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1.
Environ Toxicol ; 35(6): 714-721, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32149473

RESUMO

Spinal cord injury (SCI) is the most commonly seen trauma leading to disability in people worldwide. The purpose of current study was to determine the protective effect of methoxytetrahydro-2H-pyran-2-yl)methyl benzoate (HMPB) on SCI in rat model. TUNEL staining was used to examine apoptotic changes in spinal cord of SCI rats. The ELISA kits were employed to assess inflammatory processes and oxidative factors in the spinal cord tissues. Behavioral changes in SCI rats were assessed using Basso, Beattie, and Bresnahan (BBB) scoring system. Western blotting was used for assessment of proteins. The HMPB treatment of SCI rats reduced apoptotic cell number based on the concentration of dose administered. Treatment of SCI rats with HMPB enhanced BBB score and decreased accumulation of water content in SCI rats significantly. On treatment with HMPB the TNF-α and interleukin-6/1ß/18 levels were suppressed in SCI rats. Treatment with HMPB induced excessive release of SOD, CAT, and GSH molecules and decreased overproduction of MDA. The SCI induced upregulation of caspase-3/9 activity was completely alleviated by HMPB at 2 mg/kg dose. The HMPB treatment of SCI rats promoted peroxisome proliferator-activated receptor γ (PPAR-γ) expression, reduced cyclooxygenase (COX)-2 production and increased expression of p-Akt and phosphoinositide 3-kinase (p-PI3K). The study demonstrated that HMPB suppressed apoptosis, raised BBB score and inhibited inflammation in SCI rats. Moreover, activation of PI3K/Akt in the spinal cord tissues of SCI rats was promoted by HMPB. Therefore, HMPB has protective effect on SCI in the rat model.


Assuntos
PPAR gama/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Extratos Vegetais/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Piranos/uso terapêutico , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Crataegus , Citocinas/metabolismo , Modelos Animais de Doenças , Marcação In Situ das Extremidades Cortadas , Inflamação , Masculino , Estrutura Molecular , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Piranos/isolamento & purificação , Ratos , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologia
2.
Nat Prod Res ; 34(2): 300-304, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30375259

RESUMO

A phytochemical study was carried out on Ajuga multiflora, and obtained a novel ursane-type triterpene saponin, i.e., 3-epi-ursolic acid 3-O-palmitoyl 28-O-α-L-arabinofuranosyl ester (1), named ajugoside. Its structure and relative configuration were identified mainly by spectroscopic methods including 1D- and 2D-NMR techniques as well as HR-MS analysis. This paper described the isolation and structural elucidation of ajugoside (1) for the first time.


Assuntos
Ajuga/química , Glucosídeos/química , Piranos/química , Saponinas/isolamento & purificação , Triterpenos/isolamento & purificação , Glucosídeos/isolamento & purificação , Conformação Molecular , Estrutura Molecular , Extratos Vegetais/análise , Extratos Vegetais/química , Piranos/isolamento & purificação , Saponinas/química , Triterpenos/química
3.
Talanta ; 205: 120107, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31450415

RESUMO

A comprehensive structural characterization of the complex family of isomeric forms related to Oleuropein aglycone (OA) detected in virgin olive oil (VOO) was performed by reverse phase liquid chromatography with electrospray ionization and Fourier-transform mass spectrometry (RPLC-ESI-FTMS), integrated by enzymatic/chemical reactions performed on Oleuropein, the natural precursor of OA. First, some of the OA-related isomers typically observed in VOO extracts were generated upon enzymatic hydrolysis of the glycosidic linkage of Oleuropein. This step mimicked the process occurring during olive drupes crushing in the first stage of oil production. The incubation of the enzymatic reaction mixture at a more acidic pH was subsequently performed, to simulate the conditions of olive paste malaxation during oil production. As a result, further isomeric forms were generated and the complex chromatographic profile typically observed for OA in olive oil extracts, including at least 13 different peaks/bands/groups of peaks, was carefully reproduced. Each of those chromatographic features could be subsequently assigned to specific types of OA-related isomers, belonging to one of four structurally different classes. Specifically, diastereoisomers/geometrical isomers corresponding to two different types of open-structure forms and to as many types of closed-structure, di-hydropyranic forms of OA, characterized by the presence of one or two carbonyl groups, according to the case, were evidenced. In addition, the presence of stable enolic/dienolic tautomers, providing an indirect structural confirmation for some OA isomers, was ascertained through RPLC-ESI-FTMS analyses performed under H/D exchange conditions, i.e. in the presence of deuterated water as one of the mobile phase solvents.


