against HepG2, Huh7, and SK-Hep-1 cell lines with inhibitory ratios of 65.5%, 28.1%, 84.6%, and 93.5%, 82.0%, 89.0% at 200 µg/mL. Twenty-three undescribed guaiane-type sesquiterpene lactones, artemisacrolides A‒W, were isolated from A. sacrorum under the guidance of antihepatoma activity. Their structures were elucidated by spectral data (HRESIMS, IR, UV, 1D and 2D NMR), ECD calculations, and a single-crystal X-ray diffraction. Artemisacrolides A‒U were guaiane-type sesquiterpene lactones possessing α-methylene-γ-lactone and containing acetoxyl groups at C-8, and artemisacrolides V and W represented the first report from the genus Artemisia with a 1,10-rearranged guaiane-type sesquiterpene lactone. Antihepatoma assay suggested that artemisacrolides A‒U demonstrated better inhibitory activity in Huh7 and SK-Hep-1 cells than those of HepG2 cells. Among them, nine compounds exhibited significant inhibitory activity against Huh7 cells with IC50 values of 8.2-14.3 µM, superior or equal to that of sorafenib; seven compounds demonstrated obvious activity against SK-Hep-1 cells with IC50 values of 13.5-19.2 µM, which were equivalent to that of sorafenib. Artemisacrolides B and E were the most active ones in three human hepatoma cell lines with IC50 values of 21.9, 8.2, 16.9 and 22.6, 9.0, 17.3 µM.

[Chemical constituents of Lindera aggregata and their bioactivities: a review].

The medicinal Lindera aggregata(Lindera, Lauraceae) boasts abundant resources, which is widely used in clinical settings. It has been found that the main chemical constituents of this medicinal species are sesquiterpenoids, alkaloids, sesquiterpenoid dimers, flavonoids, and phenolic acids. Some unreported novel structures, including lindenane-type sesquiterpene dimers and trimers, have been discovered from L. aggregata in recent years. The extracts and active components of L. aggregata have anti-tumor, anti-inflammatory, antalgic, liver-protecting, antioxidant, lipid-lowering, and glucose-lowering activities, and their mechanisms of action have been comprehensively investigated. This study summarizes the research on the chemical constituents and bioactivities of L. aggregata over the past decade, which is expected to serve as a reference for the future research and utilization of L. aggregata.

[A new allo-aromadendrane sesquiterpene from Dendrobium nobile].

To study the chemical constituents in the non-alkaloid part of stems of Dendrobium nobile. The macroporous adsorption resin, MCI, silica gel, RP-C_(18), and Sephadex LH-20 gel, preparative thin layer chromatography, and preparative high-performance liquid chromatography(HPLC) were used to isolate and purify the compounds. The structures of the compound were determined according to the spectra data, physicochemical properties, and relevant references. A total of 8 compounds were isolated from D. nobile, which were soltorvum F(1), p-hydroxyphenylpropionic acid(2), vanillic acid(3), p-hydroxybenzoic acid(4), N-trans-cinnamic acid acyl-p-hydroxybenzene ethylamine(5),(+)-(1R,2S,3R,4S,5R,6S,9R)-2,11,12-trihydroxypicrotoxane-3(15)-lactone(6), dendronobilin H(7), soltorvum E(8). Compound 1 was a novel compound, named as soltorvum F. Compound 8 was isolated from Dendrobium species for the first time.

Artemdubinoids A-N: novel sesquiterpenoids with antihepatoma cytotoxicity from Artemisia dubia.

In pursuit of effective agents for hepatocellular carcinoma derived from the Artemisia species, this study built upon initial findings that an ethanol (EtOH) extract and ethyl acetate (EtOAc) fraction of the aerial parts of Artemisia dubia Wall. ex Bess. exhibited cytotoxicity against HepG2 cells with inhibitory rates of 57.1% and 84.2% (100 µg·mL-1), respectively. Guided by bioactivity, fourteen previously unidentified sesquiterpenes, artemdubinoids A-N (1-14), were isolated from the EtOAc fraction. Their structural elucidation was achieved through comprehensive spectroscopic analyses and corroborated by the comparison between the experimental and calculated ECD spectra. Single crystal X-ray diffraction provided definitive structure confirmation for artemdubinoids A, D, F, and H. Artemdubinoids A and B (1-2) represented unique sesquiterpenes featuring a 6/5-fused bicyclic carbon scaffold, and their putative biosynthetic pathways were discussed; artemdubinoid C (3) was a novel guaianolide derivative that might be formed by the [4 + 2] Diels-Alder reaction; artemdubinoids D and E (4-5) were rare 1,10-seco-guaianolides; artemdubinoids F-K (6-11) were chlorine-containing guaianolides. Eleven compounds exhibited cytotoxicity against three human hepatoma cell lines (HepG2, Huh7, and SK-Hep-1) with half-maximal inhibitory concentration (IC50) values spanning 7.5-82.5 µmol·L-1. Artemdubinoid M (13) exhibited the most active cytotoxicity with IC50 values of 14.5, 7.5 and 8.9 µmol·L-1 against the HepG2, Huh7, and SK-Hep-1 cell lines, respectively, which were equivalent to the positive control, sorafenib.

Three rare nor-sesquiterpenoids with lipid-lowering activity from Belamcanda chinensis.

Belchinoids A-C (1-3), three unusual nor-sesquiterpenoids, along with a new isoflavone (4), were isolated from the roots of Belamcanda chinensis, a traditional Chinese medicine. To the best of our knowledge, compound 1 represents the first C13 nor-sesquiterpenoid with a five membered carbon ring. Compounds 2 and 3 are rare C14 chained nor-sesquiterpenoids. Their structures were fully characterized based on extensive spectroscopic data and quantum chemistry calculation. Three compounds (1, 2, and 4) showed potent inhibitory effects on lipid accumulation in an oleic acid-treated HepG2 cell model. In particular, compound 2 exhibited the most potent inhibitory effect on triglyceride accumulation at a low concentration of 2.5 µM, better than the positive control atorvastatin. The plausible biosynthetic pathway of the three nor-sesquiterpenoids (1-3) is also proposed.