Two new oleanane triterpenes from Maytenus hookeri.

Two new triterpenes mayteneri A (1), mayteneri B (2), and seven known compounds (3-9) were isolated from stems of Maytenus hookeri Loes. The chemical structures of compounds 1 and 2 were established by 1D, 2D NMR, HRESIMS analysis, and calculating electronic circular dichroism (ECD). The structures of known compounds 3-9 were determined by comparison of their spectral with those reported. Compounds 4-7 showed significant inhibitory activity for NLRP3 inflammasome, with the IC50 values of 2.36-3.44 µM.

New meroterpenoids and polyketides from the endophytic fungus Paraphaeosphaeria sp. C-XB-J-1 and their anti-inflammatory and SARS-CoV-2 Mpro inhibitory activities.

Seven new meroterpenoids, paraphaeones A-G (1-7), and two new polyketides, paraphaeones H-I (8-9), along with eight known compounds (10-17), were isolated from the endophytic fungus Paraphaeosphaeria sp. C-XB-J-1. The structures of 1-9 were identified through the analysis of 1H, 13C, and 2D NMR spectra, assisted by HR-ESI-MS data. Compounds 1 and 7 exhibited a dose-dependent decrease in lactate dehydrogenase levels, with IC50 values of 1.78 µM and 1.54 µM, respectively. Moreover, they inhibited the secretion of IL-1ß and CASP-1, resulting in a reduction in the activity levels of NLRP3 inflammasomes. Fluorescence microscopy results indicated that compound 7 concentration-dependently attenuated cell pyroptosis. Additionally, compounds 4 and 7 showed potential inhibitory effects on the severe acute respiratory syndrome coronavirus-2 main protease (SARS-CoV-2 Mpro), with IC50 values of 10.8 ± 0.9 µM and 12.9 ± 0.7 µM, respectively.

Asiaticasics A-O, structurally intriguing coumarins from Toddalia asiatica with potential inflammatory inhibitory activity.

Ethyl acetate fraction of Toddalia asiatica was fractionated to yield fifteen previously undescribed prenylated coumarins, asiaticasics A-O (1-15) along with nine (16-24) known derivatives. The structures of these undescribed coumarins were established by spectroscopic analysis and reference data. Biological activity evaluation showed that compound 3 with the IC50 value of 2.830 µM and compound 12 with the IC50 value of 0.682 µM owned anti-inflammatory activity by detecting the rate of lactate dehydrogenase release in pyroptosis J774A.1 cells. The results showed that the expression of Caspase-1 and IL-1ß was decreased in a dose-dependent manner in the compound 12 treatment group, suggesting that compound 12 may reduce pyroptosis by inhibiting NLRP3 inflammasome. To further determine that compound 12 treatment can inhibit macrophage pyroptosis, morphological observation was performed and the results were consistent with the bioactivity evaluation.

Euphzycopins A - D, macrocyclic diterpenoids with potential anti-inflammatory activity from Euphorbia Helioscopia.

Four new diterpenoids (1-4) and four known diterpenoids (5-8) were purified from the whole plant of Euphorbia helioscopia L. Compounds 1 and 2 were jathophanes diterpenoids with a 5/12 polycyclic systems, compound 3 was rhamofolane diterpenoid with a 5/10 bicyclic skeleton and compound 4 was a rare class of euphorbia diterpenes featuring an unusual 5/10 fused ring system. Anti-inflammatory activity tests were conducted on the separated compounds, indicating that compound 4 had significant inhibitory effect on NLRP3 inflammasome with an IC50 value of 7.75 µM. Further, the inhibitory effect of 4 was determined using immunofluorescence assays.

Two New Prostaglandin-Like Compounds from Callicarpa arborea Roxb and Their NLRP3 Inflammasome Activation Inhibitory Activity.

Two new prostaglandin-like compounds callicarboric acids A-B (1-2), along with six known compounds (3-8) were isolated from the stems of Callicarpa arborea Roxb. Their structures were determined with the help of modern spectroscopic techniques such as NMR, UV, IR, HR-ESI-MS, ECD, and ORD with the assistance of quantum chemical calculations. Compound 1 exhibited remarkable anti-NLRP3 inflammasome activation potential, demonstrating an IC50 value of 0.74 µM. Additionally, by reducing GSDMD-NT production, inhibiting caspase-1 activation, and suppressing IL-1ß secretion, it effectively mitigated NLRP3 inflammasome-induced pyroptosis in J774A.1 cells. These findings indicate that compound 1 possesses the capability to be a valuable candidate for further research and development as an NLRP3 inflammasome inhibitor.