Assuntos
Acetatos/análise , Monoterpenos Ciclopentânicos/análise , Azeite de Oliva/análise , Piranos/análise , Acetatos/química , Acetatos/isolamento & purificação , Cromatografia de Fase Reversa/métodos , Monoterpenos Ciclopentânicos/química , Monoterpenos Ciclopentânicos/isolamento & purificação , Deutério , Análise de Fourier , Hidrólise , Iridoides/química , Isomerismo , Extração Líquido-Líquido , Olea/química , Piranos/química , Piranos/isolamento & purificação , Espectrometria de Massas em Tandem/métodos , beta-Glucosidase/química
4.
Chem Biodivers ; 16(9): e1900266, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31298476

RESUMO

Two new spliceostatin analogs, designed as spliceostatins J and K (1 and 2), were isolated and identified from the culture of Pseudomonas sp., along with two known ones, FR901464 (3) and spliceostatin E (4). Their structures were elucidated by detailed interpretation of their spectroscopic data, especially 2D-NMR and HR-ESI-MS. Spliceostatin J (1) represented the first example of spliceostatins bearing an unusual hexahydrofuro[3,4-b]furan moiety. Biological assay showed all the isolated compounds except 1 displayed potent cytotoxic activities against two cancer cell lines (MDA-MB-231 and A-549). Structure-activity-relationship studies revealed that the tetrahydropyran ring in spliceostatin analogs was necessary for their bioactive retention.


Assuntos
Antineoplásicos/farmacologia , Furanos/farmacologia , Lactonas/farmacologia , Pseudomonas/química , Pironas/farmacologia , Células A549 , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Furanos/química , Furanos/isolamento & purificação , Humanos , Lactonas/química , Lactonas/isolamento & purificação , Estrutura Molecular , Piranos/química , Piranos/isolamento & purificação , Piranos/farmacologia , Pironas/química , Pironas/isolamento & purificação , Compostos de Espiro/química , Compostos de Espiro/isolamento & purificação , Compostos de Espiro/farmacologia , Relação Estrutura-Atividade
5.
Mar Drugs ; 17(7)2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31331002

RESUMO

Acanthamoeba genus is a widely distributed and opportunistic parasite with increasing importance worldwide as an emerging pathogen in the past decades. This protozoan has an active trophozoite stage, a cyst stage, and is dormant and very resistant. It can cause Acanthamoeba keratitis, an ocular sight-threatening disease, and granulomatous amoebic encephalitis, a chronic, very fatal brain pathology. In this study, the amoebicidal activity of sixteen Laurencia oxasqualenoid metabolites and semisynthetic derivatives were tested against Acanthamoeba castellanii Neff. The results obtained point out that iubol (3) and dehydrothyrsiferol (1) possess potent activities, with IC50 values of 5.30 and 12.83 µM, respectively. The hydroxylated congeners thyrsiferol (2) and 22-hydroxydehydrothyrsiferol (4), active in the same value range at IC50 13.97 and 17.00 µM, are not toxic against murine macrophages; thus, they are solid candidates for the development of new amoebicidal therapies.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Laurencia/química , Extratos Vegetais/farmacologia , Esqualeno/farmacologia , Amebicidas/isolamento & purificação , Animais , Linhagem Celular , Furanos/isolamento & purificação , Furanos/farmacologia , Concentração Inibidora 50 , Macrófagos , Camundongos , Extratos Vegetais/isolamento & purificação , Piranos/isolamento & purificação , Piranos/farmacologia , Esqualeno/análogos & derivados , Esqualeno/isolamento & purificação , Testes de Toxicidade , Trofozoítos/efeitos dos fármacos
6.
Molecules ; 24(7)2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30934811

