土震素B类似物的合成及其抑制乙酰胆碱酯酶作用的研究

 目的　探索土震素B结构类似物对乙酰胆碱酯酶抑制作用的构效关系。方法　以强效乙酰胆碱酯酶抑制剂土震素B为先导化合物 ,对天然产物酸枣仁皂苷元进行结构简化和改造 ,使其形成A/B环与土震素B一致的立体结构 ,并再引入土震素系列化合物中的芳基结构。用Elisa法测试了所合成的化合物对乙酰胆碱酯酶的抑制活性。结果　合成了两个系列的土震素B的类似物,其中化合物7c和15在10^-4mol·L^-1条件下分别显示出乙酰胆碱酯酶26%和32%的抑制活性。结论　初步探明了此类具有与土震素B的A/B环的立体化学一致的2-烯-1-酮A环结构以及含芳基酯基药效团的化合物对乙酰胆碱酯酶有一定的抑制活性。     

Scutellarin,a modulator of mTOR,attenuates hepatic insulin resistance by regulating hepatocyte lipid metabolism via SREBP‐1c suppression

High levels of consumption of saturated lipids have been largely associated with the increasing prevalence of metabolic diseases. In particular, saturated fatty acids such as palmitic acid (PA) have been implicated in the development of insulin resistance (IR). Scutellarin (Scu) is one of the effective traditional Chinese medicines considered beneficial for liver diseases and diabetes. In this study, we investigated the effect of Scu on IR and lipid metabolism disorders in vitro and in high fat diet (HFD)‐fed mice. In vitro, we found that Scu decreased insulin‐dependent lipid accumulation and the mRNA expression of CD36, Fasn, and ACC in PA‐treated HepG2 cells. Additionally, Scu upregulated Akt phosphorylation and improved the insulin signalling pathway. Moreover, Scu downregulated mammalian target of rapamycin (mTOR) phosphorylation and the n‐SREBP‐1c protein level and also reduced lipid accumulation via the mTOR‐dependent pathway, as confirmed by the molecular docking of Scu to mTOR. In HFD‐fed C57BL/6 mice, Scu improved oral glucose tolerance, pyruvate tolerance and the IR index and also increased the Akt phosphorylation level. Moreover, Scu reduced hepatocyte steatosis, decreased lipid accumulation and triglyceride levels, inhibited mTOR phosphorylation, and decreased the SREBP‐1c level in the liver. Taken together, these findings suggest that Scu ameliorates hepatic IR by regulating hepatocyte lipid metabolism via the mTOR‐dependent pathway through SREBP‐1c suppression.     

Growth inhibition of human lung cancer cells via down-regulation of epidermal growth factor receptor signaling by yuanhuadine, a daphnane diterpene from Daphne genkwa

The growth inhibition and antitumor activities of yuanhuadine (1), a daphnane diterpenoid from the flowers of Daphne genkwa, were investigated in human lung cancer cells. Compound 1 exhibited a relatively selective growth inhibition against human lung cancer cells compared to other solid human cancer cell lines. The potent antiproliferative activity by 1 was associated with cell-cycle arrest and modulation of cell-signaling pathways. Cell-cycle arrest in the G0/G1 and G2/M phase was induced by 1 in A549 human non-small-cell lung cancer cells, and these events were correlated with the expression of checkpoint proteins including the up-regulation of p21 and down-regulation of cyclins, cyclin-dependent kinases 2 (CDK2) and 4 (CDK4), and c-Myc. Compound 1 also suppressed the expression of the Akt/mammalian target of rapamycin (mTOR) and its downstream effector molecules including p70 S6 kinase (p70S6K) and eukaryotic initiation factor 4E-binding protein 1 (4EBP1). Ligand-induced epidermal growth factor receptor (EGFR) and c-Met signaling were also inhibited by 1. The oral administration of 1 (0.5 mg/kg body weight, daily) for 14 days significantly inhibited tumor growth in athymic xenograft nude mouse model bearing human lung A549 cells, without any overt toxicity. Synergistic antiproliferative effects of compound 1 were also found in combination with the EGFR inhibitor gefitinib. Cell-cycle arrest and suppression of Akt/mTOR and EGFR signaling pathways might be plausible mechanisms of actions for the antiproliferative and antitumor activity of 1 in human non-small-cell lung cancer cells.     

