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1.
J Nat Prod ; 86(2): 276-289, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36746775

RESUMO

Sixteen new quinoline alkaloids (1a-7, 8a, 9, 10, 13-15, 17, and 21) and 10 known analogs (8b, 11, 12, 16, 18-20, and 22-24), along with three known cyclopeptide alkaloids (25-27), were isolated from the roots of Waltheria indica. The structures of the new compounds were elucidated by detailed NMR and circular dichroism with computational support and mass spectrometry data interpretation. Anti-inflammatory potential of isolates was evaluated based on inhibition of lipopolysaccharide (LPS)-induced nitric oxide (NO) production and tumor necrosis factor-alpha (TNF-α)-induced nuclear factor kappa B (NF-κB) activity with cell culture models. In the absence of cell growth inhibition, compounds 6, 8a, 9-11, 13, 21, and 24 reduced TNF-α-induced NF-κB activity with IC50 values ranging from 7.1 to 12.1 µM, comparable to the positive control (BAY 11-7082, IC50 = 9.7 µM). Compounds 6, 8a, 8b, and 11 showed significant NO-inhibitory activity with IC50 values ranging from 11.0 to 12.8 µM, being more active than the positive control (l-NMMA, IC50 = 22.7 µM). Structure-activity relationships indicated that NO inhibitory activity was significantly affected by C-8 substitution. Inhibition of LPS-induced nitric oxide synthase (iNOS) by 8b [(5S)-waltherione M, IC50 11.7 ± 0.8 µM] correlated with inhibition of iNOS mRNA expression. The biological potential of W. indica metabolites supports the traditional use of this plant for the treatment of inflammatory-related disorders.


Assuntos
Alcaloides , Malvaceae , Quinolinas , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Lipopolissacarídeos/farmacologia , Alcaloides/farmacologia , Anti-Inflamatórios/farmacologia , Malvaceae/química , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico
2.
Planta ; 255(1): 4, 2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34841446

RESUMO

MAIN CONCLUSION: Metabolites in Rafflesia-infected and non-infected Tetrastigma were compared which may have applications in Rafflesia propagation. Benzylisoquinoline alkaloids, here reported for the first time in Vitaceae, were abundant in non-infected shoots and may be a form of defense. In Rafflesia-infected shoots, oxylipins, which mediate immune response, were elevated. Endemic to the forests of Southeast Asia, Rafflesia (Rafflesiaceae) is a genus of holoparasitic plants producing the largest flowers in the world, yet completely dependent on its host, the tropical grape vine, Tetrastigma. Rafflesia species are threatened with extinction, making them an iconic symbol of plant conservation. Thus far, propagation has proved challenging, greatly decreasing efficacy of conservation efforts. This study compared the metabolites in the shoots of Rafflesia-infected and non-infected Tetrastigma loheri to examine how Rafflesia infection affects host metabolomics and elucidate the Rafflesia infection process. Results from LC-MS-based untargeted metabolomics analysis showed benzylisoquinoline alkaloids were naturally more abundant in non-infected shoots and are here reported for the first time in the genus Tetrastigma, and in the grape family, Vitaceae. These metabolites have been implicated in plant defense mechanisms and may prevent a Rafflesia infection. In Rafflesia-infected shoots, oxygenated fatty acids, or oxylipins, and a flavonoid, previously shown involved in plant immune response, were significantly elevated. This study provides a preliminary assessment of metabolites that differ between Rafflesia-infected and non-infected Tetrastigma hosts and may have applications in Rafflesia propagation to meet conservation goals.