RESUMO

Although smoke-isolated karrikins (KAR1) could regulate secondary metabolism in medicinal plants, the signal transduction mechanism has not been reported. This study highlights the influence of KAR1 on tanshinone I (T-I) production in Salvia miltiorrhiza and the involved signal molecules. Results showed KAR1-induced generation of nitric oxide (NO), jasmonic acid (JA) and T-I in S. miltiorrhiza hairy root. KAR1-induced increase of T-I was suppressed by NO-specific scavenger (cPTIO) and NOS inhibitors (PBITU); JA synthesis inhibitor (SHAM) and JA synthesis inhibitor (PrGall), which indicated that NO and JA play essential roles in KAR1-induced T-I. NO inhibitors inhibited KAR1-induced generation of NO and JA, suggesting NO was located upstream of JA signal pathway. NO-induced T-I production was inhibited by SHAM and PrGall, implying JA participated in transmitting signal NO to T-I accumulation. In other words, NO mediated the KAR1-induced T-I production through a JA-dependent signaling pathway. The results helped us understand the signal transduction mechanism involved in KAR1-induced T-I production and provided helpful information for the production of S. miltiorrhiza hairy root.


Assuntos
Abietanos/biossíntese , Ciclopentanos/metabolismo , Furanos/farmacologia , Óxido Nítrico/metabolismo , Oxilipinas/metabolismo , Piranos/farmacologia , Salvia miltiorrhiza/efeitos dos fármacos , Salvia miltiorrhiza/metabolismo , Fumaça , Análise de Variância , Furanos/isolamento & purificação , Regulação da Expressão Gênica de Plantas , Redes e Vias Metabólicas/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Piranos/isolamento & purificação , Salvia miltiorrhiza/genética , Transdução de Sinais/efeitos dos fármacos , Fumaça/análise
7.
Nanoscale ; 11(13): 6072-6079, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30869704

RESUMO

A novel procedure for the preparation of magnetic covalent organic frameworks (COFs) is reported. In situ functionalization of Fe3O4 with dopamine rapidly afforded amino-functionalized magnetic nanoparticles, which after decoration with a COF building block and subsequent COF growth gave access to magnetic composite mTpBD-Me2. The optimized synthesis conditions yielded crystalline and superparamagnetic material with no loss in surface area as compared to bulk COF. The composite material was employed for the first time in magnetic solid-phase extraction of marine biotoxins from seawater with high efficiency, where calculated maximum adsorption capacities of 812 mg g-1 and 830 mg g-1 were found for okadaic acid (OA) and dinophysistoxin-1 (DTX-1), respectively, corresponding to an increase of ∼500-fold for OA and ∼300-fold for DTX-1 as compared to the commonly used non-magnetic macroporous resins. Nearly quantitative desorption efficiency of both biotoxins was obtained using 2-propanol as solvent, rendering the composite materials recyclable with merely minor losses in adsorption capacity after five consecutive cycles of adsorption/desorption. In addition, retention of crystallinity after the adsorption cycles highlights the stability of the composite in seawater. These results illustrate the great efficiency of the novel material in biotoxin adsorption and show great promise for its application in environmental monitoring programs.


Assuntos
Magnetismo , Estruturas Metalorgânicas/química , Ácido Okadáico/química , Piranos/química , 2-Propanol/química , Adsorção , Dopamina/química , Óxido Ferroso-Férrico/química , Cinética , Ácido Okadáico/isolamento & purificação , Piranos/isolamento & purificação , Extração em Fase Sólida
8.
N Biotechnol ; 48: 83-89, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30098416

RESUMO

Bioactive compounds such as karrikinolide (KAR1 from smoke) and eckol (from the seaweed Ecklonia maxima) show promising effects on several important crop plants. These plant growth-stimulating organic biomolecules, along with crude extracts (smoke-water and Kelpak® product prepared from Ecklonia maxima), were tested on spinach plants. Eckol sprayed at 10-6 M significantly increased all the growth and biochemical parameters examined compared to control spinach plants. All tested plant growth biostimulants significantly increased total chlorophyll, carotenoids and protein content of spinach leaves. The cytokinin profile of spinach plants was also determined. Cis-zeatin, dihydrozeatin and isopentenyladenine types of cytokinins were promoted by both smoke- and seaweed-based biostimulants. In comparison to the control plants, the level of free sinapic acid was greater in all spinach plants treated with these biostimulants. The application of these biostimulants can help spinach crop by improving growth, yield and nutritional quality; moreover, they are organic and cost-effective.


