Butyrolactone and sesquiterpene derivatives as inhibitors of iNOS from the roots of Lindera glauca

Linderangolides A-D, four new butanolides from the roots of Lindera angustifolia and their cytotoxic activity

Four undescribed butanolides, linderangolides A-D (1-4), along with four known congeners, lincomolide A (5), (-)-epilitsenolide C2 (6), (-)-epilitsenolide C1 (7) and litseakolide H (8), were isolated from the roots of Lindera angustifolia. The planar structures of 1-4 were elucidated based on extensive spectroscopic analyses, the relative and absolute configurations of 1-4 were determined by the NOESY spectra and the comparison of calculated and experimental ECD. The cytotoxic activities of all isolated compounds were tested, 4 showed inhibitory activity against SGC-7 cells with IC50 value of 6.62 μM.

Highly oxidized guaiane 12(8),15(6)-dilactones with neuroprotective activities from the roots of Lindera aggregata (Sims) Kosterm

In our search for neuroprotective agents, six previously undescribed highly oxidized guaiane sesquiterpenes, linderaggrols A-F (1-6), together with three known sesquiterpenes, were isolated from the roots of Lindera aggregata (Sims) Kosterm. Their structures including absolute configurations were established by a combination of NMR spectroscopic techniques and single crystal X-ray diffraction experiments. Compounds 1-6 represented the first instances of guaiane 12(8),15(6)-dilactones. Additionally, compound 6 possessed a rare 1,8-O-bridge. Neuroprotective effects against erastin-induced ferroptosis on HT-22 cells showed that some compounds demonstrated neuroprotective effects at 20.0 μM.

Sesquiterpenoids from the roots of Lindera glauca and their cytotoxicity activities

The chemical investigation of the roots of Lindera glauca guided the isolation and identification of 3 new sesquiterpenoids, namely glaucatotones J-L (1-3), and one known congener, (1β,5β)-1-hydroxyguaia-4(15),11(13)-dieno-12,5-lactone (4). The structures of new compounds were established based on comprehensive spectrographic methods, mainly including 1D & 2D NMR and HRESIMS analyses, and the absolute configurations were further confirmed by the comparison of experimental and calculated electronic circular dichroism. The cytotoxicity activities of isolates were evaluated, and the results showed that they have moderate cytotoxic activities.

Cytotoxic indole diterpenoids and rare pyridoxatin atropisomers from the endophytic fungus Tolypocladium sp. SHJJ1

Phytochemical investigation on the extract of endophytic fungus Tolypocladium sp. SHJJ1 resulted in the identification of a pair of previously undescribed pyridoxatin atropisomers [1 (M/P)] and three new indole diterpenoids (3-5), together with a pair of known pyridoxatin atropisomers [2 (M/P)] and ten known indole diterpenoids (6-15). Their structures, including their absolute configurations were elucidated by extensive spectroscopic analysis, quantum chemical calculations, and X-ray diffraction. Among the undescribed natural products, [1 (M/P)] that two rapidly interconverting atropisomers are the third example to report in the pyridoxatin atropisomers. Except for compounds 1 (M/P) and 2 (M/P), all other compounds were tested for their cytotoxicity using HepG2, A549, and MCF-7 human cell lines. Compound 9 displayed moderate cytotoxicity against the HepG2, A549, and MCF-7 cell lines with IC50 values of 32.39 ± 1.48 μM, 26.06 ± 1.14 μM, and 31.44 ± 1.94 μM, respectively, which was similar to the positive drug cisplatin (with IC50 values of 32.55 ± 1.76 μM, 18.40 ± 1.43 μM, and 27.31 ± 1.22 μM, respectively).

Glaucatotones A-I: Guaiane-type sesquiterpenoids from the roots of Lindera glauca with anti-inflammatory activity

Glaucatotones A - I, nine new guaiane-type sesquiterpenoids, along with two reported compounds, namely (1β,5β)-1-hydroxyguaia-4(15),11(13)-dieno-12,5-lactone (10) and pseudoguaianelactone C (11), were isolated from the roots of Lindera glauca. The structures and absolute configurations of these compounds were elucidated by extensive spectroscopic analyses, single-crystal X-ray diffraction, and comparison of experimental and calculated electronic circular dichroism (ECD) data. Structurally, glaucatotone A (1) is characterized as a dihomosesquiterpenoid with an unprecedented 5/5/7/6 ring system. A pair of enantiomers, (±)-glaucatotone B (2a/2b), represent the first rearranged norsesquiterpenoid with a (cyclopentylmethyl)cyclohexane skeleton. 3 is defined as a dinorsesquiterpenoid possessing a 5/7/5 ring system. 4-6 are three guaiane-type norsesquiterpenoids. In vitro bioactivity, 2a selectively inhibited Bcap-37 with IC50 value of 5.60 μM, and 9 selectively inhibited Du-145 with IC50 value of 5.52 μM. The anti-inflammatory activity of 1-9 were tested, and of these compounds, 1, 2a, 2b and 7 exhibited potent inhibitory effects.