Assuntos
Magnoliopsida , Parasitos , Vitaceae , Animais , Flores , Reprodução
3.
J Nat Prod ; 83(3): 730-737, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32163285

RESUMO

Two new helvolic acid analogues (1 and 2) and one new fumagillin derivative containing an octahydroisobenzofuran moiety (3), together with four known compounds (4-7), were isolated from an Aspergillus terreus, isolated from soil collected from Mauna Kea, the highest mountain in Hawaii. Compound 4 was recorded in SciFinder with a CAS Registry Number of 1379525-35-5, but it was not documented in the cited reference (ACS Chem. Biol. 2012, 7, 137). The structures of compounds 1-4 were elucidated by NMR spectroscopy and HRMS and ECD analysis. Compounds 5 and 6 showed significant inhibitory activity against NF-κB with IC50 values of 2.7 ± 2.6 and 6.5 ± 0.8 µM, respectively. Compounds 1 and 2 were active against S. aureus with MICs of 6.25 and 6.25 µg/mL, respectively, while compound 5 inhibited E. coli with an MIC of 3.12 µg/mL.


Assuntos
Antibacterianos/farmacologia , Aspergillus/química , Cicloexanos/farmacologia , Ácidos Graxos Insaturados/farmacologia , Ácido Fusídico/análogos & derivados , NF-kappa B/antagonistas & inibidores , Antibacterianos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Cicloexanos/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Ácidos Graxos Insaturados/isolamento & purificação , Ácido Fusídico/isolamento & purificação , Ácido Fusídico/farmacologia , Células HEK293 , Havaí , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Staphylococcus aureus/efeitos dos fármacos
4.
J Nat Prod ; 82(3): 492-499, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30649869

RESUMO

In previous studies, withanolides isolated from Physalis peruviana were found to exhibit anti-inflammatory potential by suppressing nitrite production induced by lipopolysaccharide (LPS) treatment. Currently, we selected two of the most potent compounds, 4ß-hydroxywithanolide E (1) and physalactone (2), to examine the underlying mechanism of action. With LPS-stimulated RAW 264.7 cells in culture, the compounds inhibited the mRNA and protein expression of iNOS and COX-2. To determine which upstream signaling proteins were involved in these effects, phosphorylation levels of three mitogen-activated protein kinases (MAPKs) including ERK1/2, JNK1/2, and p38, were examined, but found unaffected. Similarly, the degradation of IκBα was not attenuated by the compounds. However, phosphorylation of Akt at the Ser-473 residue was inhibited, as was the phosphorylation of STAT1. Interestingly, the compounds also reduced the protein level of total STAT1, possibly by ubiquitin-dependent protein degradation. In sum, these results indicate the potential of 1 and 2 to mediate anti-inflammatory effects through the unexpected mechanism of inhibiting the transcription of iNOS and COX-2 via Akt- and STAT1-related signaling pathways.


Assuntos
Ciclo-Oxigenase 2/metabolismo , Lactonas/farmacologia , Óxido Nítrico Sintase Tipo II/metabolismo , Physalis/química , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Transcrição STAT1/metabolismo , Vitanolídeos/farmacologia , Animais , Lactonas/isolamento & purificação , Lipopolissacarídeos , Camundongos , Fosforilação , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Vitanolídeos/isolamento & purificação
5.
Phytother Res ; 32(10): 2059-2068, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29998488

RESUMO

Toranja 'Burarama', Citrus maxima (Burm.) Merr. (Citrus grandis), is a new citrus discovered in the State of Espírito Santo, Brazil. As several varieties of citrus are known to possess antioxidant and cancer chemopreventive properties, the aim of the study was to evaluate in vitro if this Toranja possess these properties. The antioxidant activity, the potential to induce quinone reductase 1, and the influence on cell viability were measured. ESI(-)FT-ICR MS analysis was also performed and identified flavonoids, coumarins, and fatty acids in the extract. The ethyl acetate and methanolic extracts of the peels presented the highest antioxidant activity in vitro by DPPH (IC50  = 298.3 ± 2.6 µg/ml and 303.8 ± 0.4 µg/ml), ABTS assay (IC50  = 298.2 ± 6.4 µg/ml and 296.4 ± 2.5 µg/ml), and FRAP (IC50  = 234.6 ± 1.8 µg/ml and 398.1 ± 3.8 µg/ml). The ethyl acetate extract of the peel induced quinone reductase 1 activity in Hepa1c1c7 cells, indicating that C. maxima exhibited cancer chemopreventive properties.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Citrus/química , NAD(P)H Desidrogenase (Quinona)/metabolismo , Extratos Vegetais/farmacologia , Animais , Brasil , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cumarínicos/química , Cumarínicos/isolamento & purificação , Ácidos Graxos/química , Ácidos Graxos/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Frutas/química , Camundongos , Oxirredução
6.
Bioorg Med Chem Lett ; 27(20): 4630-4634, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28927792

