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1.
Microbiol Res ; 235: 126448, 2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32114363

RESUMO

Vibrio parahaemolyticus is a common foodborne pathogen in seafood and represents a major threat to human health worldwide. In this study, we identified that PhoR, a histidine kinase, is involved in the regulation of swarming and flagella assembly. RNA sequencing analysis showed that 1122 genes were differentially expressed in PhoR mutant, including 394 upregulated and 728 downregulated genes. KEGG enrichment and heatmap analysis demonstrated that the bacterial secretion system, flagella assembly and chemotaxis pathways were significantly downregulated in PhoR mutant, while the microbial metabolism in diverse environments and carbon metabolism pathways were upregulated in PhoR mutant. qRT-PCR further confirmed that genes responsible for the type III secretion system (T3SS), swarming and the thermostable direct hemolysin were positively regulated by PhoR. Phosphorylation assays suggested that PhoR was highly activated in BHI medium compared to LB medium. Taken together, these data suggested that activated PhoR contributes to the expression of swarming motility and secretion system genes in Vibrio parahaemolyticus.

2.
J Pharm Biomed Anal ; 166: 52-65, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30609394

RESUMO

Danqi Tongmai tablet (DQTT), an innovative TCM formula under clinical trials, is composed of salvianolic acids (SA) and panax notoginsenosides (PNE) for the treatment of coronary heart disease and angina pectoris. However, the in vivo herb-herb interaction of DQTT remains unclear. In the present research, a rapid, reliable and sensitive method for quantitative analysis of multi-notoginsenoside in rat plasma based on ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-TQ/MS) was established and then applied to explore the herb-herb interaction mechanism of DQTT based on the pharmacokinetics in acute myocardial ischemia (AMI) and sham rats after oral administration of DQTT and PNE. Compared with sham rats after oral administration of PNE, the values of AUC0-t for Rf and Rb2 were significantly higher in DQTT group. Compared with AMI rats after oral PNE, AUC0-t for NR1, Rg1, Re, Rb1, Rd, Rg2, Rb2, NR2, Rh1, F1 and F2 were significantly increased after oral administration of DQTT. These results hinted that SA could improve the bioavailability of notoginsenosides in AMI rats, which provides scientific information for better understanding the herb-herb interaction mechanism and offers a reference for clinical administration of DQTT. Additionally, the presently developed methodology was simple, robust, accurate, precise, and would be useful for the pharmacokinetic studies for all kinds of notoginsenosides and other herbal saponins.


Assuntos
Medicamentos de Ervas Chinesas/farmacologia , Ginsenosídeos/farmacocinética , Interações Ervas-Drogas , Panax/metabolismo , Animais , Disponibilidade Biológica , Ginsenosídeos/sangue , Masculino , Isquemia Miocárdica/sangue , Ratos , Comprimidos
3.
J Chromatogr A ; 1563: 124-134, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-29880214

RESUMO

Comprehensive chemical profiling is of great significance for understanding the therapeutic material basis and quality control of herbal medicines, which is challenging due to its inherent chemical diversity and complexity, as well as wide concentration range. In this study, we introduced an enhanced strategy integrating offline two-dimensional (2D) separation and the step-wise precursor ion list-based raster-mass defect filter (step-wise PIL-based raster-MDF) scan by tandem LTQ-Orbitrap mass spectrometer. A comprehensive analysis of indole alkaloids in five botanical origins of Uncariae Ramulus Cum Unicis (Gou-Teng) was used as an exemplary application. A positively charged reversed phase (PR) × conventional RP LC system in different pH conditions was constructed with the orthogonality of 74%. A theoretical step-wise PIL among 310-950 Da with the step-size of 2 Da was developed to selectively trigger fragmentations and extend the coverage of potential indole alkaloids. Simultaneously, by defining parent mass width (PMW) of the step-wise PIL to ±55 mDa, a raster-MDF screening was achieved in the acquisition process. Additionally, subtype classification and structural elucidation were facilitated by a four-step interpretation strategy. As a result, a total of 1227 indole alkaloids were efficiently exposed and characterized from five botanical origins of Gou-Teng, which showed high chemical diversity. A systematic comparison among five species was first performed and only 66 indole alkaloids were common. For method validation, three new alkaloid N-oxides were isolated and unambiguously identified by NMR. The present study provides a novel data-dependent acquisition method with improved target coverage and high selectivity. The integrated strategy is practical to efficiently expose and comprehensively characterize complex components in herbal medicines.