Three New Clerodane Diterpenoids and Their NLRP3 Inflammasome Activation Inhibitory Activity from Callicarpa arborea Roxb.

Three new compounds callicarpenoids A-C (1-3), were isolated from the stems of Callicarpa arborea Roxb together with fifteen known compounds (4-18). The structures of these compounds were elucidated using advanced spectroscopic techniques, including 1D and 2D NMR, UV, IR, HR-ESI-MS, ECD, ORD, and quantum chemical calculations. Compound 3, a rare rearranged diterpenoid with a fused 5/6-ring system demonstrated strong potential as an inhibitor of the NLRP3 inflammasome activation with an IC50 value of 3.153 µM. It effectively reduced GSDMD-NT production, inhibited caspase-1 activation, and suppressed IL-1ß secretion, thereby mitigating NLRP3 inflammasome-induced pyroptosis in J774A.1 cells. These findings suggest that compound 3 warrants further research and development as a promising NLRP3 inflammasome inhibitor.

Novel chlorin e6-based conjugates of tyrosine kinase inhibitors: Synthesis and photobiological evaluation as potent photosensitizers for photodynamic therapy.

Since tyrosine kinase inhibitor (TKI) could reverse ABCG2-mediated drug-resistance, novel chlorin e6-based conjugates of Dasatinib and Imatinib as photosensitizer (PS) were designed and synthesized. The results demonstrated that conjugate 10b showed strongest phototoxicity against HepG2 and B16-F10 cells, which was more phototoxic than chlorin e6 and Talaporfin. It could reduce efflux of intracellular PS by inhibiting ABCG2 in HepG2 cells, and localize in mitochondria, lysosomes, golgi and ER, resulting in higher cell apoptosis rate and ROS production than Talaporfin. Moreover, it could induce cell autophagy and block cell cycle in S phase, and significantly inhibit tumor growth and prolong survival time on BALB/c nude mice bearing HepG2 xenograft tumor to a greater extent than chlorin e6. Consequently, compound 10b could be applied as a promising candidate PS due to its good water-solubility and stability, low drug-resistance, high quantum yield of 1O2 and excellent antitumor efficacy in vitro and in vivo.

Bioactive diterpenoids isolated from the twigs and leaves of Casearia velutina.

Nine previously undescribed clerodane-type diterpenoids (1-9), named caseabalanspenes A-I, along with six know compounds (10-15), were isolated from the twigs and leaves of Casearia velutina. Spectroscopic data (1D and 2D NMR) analysis permitted the definition of their structures and then determination of the molecular formula of the compound by high resolution mass spectrometry (HR-ESI-MS). It is worth noting that compound 7 contains N- heterocycle. Compounds 1-8 were tested the anti-inflammasome activity, and compound 3 exhibited potent activity and decreased LDH level in a dose-dependent manner, with IC50 values of 2.90 µM.

Three new lanostane triterpenoids and two new amides from Alternaria sp. with NLRP3 inflammasome inhibitory activity.

Three new lanostane triterpenoids (1-3) along with two new amides fatty compounds (4-5) were isolated from the ethyl acetate extract of a culture of the endophytic fungus Alternaria sp. gx-2. Their structures were identified by 1D and 2D NMR spectral data and HRESIMS. Compounds 1-12 were evaluated for their anti-inflammatory and tyrosinase inhibition activities. The isolated compounds did not show inhibitory activities at a concentration of 100 µM against tyrosinase, while under the concentration of 10 µM, the release of lactate dehydrogenase (LDH) inhibition rate of compound 1 was 54.45%, indicating that compound 1 had moderate anti-inflammatory activity on the activation of NLRP3 inflammasome.

Abietane diterpenoids from Orthosiphon wulfenioides with NLRP3 inflammasome inhibitory activity.

Wulfenioidones A - K (1-11) were abietane diterpenoids with highly oxidized 6/6/6 aromatic tricyclic skeleton isolated from the whole plant of Orthosiphon wulfenioides, and their planar structures and absolute configurations were elucidated by spectroscopic data interpretation, electronic circular dichroism calculation as well as X-ray crystallography analysis. Bioactivity screening indicated that compounds 1-4, 6 and 8 exhibited lactate dehydrogenase (LDH) inhibition effect with IC50 values ranging from 0.23 to 3.43 µM by preventing the mononuclear macrophage cell pyroptosis induced by double signal stimulation of LPS and nigericin. Western Blot analyses of Caspase-1 and IL-1ß down-regulation exhibited that compound 1 could selectively inhibit NLRP3 inflammasome, and the cell morphological observation further supported that compound 1 prevented macrophage cell pyroptosis.