RESUMO

Two new compounds heliotropiumides A (1) and B (2), phenolamides each with an uncommon carbamoyl putrescine moiety, were isolated from the seeds of a naturalized Hawaiian higher plant, Heliotropium foertherianum Diane & Hilger in the borage family, which is widely used for the treatment of ciguatera fish poisoning. The structures of compounds 1 and 2 were characterized based on MS spectroscopic and NMR analysis, and DP4+ calculations. The absolute configuration (AC) of compound 1 was determined by comparison of its optical rotation with those reported in literature. Compound 2 showed inhibition against NF-κB with an IC50 value of 36µM.


Assuntos
Amidas/farmacologia , Benzofuranos/química , Heliotropium/química , Fenóis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Amidas/química , Amidas/toxicidade , Anti-Infecciosos/química , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antineoplásicos Alquilantes/química , Antineoplásicos Alquilantes/isolamento & purificação , Antineoplásicos Alquilantes/farmacologia , Benzofuranos/farmacologia , Benzofuranos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Heliotropium/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Conformação Molecular , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Fenóis/farmacologia , Fenóis/toxicidade , Extratos Vegetais/uso terapêutico , Putrescina/química , Intoxicação por Frutos do Mar/prevenção & controle
7.
Bioorg Med Chem Lett ; 27(24): 5393-5399, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29153737

RESUMO

In our ongoing effort of discovering anticancer and chemopreventive agents, a series of 2-arylindole derivatives were synthesized and evaluated toward aromatase and quinone reductase 1 (QR1). Biological evaluation revealed that several compounds (e.g., 2d, IC50 = 1.61 µM; 21, IC50 = 3.05 µM; and 27, IC50 = 3.34 µM) showed aromatase inhibitory activity with half maximal inhibitory concentration (IC50) values in the low micromolar concentrations. With regard to the QR1 induction activity, 11 exhibited the highest QR1 induction ratio (IR) with a low concentration to double activity (CD) value (IR = 8.34, CD = 2.75 µM), while 7 showed the most potent CD value of 1.12 µM. A dual acting compound 24 showed aromatase inhibition (IC50 = 9.00 µM) as well as QR1 induction (CD = 5.76 µM) activities. Computational docking studies using CDOCKER (Discovery Studio 3.5) provided insight in regard to the potential binding modes of 2-arylindoles within the aromatase active site. Predominantly, the 2-arylindoles preferred binding with the 2-aryl group toward a small hydrophobic pocket within the active site. The C-5 electron withdrawing group on indole was predicted to have an important role and formed a hydrogen bond with Ser478 (OH). Alternatively, meta-pyridyl analogs may orient with the pyridyl 3'-nitrogen coordinating with the heme group.


Assuntos
Antineoplásicos/síntese química , Inibidores da Aromatase/química , Aromatase/química , Indóis/química , NAD(P)H Desidrogenase (Quinona)/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Aromatase/metabolismo , Inibidores da Aromatase/metabolismo , Sítios de Ligação , Domínio Catalítico , Linhagem Celular Tumoral , Humanos , Indóis/metabolismo , Indóis/farmacologia , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , NAD(P)H Desidrogenase (Quinona)/metabolismo , Relação Estrutura-Atividade
8.
Biochim Biophys Acta ; 1852(6): 1071-113, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25652123

RESUMO

In addition to thousands of research papers related to resveratrol (RSV), approximately 300 review articles have been published. Earlier research tended to focus on pharmacological activities of RSV related to cardiovascular systems, inflammation, and carcinogenesis/cancer development. More recently, the horizon has been broadened by exploring the potential effect of RSV on the aging process, diabetes, neurological dysfunction, etc. Herein, we primarily focus on the in vivo pharmacological effects of RSV reported over the past 5 years (2009-2014). In addition, recent clinical intervention studies performed with resveratrol are summarized. Some discrepancies exist between in vivo studies with animals and clinical studies, or between clinical studies, which are likely due to disparate doses of RSV, experimental settings, and subject variation. Nevertheless, many positive indications have been reported with mammals, so it is reasonable to advocate for the conduct of more definitive clinical studies. Since the safety profile is pristine, an added advantage is the use of RSV as a dietary supplement. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.