电针通过调节AMPK/mTOR/ULK1信号通路对衰老小鼠肝脏自噬与氧化应激的影响

目的:观察电针对衰老小鼠体力及肝脏AMP活化的蛋白激酶(AMPK)、哺乳动物雷帕霉素靶蛋白(mTOR)、unc-51样自噬激活激酶1(ULK1)、Atg5、Atg7、Atg13和Beclin1表达的影响,探索其通过激活AMPK/mTOR/ULK1通路延缓衰老的机制.方法:将30周龄雄性SAMP8小鼠随机分为模型组、雷帕...     

Kaempferitrin inhibits proliferation,induces apoptosis,and ameliorates inflammation in human rheumatoid arthritis fibroblast‐like synoviocytes

Rheumatoid arthritis (RA) is a complex chronic inflammatory disease that is associated with the aberrant activation of fibroblast‐like synoviocytes (FLS). Kaempferitrin is a natural flavonoid glycoside that possesses anti‐inflammatory bioactivity. However, the effect of kaempferitrin on RA has not yet been revealed. The aim of the present study was to investigate the effect of kaempferitrin on human RA‐FLS MH7A cell line. We found that kaempferitrin inhibited proliferation and induced apoptosis of MH7A cells. Kaempferitrin decreased the levels of interleukin (IL)‐1β, IL‐6, tumor necrosis factor (TNF)‐α, matrix metalloproteinase (MMP)‐1, and MMP‐3 in MH7A cells. Moreover, kaempferitrin blocked the activation of nuclear factor‐κB (NF‐κB) and protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathways. Furthermore, treatment with kaempferitrin decreased paw thickness and arthritis scores, and reduced the serum levels of IL‐1β, IL‐6, and TNF‐α in a collagen‐induced arthritis mouse model. In conclusion, kaempferitrin inhibited cell proliferation, induced cell apoptosis, and ameliorated inflammation of RA‐FLS by suppressing the NF‐κB and Akt/mTOR pathways.     

Structural assignment of poecillastrins B and C, macrolide lactams from the deep-water Caribbean sponge Poecillastra species

Two new chondropsin-type macrolide lactams, poecillastrins B (1) and C (2), were isolated from aqueous extracts of the marine sponge Poecillastra sp. These trace metabolites were isolated in low yield (400-600 microg), and their structures were determined primarily by analysis of NMR data acquired using a cyrogenically cooled probe. High-quality 1D and 2D NMR data sets allowed complete assignment of the spectroscopic data and defined the new structures as 35-membered ring analogues of poecillastrin A (3). Compounds 1 and 2 showed potent cytotoxic activity against a human melanoma tumor cell line (LOX) with an IC50 value of less than 1 microg/mL.     

Online analysis of xestodecalactones A-C,novel bioactive metabolites from the fungus Penicillium cf. montanense and their subsequent isolation from the sponge Xestospongia exigua

Fungal isolates of Penicillium cf. montanense were obtained from the marine sponge Xestospongia exiguacollected from the Bali Sea, Indonesia. Culture filtrates of the fungi yielded three novel decalactone metabolites, xestodecalactones A, B, and C (1, 2a, and 2b), consisting of 10-membered macrolides with a fused 1,3-dihydroxybenzene ring. Online HPLC-NMR, ESI-MS/MS, and -CD spectra were acquired, and the structures of the new compounds were established and confirmed on the basis of offline NMR spectroscopic ((1)H, (13)C, COSY, ROESY, (1)H-detected direct and long-range (13)C-(1)H correlations) and mass spectrometric (EIMS) data. Quantum chemical calculations of the CD spectra proved to be difficult because of the conformational flexibility of the xestodecalactones. These compounds, of which 2a and 2b, due to the additional stereocenter at C-9, are diastereomeric compounds, are structurally related to a number of biologically active metabolites found in terrestrial fungal strains. Compound 2a was found to be active against the yeast Candida albicans.     