Assuntos
Feófitas/química , Reguladores de Crescimento de Planta/isolamento & purificação , Reguladores de Crescimento de Planta/farmacologia , Alga Marinha/química , Fumaça/análise , Spinacia oleracea/efeitos dos fármacos , Spinacia oleracea/crescimento & desenvolvimento , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Citocininas/metabolismo , Dioxinas/isolamento & purificação , Dioxinas/farmacologia , Furanos/isolamento & purificação , Furanos/farmacologia , Hidroxibenzoatos/metabolismo , Piranos/isolamento & purificação , Piranos/farmacologia , Spinacia oleracea/metabolismo
9.
PLoS One ; 13(8): e0202556, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30133513

RESUMO

Harpagide and its derivatives have valuable medicinal properties, such as anti-inflammatory, analgesic and potential antirheumatic effects. There is the demand for searching plant species containing these iridoids or developing biotechnological methods to obtain the compounds. The present study investigated the effects of methyl jasmonate (MeJa, 50 µM), ethephon (Eth, 50 µM) and L-phenylalanine (L-Phe, 2.4 g/L of medium), added to previously selected variant of Murashige and Skoog medium (supplemented with plant growth regulators: 6-benzylaminopurine 1.0 mg/L, α-naphthaleneacetic acid 0.5 mg/L, gibberellic acid 0.25 mg/L) on the accumulation of harpagide and 8-O-acetyl-harpagide in Melittis melissophyllum L. agitated shoot cultures. Plant material was harvested 2 and 8 days after the supplementation. Iridoids were quantitatively analyzed by the UPLC-MS/MS method in extracts from the biomass and the culture medium. It was found that all of the variants caused an increase in the accumulation of harpagide. In the biomass harvested after 2 days, the highest harpagide content of 247.3 mg/100 g DW was found for variant F (L-Phe and Eth), and the highest 8-O-acetyl-harpagide content of 138 mg/100 g DW for variant E (L-Phe and MeJa). After 8 days, in some variants, a portion of the metabolites was released into the culture medium. Considering the total amount of the compounds (in the biomass and medium), the highest accumulation of harpagide, amounting to 619 mg/100 g DW, was found in variant F, and the highest amount of 8-O-acetyl-harpagide, of 255.4 mg/100 g DW, was found in variant H (L-Phe, MeJa, Eth) when harvested on the 8th day. These amounts were, respectively, 24.7 and 4.8 times higher than in the control culture, and were, respectively, 15 and 6.7 times higher than in the leaves of the soil-grown plant. The total amount of the two iridoids was highest for variant F (0.78% DW) and variant H (0.68% DW) when harvested on the 8th day. The results indicate that the agitated shoot cultures of M. melissophyllum can be a rich source of harpagide and 8-O-acetyl-harpagide, having a potential practical application. To the best of our knowledge we present for the first time the results of the quantitative UPLC-MS/MS analysis of harpagide and 8-O-acetyl-harpagide in M. melissophyllum shoot cultures and the enhancement of their accumulation by means of medium supplementation with elicitors and precursor.