Assuntos
Cromatografia Líquida de Alta Pressão , Alcaloides Indólicos/análise , Espectrometria de Massas em Tandem , Cromatografia de Fase Reversa , Medicamentos de Ervas Chinesas/química , Concentração de Íons de Hidrogênio , Alcaloides Indólicos/química , Alcaloides Indólicos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Conformação Molecular , Peso Molecular , Uncaria/química , Uncaria/metabolismo
4.
Planta Med ; 84(6-07): 449-456, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29216668

RESUMO

It remains a challenge to establish new monographs for herbal drugs derived from multiple botanical sources. Specifically, the difficulty involves discriminating and quantifying these herbs with components whose levels vary markedly among different samples. Using Uncaria stem with hooks as an example, a characteristic chromatogram was proposed to discriminate its five botanical origins and to quantify its characteristic components in the chromatogram. The characteristic chromatogram with respect to the components of Uncaria stem with hooks with the five botanical origins was established using 0.02% diethylamine and acetonitrile as the mobile phase. The total analysis time was 50 min and the detection wavelength was 245 nm. Using the same chromatogram parameters, the single standard to determine multicomponents method was validated to simultaneously quantify nine indole alkaloids, including vincosamide, 3α-dihydrocadambine, isocorynoxeine, corynoxeine, isorhynchophylline, rhynchophylline, hirsuteine, hirsutine, and geissoschizine methyl ether. The results showed that only the Uncaria stem with hooks from Uncaria rhynchophylla, the most widely used in the herbal market, showed the presence of these nine alkaloids. The conversion factors were 1.27, 2.32, 0.98, 1.04, 1.00, 1.02, 1.26, 1.33, and 1.25, respectively. The limits of quantitation were lower than 700 ng/mL. The total contents of 31 batches of Uncaria stem with hooks were in the range of 0.1 - 0.6%, except for Uncaria hirsuta Havil and Uncaria sinensis (Oliv.) Havil. The results also showed that the total content of indole alkaloids tended to decrease with an increase in the hook diameter. This showed that the characteristic chromatogram is practical for controlling the quality of traditional Chinese medicines with multiple botanical origins.


Assuntos
Caules de Planta/química , Uncaria/química , Cromatografia Líquida de Alta Pressão/métodos , Medicina Herbária/métodos , Alcaloides Indólicos/análise , Controle de Qualidade
5.
J Chromatogr A ; 1516: 102-113, 2017 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-28838651

RESUMO

Discovery of new natural compounds is becoming increasingly challenging because of the interference from those known and abundant components. The aim of this study is to report a dereplication strategy, by integrating mass defect filtering (MDF)-oriented novelty classification and precursor ions list (PIL)-triggered high-resolution mass spectrometry analysis, and to validate it by discovering new indole alkaloids from the medicinal herb Uncaria sinensis. Rapid chromatographic separation was achieved on a Kinetex® EVO C18 column (<16min). An in-house MDF algorithm, developed based on the informed phytochemistry information and molecular design, could more exactly screen the target alkaloids and divide them into three novelty levels: Known (KN), Unknown-but-Predicted (UP), and Unexpected (UN). A hybrid data acquisition method, namely PIL-triggered collision-induced dissociation-MS2 and high-energy C-trap dissociation-MS3 with dynamic exclusion on a linear ion trap/Orbitrap mass spectrometer, facilitated the acquisition of diverse product ions sufficient for the structural elucidation of both indole alkaloids and the N-oxides. Ultimately, 158 potentially new alkaloids, including 10 UP and 108 UN, were rapidly characterized from the stem, leaf, and flower of U. sinensis. Two new alkaloid compounds thereof were successfully isolated and identified by 1D and 2D NMR analyses. The varied ring E and novel alkaloid-acylquinic acid conjugates were first reported from the whole Uncaria genus. Conclusively, it is a practical chemical dereplication strategy that can enhance the efficiency and has the potential to be a routine approach for the discovery of new natural compounds.