Alpha-glucosidase inhibitory anthranols, kenganthranols A-C, from the stem bark of Harungana madagascariensis

One new prenylated 1,4-anthraquinone and three new prenylated anthranols, named kengaquinone (1) and kenganthranols A (2), B (3), and C (4), were isolated from a hexane extract of the stem bark of Harungana madagascariensis. Six known compounds including anthraquinones, anthrones, and xanthones were also isolated and identified. The structures of the new compounds were determined by analysis of spectroscopic data and comparison with data of previously known analogues. Some isolated compounds (3-5, 7-11) were evaluated for their alpha-glucosidase inhibition activity. Compounds 3, 4, 8, and 11 showed significant activity, whereas compounds 7, 9, and 10 were inactive in this test.     

Myo-inositol-derived glycolipids with anti-inflammatory activity from Solanum lanceolatum

Lanceolitols A1-A7 (1-7) and B1-B7 (9-15), two series of new myo-inositol-derived glycolipid analogues, in which a sugar moiety is replaced by a fatty acid esterified myo-inositol moiety, were isolated from the leaves of Solanum lanceolatum. Their structures were elucidated on the basis of spectroscopic analysis (1H NMR, 13C NMR, 1H-1H COSY, HMQC, HMBC, and HRFABMS), as well as chemical analysis. All the compounds showed in vivo anti-inflammatory activity against ear edema in mice produced by 12-O-tetradecanoylphorbol-13-acetate (TPA). In vitro enzyme inhibition studies showed that the mixture of lanceolitols A1-A7 inhibited by 58.56% phospholipase A2 from bee venom, while the mixture of lanceolitols B1-B7 was cyclooxygenase-2 (COX-2) inhibitors (IC50 = 237 microM).     

Formononetin attenuates cigarette smoke-induced COPD in mice by suppressing inflammation,endoplasmic reticulum stress,and apoptosis in bronchial epithelial cells via AhR/CYP1A1 and AKT/mTOR signaling pathways

Chronic obstructive pulmonary disease (COPD) is a chronic, progressive, and lethal lung disease with few treatments. Formononetin (FMN) is a clinical preparation extract with extensive pharmacological actions. However, its effect on COPD remains unknown. This study aimed to explore the effect and underlying mechanisms of FMN on COPD. A mouse model of COPD was established by exposure to cigarette smoke (CS) for 24 weeks. In addition, bronchial epithelial BEAS-2B cells were treated with CS extract (CSE) for 24 h to explore the in vitro effect of FMN. FMN significantly improved lung function and attenuated pathological lung damage. FMN treatment reduced inflammatory cell infiltration and pro-inflammatory cytokines secretion. FMN also suppressed apoptosis by regulating apoptosis-associated proteins. Moreover, FMN relieved CS-induced endoplasmic reticulum (ER) stress in the mouse lungs. In BEAS-2B cells, FMN treatment reduced CSE-induced inflammation, ER stress, and apoptosis. Mechanistically, FMN downregulated the CS-activated AhR/CYP1A1 and AKT/mTOR signaling pathways in vivo and in vitro. FMN can attenuate CS-induced COPD in mice by suppressing inflammation, ER stress, and apoptosis in bronchial epithelial cells via the inhibition of AhR/CYP1A1 and AKT/mTOR signaling pathways, suggesting a new therapeutic potential for COPD treatment.     

