Structurally diverse stilbenes from Gnetum parvifolium and their anti-neuroinflammatory activities.

Phytochemical investigation on the aerial parts of Gnetum parvifolium led to the isolation of 15 new and eight known structurally diverse stilbenes. The isolated compounds comprised (E)- or (Z)-stilbene (1-6, 15-20), dihydrostilbene (21), phenylbenzofuran (7, 8, 22), benzylated stilbene (9-11), benzylated stilbene dimer (12), and nitrogen-containing stilbene (13a, 13b, 14) types. The structures of the new compounds (1-12, 13a, 13b, 14) were established through spectroscopic analyses and experimental and calculated ECD data. Compound 12 is the first stilbene dimer connected through a benzyl group. In the anti-neuroinflammatory activity assay, compounds 4, 5, 9-11, 13b, and 16-21 displayed significant inhibitory effects against LPS-induced NO release in BV-2 microglial cells, with IC50 values of 0.35-16.1 µM. Compound 10 had the most potent activity (IC50 = 0.35 µM), and the further research indicated that it could decrease the mRNA levels of iNOS, IL-1ß, IL-6, and TNF-α in a dose-dependent manner.

Diisoprenyl Cyclohexene-Type Meroterpenoids with Cytotoxic Activity from a Mangrove Endophytic Fungus Aspergillus sp. GXNU-Y85.

Five new diisoprenyl cyclohexene-type meroterpenoids, aspergienynes J-N (1-5), along with three known analogues (6-8), were obtained from the mangrove endophytic fungal strain Aspergillus sp. GXNU-Y85. The chemical structures, including their absolute configurations, were established via spectroscopic data and comparison of experimental and calculated ECD spectra. Cytotoxicity assay results indicated that compound 8 had strong cytotoxicity against HeLa cancer cells, and its IC50 value was 11.8 µM. In addition, flow cytometry analysis revealed that the cytotoxicity of 8 was due to the induction of G1 cell cycle arrest and apoptosis in HeLa cells.

Sesquilignans PD from Zanthoxylum nitidum var. tomentosum exerts antitumor effects via the ROS/MAPK pathway in liver cancer cells.

Sesquilignans PD is a natural phenylpropanoid compound that was isolated from Zanthoxylum nitidum var. tomentosum. In this study, we assessed the antitumor effect of PD on SK-Hep-1 and HepG2 cells and the underlying molecular mechanisms. The results revealed that PD markedly inhibited the proliferation and migration of both liver cancer cells. Moreover, PD induced apoptosis, autophagy, and reactive oxygen species (ROS) production in liver cancer cells. Notably, PD increased the protein levels of p-p38 MAPK and p-ERK1/2 in liver cancer cells. This is the first report on the anticancer effect of PD, which is mediated via increased ROS production and MAPK signaling activation.

Discovery of novel 2-oximino-2-indolylacetamide derivatives as potent anticancer agents capable of inducing cell autophagy and ferroptosis.

A series of 2-oximino-2-indolylacetamide derivatives were designed, synthesized and evaluated for their antitumour effects. Among them, 4d exhibited the most potent antiproliferative effect in vitro on the tested human cancer cells. Additionally, 4d significantly induced cell apoptosis, caused mitochondrial dysfunction, promoted Bax, cleaved-PARP and p53 expression and inhibited Bcl-2 expression in 5-8F cells. Moreover, 4d remarkably promoted autophagosome formation, leading to cell apoptosis. Further investigation indicated that 4d could trigger cell death through cell ferroptosis, including increased ROS generation and lipid peroxidation and decreased glutathione peroxidase 4 (GPx4) expression and glutathione (GSH) levels. More importantly, 4d induced 5-8F cell death by activating ROS/MAPK and inhibiting the AKT/mTOR and STAT3 signalling pathways. Interestingly, 4d significantly suppressed tumour growth in a 5-8F cell xenograft model without obvious toxicity to mice. Overall, these results demonstrate that 4d may be a potential compound for cancer therapy.

Novel lignans from Zanthoxylum nitidum and antiproliferation activity of sesaminone in osimertinib-resistant non-small cell lung cancer cells.

