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1.
Int J Mol Sci ; 25(17)2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39273225

RESUMEN

Cancer-associated fibroblast (CAF)s in the tumour microenvironment (TME) modulate the extracellular matrix, interact with cancer cells, and facilitate communication with infiltrating leukocytes, significantly contributing to cancer progression and therapeutic response. In prostate cancer (PCa), CAFs promote malignancy through metabolic rewiring, cancer stem cell regulation, and therapy resistance. Pre-clinical studies indicate that targeting amino acid metabolism, particularly glutamine (Gln) metabolism, reduces cancer proliferation and stemness. However, most studies lack the context of CAF-cancer interaction, focusing on monocultures. This study assesses the influence of CAFs on PCa growth by manipulating Gln metabolism using colour-labelled PCa cell lines (red) and fibroblast (green) in a co-culture system to evaluate CAFs' effects on PCa cell proliferation and clonogenic potential. CAFs increased the proliferation of hormone-sensitive LNCaP cells, whereas the castration-resistant C4-2 cells were unaffected. However, clonogenic growth increased in both cell lines. Gln deprivation and GLS1 inhibition experiments revealed that the increased growth rate of LNCAP cells was associated with increased dependence on Gln, which was confirmed by proteomic analyses. Tissue analysis of PCa patients revealed elevated GLS1 levels in both the PCa epithelium and stroma, suggesting that GLS1 is a therapeutic target. Moreover, the median overall survival analysis of GLS1 expression in the PCa epithelium and stroma identified a "high-risk" patient group that may benefit from GLS1-targeted therapies. Therefore, GLS1 targeting appears promising in castration-resistant PCa patients with high GLS1 epithelium and low GLS1 stromal expression.


Asunto(s)
Fibroblastos Asociados al Cáncer , Proliferación Celular , Técnicas de Cocultivo , Glutamina , Neoplasias de la Próstata , Microambiente Tumoral , Humanos , Glutamina/metabolismo , Masculino , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Fibroblastos Asociados al Cáncer/metabolismo , Fibroblastos Asociados al Cáncer/patología , Línea Celular Tumoral , Glutaminasa/metabolismo , Fibroblastos/metabolismo
2.
Curr Issues Mol Biol ; 44(2): 597-608, 2022 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-35723327

RESUMEN

The androgen receptor (AR) plays a central role in prostate, muscle, bone and adipose tissue. Moreover, dysregulated AR activity is a driving force in prostate cancer (PCa) initiation and progression. Consequently, antagonizing AR signalling cascades via antiandrogenic therapy is a crucial treatment option in PCa management. Besides, very high androgen levels also inhibit PCa cells' growth, so this effect could also be applied in PCa therapy. However, on the molecular and cellular level, these mechanisms have hardly been investigated so far. Therefore, the present study describes the effects of varying androgen concentrations on the viability of PCa cells as well as localization, transactivation, and protein stability of the AR. For this purpose, cell viability was determined via WST1 assay. Alterations in AR transactivity were detected by qPCR analysis of AR target genes. A fluorescent AR fusion protein was used to analyse AR localization microscopically. Changes in AR protein expression were detected by Western blot. Our results showed that high androgen concentrations reduce the cell viability in LNCaP and C4-2 cell lines. In addition, androgens have been reported to increase AR transactivity, AR localization, and AR protein expression levels. However, high androgen levels did not reduce these parameters. Furthermore, this study revealed an androgen-induced increase in AR protein synthesis. In conclusion, inhibitory effects on cell viability by high androgen levels are due to AR downstream signalling or non-genomic AR activity. Moreover, hormonal activation of the AR leads to a self-induced stabilization of the receptor, resulting in increased AR activity. Therefore, in clinical use, a therapeutic reduction in androgen levels represents a clinical target and would lead to a decrease in AR activity and, thus, AR-driven PCa progression.