Nudifloids A-N, structurally diverse 3,4-seco-labdane diterpenoids from Callicarpa nudiflora with inflammatory inhibitory activity.

Fourteen undescribed seco-type diterpenoids, named nudifloids A-N, together with ten known analogs, were isolated from the leaves of Callicarpa nudiflora. Nudifloids A-N had a characteristic 3,4-seco-labdane-type diterpenoid skeleton, whereas nudifloids A-C and K-N were 3,4-seco-norditerpenoids. Nudifloid A was the first example of a 3,4-seco-12,13,14,15,16-quartnor-labdane diterpenoid, with a seven-membered lactone ring formed through esterification between C-3 and C-11. Nudifloids B and C were a pair of highly modified 3,4-seco-labdane nor-diterpenoid epimers, of which C-2 and C-18 were cyclized together to form a cyclohexene fragment. The structures of these undescribed diterpenoids were established by spectroscopic analysis and reference data. The anti-inflammatory activity of diterpenoids in rich yield was evaluated by analyzing the inhibition of lipopolysaccharide plus nigericin-induced pyroptosis in J774A.1 cells. Nudifloids D and E exhibited prominent anti-NLRP3 inflammasome activity, with IC50 values of 1.80 and 1.59 µM, respectively. Cell permeability assays revealed that nudifloid D inhibited pyroptosis, which could ameliorate inflammation by blocking the activation of the NLRP3 inflammasome.

16,17-dinor-abietane diterpenoids from Casearia kurzii.

Eleven undescribed 16,17-dinor-abietane diterpenoids, caseazins A-K (1-11), and ten known diterpenoids (12-21) were isolated from the twigs and leaves of Casearia kurzii (Flacourtiaceae). Caseazins A-K were the first abietane -type dinorditerpenoids to have been isolated from the plant of Casearia kurzii. Their chemical structures were elucidated using a combination of 1D and 2D NMR spectroscopy and mass spectrometry. The absolute configurations of 5 and 10 were established by electronic circular dichroism calculations. Moreover, compounds 2, 3, 13, 14, and 18 exhibited anti-inflammatory activity with IC50 values of 0.17, 0.36, 6.55, 1.30, and 4.53 µM, respectively. IL-1ß and caspase-1 analyses suggested that compound 14 inhibited NLRP3 inflammasome activation and blocked macrophage pyroptosis.

Chemical constituents from the twigs and leaves of Picrasma quassioides.

Two new compounds, including a norsesquiterpenoid, annuionone H (1), and a quassinoid, picraqualide G (2), along with eleven known compounds (3-13), were isolated from the twigs and leaves of Picrasma quassioides. Comprehensive spectroscopic analyses and NMR calculation with DP4+ analysis were used to identify their structures. Moreover, of all these compounds, compound 4 showed a week inhibition rate in the anti-inflammatory screening results against mouse macrophage J774A.1 cell.

Chemical Constituents of the Branches and Leaves of Picrasma chinensis P.Y. Chen and Tyrosinase Inhibiting Activity.

One new alkaloid, picrasine A, two new quassinoids, picralactones A-B, together with eleven known compounds were isolated from Picrasma chinensis P.Y. Chen. The structures of these compounds were determined using 1D and 2D NMR, HR-ESI-MS, and IR spectroscopic data, and by comparison with published data. Some compounds were tested for tyrosinase inhibiting activity, however, none of them exhibited strong inhibitory effects.

Callicarpanes A-L, Twelve New Clerodane Diterpenoids with NLRP3 Inflammasome Inhibitory Activity from Callicarpa integerrima.

Twelve new clerodane diterpenoids named callicarpanes A-L (1-12), together with eight known compounds (13-20), were isolated from Callicarpa integerrima. Their structures were determined by comprehensive spectroscopic data. The calculated chemical shifts were used to identify relative configurations using DP4+ analysis. The absolute configurations (AC) were assigned based on quantum chemical calculations and X-ray single-crystal diffraction methods. Compounds 1, 3, 5, 9, 10, 12, 15, 16, and 19 showed significant inhibitory activity for NLRP3 inflammasome activation, with the IC50 against lactate dehydrogenase (LDH) release ranging from 0.08 to 4.78 µM. Further study revealed that compound 10 repressed IL-1ß secretion and caspase-1 maturation in J774A.1 cell as well as blocked macrophage pyroptosis.

Two new compounds from Verbena bonariensis.