Assuntos
Glicosídeos Iridoides/metabolismo , Lamiaceae/metabolismo , Folhas de Planta/metabolismo , Brotos de Planta/metabolismo , Piranos/metabolismo , Acetatos/farmacologia , Cromatografia Líquida de Alta Pressão , Meios de Cultura , Ciclopentanos/farmacologia , Glicosídeos Iridoides/isolamento & purificação , Iridoides/farmacologia , Lamiaceae/efeitos dos fármacos , Lamiaceae/crescimento & desenvolvimento , Espectrometria de Massas , Compostos Organofosforados/farmacologia , Oxilipinas/farmacologia , Fenilalanina/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Piranos/isolamento & purificação
10.
Molecules ; 23(6)2018 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-29895732

RESUMO

We previously reported on the isolation and biological activities of plagiochiline A (1), a 2,3-secoaromadendrane-type sesquiterpenoid from the Peruvian medicinal plant, Plagiochila disticha. This compound was found to have antiproliferative effects on a variety of solid tumor cell lines, as well as several leukemia cell lines. Other researchers have also noted the cytotoxicity of plagiochiline A (isolated from different plant species), but there are no prior reports regarding the mechanism for this bioactivity. Here, we have evaluated the effects of plagiochiline A on cell cycle progression in DU145 prostate cancer cells. A cell cycle analysis indicated that plagiochiline A caused a significant increase in the percentage of cells in the G2/M phase when compared with control cells. When cells were stained and observed by fluorescence microscopy to examine progress through the mitotic phase, we found a significant increase in the proportion of cells with features of late cytokinesis (cells connected by intercellular bridges) in the plagiochiline A-treated samples. These results suggest that plagiochiline A inhibits cell division by preventing completion of cytokinesis, particularly at the final abscission stage. We also determined that plagiochiline A reduces DU145 cell survival in clonogenic assays and that it induces substantial cell death in these cells.


Assuntos
Citocinese/efeitos dos fármacos , Embriófitas/química , Compostos de Epóxi/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Piranos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Compostos de Epóxi/química , Compostos de Epóxi/isolamento & purificação , Humanos , Masculino , Extratos Vegetais/química , Piranos/química , Piranos/isolamento & purificação
11.
J Org Chem ; 83(1): 194-202, 2018 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-29185743

RESUMO

Following isolation of the polyhydroxy compound, ostreol B, from cultivated cells of the toxic dinoflagellate Ostreopsis cf. ovata collected in South Korea, 1D and 2D NMR spectroscopy were employed to determine the planar chemical structure of this compound, which contained a tetrahydropyran ring, two terminal double bonds, and 21 hydroxyl groups. The absolute configurations of all stereogenic carbon centers in ostreol B were then determined through a combination of the J-based configuration analysis, rotating frame Overhauser effect correlations, and the modified Mosher method following cleavage of the 1,2-diol bonds. Ostreol B was also found to exhibit moderate cytotoxicity in HepG2, Neuro-2a and HCT-116 cells.


Assuntos
Dinoflagelados/química , Piranos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HCT116 , Células Hep G2 , Humanos , Conformação Molecular , Piranos/química , Piranos/isolamento & purificação , Relação Estrutura-Atividade
12.
Fitoterapia ; 122: 45-51, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28842357

RESUMO

Six new alkenylated tetrahydropyran derivatives belonged to polyketides, designated as (12R,13R)-dihydroxylanomycinol (1), (12S,13S)-dihydroxylanomycinol (2), (12R,13S)-dihydroxylanomycinol (3) and (12S,13R)-dihydroxylanomycinol (4), (12S,13R)-N-acetyl-dihydroxylanomycin (5) and (12S,13S)-N-acetyl-dihydroxylanomycin (6), together with one related known compound lanomycinol (7) were isolated from the liquid cultures of Westerdykella dispersa obtained from the marine sediments. Their structures and absolute configurations were determined on the basis of extensive analysis of NMR spectra combined with comparison of NMR data to those of known compound, and computational method via calculation of the electronic circular dichroism (ECD). The anti-agricultural pathogenic fungal and antibacterial activities of all isolated compounds were evaluated. Compounds 1-7 exhibited moderate antifungal activities selectively against tested fungal strains with minimum inhibitory concentration (MIC) values ranging from 12.5 to 50µg/mL, and weak antibacterial activities selectively against tested antibacterial strains with MIC value at 100µg/mL.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Ascomicetos/química , Sedimentos Geológicos/microbiologia , Piranos/farmacologia , Antibacterianos/isolamento & purificação , Antifúngicos/isolamento & purificação , Testes de Sensibilidade Microbiana , Piranos/isolamento & purificação
13.
Arch Pharm Res ; 40(7): 836-853, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28589255