Assuntos
Alcaloides Indólicos/análise , Alcaloides Indólicos/isolamento & purificação , Espectrometria de Massas , Uncaria/química , Produtos Biológicos/isolamento & purificação , Íons/química , Peso Molecular , Extratos Vegetais/química , Folhas de Planta/química , Caules de Planta/química , Plantas Medicinais/química
6.
Acta Pharm Sin B ; 7(4): 439-446, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28752028

RESUMO

Traditional Chinese medicine (TCM) has played a pivotal role in maintaining the health of Chinese people and is now gaining increasing acceptance around the global scope. However, TCM is confronting more and more concerns with respect to its quality. The intrinsic "multicomponent and multitarget" feature of TCM necessitates the establishment of a unique quality and bioactivity evaluation system, which is different from that of the Western medicine. However, TCM is investigated essentially as "herbal medicine" or "natural product", and the pharmacopoeia quality monographs are actually chemical-markers-based, which can ensure the consistency only in the assigned chemical markers, but, to some extent, have deviated from the basic TCM theory. A concept of "quality marker" (Q-marker), following the "property-effect-component" theory, is proposed. The establishment of Q-marker integrates multidisciplinary technologies like natural products chemistry, analytical chemistry, bionics, chemometrics, pharmacology, systems biology, and pharmacodynamics, etc. Q-marker-based fingerprint and multicomponent determination conduce to the construction of more scientific quality control system of TCM. This review delineates the background, definition, and properties of Q-marker, and the associated technologies applied for its establishment. Strategies and approaches for establishing Q-marker-based TCM quality control system are presented and highlighted with a few TCM examples.

7.
Chin J Nat Med ; 15(4): 301-309, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28527516

RESUMO

Aconiti Lateralis Radix Praeparata (Fuzi) is a commonly used traditional Chinese medicine in clinic for its potency in restoring yang and rescuing from collapse. Aconiti alkaloids, mainly including monoester-diterpenoidaconitines (MDAs) and diester-diterpenoidaconitines (DDAs), are considered to act as both bioactive and toxic constituents. In the present study, a feasible, economical, and accurate HPLC method for simultaneous determination of six alkaloid markers using the Single Standard for Determination of Multi-Components (SSDMC) method was developed and fully validated. Benzoylmesaconine was used as the unique reference standard. This method was proven as accurate (recovery varying between 97.5%-101.8%, RSD < 3%), precise (RSD 0.63%-2.05%), and linear (R > 0.999 9) over the concentration ranges, and subsequently applied to quantitative evaluation of 62 batches of samples, among which 45 batches were from good manufacturing practice (GMP) facilities and 17 batches from the drug market. The contents were then analyzed by principal component analysis (PCA) and homogeneity test. The present study provided valuable information for improving the quality standard of Aconiti Lateralis Radix Praeparata. The developed method also has the potential in analysis of other Aconitum species, such as Aconitum carmichaelii (prepared parent root) and Aconitum kusnezoffii (prepared root).


Assuntos
Aconitum/química , Alcaloides/análise , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Aconitina/análogos & derivados , Aconitina/química , Biomarcadores/análise , Cromatografia Líquida de Alta Pressão/economia , Diterpenos/química , Estudos de Viabilidade , Estrutura Molecular
8.
Fitoterapia ; 116: 85-92, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27889541

RESUMO

Four new alkaloids, comprising three 3-oxo-3,7-seco-oxindole alkaloids (hirsutanine D-F, 1-3) and one oxindole alkaloid N-oxide (uncarine B N-oxide, 4), together with four known heteroyohimbine-type oxindole alkaloids, were isolated from the stems of Uncaria hirsuta Havil. Structures of 1-4 were elucidated by extensive NMR and HR-ESIMS data analyses. Compound 3 is the first 3-oxo-3,7-seco-oxindole alkaloid with ring B opened and degraded isolated from the Uncaria genus. Compounds 1-3 exhibited slight inhibition effect on the proliferation of the breast cancer cell MDA-MB-231. The positive mode collision-induced dissociation of the 3-oxo-3,7-seco-oxindole alkaloids (1-3) was featured by the ß-cleavage and α-cleavage of the amido bond, while the N-oxide (4) showed characteristic neutral eliminations of ·OH and H2O.