Two new compounds verboncin A (1) and verboncin B (4) and 14 known compounds (2-3 and 5-16) were isolated from Verbena bonariensis, and these 14 compounds were first obtained from this plant. Their chemical structures were established by one and two-dimensional NMR and HRESIMS analysis and the results were compared with literature values. The absolute configuration of 1 was determined by calculating electronic circular dichroism (ECD). The cytotoxicity of some of the compounds against MCF-7, HCT-116, MDA-MB-231, and SW620 human cancer cell lines were evaluated, in which compound 4 showed negligible cytotoxic activity with an IC50 value of 68.08 ± 0.35 µM against the MCF-7 cell line.

Highly Oxygenated Labdane Diterpenoids from Stevia rebaudiana and Their Anti-Atherosclerosis Activities.

Five unknown labdane diterpenoids Stevelins A-E (1-5), three known labdane diterpenoids (6-8) and three labdane norditerpenoids (9-11) were isolated from the Stevia rebaudiana. The structures were determined primarily via NMR spectroscopic data and HR-ESI-MS experiments. X-ray crystallography using CuKα radiation was used to determine the absolute configurations of 1, and the absolute configurations of 2-5 were deduced by electronic circular dichroism (ECD) calculations. The potential anti-atherosclerosis activities of all compounds were evaluated by measuring their inhibitory effects on the macrophage foam cell formation. As a result, most isolated compounds could significantly inhibit oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation, which suggests that these compounds may be promising candidates in the treatment for atherosclerosis.

Fluoro-functionalized ionic covalent organic frameworks (F-iCOFs) for highly selective enrichment and sensitive determination of perfluorinated sulfonates by MALDI-MS.

An easily prepared fluoro-functionalized ionic covalent organic framework (F-iCOF) has been implemented into MALDI-TOF MS, enabling the highly selective enrichment and sensitive determination of perfluorinated sulfonate (PFS) contaminants in a rapid and convenient manner. The good thermal stability and excellent optical absorption properties of F-iCOF makes it a brilliant matrix with no background noise. Moreover, benefitting from the large surface area, appropriate pore size, good water dispersibility, and abundant fluorine atom and cationic characteristic of F-iCOF, it exhibited superior adsorption capacity and enrichment selectivity towards PFSs. Good signal responses for PFSs were obtained in the presence of various interfering compounds such as BSA, HA, or even more than 100-fold excess of glutamic acid and similar in structure sodium alkyl sulfonates, highlighting the specific selectivity of F-iCOF. Calibration curves for potassium perflurobutane sulfonate (PFBSK) in tap water and whole blood were established with good linear correlation in the range 1-500 pg mL-1. The limits of detection and quantification for PFBSK were as low as 0.04 pg mL-1 and 0.05 pg mL-1, respectively, which are comparable or better than the existing methods for the determination of PFSs.

Caseatardies A-K, eleven undescribed clerodane diterpenoids isolated from Casearia tardieuae and their anti-inflammatory activity.

A phytochemical investigation to obtain bioactive substances as lead compounds or agents for anti-inflammatory led to the obtainment of eleven previously undescribed clerodane diterpenoids, named caseatardies A-K (1-11), and four known clerodane diterpenoids (12-15) from the twigs and leaves of Casearia tardieuae. The structural elucidation of these clerodane diterpenoids was based on 1D and 2D-NMR spectroscopy (COSY, HSQC, HMBC and ROESY) as well as high resolution mass spectrometry (HR-ESI-MS). The relative configurations were defined by ROESY correlations. The anti-inflammatory activity of all the isolated compounds was screened and compound 15 decreased LDH level in a dose-dependent manner, showing IC50 value of 2.89 µM.

Callintegers A and B, Unusual Tricyclo[4.4.0.09,10]tetradecane Clerodane Diterpenoids from Callicarpa integerrima with Inhibitory Effects on NLRP3 Inflammasome Activation.

Callintegers A (1) and B (2), unprecedented clerodane norditerpenoids based on a novel carbon skeleton, were isolated from Callicarpa integerrima. Compounds 1 and 2 possess a novel 6/6/6-fused tricyclic ring system. Their structures and absolute configurations were determined by quantum chemical calculations, spectroscopic analysis, and single-crystal X-ray diffraction methods. Biological evaluation showed that compound 2 inhibited IL-1ß secretion in a dose-dependent manner with an IC50 value of 5.5 ± 3.2 µM. Caspase-1 maturation and IL-1ß secretion were also reduced, indicating that compound 2 impaired NLRP3 inflammasome activation.