RESUMO

Cholinesterase (ChE) and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors are promising agents for the treatment of Alzheimer's disease (AD). In the present study, we examined the inhibitory activity of seven compounds isolated from the fruits of Cornus officinalis, cornuside, polymeric proanthocyanidins, 1,2,3-tri-O-galloyl-ß-D-glucose, 1,2,3,6-tetra-O-galloyl-ß-D-glucose, tellimagrandin I, tellimagrandin II, and isoterchebin, against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and BACE1. All of the compounds displayed concentration-dependent in vitro inhibitory activity toward the ChEs and BACE1. Among them, tellimagrandin II exhibited the best inhibitory activity toward ChEs, whereas the best BACE1 inhibitor was 1,2,3,6-tetra-O-galloyl-ß-D-glucose. Isoterchebin and polymeric proanthocyanidins were also significant ChE inhibitors. The kinetic and docking studies demonstrated that all compounds interacted with both the catalytic active sites and the peripheral anionic sites of the ChEs and BACE1. Tellimagrandin II, isoterchebin, and the polymeric proanthocyanidins exhibited concentration-dependent inhibition of peroxynitrite-mediated protein tyrosine nitration. In conclusion, we identified significant ChE and BACE1 inhibitors from Corni Fructus that could have value as new multi-targeted compounds for anti-AD agents.


Assuntos
Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Inibidores da Colinesterase/farmacologia , Cornus/química , Extratos Vegetais/farmacologia , Acetilcolinesterase/efeitos dos fármacos , Doença de Alzheimer/tratamento farmacológico , Butirilcolinesterase/efeitos dos fármacos , Inibidores da Colinesterase/administração & dosagem , Inibidores da Colinesterase/isolamento & purificação , Relação Dose-Resposta a Droga , Frutas , Glucosídeos/administração & dosagem , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Humanos , Taninos Hidrolisáveis/administração & dosagem , Taninos Hidrolisáveis/isolamento & purificação , Taninos Hidrolisáveis/farmacologia , Simulação de Acoplamento Molecular , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Piranos/administração & dosagem , Piranos/isolamento & purificação , Piranos/farmacologia
14.
J Sep Sci ; 40(14): 2906-2913, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28513110

RESUMO

A novel method was developed for the purification of two typical diarrhetic shellfish poisoning toxins from toxin-producing marine microalgae using macroporous resin, high-speed countercurrent chromatography-mass spectrometry, and semipreparative high-performance liquid chromatography-mass spectrometry. Analytical high-performance liquid chromatography-mass spectrometry was used for identification and purity analysis of okadaic acid and dinophysistoxin-1 because they exhibit no visible or ultraviolet absorption. First, four kinds of macroporous resins were investigated, and HP-20 macroporous resin was selected for the preenrichment and cleanup of the two target toxins. Second, the resin-purified sample was further purified using high-speed countercurrent chromatography coupled with a mass spectrometer. The purities of the obtained okadaic acid and dinophysistoxin-1 were 89.0 and 83.0%, respectively, as determined through analytical high-performance liquid chromatography-mass spectrometry. Finally, further purification was carried out using semipreparative high-performance liquid chromatography with mass spectrometry, and the purities of the final okadaic acid and dinophysistoxin-1 products were both over 98.0% based on the analytical high-performance liquid chromatography-mass spectrometry chromatograms and fraction spectra. This work demonstrates that the proposed purification process is a powerful method for the preparation of high-purity okadaic acid and dinophysistoxin-1 from toxin-producing marine microalgae. Moreover, it is particularly important for the purification and preparation of minor toxins that exhibit no visible or ultraviolet absorption from harmful marine algae.