Seven previously undescribed tetrahydrofuran lignans with different configurations and unusual isopentenyl substitutions, nitidumlignans D-J (corresponding to compounds 1, 2, 4, 6, 7, 9 and 10), along with 14 known lignans, were isolated from Zanthoxylum nitidum. Notably, compound 4 is an uncommon naturally occurring furan-core lignan derived from tetrahydrofuran aromatization. The antiproliferation activity of the isolated compounds (1-21) was determined in various human cancer cell lines. The structure-activity study revealed that the steric positioning and chirality of the lignans exert important effects on their activity and selectivity. In particular, compound 3 (sesaminone) exhibited potent antiproliferative activity in cancer cells, including acquired osimertinib-resistant non-small-cell lung cancer (HCC827-osi) cells. Compound 3 also inhibited colony formation and induced the apoptotic death of HCC827-osi cells. The underlying molecular mechanisms revealed that 3 downregulated the activation of the c-Met/JAK1/STAT3 and PI3K/AKT/mTOR signaling pathways in the HCC827-osi cells. In addition, the combination of 3 and osimertinib exhibited synergistic effects on the antiproliferative activity against HCC827-osi cells. Overall, these findings inform the structure elucidation of novel lignans isolated from Z. nitidum, and sesaminone was identified as a potential compound for exerting antiproliferative effects on osimertinib-resistant lung cancer cells.

Synthesis and Biological Evaluation of Novel 2-Amino-1,4-Naphthoquinone Amide-Oxime Derivatives as Potent IDO1/STAT3 Dual Inhibitors with Prospective Antitumor Effects.

Indoleamine-2,3-dioxygenase 1 (IDO1) and signal transducer and activator of transcription 3 (STAT3) have emerged as significant targets in the tumor microenvironment for cancer therapy. In this study, we synthesized three novel 2-amino-1,4-naphthoquinone amide-oxime derivatives and identified them as dual inhibitors of IDO1 and STAT3. The representative compound NK3 demonstrated effective binding to IDO1 and exhibited good inhibitory activity (hIDO1 IC50 = 0.06 µM), leading to its selection for further investigation. The direct interactions between compound NK3 and IDO1 and STAT3 proteins were confirmed through surface plasmon resonance analysis. A molecular docking study of compound NK3 revealed key interactions between NK3 and IDO1, with the naphthoquinone-oxime moiety coordinating with the heme iron. In the in vitro anticancer assay, compound NK3 displayed potent antitumor activity against selected cancer cell lines and effectively suppressed nuclear translocation of STAT3. Moreover, in vivo assays conducted on CT26 tumor-bearing Balb/c mice and an athymic HepG2 xenograft model revealed that compound NK3 exhibited potent antitumor activity with low toxicity relative to 1-methyl-L-tryptophan (1-MT) and doxorubicin (DOX). Overall, these findings provided evidence that the dual inhibitors of IDO1 and STAT3 may offer a promising avenue for the development of highly effective drug candidates for cancer therapy.

Design and Synthesis of Novel Indole Ethylamine Derivatives as a Lipid Metabolism Regulator Targeting PPARα/CPT1 in AML12 Cells.

Peroxisome proliferator-activated receptor alpha (PPARα) and carnitine palmitoyltransferase 1 (CPT1) are important targets of lipid metabolism regulation for nonalcoholic fatty liver disease (NAFLD) therapy. In the present study, a set of novel indole ethylamine derivatives (4, 5, 8, 9) were designed and synthesized. The target product (compound 9) can effectively activate PPARα and CPT1a. Consistently, in vitro assays demonstrated its impact on the lipid accumulation of oleic acid (OA)-induced AML12 cells. Compared with AML12 cells treated only with OA, supplementation with 5, 10, and 20 µM of compound 9 reduced the levels of intracellular triglyceride (by 28.07%, 37.55%, and 51.33%) with greater inhibitory activity relative to the commercial PPARα agonist fenofibrate. Moreover, the compound 9 supplementations upregulated the expression of hormone-sensitive triglyceride lipase (HSL) and adipose triglyceride lipase (ATGL) and upregulated the phosphorylation of acetyl-CoA carboxylase (ACC) related to fatty acid oxidation and lipogenesis. This dual-target compound with lipid metabolism regulatory efficacy may represent a promising type of drug lead for NAFLD therapy.

New enantiomeric lignans and new meroterpenoids with nitric oxide release inhibitory activity from Piper puberulum.

