Diterpenoids from Euphorbia fischeriana with Kv1.3 Inhibitory Activity.

Euphorbia diterpenoids possess inhibitory effects of Kv1.3 ion channel, but most of this research has focused on diterpenoids with jatrophane-related or ingenane-related skeletons. In the present study, nine undescribed (1-9) and 16 known (10-25) diterpenoids, based on jatrophane, lathyrane, ingenane, abietane, and atisane skeletons, were identified from the methanol extract of the aerial parts of Euphorbia fischeriana. The structures were established by analysis of the spectroscopic data as well as by single-crystal X-ray diffraction analysis. Among the isolated diterpenoids, macrocyclic jatrophanes and lathyranes exerted Kv1.3 blocking activity. Compound 8 exhibited good selectivity on the inhibition of the Kv 1.3 channel rather than hERG channel, with a selectivity index over 7.0. The selective activity of lathyrane diterpenoids indicates that macrocyclic diterpenoids have the potential to be further investigated as therapeutic agents for the treatment of autoimmune diseases.

Anti-inflammatory lanostane triterpenoids with rearranged spirobi[indene] scaffold and their biogenetically related analogues from Euphorbia maculata.

Phytochemical investigations on the ethanol extract of the whole plant of Euphorbia maculata Linn. Resulted in the identification of 16 lanostane-related triterpenoids, including 11 undescribed ones, namely spiromaculatols A-C (1-3) and euphomaculatoids A-H (4-11). The structural determinations of the previously undescribed ones (1-11) were elucidated based on the interpretation of comprehensive spectroscopic data, quantum chemical calculation, as well as X-ray crystallographic experiments. Spiromaculatols A-C (1-3) possess a rare spirobi [indane] skeleton, which was biosynthetically derived from the 7 (8 â†’ 9)-abeo bond migration of lanostane precursors. The biological activity of compounds 1-3, 5, 7, and 12-13 displayed inhibitory effect on the release of NO in an LPS-activated RAW264.7 cells model. Molecular mechanism study indicated that the most potent spiromaculatol C (3) can reduce the nuclear translocation of NF-κB p65 and decrease the transcriptional expressions of its downstream pro-inflammatory mediators.

Brujavanoids A-U, structurally diverse apotirucallane-type triterpenoids from Brucea javanica and their anti-inflammatory effects.

Extensive phytochemical investigation on the methanol extract of the inflorescences, twigs, and leaves of Brucea javanica led to the isolation and identification of 27 triterpenoids, including 21 previously undescribed ones, named brujavanoids A-U (1-21). Their structures were determined based on comprehensive spectroscopic analysis and single-crystal X-ray diffraction. Of these compounds, brujavanoid A (1) represents the first apotirucallane-type triterpenoid with a novel 19(10 â†’ 9)abeo motif, and brujavanoids B and C (2-3) are the first apotirucallane-type triterpenoids with a rarely occurring 14-hydorxy-15,16-epoxy fragment. All the isolates were evaluated for their anti-inflammatory effect in an LPS-activated RAW264.7 cells model. Furthermore, the most active one, brujavanoid E (5), can suppress the transcriptional expression of typical pro-inflammatory mediators and inhibit the nuclear translocation of NF-κB p65 in the LPS- activated RAW264.7 cells.

Jatrophane Diterpenoids with Kv1.3 Ion Channel Inhibitory Effects from Euphorbia helioscopia.

Chemical investigation of bioactive components from the whole plant of Euphorbia helioscopia resulted in the isolation and identification of 17 new jatrophane diterpenoids, namely, heliojatrone D (1) and helioscopids A-P (2-17), along with 11 known analogues (18-28). The structural elucidation of the new diterpenoids was achieved by the comprehensive analysis of HRESIMS, NMR, and X-ray crystallographic data, as well as using electronic circular dichroism. Structurally, heliojatone D (1) is the fourth natural diterpenoid with a rare bicyclo[8.3.0]tridecane skeleton. The inhibitory effect of the isolated diterpenoids against Kv1.3 ion channels was evaluated in a human embryonic kidney 293 cell model transfected with plasmid encoding Kv1.3, resulting in the identification of a series of potent Kv1.3 ion channel inhibitors, with the most active ones (2 and 15) showing IC50 values of 0.9 µM.

Diterpenoids with Rearranged 9(10→11)-abeo-10,12-Cyclojatrophane Skeleton and the First (15S)-Jatrophane from Euphorbia helioscopia: Structural Elucidation, Biomimetic Conversion, and Their Immunosuppressive Effects.