Retracted: Ganoderic acid A alleviates hypoxia‐induced apoptosis,autophagy, and inflammation in rat neural stem cells through the PI3K/AKT/mTOR pathways

Effects of ganoderic acid A (GAA), a lanostane triterpene, on hypoxia‐ischemia encephalopathy (HIE) remain unclear. We aimed to figure out the specific role of GAA in hypoxia‐treated neural stem cells (NSCs) as well as the regulatory mechanisms. Primary rat NSCs were incubated under hypoxia to simulate HIE. Viability and apoptosis of hypoxia‐injured NSCs were measured by cell counting kit‐8 and flow cytometry assays, respectively. Proteins related to apoptosis, autophagy, and the PI3K/AKT/mTOR pathways were evaluated by Western blot analysis. LY294002 and rapamycin were added to inhibit the PI3K/AKT pathway and mTOR pathway, respectively. Enzyme‐linked immunosorbent assay was carried out to test the release of proinflammatory cytokines. We found that hypoxia‐induced decrease of cell viability, increases of apoptotic cells and autophagy, and the release of IL‐6, IL‐1β, and TNF‐α were all attenuated by GAA stimulation. Activation of caspases induced by hypoxia was alleviated by GAA. Furthermore, we found that inhibition of the PI3K/AKT pathway eliminated the effects of GAA on apoptosis and proinflammatory cytokines release in hypoxia‐injured NSCs. Meanwhile, inhibition of the mTOR pathway abrogated the effects of GAA on cell autophagy in hypoxia‐injured NSCs. In conclusion, GAA alleviated hypoxia‐induced injury in NSCs might be through activating the PI3K/AKT and mTOR pathways.     

Saponins and flavonoids of Allium triquetrum

A phytochemical investigation of the flowers and bulbs of Allium triquetrum has been undertaken, leading to the isolation of five new furostanol saponins, triquetrosides A1/A2 (1a/1b), B (3), and C1/C2 (4a/4b), from the flowers, along with ascalonisides A1/A2 (6a/6b). The 22-O-methyl derivatives of triquetrosides A1/A2 (2a and 2b) and C1/C2 (5a and 5b) were also isolated, but they are considered extraction artifacts. Large amounts of seven kaempferol glycosides, of which one (7) has a new structure, were also isolated from both flowers and bulbs. The structures of the new compounds were determined by spectral and chemical methods.     

Iridoid glucosides and p-coumaroyl iridoids from Viburnum luzonicum and their cytotoxicity

Four new iridoids glucosides (1-4) and seven new iridoid aglycons (5-11) bearing (E)- or (Z)-p-coumaroyl groups were isolated from a methanol extract of the dried leaves of Viburnum luzonicum collected in Kaoshiung, Taiwan. The structures of the new compounds, named luzonoside A (1), luzonoside B (2), luzonoside C (3), luzonoside D (4), luzonoid A (5), luzonoid B (6), luzonoid C (7), luzonoid D (8), luzonoid E (9), luzonoid F (10), and luzonoid G (11), were elucidated by analysis of spectroscopic data and comparison with values for previously known analogues. Among the iridoids isolated in the present study, glucosides 1 and 2, and their aglycons 5-9, exhibited moderate inhibitory activity against HeLa S3 cancer cells, whereas 3 and 4 showed no cytotoxicity even at 100 microM.     