Six new lignans with various type of linkage between two C6-C3 fragments (1a, 1b, 2a, 2b, 3, 4), two new meroterpenoids (5, 6) and 24 known compounds (7-30) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of enantiomers 1a and 1b were determined by single-crystal X-ray diffraction analysis, 2a and 2b were determined by comparing their calculated and experimental ECD spectra. Biogenetically, all the new lignans may come from the polymerization of two molecules of hydroxychavicol (30). In the anti-neuroinflammation activity assay, the IC50 values of fifteen compounds were lower than those of the positive control minocycline, and compound 1a showed good activity, but its enantiomer 1b showed no activity. Compound 1a have notable anti-neuroinflammatory activity, and can significantly decrease mRNA levels of proinflammatory cytokines (IL-1ß, IL-6, TNF-α) in a dose-dependent manner.

Four New Sesquiterpenoids from Zanthoxylum nitidum.

Zanthoxylum nitidum (Roxb.) DC., is one of Guangxi's characteristic national medicines, and is the classic Laoban medicine of Yao people "Ru Shan Hu" and Zhuang medicine "Liang Bei Zhen". It has been used as an anti-inflammatory, analgesic and haemostatic medicine for thousands of years. In this study, four new sesquiterpenoids (1-4), along with six previously described coumarins (5-10), were isolated from 95 % EtOH extract of Zanthoxylum nitidum. Comprehensive spectroscopic analyses (NMR and HR-ESI-MS) were used to elucidate the structures of these isolates. The absolute configurations of nitidumine A-D (1-4) were established by electronic circular dichroism (ECD). Their cytotoxicity of all the isolates against five cancer cell lines (T24, HeLa, MGC-803, A549, and HepG2) was evaluated by MTT experiment and found not to be cytotoxicity.

Nitidumpeptins A and B, Cyclohexapeptides Isolated from Zanthoxylum nitidum var. tomentosum: Structural Elucidation, Total Synthesis, and Antiproliferative Activity in Cancer Cells.

Nitidumpeptins A and B (1 and 2), two novel cyclic hexapeptides, were isolated from the herb Zanthoxylum nitidum var. tomentosum. Their planar structures were elucidated based on NMR and MS spectrometric analysis, and the absolute configurations were determined by the Marfey's method. Structurally, 1 is a unique peptide with a backbone bearing a pyrrolidine-2,5-dione unit, which is the first occurrence moiety specifically in a naturally occurring cyclohexapeptide. The total synthesis of 1 and 2 was achieved by solution-phase in parallel with solid-phase peptide synthesis, and their absolute configurations were further confirmed. The combination of 2 with gefitinib exhibited synergistic antiproliferative activity in acquired gefitinib-resistant non-small cell lung cancer cells (HCC827-gef). The underlying mechanism for the antiproliferative activity of 2 was in part associated with the suppression of YAP expression in HCC827-gef cells.

New Tyramine- and Aporphine-Type Alkamides with NO Release Inhibitory Activities from Piper puberulum.

Three new tyramine-type alkamides (1-3), three new natural products (4-6), five new N-acylated/formylated aporphine alkamides with different ratios of rotational isomers (7-11), and 20 known alkamides (12-31) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of compounds 7, 8, and 10 were determined by single-crystal X-ray diffraction analysis. In the biological activity assay, compounds 3, 5, and 10-23 displayed inhibitory effects against lipopolysaccharide-induced NO release in BV-2 microglial cells, exhibiting IC50 values of 0.93-45 µM.

Chebulic acid derivatives from Balakata baccata and their antineuroinflammatory and antioxidant activities.

Sixteen chebulic acid derivatives, including nine new (1-9) and seven known (10-16) ones, were isolated from an ethanol extract of the branches and leaves of Balakata baccata. The structures of the new compounds were elucidated by their UV, IR, HRESIMS, NMR, electronic circular dichroism (ECD) and single-crystal X-ray diffraction data. The effects of all the isolates on antineuroinflammatory and antioxidant activities were evaluated. Compared with the positive control minocycline (IC50 = 1.21 ± 0.71 µM), compounds 1-16 with IC50 values being greater than 50 µM, displayed almost no effects on the inhibition of NO production in LPS-induced BV-2 microglial cells, however, the results of antioxidant activity for compounds 1-16 showed significant DPPH-radical scavenging abilities with EC50 value ranging from 3.98 to 14.24 µM, while the EC50 value of positive control vitamin C was 14.31 µM. At last, the results of PCR (qRT-PCR) analysis showed that compound 1 could enhance the expression of antioxidases (HO-1, GCLC, and NQO1) at the mRNA levels.