Assuntos
Alcaloides/química , Indóis/química , Monoterpenos/química , Alcaloides/isolamento & purificação , Linhagem Celular Tumoral , Humanos , Indóis/isolamento & purificação , Estrutura Molecular , Monoterpenos/isolamento & purificação , Oxindois , Caules de Planta/química , Uncaria/química
9.
J Pharm Biomed Anal ; 134: 352-360, 2017 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-27843099

RESUMO

Increasing challenge arising from configurational interconversion in aqueous solvent renders it rather difficult to isolate high-purity tautomeric reference standards and thus largely hinders the holistic quality control of traditional Chinese medicine (TCM). Spiro oxindole alkaloids (SOAs), as the markers for the medicinal Uncaria herbs, can easily isomerize in polar or aqueous solvent via a retro-Mannich reaction. In the present study, supercritical fluid chromatography (SFC) is utilized to separate and isolate two pairs of 7-epimeric SOAs, including rhynchophylline (R) and isorhynchophylline (IR), corynoxine (C) and corynoxine B (CB), from Uncaria macrophylla. Initially, the solvent that can stabilize SOA epimers was systematically screened, and acetonitrile was used to dissolve and as the modifier in SFC. Then, key parameters of ultra-high performance SFC (ultra-performance convergence chromatography, UPC2), comprising stationary phase, additive in modifier, column temperature, ABPR pressure, and flow rate, were optimized in sequence. Two isocratic UPC2 methods were developed on the achiral Torus 1-AA and Torus Diol columns, suitable for UV and MS detection, respectively. MCI gel column chromatography fractionated the U. macrophylla extract into two mixtures (R/IR and C/CB). Preparative SFC, using a Viridis Prep Silica 2-EP OBD column and acetonitrile-0.2% diethylamine in CO2 as the mobile phase, was finally employed for compound purification. As a result, the purity of four SOA compounds was all higher than 95%. Different from reversed-phase HPLC, SFC, by use of water-free mobile phase (inert CO2 and aprotic modifier), provides a solution to rapid analysis and isolation of tautomeric reference standards for quality control of TCM.


Assuntos
Alcaloides/análise , Cromatografia com Fluido Supercrítico/métodos , Indóis/análise , Uncaria , Alcaloides/química , Indóis/química , Oxindois
10.
Food Chem ; 192: 612-7, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26304390

RESUMO

A method was described for monitoring four nitrofuran metabolites including 5-methylmorpholino-3-amino-2-oxazolidinone (AMOZ), 3-amino-2-oxazolidone (AOZ), 1-amino-hydantoin (AHD) and semicarbazide (SEM) in aquatic products. The analytes were quantified by ultra-performance liquid chromatography-tandem mass spectrometry operating in positive ion multiple monitoring mode (MRM) after 2-nitrobenzaldehyde derivatization. The matrix calibration curve was established with correlation coefficient (R(2)>0.99) in the range of 1-100 ng ml(-1). Limit of detection and limit of quantification for all analytes were 0.5 and 1.5 µg kg(-1), respectively. Recovery rates and relative standard deviations ranged from 88% to 112% and 2% to 4%, respectively. The validated method was successfully applied to detect nitrofuran metabolites in 120 fish samples. The analytes were detected in 6/16 species of fish samples, with a total detection rate of 6.5%. AOZ was most frequently detected (8.3%), followed by AMOZ (7.5%), AHD (5.0%) and SEM (5.0%). The method is proposed for monitoring nitrofuran metabolites in aquatic products.


Assuntos
Cromatografia Líquida/métodos , Nitrofuranos/química , Espectrometria de Massas em Tandem/métodos , Nitrofuranos/análise
11.
Mol Cancer ; 14: 189, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26546412