Assuntos
Estilbenos/farmacologia , Animais , Ensaios Clínicos como Assunto , Humanos , Publicações Periódicas como Assunto , Resveratrol , Estilbenos/uso terapêutico
9.
Bioorg Med Chem Lett ; 26(12): 2755-2759, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27210437

RESUMO

Three new withanolides, physaperuvin G (1), with physaperuvins I (2), and J (3), along with seven known derivatives (4-10), were isolated from the aerial parts of Physalis peruviana. The structures of 1-3 were determined by NMR, X-ray diffraction, and mass spectrometry. Compounds 1-10 were evaluated in lipopolysaccharide (LPS)-activated murine macrophage RAW 264.7 cells. Compounds 4, 5, and 10 with potent nitric oxide inhibitory activity in LPS-activated RAW 264.7 cells, with IC50 values in the range of 0.32-7.8µM. In addition, all compounds were evaluated for potential to inhibit tumor necrosis factor-alpha (TNF-α)-activated nuclear factor-kappa B (NF-κB) activity with transfected human embryonic kidney cells 293. Compounds 4-7 inhibited TNF-α-induced NF-κB activity with IC50 values in the range of 0.04-5.6µM.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , NF-kappa B/antagonistas & inibidores , Physalis/química , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Vitanolídeos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Linhagem Celular , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Camundongos , Modelos Moleculares , Conformação Molecular , NF-kappa B/metabolismo , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismo , Vitanolídeos/síntese química , Vitanolídeos/química
10.
J Nat Prod ; 79(6): 1508-13, 2016 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-27196335

RESUMO

A new fatty acid ester disaccharide, 2-O-(ß-d-glucopyranosyl)-1-O-(2E,4Z,7Z)-deca-2,4,7-trienoyl-ß-d-glucopyranose (1), a new ascorbic acid derivative, 2-caffeoyl-3-ketohexulofuranosonic acid γ-lactone (2), and a new iridoid glycoside, 10-dimethoxyfermiloside (3), were isolated along with 13 known compounds (4-16) from fermented noni fruit juice (Morinda citrifolia). The structures of the new compounds, together with 4 and 5, were determined by 1D and 2D NMR experiments, as well as comparison with published values. Compounds 2 and 7 showed moderate inhibitory activities in a TNF-α-induced NF-κB assay, and compounds 4 and 6 exhibited considerable quinone reductase-1 (QR1) inducing effects.


Assuntos
Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Dissacaridases/isolamento & purificação , Dissacaridases/farmacologia , Morinda/química , NAD(P)H Desidrogenase (Quinona)/efeitos dos fármacos , Anti-Inflamatórios/análise , Anti-Inflamatórios/química , Dissacaridases/química , Ácidos Graxos/química , Fermentação , Frutas/química , Iridoides/análise , Iridoides/química , Iridoides/isolamento & purificação , Iridoides/farmacologia , Estrutura Molecular , NAD(P)H Desidrogenase (Quinona)/metabolismo , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/análise
11.
Phytother Res ; 30(3): 447-53, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26692176