活血消瘿方含药血清调控AMPK/mTOR通路对脂多糖诱导的甲状腺滤泡上皮细胞自噬和凋亡的影响

目的 探讨活血消瘿方含药血清对脂多糖(LPS)诱导的甲状腺滤泡上皮细胞(TFECs)自噬和凋亡的影响以及作用机制。方法 光学显微镜观察分离培养的SD大鼠TFECs细胞的形态;免疫荧光染色鉴定TFECs中特异抗原甲状腺球蛋白(Tg)。取对数生长期的TFECs,分为对照组、LPS组、含药血清组、含药血清+compound C(AMPK抑制剂)组、含药血清+MHY1485(mTOR激活剂)组,MTT法检测各组细胞活力;绿色荧光蛋白(GFP)标记质粒转染检测各组细胞自噬小体变化;流式细胞术检测各组细胞凋亡;western blot检测各组细胞中微管相关蛋白1轻链3(LC3)I、LC3II、Beclin1、Bcl-2相关X蛋白(Bax)、B淋巴细胞瘤-2(Bcl-2)及AMP活化蛋白激酶(AMPK)/哺乳动物雷帕霉素靶蛋白(mTOR)通路相关蛋白表达。结果 光学显微镜观察显示,TFECs形态为梭形、形态均一,且可成簇生长。免疫荧光结果显示,TFECs细胞质中可见较强的Tg荧光染色。与对照组比较,LPS组TFECs细胞活力、自噬小体数量、LC3II/LC3I、Beclin1、Bcl-2、p-AMPK/AMPK蛋白相对表达量显著降低,炎性因子IL-6 、TNF-α水平、细胞凋亡率、Bax、p-mTOR/mTOR蛋白相对表达量显著升高(P< 0.05);与LPS组比较,含药血清组TFECs细胞活力、自噬小体数量、LC3II/LC3I、Beclin1、Bcl-2、p-AMPK/AMPK蛋白相对表达量显著升高,炎性因子IL-6 、 TNF-α水平、细胞凋亡率、Bax、p-mTOR/mTOR蛋白相对表达量显著降低(P< 0.05);与含药血清组比较,含药血清+compound C组、含药血清+MHY1485组TFECs中相应指标与上述趋势相反。结论 活血消瘿方含药血清对LPS诱导的TFECs自噬的促进作用及细胞凋亡的抑制作用可能与激活AMPK/mTOR通路有关。     

Dictyoquinazols A,B, and C,new neuroprotective compounds from the mushroom Dictyophora indusiata

In an effort to identify neuroprotective compounds against excitatory neurotoxins from edible and medicinal mushrooms, dictyoquinazols A (1), B (2), and C (3) have been isolated from the methanolic extract of the mushroom Dictyophora indusiata. On the basis of NMR studies, their structures have been assigned as unique quinazoline compounds, which are very rare in nature. 2 and 3 existed as mixtures of rotamers (2a, 2b and 3a, 3b) inseparable by HPLC because of fast interconversion. The E/Z isomers of these compounds were assigned by comparison of (1)H NMR, (13)C NMR, and NOESY spectra and by (3)J(C,H) coupling constants. Dictyoquinazols protected primary cultured mouse cortical neurons from glutamate- and NMDA-induced excitotoxicities in a dose-dependent manner.     

Inhibitory potential of three Yin-tonification herbal formulas on the activities of human major cytochrome P450 and UDP-glucuronosyltransferases isozymes in vitro

OBJECTIVE:To investigate the influence of Yin-tonification herbal formulas Jaeumganghwa-tang(Ziyin Jianghuo Tang,JEGHT),Ssanghwa-tang(Shuanghe Tang,SHT) and Yukmijihwang-tang(Liuwei Di huang Tang,YMJHT) on the activities of human major cytochrome P450(CYP450 s) and UDP-glucuronosyltransferases isozymes(UGTs) in vitro.METHODS:The activities of CYP450 s(CYP1 A2,CYP3 A4,CYP2 B6,CYP2 C9,CYP2 C19,CYP2 D6 and CYP2 E1) and UGTs(UGT1 A1,UGT1 A4 and UGT2 B7)were assessed using in vitro fluorescence-and luminescence-based enzyme assays,respectively.The effects of herbal formulas on the activities of CYP450 s and UGTs were presented as IC50 values.RESULTS:JEGHT showed the potent inhibition of the CYP2 D6 activity,with weak inhibition on the activities of CYP1 A2,CYP2 B6,CYP2 C9,CYP2 C19,CYP2 E1,CYP3 A4,UGT1 A1,UGT1 A4 and UGT2 B7.SHT inhibited the activities of CYP1 A2 and CYP2 E1,whereas the negligible inhibition of the activities of CYP2 B6,CYP2 C9,CYP2 C19,CYP2 D6,CYP3 A4,UGT1 A1,UGT1 A4 and UGT2 B7 through SHT was observed.YMJHT inhibited CYP2 E1 activity,with a negligible inhibition on the activities of CYP1 A2,CYP2 B6,CYP2 C9,CYP2 C19,CYP2 D6,CYP3 A4,UGT1 A1,UGT1 A4 and UGT2 B7.CONCLUSION:These findings provide information about the potential interactions between three Yin-tonification herbal formulas and conventional drugs.     

