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.

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.

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.

Diterpenoids from Strophioblachia glandulosa and Their NLRP3 Inflammasome Inhibitory Effects.

Our study on the roots and leaves of the never-hitherto-chemically studied S. glandulosa led to the isolation of five new diterpenes, referred to as stroglandulons A-E (1-5), alongside 18 known constituents (6-23). The structures of the new compounds were elucidated on the basis of their spectroscopic data, while the known ones were determined based on the comparison of their data with the literature values. Compounds 1-5 were evaluated for their inhibitory effects against NLRP3 inflammasome activation; compound 5 showed inhibition by an IC50 value of 6.12±0.03 µM.

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.

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.

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.

Callicarpnoids A-C, structurally intriguing ent-Clerodane diterpenoid dimers with cytotoxicity against MCF-7 and HCT-116 cell lines from Callicarpa arborea Roxb.

Callicarpnoids A-C (1-3), three new ent-clerodane diterpenoid dimers formed via a [4 + 2] hetero Diels-Alder cycloaddition, appeared as a third example of this type of dimers, were isolated from the stems of Callicarpa arborea Roxb.. Their structures were elucidated by comprehensive spectroscopic analysis, and the absolute configurations were confirmed by single-crystal X-ray diffraction and electronic circular dichroism (ECD) calculations, as well as DP4 + analysis. Cytotoxicity test in two cell lines indicated that compounds 2 and 3 had significant cytotoxic effect against breast cancer cell (MCF-7) and colorectal cancer cell (HCT-116) with IC₅₀ ranging from 5.2 to 7.2 µM, comparable to those of the positive control. Furthermore, the western blot analysis revealed that the protein expression levels of Bax were increased following compounds 2 and 3 treatment, whereas the expression levels of caspase 8, caspase 3, caspase 9 and Bcl₂ were decreased in a dose-dependent manner, indicating that compounds 2 and 3 may induce apoptosis via both intrinsic and extrinsic pathways in MCF-7 and HCT-116 cells.

Triterpene constituents from the fruits of Cyclocarya paliurus and their anti-HIV-1IIIB activity.

Four new norceanothane-type triterpenes, cyclopalin A-D (1-4), and sixteen known compounds (5-20) were obtained from the fruits of Cyclocarya paliurus. Their structures were determined by spectroscopic data, experimental electronic circular dichroism (ECD) and X-ray single crystal analyses. All isolated compounds were assayed for their anti-HIV-1IIIB activity. Compound 18 exhibited potent anti-HIV-1IIIB activity with an EC50 value of 1.32 µM (SI = 151.52).

Ten new prenylated flavonoids from Macaranga denticulata and their antitumor activities.

Ten new prenylated flavonoids, named denticulains A-J (1-10), together with seven known prenylated flavonoids (11-17) were isolated from Macaranga denticulata. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with literature data. In addition, compounds 1 and 14 inhibited the proliferation of SW620 and HCT-116 cell lines with an IC50 value of 46.08 µM and 56.83 µM, respectively.

The discovery of potentially active diterpenoids to inhibit the pyroptosis from Callicarpa arborea.

Pyroptosis is a programmed-inflammatory cell death, which leads to release of inflammatory cellular contents and formation of inflammation. Uncontrollable pyroptosis can result in serious immune diseases, such as cytokine release syndrome (CRS), sepsis, disseminated intravascular coagulation (DIC), and acute organ damage, including acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI). Members of the Callicarpa genus are significant raw materials for traditional Chinese medicine, widely used for analgesia, hemostasis, and anti-inflammation. Previously, we have reported some ent-clerodane diterpenoids from Callicarpa arborea, shown potent inhibitory effects against pyroptosis. In this study, we went on investigating this kind of diterpenoids, and yielded 66 ent-clerodane diterpenoids, including 52 new compounds, from Callicarpa arborea. Their structures featured with a 5/6- (1-25) or a 6/6- (26-66)-fused double-ring scaffolds, were elucidated using spectroscopic data, electrostatic circular dichroism (ECD) and X-ray diffraction analyses. Screening for the inhibitory activity against pyroptosis by detecting of IL-1ß secretion in J771A.1 cells, revealed 28 compounds with an IC50 below 10.5 µM. Compound 1 was the most potent with an IC50 of 0.68 µM and inhibited the J774A.1 macrophage pyroptosis by blocking the NLR pyrin domain containing 3 (NLRP3) inflammasome activation. An in vivo study further revealed that compound 1 decreased infiltration of CD11b + F4/80 + macrophages into lung and attenuated the lipopolysaccharide (LPS)-induced lung injury. Taken together, this study indicated the potential of compound 1 as a candidate for pyroptosis-related inflammation treatment, as well as provided the chemical and pharmacological basis for the further development of Callicarpa genus as a herbal medicine.