RESUMO

Traditional medicinal plants are often used for both the prevention and the treatment of local diseases. Taking into consideration the medicinal importance of Hedera nepalensis within local Pakistani traditions, the present study was undertaken to analyze the in vitro cancer chemopreventive and cytotoxic properties of the plant. The in vitro cancer chemopreventive testing was performed using nitrite assay, NFκB assay, aromatase assay, and quinone reductase 1 (QR1) assay. The cytotoxic potential was evaluated on three cancer-cell lines: MCF-7, MDA-MB-231, and HeLa using sulforhodamine B (SRB) assay. The results of cancer chemopreventive assays show that n-hexane and ethyl acetate fractions of tested plant have promising cancer chemopreventive potential. Lupeol isolated from n-hexane as well as ethyl acetate fraction showed lowest IC50 (0.20 ± 1.9 µM) in NFκB assay. Crude extract and its fractions inhibited the growth of three cancer cell lines by more than 60%, IC50 value of lupeol varied from 2.32 to 10.2 µM. HPLC-DAD-based quantification of lupeol in different plant tissues demonstrated that leaves of H. nepalensis are a rich source of lupeol (0.196 mg/100 mg dry weight). Our data have shown that H. nepalensis harbors cancer chemopreventive and cytotoxic agents.


Assuntos
Anticarcinógenos/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Hedera/química , Neoplasias/tratamento farmacológico , Triterpenos Pentacíclicos/uso terapêutico , Fitoterapia , Extratos Vegetais/uso terapêutico , Anticarcinógenos/isolamento & purificação , Anticarcinógenos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Células HeLa , Humanos , Células MCF-7 , Triterpenos Pentacíclicos/isolamento & purificação , Triterpenos Pentacíclicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Plantas Medicinais
12.
Med Princ Pract ; 25 Suppl 2: 41-59, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26679767

RESUMO

Throughout history, natural products have played a dominant role in the treatment of human ailments. For example, the legendary discovery of penicillin transformed global existence. Presently, natural products comprise a large portion of current-day pharmaceutical agents, most notably in the area of cancer therapy. Examples include Taxol, vinblastine, and camptothecin. These structurally unique agents function by novel mechanisms of action; isolation from natural sources is the only plausible method that could have led to their discovery. In addition to terrestrial plants as sources for starting materials, the marine environment (e.g., ecteinascidin 743, halichondrin B, and dolastatins), microbes (e.g., bleomycin, doxorubicin, and staurosporin), and slime molds (e.g., epothilone B) have yielded remarkable cancer chemotherapeutic agents. Irrespective of these advances, cancer remains a leading cause of death worldwide. Undoubtedly, the prevention of human cancer is highly preferable to treatment. Cancer chemoprevention, the use of vaccines or pharmaceutical agents to inhibit, retard, or reverse the process of carcinogenesis, is another important approach for easing this formidable public health burden. Similar to cancer chemotherapeutic agents, natural products play an important role in this field. There are many examples, including dietary phytochemicals such as sulforaphane and phenethyl isothiocyanate (cruciferous vegetables) and resveratrol (grapes and grape products). Overall, natural product research is a powerful approach for discovering biologically active compounds with unique structures and mechanisms of action. Given the unfathomable diversity of nature, it is reasonable to suggest that chemical leads can be generated that are capable of interacting with most or possibly all therapeutic targets.


Assuntos
Antineoplásicos/uso terapêutico , Produtos Biológicos/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/prevenção & controle , Compostos Fitoquímicos/uso terapêutico , Antimetabólitos Antineoplásicos/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Vacinas Anticâncer/uso terapêutico , Quimioprevenção/métodos , Citarabina/uso terapêutico , Suplementos Nutricionais , Humanos , Resveratrol , Estilbenos/uso terapêutico
13.
Pharm Biol ; 54(11): 2547-2554, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27159021