Chrysophanic acid blocks proliferation of colon cancer cells by inhibiting EGFR/mTOR pathway

Inactivation of epidermal growth factor receptor (EGFR) is a prime method used in colon cancer therapy. Here it is shown that chrysophanic acid, a natural anthraquinone, has anticancer activity in EGFR-overexpressing SNU-C5 human colon cancer cells. Chrysophanic acid preferentially blocked proliferation in SNU-C5 cells but not in other cell lines (HT7, HT29, KM12C, SW480, HCT116 and SNU-C4) with low levels of EGFR expression. Chrysophanic acid treatment in SNU-C5 cells inhibited EGF-induced phosphorylation of EGFR and suppressed activation of downstream signaling molecules, such as AKT, extracellular signal-regulated kinase (ERK) and the mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase (p70S6K). Chrysophanic acid (80 and 120 μm) significantly blocked cell proliferation when combined with the mTOR inhibitor, rapamycin. These findings offer the first evidence of anticancer activity for chrysophanic acid via EGFR/mTOR mediated signaling transduction pathway.     

Octanorcucurbitane and cucurbitane triterpenoids from the tubers of Hemsleya endecaphylla with HIV-1 inhibitory activity

Two new cucurbitacins, endecaphyllacins A (1) and B (2), together with six known analogues (3-8), were isolated from the tubers of Hemsleya endecaphylla. The structures of 1 and 2 were elucidated by NMR and MS spectroscopic analysis. The relative stereochemistry of 1 was determined by single-crystal X-ray diffraction. Compound 4 (cucurbitacin B) showed potent anti-HIV-1 in C8166 cells (EC=0.09 microg/mL) with a selectivity index of 16.7.     

Olive Oil‐derived Oleocanthal as Potent Inhibitor of Mammalian Target of Rapamycin: Biological Evaluation and Molecular Modeling Studies

The established anticancer and neuroprotective properties of oleocanthal combined with the reported role of mammalian target of rapamycin (mTOR) in cancer and Alzheimer's disease development encouraged us to examine the possibility that oleocanthal inhibits mTOR. To validate this hypothesis, we docked oleocanthal into the adenosine triphosphate binding pocket of a close mTOR protein homologue, namely, PI3K‐γ. Apparently, oleocanthal shared nine out of ten critical binding interactions with a potent dual PIK3‐γ/mTOR natural inhibitor. Subsequent experimental validation indicated that oleocanthal indeed inhibited the enzymatic activity of mTOR with an IC₅₀ value of 708 nM. Oleocanthal inhibits the growth of several breast cancer cell lines at low micromolar concentration in a dose‐dependent manner. Oleocanthal treatment caused a marked downregulation of phosphorylated mTOR in metastatic breast cancer cell line (MDA‐MB‐231). These results strongly indicate that mTOR inhibition is at least one of the factors of the reported anticancer and neuroprotective properties of oleocanthal. Copyright © 2015 John Wiley & Sons, Ltd.     

Terpenoids Produced by Actinomycetes: Napyradiomycins from Streptomyces antimycoticus NT17

Napyradiomycin SR ( 1), 16-dechloro-16-hydroxynapyradiomycin C2 ( 2), 18-hydroxynapyradiomycin A1 ( 3), 18-oxonapyradiomycin A1 ( 4), 16-oxonapyradiomycin A2 ( 5), 7-demethyl SF2415A3 ( 6), 7-demethyl A80915B ( 7), and ( R)-3-chloro-6-hydroxy-8-methoxy-alpha-lapachone ( 8) were isolated from the culture broth of Streptomyces antimycoticus NT17. These compounds are derivatives of the napyradiomycins isolated previously from Chainia rubra or Streptomyces aculeolatus. The structures of the new compounds, some of which exhibit antibacterial activities, were established by comparing their NMR data with data of related known compounds. The unique structure of 1, containing a highly strained ring, was established by NMR and was confirmed by X-ray analysis. Two of the compounds are C-16 stereoisomers of napyradiomycin A2 and are named napyradiomycins A2a ( 9a) and A2b ( 9b).