Ainslides A-F, Six Sesquiterpenoids Isolated from Ainsliaea pertyoides and Their NLRP3-Inflammasome Inhibitory Activity.

Six new sesquiterpenoids, named as ainslides A-F (1-6), including one carotene-type sesquiterpene (1), one eudesmane (2), four guaianolides (3-6), together with eight known sesquiterpenoids (7-14), were purified from the whole plants of Ainsliaea pertyoides. The structures of these sesquiterpenoids were characterized based on spectroscopic methods including 1D and 2D NMR, HR-ESI-MS, UV, and IR spectra, together with ECD calculations and X-ray diffraction experiments. The anti-inflammatory activity of all the isolated compounds was screened and compounds 3 and 7-13 exhibited NLRP3-inflammasome inhibitory activity with IC50 values of 1.80-4.33 µM.

Aspulvins A-H, Aspulvinone Analogues with SARS-CoV-2 Mpro Inhibitory and Anti-inflammatory Activities from an Endophytic Cladosporium sp.

Eight new aspulvinone analogues, aspulvins A-H (1-8) and aspulvinones D, M, O, and R (9-12), were isolated from cultures of the endophytic fungus Cladosporium sp. 7951. Detailed spectroscopic analyses were conducted to determine the structures of the new compounds. All isolates displayed different degrees of inhibitory activity against the severe acute respiratory syndrome coronavirus 2 main protease (SARS-CoV-2 Mpro) at 10 µM. Notably, compounds 9, 10, and 12 showed potential SARS-CoV-2 Mpro inhibition with IC50 values of 10.3 ± 0.6, 9.4 ± 0.6, and 7.7 ± 0.6 µM, respectively. For all compounds except 3 and 4, the anti-inflammatory activity occurred by inhibiting the release of lactate dehydrogenase (LDH) with IC50 values ranging from 0.7 to 7.4 µM. Compound 10 showed the most potent anti-inflammatory activity by inhibiting Casp-1 cleavage, IL-1ß maturation, NLRP3 inflammasome activation, and pyroptosis. The findings reveal that the aspulvinone analogues 9, 10, and 12 could be promising candidates for coronavirus disease 2019 (COVID-19) treatment as they inhibit SARS-CoV-2 infection and reduce inflammatory reactions caused by SARS-CoV-2.

Euphzycopias A-I, macrocyclic diterpenes with NLRP3 inflammasome inhibitory activity from Euphorbia helioscopia L.

A phytochemical investigation was conducted on Euphorbia helioscopia, resulting in the isolation of thirteen compounds, including nine undescribed diterpenoids, Euphzycopias A - I (1-9), of which the skeletons of compounds 1-4 were found in E. helioscopia L. Compounds 1-3 had 5/7/6 cyclic systems, while compound 4 had a 4/11 polycyclic system with a 4,7-cyclic ether between C-4 and C-7. The anti-inflammasome test using the isolated compounds (1-6, 8-13) showed that the diterpenes from E. helioscopia L. had a strong inhibitory effect on NLRP3 inflammasomes with IC50 values of 3.34-14.92 µM.

Design, synthesis and anti-breast cancer evaluation of biaryl pyridine analogues as potent RSK inhibitors.

In order to discover and develop the new RSK kinase inhibitor, 50 pyridyl biaryl derivatives were designed and synthesized with LJH685 as the lead compound and their anti-tumor ability was tested. The results showed that the ability of 7d compound to inhibit the phosphorylation of YB-1 was comparable to that of LJH685. Among them, after preliminary screening, compound 7d showed good activity in inhibiting cell proliferation. Therefore, we took 7d as an example and performed molecular docking analysis on it. Judging from the overlapping combination diagram with LJH685, the results have verified that compound 7d has a similar skeleton to LJH685 and has a similar docking effect with RSK. Therefore, compound 7d is in line with the RSK inhibitor we designed and could be developed to a promising anti-tumor drug in the future.