RESUMO

CONTEXT: Endophytic fungi, being a prolific source of bioactive secondary metabolites, are of great interest for natural product discovery. OBJECTIVE: Isolation and partial characterization of endophytic fungi inhabiting the leaves and woody parts of Taxus fuana Nan Li & R.R. Mill. (Taxaceae) and evaluation of biological activity. MATERIALS AND METHODS: Endophytic fungal isolates were identified by molecular analysis of internal transcribed spacer (ITS) regions of 18S rDNA. Extracts of the endophytic fungi cultured on potato dextrose agar and modified medium were evaluated using cancer chemoprevention bioassays [inhibition of TNF-α-induced NFκB, aromatase and inducible nitric oxide synthase (iNOS); induction of quinone reductase 1 (QR1)] and growth inhibition with MCF-7 cells. RESULTS: Nine of 15 fungal isolates were identified as belonging to Epicoccum, Mucor, Penicillium, Chaetomium, Paraconiothriym, Plectania or Trichoderma. Five of the 15 extracts inhibited NFκB activity (IC50 values ranging between 0.18 and 17 µg/mL) and five inhibited iNOS (IC50 values ranging between 0.32 and 12.9 µg/mL). In the aromatase assay, only two isolates mediated inhibition (IC50 values 12.2 and 10.5 µg/mL). With QR1 induction, three extracts exhibited significant activity (concentrations to double activity values ranging between 0.20 and 5.5 µg/mL), and five extracts inhibited the growth of MCF-7 cells (IC50 values ranging from 0.56 to 17.5 µg/mL). Six active cultures were derived from woody parts of the plant material. CONCLUSION: The endophytic fungi studied are capable of producing pharmacologically active natural compounds. In particular, isolates derived from the wood of Taxus fuana should be prioritized for the isolation and characterization of bioactive constituents.


Assuntos
Anticarcinógenos/isolamento & purificação , Endófitos/isolamento & purificação , Taxus/microbiologia , Anticarcinógenos/farmacologia , Inibidores da Aromatase/farmacologia , Endófitos/metabolismo , Humanos , Células MCF-7 , NAD(P)H Desidrogenase (Quinona)/biossíntese , NF-kappa B/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores
14.
Mol Pharmacol ; 88(3): 524-33, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26138072

RESUMO

(E)-4-(3,5-dimethoxystyryl)phenyl acetate (Cmpd1) is a resveratrol analog that preferentially inhibits glioma, breast, and pancreatic cancer cell growth, with IC50 values of 6-19 µM. Notably, the human U251MG glioblastoma tumor line is the most sensitive, with an IC50 of 6.7 µM, compared with normal fibroblasts, which have an IC50 > 20 µM. Treatment of U251MG cells that harbor aberrantly active signal transducer and activator of transcription (Stat) 3 with Cmpd1 suppresses Stat3 tyrosine705 phosphorylation in a dose-dependent manner in parallel with the induction of pserine727 Stat3 and extracellular signal-regulated kinase/mitogen-activated protein kinase 1/2 (pErk1/2(MAPK)). Inhibition of pErk1/2(MAPK) induction by the mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor PD98059 [2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one] blocked both the pserine727 Stat3 induction and ptyrosine705 Stat3 suppression by Cmpd1, indicating dependency on the mitogen-activated protein/extracellular signal-regulated kinase kinase-Erk1/2(MAPK) pathway for Cmpd1-induced modulation of Stat3 signaling. Cmpd1 also blocked epidermal growth factor-stimulated pStat1 induction, whereas upregulating pSrc, pAkt, p-p38, pHeat shock protein 27, and pmammalian target of rapamycin levels. However, pJanus kinase 2 and pEpidermal growth factor receptor levels were not significantly altered. Treatment of U251MG cells with Cmpd1 reduced in vitro colony formation, induced cell cycle arrest in the G2/M phase and cleavage of caspases 3, 8, and 9 and poly(ADP ribose) polymerase, and suppressed survivin, myeloid cell leukemia 1, Bcl-xL, cyclin D1, and cyclin B1 expression. Taken together, these data identify a novel mechanism for the inhibition of Stat3 signaling by a resveratrol analog and suggest that the preferential growth inhibitory effects of Cmp1 occur in part by Erk1/2(MAPK)-dependent modulation of constitutively active Stat3.