3.
Int J Mol Sci ; 23(3)2022 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-35162969

RESUMEN

Prostate-specific membrane antigen (PSMA) is an essential molecular regulator of prostate cancer (PCa) progression coded by the FOLH1 gene. The PSMA protein has become an important factor in metastatic PCa diagnosis and radioligand therapy. However, low PSMA expression is suggested to be a resistance mechanism to PSMA-based imaging and therapy. Clinical studies revealed that androgen receptor (AR) inhibition increases PSMA expression. The mechanism has not yet been elucidated. Therefore, this study investigated the effect of activation and inhibition of androgen signaling on PSMA expression levels in vitro and compared these findings with PSMA levels in PCa patients receiving systemic therapy. To this end, LAPC4, LNCaP, and C4-2 PCa cells were treated with various concentrations of the synthetic androgen R1881 and antiandrogens. Changes in FOLH1 mRNA were determined using qPCR. Open access databases were used for ChIP-Seq and tissue expression analysis. Changes in PSMA protein were determined using western blot. For PSMA staining in patients' specimens, immunohistochemistry (IHC) was performed. Results revealed that treatment with the synthetic androgen R1881 led to decreased FOLH1 mRNA and PSMA protein. This effect was partially reversed by antiandrogen treatment. However, AR ChIP-Seq analysis revealed no canonical AR binding sites in the regulatory elements of the FOLH1 gene. IHC analysis indicated that androgen deprivation only resulted in increased PSMA expression in patients with low PSMA levels. The data demonstrate that AR activation and inhibition affects PSMA protein levels via a possible non-canonical mechanism. Moreover, analysis of PCa tissue reveals that low PSMA expression rates may be mandatory to increase PSMA by androgen deprivation.


Asunto(s)
Antígenos de Superficie/genética , Biomarcadores de Tumor/genética , Glutamato Carboxipeptidasa II/genética , Neoplasias de la Próstata/diagnóstico , Receptores Androgénicos/metabolismo , Antagonistas de Andrógenos/farmacología , Biomarcadores de Tumor/metabolismo , Línea Celular Tumoral , Regulación hacia Abajo , Detección Precoz del Cáncer , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Metribolona/farmacología , Células PC-3 , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Elementos Reguladores de la Transcripción
4.
Environ Monit Assess ; 190(8): 456, 2018 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-29992364

RESUMEN

PM10 samples were collected simultaneously at three representative areas (urban, industrial, and rural areas). Their morphology and elemental composition were determined by scanning electron microscopy coupled with energy-dispersive analysis (SEM-EDS). Twenty-four chemical parameters (C, O, Na, Mg, Al, Si, P, Cd, Cl, K, Ca, S, Sn, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, W, and Pb) were determined and three morphological parameters (area, roundness, and fractal dimension) were measured by Image Pro Analyzer 6.3. The particles were classified into ten groups based on morphology and elemental composition: Ca-rich and metal particles, soot aggregates, cenosphere, alumosilicates, sea salt, calcium sulfate, spherical particles of iron, biological carbonaceous particles, and various. Particles of natural origin were predominantly found in the coarse size fraction and particles of anthropogenic origin in the fine size fraction. The greatest contribution to particulate matter belonged to aluminum-silicates and calcium-rich particles. The cenosphere were recognized only in the coastal urban site, while all the other particles were present in each site. The coastal industrial site was characterized by the prevalence of alumosilicates and Ca-rich particles, due to construction activity in this site during the sampling period (movement of vehicles, transport of terrigenous materials, and use of construction products). The coastal urban site was characterized by a higher amount of soot and by the presence of cenosphere, due to the presence of vehicular traffic.


Asunto(s)
Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Ambiente , Italia , Metales/análisis , Microscopía Electrónica de Rastreo , Tamaño de la Partícula , Material Particulado/análisis , Hollín/análisis
6.
Oncogene ; 43(26): 2038-2050, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38750263

RESUMEN

Docetaxel (DX) serves as a palliative treatment option for metastatic prostate cancer (PCa). Despite initial remission, acquired DX resistance is inevitable. The mechanisms behind DX resistance have not yet been deciphered, but a mesenchymal phenotype is associated with DX resistance. Mesenchymal phenotypes have been linked to metabolic rewiring, obtaining most ATP production by oxidative phosphorylation (OXPHOS) powered substantially by glutamine (Gln). Likewise, Gln is known to play an essential role in modulating bioenergetic, redox homeostasis and autophagy. Herein, investigations of Gln deprivation on DX-sensitive and -resistant (DR) PCa cells revealed that the DR cell sub-lines were susceptible to Gln deprivation. Mechanistically, Gln deprivation reduced OXPHOS and ATP levels, causing a disturbance in cell cycle progression. Genetic and chemical inhibition of the Gln-metabolism key protein GLS1 could validate the Gln deprivation results, thereby representing a valid therapeutic target. Moreover, immunohistological investigation of GLS1 revealed a high-expressing GLS1 subgroup post-docetaxel failure, exhibiting low overall survival. This subgroup presents an intriguing opportunity for targeted therapy focusing on glutamine metabolism. Thus, these findings highlight a possible clinical rationale for the chemical inhibition of GLS1 as a therapeutic strategy to target mesenchymal DR PCa cells, thereby delaying accelerated tumour progression.