Two novel diterpenoids, one with a rearranged trans,trans-fused tricyclo[10.3.0.04,6]pentadecane framework (1) and the other with an unprecedented 15S configuration (2), were isolated from Euphorbia helioscopia. Their structures were elucidated by extensive analysis of HR-ESI-MS, NMR, quantum-chemical calculation, and X-ray crystallographic data. Biosynthetically, 1 has a unique "cyclopropane-shift-like" biogenesis involving an oxa-di-π-methane (ODPM) rearrangement, which inspired us to accomplish the biomimetic conversion of 3 to 1. Moreover, compound 1 displayed a potent immunosuppressive effect by inhibiting Kv1.3 voltage-gated channels.

Sesquiterpenoids from Ixeris sonchifolia and their neuroprotective activities.

The phytochemical investigation of the methanol extract of Ixeris sonchifolia led to the isolation and identification of nine analogs, including one new guaiane-type sesquiterpenoid, named ixerinoid A (1). The structure of 1 was determined by extensive analysis of the 1 D and 2 D nuclear magnetic resonance spectroscopic data, as well as quantum chemical calculations. Additionally, all the isolates were tested for their neuroprotective activity using the oxygen-glucose deprivation/reperfusion-induced SH-SY5Y cell injury model. Compounds 3, 5, 6, 8, and 9 displayed remarkable protective effects at concentrations of 1, 5, and 10 µM, respectively.

Stelleranoids A-M, guaiane-type sesquiterpenoids based on [5,7] bicyclic system from Stellera chamaejasme and their cytotoxic activity.

Thirteen previously undescribed guaiane-type sesquiterpenoids based on [5,7] bicyclic system, stelleranoids A-M (1-13), along with six known analogues (14-20), were isolated from the roots of Stellera chamaejasme with chromatographic techniques. Their structures including absolute configurations were determined by HRESIMS and spectroscopic data, quantum chemical calculations, as well as X-ray crystallographic analysis. Cytotoxicity test in three cell lines indicated that compound 14 had relatively stronger cytotoxic effect against MKN-45, SKOV3, and Du145 cell lines with IC50 of 9.8, 17.4 and 7.3 µM, respectively; compounds 3 and 8 displayed moderate cytotoxic effect against MKN-45 and Du145 cell lines with IC50 ranged from 14.5 to 18.8 µM, comparable to those of the positive control. As determined by fluorescent microscopy and flow cytometry in Du145 cell line, compound 14 could promote cell apoptosis and cause cell cycle arrest at the G0/G1 phase, leading to the inhibition of cell proliferation. Further Western blot analysis revealed that this inhibitory effect was accompanied by upregulating pro-apoptosis proteins cleaved-PARP, cleaved-Caspase-9 and tumor suppressor protein p53 while downregulating anti-apoptotic protein Bcl-2 in 14-treated Du145 cells.

Structurally diverse alkaloids from Buxus sempervirens with cardioprotective activity.

Extensive phytochemical study of the methanol extract of twigs and leaves of Buxus sempervirens resulted in the identification of 17 Buxus alkaloids, including 12 new ones, namely buxusemines A-L (1-12). Their structures were delineated by detailed analysis of the HRESIMS and NMR data, as well as quantum chemical NMR calculations. Buxusemine A (1) represents the second Buxus alkaloid with a unique spiro[4.6]undecatriene moiety, buxusemines B-C (2-3) are a rarely occurring class of Buxus alkaloids featured with an additional five-membered ring through the ether or lactone linkage between C-10 and C-23, and buxusemines D-F (4-6) are another rare type of Buxus alkaloids with an epoxy motif. In the assessment of their bioactivities, buxusemine F (6) and buxanoldine (17) displayed more potent protective effects than the positive control cyclovirobuxinum D in the doxorubicin-induced cardiac injury model.

Pyrrolizidine alkaloids from the seeds of Scleropyrum wallichianum.

Two new pyrrolizidine alkaloids, sclerwalins A and B (1 and 2), and one known 9-O-E-hydroxysenecioylretronecine (3) were first isolated from the seeds of Scleropyrum wallichianum. Their chemical structures were elucidated by extensive 1 D NMR and 2 D NMR (HSQC, HMBC, COSY, and ROESY), MS and IR spectra. Cytotoxicities of all isolates were evaluated against five human tumor cell lines (HL-60, A-549, SMMC-7721, MCF-7 and SW480).[Formula: see text].