Assuntos
Acetatos/farmacologia , Antineoplásicos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Estilbenos/farmacologia , Acetatos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Fosforilação , Resveratrol , Serina/metabolismo , Estilbenos/química , Tirosina/metabolismo
15.
Bioorg Med Chem Lett ; 25(15): 2980-4, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26048799

RESUMO

Chiral peptides and iso-peptides were synthesized in excellent yield by using benzotriazole mediated solution phase synthesis. Benzotriazole acted both as activating and leaving group, eliminating frequent use of protection and subsequent deprotection. The procedure was based on the hypothesis that epimerization should be suppressed in solution due to a faster coupling rate than SPPS. All the synthesized peptides complied with Lipinski's Ro5 except for the rotatable bonds. Inhibition of cell proliferation of cancer cell lines is one of the most commonly used methods to study the effectiveness of any anticancer agents. Synthesized peptides and iso-peptides were tested against three cancer cell lines (MCF-7, MDA-MB 231) to determine their anti-proliferative potential. NFkB was also determined. Molecular docking studies were also carried out to complement the experimental results.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Antineoplásicos/síntese química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Células MCF-7 , Simulação de Acoplamento Molecular , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Peptídeos/síntese química , Triazóis/química
16.
Bioorg Med Chem Lett ; 25(21): 4719-4723, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26343828

RESUMO

Chemical investigation of an endophytic fungus Chaetomium globosum isolated from leaves of Wikstroemia uva-ursi led to the isolation of two new azaphilones, chaetoviridins J and K (1 and 3), along with five known derivatives (2 and 4-7). The structures of azaphilones were determined by NMR, X-ray diffraction, Mosher's method, and CD analysis. The isolated compounds were evaluated for their cancer chemopreventive-potential based on their abilities to inhibit tumor necrosis factor alpha (TNF-α)-induced nuclear factor-kappa B (NF-κB). Compounds 4, 5, 7, and synthetic 8 and 9 inhibit nitric oxide (NO) production with IC50 values in the range of 0.3-5.8 µM. Compounds 4, 5, and 9 also displayed (TNF-α)-induced NF-κB activity with IC50 values in the range of 0.9-5.1 µM.


Assuntos
Benzopiranos/farmacologia , Chaetomium/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Animais , Benzopiranos/química , Benzopiranos/isolamento & purificação , Linhagem Celular , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/isolamento & purificação , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Modelos Moleculares , Conformação Molecular , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismo
17.
J Nat Prod ; 77(3): 527-35, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24299616

RESUMO

In previous studies, (R)-2-isobutyl 3-methyl 3,4-dihydro-1H-pyrido[3,4-b]indole-2,3(9H)-dicarboxylate (1), a callophycin A derivative, was found to strongly inhibit nitrite production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, while (R)- or (S)-callophycin A showed only weak inhibition. We currently report additional studies to define the mechanisms underlying the inhibitory action of 1. Expression of inducible nitric oxide synthase (iNOS) was reduced at both protein and mRNA levels. Major upstream signaling molecules and transcription factors regulating iNOS expression were examined, but it was found that 1 did not affect the phosphorylated and total protein levels of p38 mitogen-activated protein kinase (p38 MAPK), Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (ERK1/2), and signal transducer and activator of transcription 1 (STAT1), nor did it mediate the degradation of the inhibitor of nuclear factor-κB α-isoform (IκBα). However, starting at early time points, 1 consistently inhibited the phosphorylation of protein kinase B/Akt at serine 473. In addition, 1 suppressed the protein expression of octamer-binding transcription factor-2 (Oct-2) and the expression of microRNA 155 (miR-155). In sum, compound 1 inhibits LPS-induced nitrite production by a unique and complex mechanism. Reduction of iNOS expression is accompanied by inhibition of Akt activation, Oct-2 protein expression, and miR-155 expression.


Assuntos
Carbolinas/farmacologia , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Animais , Western Blotting , Carbolinas/química , Proteínas I-kappa B , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , MicroRNAs/análise , MicroRNAs/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estrutura Molecular , Inibidor de NF-kappaB alfa , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Fator 2 de Transcrição de Octâmero/antagonistas & inibidores , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
18.
J Nat Prod ; 77(7): 1644-9, 2014 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-24992702