RESUMO

BACKGROUND: Temozolomide (TMZ) is an oral DNA-alkylating agent used for treating patients with glioblastoma. However, therapeutic benefits of TMZ can be compromised by the expression of O6-methylguanine methyltransferase (MGMT) in tumor tissue. Here we used MGMT-expressing glioblastoma stem cells (GSC) lines as a model for investigating the molecular mechanism underlying TMZ resistance, while aiming to explore a new treatment strategy designed to possibly overcome resistance to the clinically relevant dose of TMZ (35 µM). METHODS: MGMT-expressing GSC cultures are resistant to TMZ, and IC50 (half maximal inhibitory concentration) is estimated at around 500 µM. Clonogenic GSC surviving 500 µM TMZ (GSC-500 µM TMZ), were isolated. Molecular signatures were identified via comparative analysis of expression microarray against parental GSC (GSC-parental). The recombinant protein of top downregulated signature was used as a single agent or in combination with TMZ, for evaluating therapeutic effects of treatment of GSC. RESULTS: The molecular signatures characterized an activation of protective stress responses in GSC-500 µM TMZ, mainly including biotransformation/detoxification of xenobiotics, blocked endoplasmic reticulum stress-mediated apoptosis, epithelial-to-mesenchymal transition (EMT), and inhibited growth/differentiation. Bone morphogenetic protein 7 (BMP7) was identified as the top down-regulated gene in GSC-500 µM TMZ. Although augmenting BMP7 signaling in GSC by exogenous BMP7 treatment did not effectively stop GSC growth, it markedly sensitized both GSC-500 µM TMZ and GSC-parental to 35 µM TMZ treatment, leading to loss of self-renewal and migration capacity. BMP7 treatment induced senescence of GSC cultures and suppressed mRNA expression of CD133, MGMT, and ATP-binding cassette drug efflux transporters (ABCB1, ABCG2), as well as reconfigured transcriptional profiles in GSC by downregulating genes associated with EMT/migration/invasion, stemness, inflammation/immune response, and cell proliferation/tumorigenesis. BMP7 treatment significantly prolonged survival time of animals intracranially inoculated with GSC when compared to those untreated or treated with TMZ alone (p = 0.0017), whereas combination of two agents further extended animal survival compared to BMP7 alone (p = 0.0489). CONCLUSIONS: These data support the view that reduced endogenous BMP7 expression/signaling in GSC may contribute to maintained stemness, EMT, and chemoresistant phenotype, suggesting that BMP7 treatment may provide a novel strategy in combination with TMZ for an effective treatment of glioblastoma exhibiting unmethylated MGMT.


Assuntos
Proteína Morfogenética Óssea 7/metabolismo , Metilases de Modificação do DNA/metabolismo , Dacarbazina/análogos & derivados , Glioblastoma/enzimologia , Glioblastoma/metabolismo , Guanina/análogos & derivados , Células-Tronco Neoplásicas/enzimologia , Antineoplásicos Alquilantes , Proteína Morfogenética Óssea 7/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Metilases de Modificação do DNA/genética , Dacarbazina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Glioblastoma/genética , Guanina/metabolismo , Humanos , Células-Tronco Neoplásicas/metabolismo , Temozolomida , Células Tumorais Cultivadas
12.
J Chromatogr A ; 1409: 159-65, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26209189

RESUMO

An efficient and target-oriented sample enrichment method was established to increase the content of the minor alkaloids in crude extract by using the corresponding two-phase solvent system applied in pH-zone-refining counter-current chromatography. The enrichment and separation of seven minor indole alkaloids from Uncaria rhynchophylla (Miq.) Miq. ex Havil(UR) were selected as an example to show the advantage of this method. An optimized two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (3:7:1:9, v/v) was used in this study, where triethylamine (TEA) as the retainer and hydrochloric acid (HCl) as the eluter were added at the equimolar of 10mM. Crude alkaloids of UR dissolved in the corresponding upper phase (containing 10mM TEA) were extracted twice with lower phase (containing 10mM TEA) and lower phase (containing 10mM HCl), respectively, the second lower phase extract was subjected to pH-zone-refining CCC separation after alkalization and desalination. Finally, from 10g of crude alkaloids, 4g of refined alkaloids was obtained and the total content of seven target indole alkaloids was increased from 4.64% to 15.78%. Seven indole alkaloids, including 54mg isocorynoxeine, 21mg corynoxeine, 46mg isorhynchophylline, 35mg rhynchophylline, 65mg hirsutine, 51mg hirsuteine and 27mg geissoschizine methylether were all simultaneously separated from 2.5g of refined alkaloids, with the purity of 86.4%, 97.5%, 90.3%, 92.1%, 98.5%, 92.3%, and 92.8%, respectively. The total content and purities of the seven minor indole alkaloids were tested by HPLC and their chemical structures were elucidated by ESI-HRMS and (1)H NMR.