Seven new meroterpenoids from the fungus Penicillium sclerotiorum GZU-XW03-2

Seven previously undescribed meroterpenoids, peniscmeroterpenoids H - N (1-7), were isolated from the marine-derived fungus Penicillium sclerotiorum GZU-XW03-2. Their structures were established by the spectroscopic methods and the electronic circular dichroism (ECD) calculations. Peniscmeroterpenoid H was a 6/6/6/5/6 rearranged pentacyclic meroterpenoid, featuring a unique 2-oxaspiro[5.5] undeca-4,7-dien-3-one motif. Peniscmeroterpenoids I and J (2 and 3) owned rare 6(D)/5(E) fused rings were not common in natural products, and compound 2 was the second example of a berkeleyone analogue stripped of the methyl ester fragment. Peniscmeroterpenoid K (4) was the first case where the C-24 was oxidized. In bioassay, compound 5 showed moderate anti-inflammatory activity.

Meroterpenoids from the fungus Penicillium sclerotiorum GZU-XW03-2 and their anti-inflammatory activity

Seven undescribed meroterpenoids, peniscmeroterpenoids A - G, were isolated from the marine-derived fungus Penicillium sclerotiorum GZU-XW03-2. Their structures were established by the spectroscopic methods and the electronic circular dichroism (ECD) calculations. Peniscmeroterpenoid A possessed an unprecedented and highly oxidized 6/7/6/5/5 pentacyclic system, featuring a unique tetrahydrofuro [2,3-b]furan-2(3H)-one motif. Peniscmeroterpenoids B - E owned rare 6(D)/5(E) fused rings were not common in natural products, and peniscmeroterpenoid E is the first example of a berkeleyone analogue stripped of the methyl ester fragment. In bioassays, peniscmeroterpenoids A and D inhibited the production of nitric oxide (NO) in RAW264.7 cells with IC₅₀ values of 26.60 ± 1.15 and 8.79 ± 1.22 μM. Moreover, peniscmeroterpenoid D significantly suppressed the production of pro-inflammatory mediators (COX-2, IL-1β and IL-6) and the protein expression of the enzyme iNOS.

Butyrolactone I attenuates inflammation in murine NASH by inhibiting the NF-κB signaling pathway

Nonalcoholic steatohepatitis (NASH) is the development of non-alcoholic fatty liver disease (NAFLD) and a key element in the exacerbation of NAFLD. Since there are currently no drugs approved by the U.S. Food and Drug Administration to treat this disease, the search for treatments that can be translated into clinical use is urgent. Butyrolactone I (BLI), isolated from Aspergillus terreus, is an active compound possessing multiple biological activities. However, the effects of BLI on NASH have never been reported. In this study, RAW264.7 cells stimulated by lipopolysaccharide (LPS) were applied to study the anti-inflammatory effect and the underlying mechanisms of BLI in vitro. Following this, mice fed with high-fat and -fructose diet (HFFD) were used to explore the alleviation of NASH by BLIin vivo. We found that BLI attenuated inflammation in LPS-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway and downregulating the expression of iNOS and COX-2. Moreover, results of experiments in vivo demonstrated that BLI reduced serum transaminase levels, decreased hepatic fat accumulation, inhibited inflammation, suppressed oxidative stress, and ameliorated liver fibrosis. For the first time, we investigated the role of BLI in the treatment of murine NASH. We found that BLI alleviates NASH partly by inhibiting the NF-κB pathway of signaling. Given its hepatoprotective effects and non-toxic properties, BLI can be a novel and effective drug for NASH patients.

Linderasesterterpenoids A and B: Two 7-Cyclohexyldecahydroazulene Carbon Skeleton Sesterterpenoids Isolated from the Root of Lindera glauca

Two novel sesterterpenoids linderasesterterpenoids A (1) and B (2) with an unprecedented 7-cyclohexyldecahydroazulene carbon skeleton isolated from the root of Lindera glauca. Their structures were elucidated by X-ray diffraction, quantum chemical calculations, and spectroscopic methods. The biogenetic pathway for 1 and 2 is proposed. In the bioassay, linderasesterterpenoids A and B showed good inhibitory activities against LPS-induced NO production in RAW 264.7 cells compared to a positive control.

13,13a-seco-protoberberines from the tubers of Corydalis yanhusuo and their anti-inflammatory activity

Six undescribed protoberberine derivatives including two pairs of enantiomers, named yanhusanines G-L, along with fifteen reported protoberberine alkaloids, were isolated from the tubers of Corydalis yanhusuo. Among them, yanhusanines H-L feature a unique 13,13a-seco skeleton which is rare in nature. Their structural elucidations were achieved by extensive spectroscopic analysis and quantum chemistry calculations. A biogenetic route for yanhusanines H-L was proposed. Bioassay results showed that yanhusanine J exhibited potent inhibitory effect against the nitric oxide (NO) production in lipopolysaccharide (LPS) induced RAW 264.7 cells (IC₅₀ = 2.25 ± 1.32 μM). Western blot analysis demonstrated that yanhusanine J exerted its anti-inflammatory effect via suppressing the nuclear factor kappa B (NF-κB) pathway, together with the decrease of the inflammatory factors TNF-α, IL-6 and IL-1β. Furthermore, molecular simulation docking indicated that yanhusanine J had strong interaction with the active site of the inducible nitric oxide synthase (iNOS) protein.