RESUMO

New compounds 18-nor-3,17-dihydroxyspongia-3,13(16),14-trien-2-one (1), 18-nor-3,5,17-trihydroxyspongia-3,13(16),14-trien-2-one (2), and spongiapyridine (3) and the known compound 17-hydroxy-4-epi-spongialactone A (4) were isolated from an Indonesian sponge of the genus Spongia. The structures of 1-3 were deduced by analyses of physical and spectroscopic data. Diterpene 3 is unusual, as the D-ring is a pyridyl ring system rather than the standard δ-lactone. The structure elucidation of this compound was complicated by facile exchange of the axial proton at the C-11 methylene with deuterium from methanol-d4. The isolated compounds were tested for biological activity in a battery of in vitro assays (TNF-α-induced NFκB, LPS-induced iNOS, RXR stimulation, quinone reductase 1 induction, aromatase inhibition, TRPM7 ion channels, and aspartic protease BACE1 inhibition). Norditerpene 2 modestly inhibited aromatase with an IC50 of 34 µM and induced quinone reductase 1 activity with a CD (the concentration needed to double the enzymatic response) of 11.2 µM. The remaining isolates were inactive.


Assuntos
Diterpenos/isolamento & purificação , Poríferos/química , Animais , Diterpenos/química , Diterpenos/farmacologia , Lactonas/química , Lipopolissacarídeos/farmacologia , Estrutura Molecular , NAD(P)H Desidrogenase (Quinona)/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Fator de Necrose Tumoral alfa/farmacologia
19.
J Nat Prod ; 77(2): 227-33, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24533857

RESUMO

Four new undecose nucleosides (herbicidin congeners), three known herbicidins, and 9-(ß-d-arabinofuranosyl)hypoxanthine (Ara-H) were isolated from the organic extract of a fermentation culture of Streptomyces sp. L-9-10 using proton NMR-guided fractionation. Their structures were elucidated on the basis of comprehensive 1D and 2D NMR and mass spectrometry analyses. These structures included 2'-O-demethylherbicidin F (1), 9'-deoxy-8',8'-dihydroxyherbicidin B (2), 9'-deoxy-8'-oxoherbicidin B (2a), and the 8'-epimer of herbicidin B (3). This is the first detailed assignment of proton and carbon chemical shifts for herbicidins A, B, and F. The isolated compounds were evaluated for cancer chemopreventive potential based on inhibition of tumor necrosis factor alpha (TNF-α)-induced nuclear factor-kappa B (NF-κB) activity.


Assuntos
Nucleosídeos de Purina/isolamento & purificação , Streptomyces/química , Arabinonucleosídeos/química , Arabinonucleosídeos/isolamento & purificação , Humanos , Estrutura Molecular , NF-kappa B , Ressonância Magnética Nuclear Biomolecular , Nucleosídeos de Purina/química , Nucleosídeos de Purina/farmacologia , Fator de Necrose Tumoral alfa
20.
J Nat Prod ; 77(3): 663-7, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24404757

RESUMO

A new lignan, vitexkarinol (1), as well as a known lignan, neopaulownin (2), a known chalcone, 3-(4-hydroxyphenyl)-1-(2,4,6-trimethoxyphenyl)-2-propen-1-one (3), two known dehydroflavones, tsugafolin (4) and alpinetin (5), two known dipeptides, aurantiamide and aurantiamide acetate, a known sesquiterpene, vemopolyanthofuran, and five known carotenoid metabolites, vomifoliol, dihydrovomifoliol, dehydrovomifoliol, loliolide, and isololiolide, were isolated from the leaves and twigs of Vitex leptobotrys through bioassay-guided fractionation. The chalcone (3) was found to inhibit HIV-1 replication by 77% at 15.9 µM, and the two dehydroflavones (4 and 5) showed weak anti-HIV activity with IC50 values of 118 and 130 µM, respectively, while being devoid of cytotoxicity at 150 µM. A chlorophyll-enriched fraction of V. leptobotrys, containing pheophorbide a, was found to inhibit the replication of HIV-1 by 80% at a concentration of 10 µg/mL. Compounds 1 and 3 were further selected to be evaluated against 21 viral targets available at NIAID (National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA).


Assuntos
Fármacos Anti-HIV/isolamento & purificação , Fármacos Anti-HIV/farmacologia , Lamiaceae/química , Lignanas/isolamento & purificação , Lignanas/farmacologia , Fármacos Anti-HIV/química , Lignanas/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Caules de Planta/química , Vietnã
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