Acetylated Rhamnose Triterpenoid Saponins from Glechoma longituba Analyzed by LC-Q-TOFMS.

The aim of the present work is to isolate a series of triterpene derivatives with rhamnosyl linking acetyl groups from Glechoma longituba according to the structural characteristics of previously described triterpene saponins. The extract ion chromatography spectrum of the crude extract of G. longituba was detected and analyzed by HPLC-HR-ESI-MS to determine possible components, and these metabolites were traced and separated by combining high-resolution mass spectrometry and predicted liquid chromatography retention time. Three 11α, 12α-epoxypentacyclic oleanolic acid triterpene saponins (glechomanosides H-J) and one ursane triterpene aldehyde saponin with a C-28 aldehyde group were isolated from G. longituba. The structure of these compounds was confirmed by NMR and compared with those of previously characterized compounds. The strategy described in this report enables a rapid, reliable, and complete analysis of glycoside compounds containing different numbers of acetyl groups at different positions on the sugar.

Altered allostery of the left flipper domain underlies the weak ATP response of rat P2X5 receptors.

Although the extracellular ATP-gated cation channel purinergic receptor P2X5 is widely expressed in heart, skeletal muscle, and immune and nervous systems in mammals, little is known about its functions and channel-gating activities. This lack of knowledge is due to P2X5's weak ATP responses in several mammalian species, such as humans, rats, and mice. WT human P2X5 (hP2X5Δ328-349) does not respond to ATP, whereas a full-length variant, hP2X5 (hP2X5-FL), containing exon 10 encoding the second hP2X5 transmembrane domain (TM2), does. However, although rat P2X5 (rP2X5) has a full-length TM2, ATP induces only weak currents in rP2X5, which prompted us to investigate the mechanism underlying this small ATP response. Here, we show that single replacements of specific rP2X5 residues with the corresponding residues in hP2X5 (S191F or F195H) significantly enhance the current amplitude of rP2X5. Using a combination of engineered disulfide cross-linking, single-channel recording, and molecular modeling, we interrogated the effects of S191F and F195H substitutions on the allostery of the left flipper (LF) domain. On the basis of our findings, we propose that the bound ATP-induced distinct allostery of the LF domain with that of other functional subtypes has caused the weak ATP response of rP2X5 receptors. The findings of our study provide the prerequisite for future transgenic studies on the physiological and pathological functions of P2X5 receptors.

Diterpenoids and triterpenoids from Triadica rotundifolia and their effects on microglial nitric oxide production.

Four new diterpenoids (1-4), three new triterpenoids (12-14), and seven known diterpenoids (5-11) were obtained from an aqueous EtOH extract of the aerial parts of Triadica rotundifolia. The structures of new compounds were determined by spectroscopic techniques. Their absolute configurations were verified via single-crystal X-ray diffraction data, Mo2(OAc)4 induced electronic circular dichroism (ECD), and ECD calculations. The antineuroinflammatory effects of the isolates were assessed by inhibiting NO production in LPS-induced BV-2 microglial cells. Compared with the positive control minocycline (IC50 = 16.1 µM), compounds 3, 8, 11 showed moderate inhibitory activities with IC50 values of 35.9, 17.0, 31.5 µM, respectively.

Glechomanamides A-C, Germacrane Sesquiterpenoids with an Unusual Δ8-7,12-Lactam Moiety from Salvia scapiformis and Their Antiangiogenic Activity.

Three new germacrane sesquiterpenoid-type alkaloids with an unusual Δ8-7,12-lactam moiety, glechomanamides A-C (1-3), and two pairs of 7,12-hemiketal sesquiterpenoid epimers (4a/b, 5a/b) were isolated from Salvia scapiformis. Their structures were elucidated by spectroscopic methods including HRESIMS, IR, UV, and 1D and 2D NMR and also confirmed by single-crystal X-ray diffraction analysis. The chemical transformation of compounds 1-5 in a solution environment was analyzed by 2D NMR spectroscopy. The aza acetallactams (1-3) were stable in organic solvent, while single crystals of the hemiacetal esters (4a/b, 5a/b) underwent a tautomeric equilibrium after being dissolved. Single crystals of 4a, 4b, and 5a were obtained for the first time as their naturally occurring forms. Glechomanamide B (2) exhibited antiangiogenic activity by suppression of vascular endothelial growth factor (VEGF)-induced tube formation through modulation of VEGF receptor 2 (VEGFR2)-mediated signaling pathways in human umbilical vascular endothelial cells (HUVECs). In addition, compound 2 also showed the significant suppression of mRNA expression associated with glycolysis and angiogenesis biomarkers in high glucose (30 mM)-induced HUVECs. These findings suggest that compound 2 might be a potential lead compound candidate for the management of diabetic retinopathy.