Assuntos
Alcaloides Indólicos/isolamento & purificação , Acetatos , Cromatografia Líquida de Alta Pressão/métodos , Distribuição Contracorrente/métodos , Hexanos , Concentração de Íons de Hidrogênio , Metanol , Extratos Vegetais/química , Solventes , Uncaria/química
13.
Anal Bioanal Chem ; 407(20): 6057-70, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26055881

RESUMO

The exploration of new chemical entities from herbal medicines may provide candidates for the in silico screening of drug leads. However, this significant work is hindered by the presence of multiple classes of plant metabolites and many re-discovered structures. This study presents an integrated strategy that uses ultrahigh-performance liquid chromatography/linear ion-trap quadrupole/Orbitrap mass spectrometry (UHPLC/LTQ-Orbitrap-MS) coupled with in-house library data for the systematic characterization and discovery of new potentially bioactive molecules. Exploration of the indole alkaloids from Uncaria rhynchophylla (UR) is presented as a model study. Initially, the primary characterization of alkaloids was achieved using mass defect filtering and neutral loss filtering. Subsequently, phytochemical isolation obtained 14 alkaloid compounds as reference standards, including a new one identified as 16,17-dihydro-O-demethylhirsuteine by NMR analyses. The direct-infusion fragmentation behaviors of these isolated alkaloids were studied to provide diagnostic structural information facilitating the rapid differentiation and characterization of four different alkaloid subtypes. Ultimately, after combining the experimental results with a survey of an in-house library containing 129 alkaloids isolated from the Uncaria genus, a total of 92 alkaloids (60 free alkaloids and 32 alkaloid O-glycosides) were identified or tentatively characterized, 56 of which are potential new alkaloids for the Uncaria genus. Hydroxylation on ring A, broad variations in the C-15 side chain, new N-oxides, and numerous O-glycosides, represent the novel features of the newly discovered indole alkaloid structures. These results greatly expand our knowledge of UR chemistry and are useful for the computational screening of potentially bioactive molecules from indole alkaloids. Graphical Abstract A four-step integrated strategy for the systematic characterization and efficient discovery of new indole alkaloids from Uncaria rhynchophylla.


Assuntos
Alcaloides Indólicos/análise , Extratos Vegetais/química , Uncaria/química , Cromatografia Líquida de Alta Pressão/métodos , Glicosídeos/análise , Espectrometria de Massas/métodos , Caules de Planta/química
14.
J Nat Prod ; 77(11): 2342-51, 2014 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-25338180

RESUMO

Five new ent-pimarane (1-3, 7, and 8) and three new ent-kaurane diterpenoids (4-6) and a new oleanane triterpene acid (9), together with 22 known compounds, were isolated from the root bark of the medicinal herb Acanthopanax gracilistylus. The structures of 1-9 were established based on the interpretation of high-resolution MS and 1D- and 2D-NMR data. The absolute configurations of 7 and 11 were determined by single-crystal X-ray diffraction and electronic circular dichroism analysis. Compounds 7 and 8 represent rare naturally occurring structures based on the devinyl ent-pimarane skeleton. Compounds 3, 10, 14, 16, and 17 exhibited potent inhibitory effects on the release of interleukin-1ß (IL-1ß), interleukin-8 (IL-8), and tumor necrosis factor (TNF-α) in lipopolysaccharide-stimulated peripheral blood mononuclear cells.


Assuntos
Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Diterpenos de Caurano/isolamento & purificação , Diterpenos de Caurano/farmacologia , Eleutherococcus/química , Plantas Medicinais/química , Anti-Inflamatórios/química , Cristalografia por Raios X , Diterpenos de Caurano/química , Interleucina-1beta/efeitos dos fármacos , Interleucina-8/efeitos dos fármacos , Leucócitos Mononucleares/efeitos dos fármacos , Lipopolissacarídeos/sangue , Lipopolissacarídeos/farmacologia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Casca de Planta/química , Fator de Necrose Tumoral alfa/efeitos dos fármacos
15.
Fitoterapia ; 96: 39-47, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24727084

