RESUMEN
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.
Asunto(s)
Alcaloides , Malvaceae , Quinolinas , FN-kappa B/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Lipopolisacáridos/farmacología , Alcaloides/farmacología , Antiinflamatorios/farmacología , Malvaceae/química , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido NítricoRESUMEN
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.
Asunto(s)
Magnoliopsida , Parásitos , Vitaceae , Animales , Flores , ReproducciónRESUMEN
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.
Asunto(s)
Antibacterianos/farmacología , Aspergillus/química , Ciclohexanos/farmacología , Ácidos Grasos Insaturados/farmacología , Ácido Fusídico/análogos & derivados , FN-kappa B/antagonistas & inhibidores , Antibacterianos/aislamiento & purificación , Productos Biológicos/aislamiento & purificación , Productos Biológicos/farmacología , Ciclohexanos/aislamiento & purificación , Escherichia coli/efectos de los fármacos , Ácidos Grasos Insaturados/aislamiento & purificación , Ácido Fusídico/aislamiento & purificación , Ácido Fusídico/farmacología , Células HEK293 , Hawaii , Humanos , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Sesquiterpenos/aislamiento & purificación , Sesquiterpenos/farmacología , Staphylococcus aureus/efectos de los fármacosRESUMEN
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.
Asunto(s)
Ciclooxigenasa 2/metabolismo , Lactonas/farmacología , Óxido Nítrico Sintasa de Tipo II/metabolismo , Physalis/química , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factor de Transcripción STAT1/metabolismo , Witanólidos/farmacología , Animales , Lactonas/aislamiento & purificación , Lipopolisacáridos , Ratones , Fosforilación , Células RAW 264.7 , Transducción de Señal/efectos de los fármacos , Witanólidos/aislamiento & purificaciónRESUMEN
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.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Antioxidantes/farmacología , Citrus/química , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Extractos Vegetales/farmacología , Animales , Brasil , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Cumarinas/química , Cumarinas/aislamiento & purificación , Ácidos Grasos/química , Ácidos Grasos/aislamiento & purificación , Flavonoides/química , Flavonoides/aislamiento & purificación , Frutas/química , Ratones , Oxidación-ReducciónRESUMEN
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, IC50â¯=â¯1.61⯵M; 21, IC50â¯=â¯3.05⯵M; and 27, IC50â¯=â¯3.34⯵M) 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 (IRâ¯=â¯8.34, CDâ¯=â¯2.75⯵M), while 7 showed the most potent CD value of 1.12⯵M. A dual acting compound 24 showed aromatase inhibition (IC50â¯=â¯9.00⯵M) as well as QR1 induction (CDâ¯=â¯5.76⯵M) 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.
Asunto(s)
Antineoplásicos/síntesis química , Inhibidores de la Aromatasa/química , Aromatasa/química , Indoles/química , NAD(P)H Deshidrogenasa (Quinona)/química , Antineoplásicos/química , Antineoplásicos/farmacología , Aromatasa/metabolismo , Inhibidores de la Aromatasa/metabolismo , Sitios de Unión , Dominio Catalítico , Línea Celular Tumoral , Humanos , Indoles/metabolismo , Indoles/farmacología , Concentración 50 Inhibidora , Simulación del Acoplamiento Molecular , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Relación Estructura-ActividadRESUMEN
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.
Asunto(s)
Amidas/farmacología , Benzofuranos/química , Heliotropium/química , Fenoles/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Amidas/química , Amidas/toxicidad , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Antineoplásicos Alquilantes/química , Antineoplásicos Alquilantes/aislamiento & purificación , Antineoplásicos Alquilantes/farmacología , Benzofuranos/farmacología , Benzofuranos/toxicidad , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Hongos/efectos de los fármacos , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Heliotropium/metabolismo , Humanos , Espectroscopía de Resonancia Magnética , Conformación Molecular , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Fenoles/farmacología , Fenoles/toxicidad , Extractos Vegetales/uso terapéutico , Putrescina/química , Intoxicación por Mariscos/prevención & controlRESUMEN
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.
Asunto(s)
Estilbenos/farmacología , Animales , Ensayos Clínicos como Asunto , Humanos , Publicaciones Periódicas como Asunto , Resveratrol , Estilbenos/uso terapéuticoRESUMEN
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.
Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , FN-kappa B/antagonistas & inhibidores , Physalis/química , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Witanólidos/farmacología , Animales , Antiinflamatorios no Esteroideos/síntesis química , Antiinflamatorios no Esteroideos/química , Línea Celular , Relación Dosis-Respuesta a Droga , Células HEK293 , Humanos , Ratones , Modelos Moleculares , Conformación Molecular , FN-kappa B/metabolismo , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/metabolismo , Witanólidos/síntesis química , Witanólidos/químicaRESUMEN
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.