Hypolipidemic and Hepatoprotective Effects of Polysaccharides Extracted from Liriope spicata Var. Prolifera in C57BL/6J Mice with High-Fat Diet-Induced Hyperlipidemia.

In this study, C57BL/6J mice with high-fat diet- (HFD-) induced hyperlipidemia were treated with total Liriope spicata var. prolifera polysaccharides (TLSP: 200, 400, and 800 mg/kg body weight), simvastatin (3 mg/kg body weight), or saline for 8 weeks, respectively. The results showed that TLSP had strong lipid-lowering and hepatoprotective effects on C57BL/6J mice with HFD-induced hyperlipidemia. TLSP administration significantly reduced serum total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C) levels and downregulated the expressions of peroxisome proliferator-activated receptor (PPAR)γ and fatty acid synthase (FAS) in the adipose and liver tissues of the mice. TLSP exerted hypolipidemic and hepatoprotective effects by activating lipid/bile acid metabolism via the FXH-SHP/CYP7A1 and SEBP-1c/FAC/ACC signaling pathways. Thus, TLPS is a promising natural polymer with hepatoprotective and hypolipidemic properties.

Buxus alkaloid compound destabilizes mutant p53 through inhibition of the HSF1 chaperone axis.

BACKGROUND: P53 is the most frequently mutated gene in most tumour types, and the mutant p53 protein accumulates at high levels in tumours to promote tumour development and progression. Thus, targeting mutant p53 for degradation is one of the therapeutic strategies used to manage tumours that depend on mutant p53 for survival. Buxus alkaloids are traditionally used in the treatment of cardiovascular diseases. We found that triterpenoid alkaloids extracted from Buxus sinica found in the Yunnan Province exhibit anticancer activity by depleting mutant p53 levels in colon cancer cells. PURPOSE: To explore the anticancer mechanism of action of the triterpenoid alkaloid KBA01 compound by targeting mutant p53 degradation. STUDY DESIGN AND METHODS: Different mutant p53 cell lines were used to evaluate the anticancer activity of KBA01. MTT assay, colony formation assay and cell cycle analysis were performed to examine the effect of KBA01 on cancer cell proliferation. Western blotting and qPCR were used to investigate effects of depleting mutant p53, and a ubiquitination assay was used to determine mutant p53 ubiquitin levels after cells were treated with the compound. Co-IP and small interfering RNA assays were used to explore the effects of KBA01 on the interaction of Hsp90 with mutant p53. RESULTS: The triterpenoid alkaloid KBA01 can induce G2/M cell cycle arrest and the apoptosis of HT29 colon cancer cells. KBA01 decreases the stability of DNA contact mutant p53 proteins through the proteasomal pathway with minimal effects on p53 mutant protein conformation. Moreover, KBA01 enhances the interaction of mutant p53 with Hsp70, CHIP and MDM2, and knocking down CHIP and MDM2 stabilizes mutant p53 levels in KBA01-treated cells. In addition, KBA01 disrupts the HSF1-mutant p53-Hsp90 complex and releases mutant p53 to enable its MDM2- and CHIP-mediated degradation. CONCLUSION: Our study reveals that KBA01 depletes mutant p53 protein in a chaperone-assisted ubiquitin/proteasome degradation pathway in cancer cells, providing insights into potential strategies to target mutant p53 tumours.

A new bile acid from the traditional chinese medicine shedan.

A new bile acid tauro-16ß-hydroxy-12α-sulfate-5ß-cholenoic acid (1), along with six known ones (2-7), was isolated from the snake bile. Its planar structure and relative configuration were elucidated based on extensive spectroscopic analyses. Moreover, compound 2 showed inhibitory effect on NO production in RAW 264.7 macrophages at non-cytotoxic concentration (20 µM) with inhibitory rate of 69.7%. [Formula: see text].

Buxaustroines A-N, a Series of 17(13→18)abeo-Cycloartenol Triterpenoidal Alkaloids from Buxus austro-yunnanensis and Their Cardioprotective Activities.

Buxaustroines A-N (1-14), a series of triterpenoidal alkaloids featuring a novel 17(13→18)abeo motif, were obtained from the extract of Buxus austro-yunnanensis. Their structures were assigned based on NMR data analysis and X-ray diffraction crystallography. A putative biosynthetic pathway for one of the alkaloids from a co-isolate 15 is proposed. In the assessment of their bioactivities, some of the compounds displayed protective effects against doxorubicin-induced injury of myocardial cells. Preliminary structure-activity relationship studies of 1-14, which are based on the same skeleton, were conducted.