Assuntos
Toxinas Marinhas/isolamento & purificação , Microalgas/química , Ácido Okadáico/isolamento & purificação , Piranos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Espectrometria de Massas , Intoxicação por Frutos do Mar
15.
Nat Prod Res ; 31(21): 2513-2519, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28412841

RESUMO

Phytochemical studies on the stem bark of Garcinia nervosa has resulted in the discovery of one new pyranoxanthone derivative, garner xanthone (1) and five other compounds, 1,5-dihydroxyxanthone (2), 6-deoxyisojacareubin (3), 12b-hydroxy-des-D-garcigerrin A (4) stigmasterol (5), and ß-sitosterol (6). The structures of these compounds were elucidated with the aid of spectroscopic techniques, such as NMR and MS. The crude extracts of the plant were assessed for their antimicrobial activity.


Assuntos
Anti-Infecciosos/farmacologia , Garcinia/química , Avaliação Pré-Clínica de Medicamentos/métodos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Estrutura Molecular , Casca de Planta/química , Piranos/química , Piranos/isolamento & purificação , Sitosteroides/química , Sitosteroides/isolamento & purificação , Estigmasterol/química , Xantenos/química , Xantenos/isolamento & purificação , Xantonas/química
16.
J Nat Prod ; 80(5): 1688-1692, 2017 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-28383915

RESUMO

Limaol (1), along with a dinophysistoxin 1 derivative and an okadaic acid (OA) derivative, was isolated from the large-scale cultivation of the benthic marine dinoflagellate Prorocentrum lima. The structure of 1 was determined by a combination of NMR spectroscopy and mass spectrometry and contained tetrahydropyran, 1,3,5,7-tetra(methylene)heptane, and octahydrospiro[pyran-2,2'-pyrano[3,2-b]pyran] moieties. The absolute configuration of 1 was completely elucidated on the basis of ROESY correlations, J-based configuration analysis, and modified Mosher's ester analysis. Limaol showed moderate cytotoxicity when compared to OA against three cancer cell lines.


Assuntos
Dinoflagelados/química , Toxinas Marinhas/química , Ácido Okadáico/química , Ácido Okadáico/isolamento & purificação , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , Piranos/isolamento & purificação , Compostos de Espiro/isolamento & purificação , Compostos de Espiro/farmacologia , Animais , Linhagem Celular Tumoral , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Ácido Okadáico/farmacologia , Policetídeos/química , Piranos/química , Piranos/farmacologia , Compostos de Espiro/química
17.
Angew Chem Int Ed Engl ; 56(11): 3064-3068, 2017 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-28165181

RESUMO

Recently, the phenomenon of enantiodivergence was uncovered as a new phenomenon in the biosynthesis of natural products. In nature, chiral natural products are usually produced in optically active form, but both enantiomers sometimes arise in different genera and/or species or in a single species. Here we show through enantioselective total synthesis that the natural product isodehydrothyrsiferol shows partial enantiodivergency in that six of the nine or ten asymmetric centers are enantiomeric to those of other members of the marine squalene-derived triterpenoid thyrsiferol family. In addition, isodehydrothyrsiferol and dehydrothyrsiferol, which show partial enantiodivergency, were isolated from the same producer, the red alga Laurencia viridis. These results demonstrate that partial enantiodivergence can develop even between natural products originating from a single species.


Assuntos
Produtos Biológicos/síntese química , Furanos/síntese química , Laurencia/química , Piranos/síntese química , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Furanos/química , Furanos/isolamento & purificação , Conformação Molecular , Piranos/química , Piranos/isolamento & purificação , Estereoisomerismo
18.
Phytochem Anal ; 28(3): 242-246, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28028854