RESUMO

Five new oleanane and ursane type triterpenes, namely uncarinic acids F-J (1-5), together with six known triterpenic acids (6-11) were isolated from the stems and hooks of Uncaria rhynchophylla. Structure elucidation of 1-5 was based on the integrated analyses of high-resolution MS data, 1D ((1)H NMR, (13)C NMR, DEPT) and 2D (HSQC, HMBC, ROESY) NMR spectra. Compounds 4, 10, and 11 exhibited weak inhibitory effects on LPS-induced NO production in RAW264.7 cells (with IC50 1.48, 7.01, and 1.89 µM, respectively) with dexamethasone (IC50 0.04 µM) and quercetin (IC50 0.86 µM) as the positive controls. 19-OH substituted oleanane triterpenic acids (1, 2, 5, 8) were prone to eliminate CH2O3, whereas those ursane-type encompassing 19-OH (3, 6, 7, 9, 4) were featured by preferred cleavage of H2O while performing the negative collision-induced MS/MS fragmentation on an LTQ/Orbitrap mass spectrometer.


Assuntos
Ácido Oleanólico/química , Espectrometria de Massas em Tandem/métodos , Triterpenos/química , Uncaria/química , Animais , Linhagem Celular Tumoral , Concentração Inibidora 50 , Lipopolissacarídeos/farmacologia , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/farmacologia , Caules de Planta/química , Triterpenos/isolamento & purificação , Triterpenos/farmacologia
16.
PLoS One ; 8(11): e80397, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24260384

RESUMO

Glioblastoma stem cells (GSC) are a significant cell model for explaining brain tumor recurrence. However, mechanisms underlying their radiochemoresistance remain obscure. Here we show that most clonogenic cells in GSC cultures are sensitive to radiation treatment (RT) with or without temozolomide (TMZ). Only a few single cells survive treatment and regain their self-repopulating capacity. Cells re-populated from treatment-resistant GSC clones contain more clonogenic cells compared to those grown from treatment-sensitive GSC clones, and repeated treatment cycles rapidly enriched clonogenic survival. When compared to sensitive clones, resistant clones exhibited slower tumor development in animals. Upregulated genes identified in resistant clones via comparative expression microarray analysis characterized cells under metabolic stress, including blocked glucose uptake, impaired insulin/Akt signaling, enhanced lipid catabolism and oxidative stress, and suppressed growth and inflammation. Moreover, many upregulated genes highlighted maintenance and repair activities, including detoxifying lipid peroxidation products, activating lysosomal autophagy/ubiquitin-proteasome pathways, and enhancing telomere maintenance and DNA repair, closely resembling the anti-aging effects of caloric/glucose restriction (CR/GR), a nutritional intervention that is known to increase lifespan and stress resistance in model organisms. Although treatment-introduced genetic mutations were detected in resistant clones, all resistant and sensitive clones were subclassified to either proneural (PN) or mesenchymal (MES) glioblastoma subtype based on their expression profiles. Functional assays demonstrated the association of treatment resistance with energy stress, including reduced glucose uptake, fatty acid oxidation (FAO)-dependent ATP maintenance, elevated reactive oxygen species (ROS) production and autophagic activity, and increased AMPK activity and NAD(+) levels accompanied by upregulated mRNA levels of SIRT1/PGC-1α axis and DNA repair genes. These data support the view that treatment resistance may arise from quiescent GSC exhibiting a GR-like phenotype, and suggest that targeting stress response pathways of resistant GSC may provide a novel strategy in combination with standard treatment for glioblastoma.


Assuntos
Adaptação Fisiológica/genética , Resistencia a Medicamentos Antineoplásicos/genética , Glioblastoma/genética , Glioblastoma/metabolismo , Glucose/metabolismo , Células-Tronco/metabolismo , Estresse Fisiológico/genética , Linhagem Celular Tumoral , Reparo do DNA/genética , Dacarbazina/análogos & derivados , Dacarbazina/farmacologia , Expressão Gênica/genética , Glioblastoma/tratamento farmacológico , Glioblastoma/radioterapia , Humanos , Transdução de Sinais/genética , Temozolomida , Regulação para Cima/genética
17.
Phytochemistry ; 94: 268-76, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23820314

RESUMO

Eleven previously unknown compounds and 23 known compounds, including 20 phenanthrene or 9,10-dihydrophenanthrene derivatives, five bibenzyls, seven malate or tartrate benzyl ester glucosides, adenosine and gastrodin were isolated from tubers of Cremastra appendiculata. Among the obtained compounds, two are the first isolated dimers with one phenanthrene or bibenzyl unit connected to C-3 of 2,3,4,5-tetrahydro-phenanthro[2,1-b]furan moiety. In addition, 33 of these compounds were evaluated in vitro for their cytotoxic activity against two cancer cell lines. Among the compounds examined, one compound showed moderate cytotoxic activity, while five showed weak cytotoxic activity against the A549 cell line.