Asunto(s)
Proliferación Celular , Docetaxel , Resistencia a Antineoplásicos , Glutamina , Neoplasias de la Próstata , Masculino , Humanos , Glutamina/metabolismo , Docetaxel/farmacología , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/genética , Proliferación Celular/efectos de los fármacos , Línea Celular Tumoral , Fosforilación Oxidativa/efectos de los fármacos , Glutaminasa/metabolismo , Glutaminasa/antagonistas & inhibidores , Glutaminasa/genética , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico
7.
Sci Rep ; 13(1): 4274, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36922643

RESUMEN

As the state of resection margins is an important prognostic factor after extirpation of colorectal liver metastases, surgeons aim to obtain negative margins, sometimes elaborated by resections of the positive resection plane after intraoperative frozen sections. However, this is time consuming and results sometimes remain unclear during surgery. Label-free multimodal multiphoton microscopy (MPM) is an optical technique that retrieves morpho-chemical information avoiding all staining and that can potentially be performed in real-time. Here, we investigated colorectal liver metastases and hepatic tissue using a combination of three endogenous nonlinear signals, namely: coherent anti-Stokes Raman scattering (CARS) to visualize lipids, two-photon excited fluorescence (TPEF) to visualize cellular patterns, and second harmonic generation (SHG) to visualize collagen fibers. We acquired and analyzed over forty thousand MPM images of metastatic and normal liver tissue of 106 patients. The morphological information with biochemical specificity produced by MPM allowed discriminating normal liver from metastatic tissue and discerning the tumor borders on cryosections as well as formalin-fixed bulk tissue. Furthermore, automated tissue type classification with a correct rate close to 95% was possible using a simple approach based on discriminant analysis of texture parameters. Therefore, MPM has the potential to increase the precision of resection margins in hepatic surgery of metastases without prolonging surgical intervention.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Hepáticas , Humanos , Márgenes de Escisión , Microscopía de Fluorescencia por Excitación Multifotónica/métodos
8.
Epidemiol Prev ; 35(2): 136-8, 2011.
Artículo en Italiano | MEDLINE | ID: mdl-21628758

RESUMEN

The Emilia-Romagna regional government decided to develop a monitoring and surveillance system, known as MonITER (Incineration Monitoring on the Emilia-Romagna Territory), in 8 areas characterized by the presence of municipal waste incinerating plants.The project was divided into 7 lines, among these the number 6 developed a procedure of Health Impact Assessments (HIA) to support the planning of new facilities for incineration or combustion. Line number 6 is divided into 3 actions n action 1 aimed to developing and validating a participative HIA methodology, as well tools for the impact assessment and recommendations for implementing HIA on future plants; n action 2 analysed connected issues on communication; n action 3 was focused to developing a methodology for integrating HIA models into existing tools for mandatory impact assessment.Tailoring the HIA model development to the waste management context has highlighted the fundamental differences of the HIA approach with the other mandatory assessment tools, being theoretically founded on the principles of public involvement, equity, sustainable development and ethical use of evidence.


Asunto(s)
Monitoreo del Ambiente/legislación & jurisprudencia , Política Ambiental , Política de Salud , Incineración/normas , Administración de Residuos/legislación & jurisprudencia , Toma de Decisiones , Ambiente , Monitoreo del Ambiente/normas , Residuos de Alimentos , Humanos , Incineración/legislación & jurisprudencia , Incineración/métodos , Incineración/estadística & datos numéricos , Italia , Modelos Teóricos , Formulación de Políticas
9.
Life (Basel) ; 11(9)2021 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-34575023