Cytotoxic Limonoids from the Twigs and Leaves of Toona ciliata.

Eight new limonoids, toononoids A-H (1-8), eight new B-seco-29-norlimonoids, toonanoronoids A-H (9-16), and seven known analogues were obtained from the EtOAc extract of the twigs and leaves of Toona ciliata. Compounds 2, 4, 8, and 16 are rare lactam-bearing limonoids. Compounds 1, 14, and 15 possess an unusual γ-methoxybutenolide moiety at C-17, while compounds 9, 10, and 15 have a rare 3ß-hydroxy group. Their 2D structure and relative configurations were identified using spectroscopic data. The absolute configurations of 1, 9, 14, and 15 were established via X-ray diffraction crystallography or comparison of experimental and calculated ECD data. The cytotoxicity of the compounds was assessed toward five human tumor cell lines, and their anti-inflammatory activity was assessed based on NO production using LPS-stimulated RAW264.7 macrophages. Compounds 11 and 12 exerted inhibition toward two tumor cell lines (MCF-7, SW-480) with IC50 values between 2.1 and 3.7 µM, while 18-22 inhibited the proliferation of HL-60, MCF-7, and SW-480 cells (IC50 0.6-4.0 µM). Only compound 4 exhibited weak anti-inflammatory activity with an IC50 value of 28.3 µM.

Pepluanols C-D, Two Diterpenoids with Two Skeletons from Euphorbia peplus.

Pepluanols C and D (1 and 2), featuring unprecedented 5/5/10 with out,out-[7.2.1]bicylcododecane core and 6/6/7/3 fused-ring skeletons, respectively, were isolated from Euphorbia peplus. Their chemical structures and absolute configurations were determined by a series of extensive spectroscopic methods, and X-ray diffraction analysis. In addition, pepluanols C and D showed 31.6 ± 8.3% and 30.5 ± 2.8% peak current inhibition on the Kv1.3 potassium channel at 30 µM.

Identification of mangiferin as a potential Glucokinase activator by structure-based virtual ligand screening.

The natural product mangiferin (compound 7) has been identified as a potential glucokinase activator by structure-based virtual ligand screening. It was proved by enzyme activation experiment and cell-based assays in vitro, with potency in micromolar range. Meanwhile, this compound showed good antihyperglycemic activity in db/db mice without obvious side effects such as excessive hypoglycaemia.

Lactam Triterpenoids from the Bark of Toona sinensis.

Three new limonoid-type triterpenoids, namely toonasins A-C (1-3) with a rare lactam E ring, along with six known compounds (4-9) were isolated from the barks of Toona sinensis. The structures of new compounds were elucidated by interpretation of spectroscopic data, and the relative configuration of compound 1 was further characterized by X-ray crystallographic analyses. The isolated compounds were evaluated for their cytotoxic activities against five human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW480), and compounds 3 and 5 showed weak cytotoxicities.

Cytotoxicity of Triterpenoid Alkaloids from Buxus microphylla against Human Tumor Cell Lines.

Three new triterpenoid alkaloids, namely buxmicrophyllines P-R (1-3), were isolated from the twigs and leaves of Buxus microphylla. Their structures were elucidated on the basis of NMR and MS spectroscopic analyses. Structurally, compounds 1-3 belong to the 9,10-cycloartane type alkaloids. In addition, compound 3 exhibited moderate cytotoxic activities in vitro against HL-60, SMMC-7221, A-549, MCF-7, and SW480 cell lines (with IC50 values ranging from 4.51 to 15.58 µM).

Characterization of New Ent-kaurane Diterpenoids of Yunnan Arabica Coffee Beans.

Five new ent-kaurane diterpenoids, named mascaroside III-V (1-3), and 20-nor-cofaryloside I-II (4-5), together with seven known diterpenoids, were isolated from methanol extracts of the green coffee beans of Yunnan Arabica Coffee. Their chemical structures were elucidated by extensive spectroscopic analyses. Meanwhile, cytotoxicity assay against HL-60, A-549, SMMC-7721, MCF-7 and SW480 cell lines showed that they have not evident inhibition of cytotoxicity.

Six New 9,19-Cycloartane Triterpenoids from Cimicifuga foetida L.

Six new 9,19-cycloartane triterpene derivatives, as well as 3 known analogues (7-9), were isolated from the roots of Cimicifuga foetida L. Their structures were established on the basis of extensive spectroscopic analyses (IR, UV, ORD, HRESIMS, 1D and 2D NMR).