Assuntos
Bibenzilas/química , Glucosídeos/química , Orchidaceae/química , Fenantrenos/química , Tubérculos/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Benzeno/química , Bibenzilas/isolamento & purificação , Bibenzilas/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ésteres/química , Glucosídeos/isolamento & purificação , Glucosídeos/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Malatos/química , Fenantrenos/isolamento & purificação , Fenantrenos/farmacologia , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Infravermelho , Tartaratos/química
18.
J Pharm Biomed Anal ; 77: 63-70, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23384551

RESUMO

A fast high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry method was developed to determine 24 components including 11 phenolic compounds, 9 phenolic amides, and 4 cyclic peptides in Cortex Lycii. The analytes were quantified by a triple quadrupole instrument in multiple reaction monitoring (MRM) mode. The fragmentation patterns of phenolic amides and cyclic peptides using ESI and collision-induced dissociation (CID) techniques are reported. This assay method was validated with respect to linearity (r(2)>0.9920), precision, repeatability, and accuracy (recovery rate between 93.0 and 105.9% with RSD<4.4%). The analytical results of 28 batches of Cortex Lycii indicated that cyclic peptides and phenolic amides were not only the abundant constituents, but also the characteristic components for Cortex Lycii to distinguish from the adulterants. Principle component analysis (PCA) was used to discriminate samples from different geographical regions of China, and cyclic peptides were considered to be the chemical markers responsible for the classification. The systematic and integrated assessment of Cortex Lycii provides sufficient evidence for the establishment of the quality standard.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Lycium/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Amidas/química , Fenóis/química , Raízes de Plantas/química
19.
Food Chem ; 138(2-3): 2016-25, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23411338

RESUMO

The aim of this study was to investigate the pesticide residues in market vegetables in Shaanxi Province of China. The concentrations of 33 pesticides were determined by gas chromatography (GC) in 285 samples. Ten organophosphorus pesticides (OPs) were found in concentrations ranging from 0.004 to 0.257 mg/kg. The mean levels of omethoate, phorate, chlorpyrifos, methidathion, ethoprophos in vegetables exceeded the maximum residue limits (MRLs) allowed by the Ministry of Health, of China. Other detectable OP pesticide residues levels were below their MRLs. Dicofol were detectable in green pepper and chives samples. Five pyrethroid pesticides (PYRs) were detectable in vegetable samples respectively. The results provide useful information on the current contamination status of a key agricultural area in China, and point to the need for urgent action to control the excessive use of some chemicals.


Assuntos
Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Verduras/química , China , Qualidade de Produtos para o Consumidor
20.
J Nat Prod ; 76(1): 51-8, 2013 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-23282106

RESUMO

Seven new neolignanamides (1-7), including two pairs of cis- and trans-isomers, and a new lignanamide (8) were isolated from the EtOAc-soluble fraction of an EtOH extract of the root bark of Lycium chinense, together with 22 known phenolic compounds (9-30), four of which were obtained from the genus Lycium for the first time. Compounds 5, 6, and 7 are unusual dimers having a rare connection mode between the two cinnamic acid amide units, while compounds 6, 7, and 8 are the first naturally occurring dimers derived from two dissimilar cinnamic acid amides. The cinnamic acid amides, neolignanamides, and lignanamides possess moderate radical-scavenging activity against the DPPH (2,2-diphenyl-1-picrylhydrazyl) and superoxide radicals.


Assuntos
Acrilamidas/isolamento & purificação , Compostos Bicíclicos Heterocíclicos com Pontes/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Depuradores de Radicais Livres/isolamento & purificação , Lycium/química , Naftalenos/isolamento & purificação , Acrilamidas/química , Acrilamidas/farmacologia , Compostos de Bifenilo/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/química , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/farmacologia , Estrutura Molecular , Naftalenos/química , Naftalenos/farmacologia , Ressonância Magnética Nuclear Biomolecular , Fenóis/química , Picratos/farmacologia , Casca de Planta/química , Estereoisomerismo
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