RESUMEN

Antiandrogen therapy is a primary treatment for patients with metastasized prostate cancer. Whilst the biologic mechanisms of antiandrogens have been extensively studied, the operating protocols used for the characterization of these drugs were not identical, limiting their comparison. Here, the antiandrogens Bicalutamide, Enzalutamide, Apalutamide, and Darolutamide were systematically compared using identical experimental setups. Androgen-dependent LNCaP and LAPC4 cells as well as androgen-independent C4-2 cells were treated with distinct concentrations of antiandrogens. Androgen receptor (AR)-mediated gene transactivation was determined using qPCR. Cell viability was measured by WST1 assay. Protein stability and AR localization were determined using western blot. Response to the tested antiandrogens across cellular backgrounds differed primarily in AR-mediated gene transactivation and cell viability. Antiandrogen treatment in LNCaP and LAPC4 cells resulted in AR protein level reduction, whereas in C4-2 cells marginal decreased AR protein was observed after treatment. In addition, AR downregulation was already detectable after 4 h, whereas reduced AR-mediated gene transactivation was not observed before 6 h. None of the tested antiandrogens displayed an advantage on the tested parameters within one cell line as opposed to the cellular background, which seems to be the primary influence on antiandrogen efficacy. Moreover, the results revealed a prominent role in AR protein stability. It is one of the first events triggered by antiandrogens and correlated with antiandrogen efficiency. Therefore, AR stability may surrogate antiandrogen response and may be a possible target to reverse antiandrogen resistance.

10.
Chemosphere ; 236: 124376, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31545188

RESUMEN

Results of a methodological study on the use of Positive Matrix Factorization (PMF) with smaller datasets are being reported in this work. This study is based on 29 PM10 and 33 PM2.5 samples from a receptor in a rural setup in Apulia (Southern Italy). Running PMF on the two size fractions separately resulted in the model not functioning correctly. We therefore, augmented the size of the dataset by aggregating the PM10 and PM2.5 data. The 5-factor solution obtained for the aggregated data was fairly rotationally stable, and was further refined by the rotational tools included in USEPA PMF version 5. These refinements include the imposition of constraints on the solution, based on our knowledge of the chemical composition of the aerosol sources affecting the receptor. Additionally, the uncertainties associated with this solution were fully characterised using the improved error estimation techniques in this version of PMF. Five factors in all, were isolated by PMF: ammonium sulfate, marine aerosol, mixed carbonaceous aerosol, crustal/Saharan dust and total traffic. The results obtained by PMF were further tested inter alia, by comparing them to those obtained by two other receptor modelling techniques: Constrained Weighted Non-negative Matrix Factorization (CW - NMF) and Chemical Mass Balance (CMB). The results of these tests suggest that the solution obtained by PMF, is valid, indicating that for this particular airshed PMF managed to extract most of the information about the aerosol sources affecting the receptor - even from a dataset with a limited number of samples.


Asunto(s)
Contaminantes Atmosféricos/análisis , Material Particulado/análisis , Aerosoles/análisis , Polvo/análisis , Monitoreo del Ambiente/métodos , Italia
11.
Sci Rep ; 9(1): 9602, 2019 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-31270378

RESUMEN

In olive trees, Xylella fastidiosa colonizes xylem vessels and compromises water transport causing the olive quick decline syndrome (OQDS). The loss of hydraulic conductivity could be attributed to vessel occlusions induced both by the bacteria biofilm and by plant responses (tyloses, gums, etc.) that could trigger embolism. The ability of the infected plants to detect embolism and to respond, by activating mechanisms to restore the hydraulic conductivity, can influence the severity of the disease symptomatology. In order to investigate these mechanisms in the X. fastidiosa-resistant olive cultivar Leccino and in the susceptible Cellina di Nardò, sections of healthy olive stems were analysed by laser scanning microscope to calculate the cavitation vulnerability index. Findings indicated that the cultivar Leccino seems to be constitutively less susceptible to cavitation than the susceptible one. Among the vascular refilling mechanisms, starch hydrolysis is a well-known strategy to refill xylem vessels that suffered cavitation and it is characterized by a dense accumulation of starch grains in the xylem parenchima; SEM-EDX analysis of stem cross-sections of infected plants revealed an aggregation of starch grains in the Leccino xylem vessels. These observations could indicate that this cultivar, as well as being anatomically less susceptible to cavitation, it also could be able to activate more efficient refilling mechanisms, restoring vessel's hydraulic conductivity. In order to verify this hypothesis, we analysed the expression levels of some genes belonging to families involved in embolism sensing and refilling mechanisms: aquaporins, sucrose transporters, carbohydrate metabolism and enzymes related to starch breakdown, alpha and beta-amylase. The obtained genes expression patterns suggested that the infected plants of the cultivar Leccino strongly modulates the genes involved in embolism sensing and refilling.