Spiroarborin, an ent-Clerodane Homodimer from Callicarpa arborea as an Inhibitor of the Eleven-Nineteen Leukemia (ENL) Protein by Targeting the YEATS Domain.

A spiro ent-clerodane homodimer with a rare 6/6/6/6/6-fused pentacyclic scaffold, spiroarborin (1), together with four new monomeric analogues (2-5), were isolated from Callicarpa arborea. Their structures were elucidated by comprehensive spectroscopic data analysis, quantum-chemical calculations, and X-ray diffraction. A plausible biosynthetic pathway of 1 was proposed, and a biomimetic synthesis of its derivative was accomplished. Compound 1 showed a potent inhibitory effect by directly binding to the YEATS domain of the 11-19 leukemia (ENL) protein with an IC50 value of 7.3 µM. This gave a KD value of 5.0 µM, as recorded by a surface plasmon resonance binding assay.

C6-structural optimizations of 2-aryl-1H-pyrazole-S-DABOs: From anti-HIV to anti-DENV activity.

Both HIV and DENV are serious threats to human life, health and social economy today. So far, no vaccine for either HIV or DENV has been developed successfully. The research on anti-HIV or DENV drugs is still of great significance. In this study we developed a series of novel 2-Aryl-1H-pyrazole-S-DABOs with C6-strucutral optimizations as potent NNRTIs, among which, 8 compounds had low cytotoxicity and EC50 values in the range of 0.0508 âˆ¼ 0.0966 µM, and their selectivity index was SI > 1415 âˆ¼ 3940. In particular, two compounds 4a and 4b were identified to have good inhibitory effects on DENV of four serotypes. The EC50 of compound 4a and 4b against DENV-II (13.2 µM and 9.23 µM, respectively) were better than that of the positive control ribavirin (EC50 = 40.78 µM). In addition, the effect of C-6 substituents on the anti-HIV or anti-DENV activity of these compounds was also discussed.

Centrantheroside F, a new ionone glycoside from Centranthera grandiflora.

One new ionone glycoside, named centrantheroside F (1), together with 9 known compounds (2-10), were isolated from the roots of Centranthera grandiflora. Their structures were determined by spectroscopic data analyses and comparing with the literature data. The absolute configuration of 1 was confirmed via 2 D NMR and electronic circular dichroism (ECD). All isolated compounds were evaluated for their inhibitory activity on lipopolysaccharide (LPS)-induced nitric oxide (NO) production.

Optimized Expression of Recombinant Human NIMA-related Kinase 7 (NEK7) with A Higher Purity in Escherichia coli.

BACKGROUND: NIMA (never in mitosis, gene A) serine/threonine kinase 7 (NEK7) is a regulator of mitosis spindle in mammals and is considered as a drug target of inflammasome related inflammatory diseases. However, most commercially available or reported recombinant NEK7 proteins are either inactive or have low purity. These shortcomings limit the pharmacological studies and development of NEK7 inhibitors. OBJECTIVE: To elucidate what causes the NEK7 low purity in E. coli, and optimize a protocol to improve the protein purity. METHODS: A comparative study of expression full length NEK7 with an N-terminal His-tag or a Cterminal His-tag was performed. His-affinity resin, ion exchange and gel filtration chromatography were used to purify NEK7. The protein was identified by mass spectrometry. The activity and folding of NEK7 were evaluated by chemiluminescent assay and thermal shift assay. RESULTS: Our results demonstrated that N-terminal tagged protein was toxic to E. coli, resulting in incomplete translated products. The C-terminal tagged NEK7-His6 had a much higher purity than that of an N-terminal tag. The Ni2+ resin one-step purification led to a purity of 91.7%, meeting the criteria of most kinase assays. With two-step and three-step procedures, the protein purities were 94.7% and ~100%, respectively. The NEK7 purified in this work maintained its kinase activity and correct conformation, and the compound-protein interaction ability. CONCLUSION: Our optimized protocol could produce good purity of His tagged NEK7 in E. coli, and the kinase activity and biophysical characteristics of which are preserved.