Inhibition potential of phenolic constituents from the aerial parts of Tetrastigma hemsleyanum against soluble epoxide hydrolase and nitric oxide synthase.

The aerial parts of Tetrastigma hemsleyanum (APTH) have been used as a functional tea in China. The purpose of the current study was to identify the bioactive constituents with inhibitory activity against soluble epoxide hydrolase (sEH) and inducible nitric oxide synthase (iNOS), which are jointly considered potential therapeutic targets for vascular system diseases. In the present study, 39 compounds (1-39) were isolated from the APTH. Among them, compounds 8, 10, 12, 16, 17, 19, and 32 displayed potential activities, with IC50 values ranging from 4.5 to 9.5 µM, respectively, and all in non-competitive inhibition mode. Compounds 5, 10, 12, 19, and 32 displayed potent iNOS inhibitory effects, with IC50 values ranging from 15.6 to 47.3 µM. The results obtained in this work contribute to a better understanding of the pharmacological activities of T. hemsleyanum and its potential application as a functional food.

Sesquiterpenoid Compounds from Curcuma kwangsiensis.

Two previously undescribed guaiane-type sesquiterpenes (1 and 2), a pair of new salvialane-type sesquiterpenes (3a and 3b), together with 11 known compounds were isolated and purified from the rhizomes of Curcuma kwangsiensis. Their structures were elucidated by the extensive spectroscopic data (1D- and 2D-NMR) analysis. All the isolated compounds were assessed for their anti-neuroinflammatory activity by inhibiting the nitric oxide (NO) production in lipopolysaccharide (LPS)-activated murine BV-2 microglial cells in vitro assay, and the isolates 3 and 11 showed anti-neuroinflammatory activity with IC50 values of 1.85 and 20.05 µm, respectively.

3α,19-Dihydroxyl-ent-pimara-8(14),15-diene, a new diterpenoid from the rhizomes of Ricinus communis.

A new natural product, 3α,19-dihydroxyl-ent-pimara-8(14),15-diene (1), which possesses an α-orientation hydroxymethyl at C-4 and ∆8,14 groups, as well as eight known compounds, was isolated from the rhizomes of Ricinus communis. The structure of 1 was elucidated by extensive spectroscopic methods and its absolute configurations were confirmed by X-ray crystallographic analysis. The inhibitory rate of 1 against protein tyrosine phosphatase 1B (PTP1B) was 49.49% at the concentration of 6.58 × 10-5 mol/L.

The nonproton ligand of acid-sensing ion channel 3 activates mollusk-specific FaNaC channels via a mechanism independent of the native FMRFamide peptide.

The degenerin/epithelial sodium channel (DEG/ENaC) superfamily of ion channels contains subfamilies with diverse functions that are fundamental to many physiological and pathological processes, ranging from synaptic transmission to epileptogenesis. The absence in mammals of some DEG/ENaCs subfamily orthologues such as FMRFamide peptide-activated sodium channels (FaNaCs), which have been identified only in mollusks, indicates that the various subfamilies diverged early in evolution. We recently reported that the nonproton agonist 2-guanidine-4-methylquinazoline (GMQ) activates acid-sensing ion channels (ASICs), a DEG/ENaC subfamily mainly in mammals, in the absence of acidosis. Here, we show that GMQ also could directly activate the mollusk-specific FaNaCs. Differences in ion selectivity and unitary conductance and effects of substitutions at key residues revealed that GMQ and FMRFamide activate FaNaCs via distinct mechanisms. The presence of two activation mechanisms in the FaNaC subfamily diverging early in the evolution of DEG/ENaCs suggested that dual gating is an ancient feature in this superfamily. Notably, the GMQ-gating mode is still preserved in the mammalian ASIC subfamily, whereas FMRFamide-mediated channel gating was lost during evolution. This implied that GMQ activation may be essential for the functions of mammalian DEG/ENaCs. Our findings provide new insights into the evolution of DEG/ENaCs and may facilitate the discovery and characterization of their endogenous agonists.