Asunto(s)
Antiinflamatorios/aislamiento & purificación , Antiinflamatorios/farmacología , Disacaridasas/aislamiento & purificación , Disacaridasas/farmacología , Morinda/química , NAD(P)H Deshidrogenasa (Quinona)/efectos de los fármacos , Antiinflamatorios/análisis , Antiinflamatorios/química , Disacaridasas/química , Ácidos Grasos/química , Fermentación , Frutas/química , Iridoides/análisis , Iridoides/química , Iridoides/aislamiento & purificación , Iridoides/farmacología , Estructura Molecular , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , FN-kappa B/metabolismo , Factor de Necrosis Tumoral alfa/análisisRESUMEN
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.
Asunto(s)
Anticarcinógenos/uso terapéutico , Antineoplásicos Fitogénicos/uso terapéutico , Hedera/química , Neoplasias/tratamiento farmacológico , Triterpenos Pentacíclicos/uso terapéutico , Fitoterapia , Extractos Vegetales/uso terapéutico , Anticarcinógenos/aislamiento & purificación , Anticarcinógenos/farmacología , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Células HeLa , Humanos , Células MCF-7 , Triterpenos Pentacíclicos/aislamiento & purificación , Triterpenos Pentacíclicos/farmacología , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Plantas MedicinalesRESUMEN
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.
Asunto(s)
Antineoplásicos/uso terapéutico , Productos Biológicos/uso terapéutico , Neoplasias/tratamiento farmacológico , Neoplasias/prevención & control , Fitoquímicos/uso terapéutico , Antimetabolitos Antineoplásicos/uso terapéutico , Antineoplásicos Fitogénicos/uso terapéutico , Vacunas contra el Cáncer/uso terapéutico , Quimioprevención/métodos , Citarabina/uso terapéutico , Suplementos Dietéticos , Humanos , Resveratrol , Estilbenos/uso terapéuticoRESUMEN
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.
Asunto(s)
Anticarcinógenos/aislamiento & purificación , Endófitos/aislamiento & purificación , Taxus/microbiología , Anticarcinógenos/farmacología , Inhibidores de la Aromatasa/farmacología , Endófitos/metabolismo , Humanos , Células MCF-7 , NAD(P)H Deshidrogenasa (Quinona)/biosíntesis , FN-kappa B/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidoresRESUMEN
(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.
Asunto(s)
Acetatos/farmacología , Antineoplásicos/farmacología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Factor de Transcripción STAT3/metabolismo , Estilbenos/farmacología , Acetatos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Humanos , Fosforilación , Resveratrol , Serina/metabolismo , Estilbenos/química , Tirosina/metabolismoRESUMEN
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.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Péptidos/química , Péptidos/farmacología , Antineoplásicos/síntesis química , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Humanos , Células MCF-7 , Simulación del Acoplamiento Molecular , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Péptidos/síntesis química , Triazoles/químicaRESUMEN
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.
Asunto(s)
Benzopiranos/farmacología , Chaetomium/química , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Animales , Benzopiranos/química , Benzopiranos/aislamiento & purificación , Línea Celular , Cristalografía por Rayos X , Relación Dosis-Respuesta a Droga , Compuestos Heterocíclicos de 4 o más Anillos/química , Compuestos Heterocíclicos de 4 o más Anillos/aislamiento & purificación , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Ratones , Modelos Moleculares , Conformación Molecular , FN-kappa B/antagonistas & inhibidores , FN-kappa B/metabolismo , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico/biosíntesis , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
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.
Asunto(s)
Carbolinas/farmacología , Óxido Nítrico Sintasa de Tipo II/antagonistas & inhibidores , Animales , Western Blotting , Carbolinas/química , Proteínas I-kappa B , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/efectos de los fármacos , Ratones , MicroARNs/análisis , MicroARNs/antagonistas & inhibidores , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Estructura Molecular , Inhibidor NF-kappaB alfa , FN-kappa B/efectos de los fármacos , FN-kappa B/metabolismo , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa de Tipo II/biosíntesis , Óxido Nítrico Sintasa de Tipo II/genética , Óxido Nítrico Sintasa de Tipo II/metabolismo , Factor 2 de Transcripción de Unión a Octámeros/antagonistas & inhibidores , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
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.
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Diterpenos/aislamiento & purificación , Poríferos/química , Animales , Diterpenos/química , Diterpenos/farmacología , Lactonas/química , Lipopolisacáridos/farmacología , Estructura Molecular , NAD(P)H Deshidrogenasa (Quinona)/efectos de los fármacos , FN-kappa B/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
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.
Asunto(s)
Nucleósidos de Purina/aislamiento & purificación , Streptomyces/química , Arabinonucleósidos/química , Arabinonucleósidos/aislamiento & purificación , Humanos , Estructura Molecular , FN-kappa B , Resonancia Magnética Nuclear Biomolecular , Nucleósidos de Purina/química , Nucleósidos de Purina/farmacología , Factor de Necrosis Tumoral alfaRESUMEN
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).