RESUMO

INTRODUCTION: Iridoid glycosides possess highly functionalised monoterpenoid aglycon with several contiguous stereocentres. For the most common, they are often present in quantities reaching several percentage of the fresh plant weight, and thus they may be regarded as starting material for the synthesis of a number of new chiral and bioactive molecules. OBJECTIVE: To quantify and to isolate 8-O-acetylharpagide (AH) from several extracts of Oxera coronata R.P.J. de Kok, a Lamiaceae species endemic to New Caledonia, using HPLC-ELSD (evaporative light scattering detector) and centrifugal partition chromatography (CPC). METHODOLOGY: Oxera coronata produces high amounts of AH in leaves, twigs and fruits. Water and methanol extracts of these plant parts were prepared. The content of AH in each extract was quantified by HPLC-ELSD, using acetonitrile-water (+0.1% formic acid) gradient elution. The HPLC method was validated for precision, linearity, limit of detection (LOD), limit of quantification (LOQ) and accuracy. A ternary solvent system ethyl acetate/n-propanol/water (3:2:5, v/v/v) was selected and applied to recover the target compound using Spot CPC from the leaves aqueous extract. RESULTS: HPLC-ELSD analysis followed by CPC purification led to the efficient isolation of AH from O. coronata leaves aqueous extract. CONCLUSION: HPLC-ELSD has proven to be a well-adapted detection and quantification method for iridoid glycosides, while CPC confirmed to be an efficient technique for the isolation of polar compounds. Copyright © 2016 John Wiley & Sons, Ltd.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Lamiaceae/química , Piranos/isolamento & purificação , Cromatografia Líquida/instrumentação , Cromatografia Líquida/métodos , Frutas/química , Nova Caledônia , Extratos Vegetais/química , Folhas de Planta/química , Piranos/análise
19.
Microb Pathog ; 103: 114-118, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28012983

RESUMO

Ajuga bracteosa Wall ex. Benth. (Lamiaceae) commonly known as Bungle Weed has been in use since ancient times and is mentioned Ayurvedic literature. The upper ground parts of the plant are used for treatment of various diseases. The weed is credited with astringent, febrifugal, stimulant, aperient, tonic, diuretic and depurative properties and is used for the treatment of gout and rheumatism, palsy and amenorrhoea. Two compounds 1) 14, 15-dihydroajugapitin and 2) 8-o-acetylharpagide were isolated from the aerial parts of the plant and tested for antibacterial activity against various pathogenic bacteria by agar well diffusion method. Compound 1 and 2 showed maximum antibacterial activity against Escherichia coli with zone of inhibitions of 25. 0 ± 1.4 mm and 22.6 ± 0.9 mm respectively. The MIC value of compound 1 and 2 ranged between 500 and 1000 µg/ml. It could be concluded that both compounds isolated from the aerial parts of Ajuga bracteosa possess antibacterial activity against pathogens.


Assuntos
Ajuga/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Extratos Vegetais/farmacologia , Piranos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Compostos Fitoquímicos/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Piranos/química , Piranos/isolamento & purificação
20.
Chem Biol Drug Des ; 90(1): 5-11, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-27995747

RESUMO

Triple-negative breast cancer (TNBC) is one of the most aggressive cancers in women. Additionally, presence of residual cancer stem cells (CSC) in TNBC has challenged the efficacy of chemotherapy. Thus, the development of new molecules with potential action against CSC is fundamental. In this study, six synthetic analogues of theonelladin C, a 3-alkylpyridine marine alkaloid, were tested for cytotoxic activity against human TNBC cell line (BT-549) and tumorspheres derived from BT-549. Cytotoxicity assay was performed by sulforhodamine B (SRB). BT-549 and tumorspheres were examined for CD44+/high /CD24-/low markers, indicative of CSC profile, by flow cytometry. Clonogenic assay was performed to verify inhibiting growth of tumorspheres by the synthetic analogues. Cell death by apoptosis was investigated employing annexin V assay. SRB assay on BT-549 cells revealed that compounds 1c and 2c were the most active of the series, with IC50 values of 18.66 and 9.8 µm, respectively. Compounds 1c and 2c were able to reduce both CSC-like population (CD44+/high /CD24-/low ) and non-CSC population (CD44+/high /CD24+/high ) in tumorsphere model. Clonogenic and annexin V assays confirmed the ability of 1c and 2c to induce growth inhibition and apoptosis in BT-549 cells and tumorspheres. These preliminary data indicate that these compounds are a promising class for development of anticancer agents.


Assuntos
Alcaloides/química , Antineoplásicos/química , Antígeno CD24/metabolismo , Receptores de Hialuronatos/metabolismo , Piranos/química , Piridinas/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Microscopia Confocal , Piranos/isolamento & purificação , Piranos/toxicidade , Piridinas/isolamento & purificação , Piridinas/toxicidade , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia
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