Asunto(s)
Olea/metabolismo , Xylella/fisiología , Xilema/fisiología , Acuaporinas/metabolismo , Susceptibilidad a Enfermedades , Microscopía Electrónica de Rastreo , Olea/microbiología , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/microbiología , Proteínas de Plantas/metabolismo , Tallos de la Planta/metabolismo , Almidón/metabolismo , Xilema/anatomía & histología , beta-Amilasa/metabolismo
12.
Magn Reson Chem ; 46(1): 88-93, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18041009

RESUMEN

Two new oleanane saponins (1 and 2) and one new flavonol glycoside (3) together with six known flavonoids, were isolated from the aerial parts of Paronychia argentea. Their structures were elucidated by 1D and 2D NMR experiments including 1D-TOCSY, DQF-COSY, NOESY, HSQC, and HMBC spectroscopy, as well as ESI-MS analysis.


Asunto(s)
Flavonoides/aislamiento & purificación , Paroniquia/metabolismo , Saponinas/aislamiento & purificación , Flavonoides/química , Espectroscopía de Resonancia Magnética , Estructura Molecular , Componentes Aéreos de las Plantas/metabolismo , Saponinas/química , Espectrometría de Masa por Ionización de Electrospray
13.
Fitoterapia ; 79(2): 123-5, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18164872

RESUMEN

The essential oil obtained from the seeds of Momordica charantia was analyzed by GC/MS. Twenty-five components, representing 90.9% of the oil, were identified. The main constituents were trans-nerolidol, apiole, cis-dihydrocarveol and germacrene D. Furthermore, the oil was tested for its antibacterial and antifungal activities. Staphylococcus aureus was found to be the most sensitive microorganism with MIC values <500 microg/ml.


Asunto(s)
Antiinfecciosos/análisis , Momordica charantia/química , Aceites Volátiles/química , Pruebas de Sensibilidad Microbiana , Semillas/química
14.
Environ Sci Pollut Res Int ; 25(24): 23929-23945, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29881969

RESUMEN

Organic and elemental carbon were measured both in daily PM10 and PM2.5 and in 6 h range time PM2.5 samples collected from September 2015 to October 2015 in a coastal rural site near Brindisi in the Apulia region (Italy), in order to determine factors affecting the carbonaceous aerosol variations. Carbon content (total carbon TC) represented a considerable fraction for both PM10 and PM2.5. In particular, in PM10 samples, organic carbon (OC) varied from 1.06 to 18.32 µg m-3 with a mean concentration of 5 ± 4 µg m-3 and EC varied from 0.11 to 0.88 µg m-3 with a mean value of 0.41 ± 0.19 µg m-3. In PM2.5 samples, OC varied from 0.54 to 12.91 µg m-3 with a mean concentration of 3.5 ± 2.8 µg m-3 and EC varied from 0.11 to 0.85 µg m-3 with a mean value of 0.35 ± 0.18 µg m-3. The highest values for both parameters were recorded when the air masses were coming from NE Europe and when Saharan Dust events were recognized. The results show that OC and EC exhibited higher concentrations during the night hours, suggesting that stable atmosphere and lower mixing conditions play important roles for the accumulation of air pollutants and promote condensation or adsorption of semivolatile organic compounds. In samples from a Saharan Dust event and in samples with the lowest and the highest OCsec, ATR-FTIR analysis allowed us to identify organic functional groups including the non-acid organic hydroxyl C-OH group (e.g., sugars, anhydrosugars, and polyols), carbonyl C=O group, carboxylic acid COOH group, aromatic and aliphatic unsaturated C=C-H group, aliphatic saturated C-C-H group, and amine NH2 group. Some inorganic ions were also identified: carbonates, sulfate, silicate, and ammonium. The dusty samples are mainly characterized by the presence of carbonate and hydrogen sulfate ions and by kaolinite (absorption at 914 and 1010 cm-1), while in samples with air masses coming from the NE, OC is mainly characterized by aliphatic and aromatic C-H and O-H and N-H groups (absorptions in the range 3500-2700 cm-1) and by the presence of organonitrate, aromatic amide and amine, and carboxylic acids (absorptions at 1630 and 1770-1700 cm-1). Graphical abstract ᅟ.


Asunto(s)
Aerosoles/análisis , Contaminantes Atmosféricos/análisis , África del Norte , Compuestos de Amonio/análisis , Carbono/análisis , Carbonatos/análisis , Polvo/análisis , Monitoreo del Ambiente/métodos , Europa (Continente) , Italia , Compuestos Orgánicos/análisis , Material Particulado/análisis , Estaciones del Año , Espectroscopía Infrarroja por Transformada de Fourier , Sulfatos/análisis
15.
J Phys Chem B ; 111(3): 598-604, 2007 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-17228918

RESUMEN

Electrospray ionization mass spectrometry applied to ionic liquids allowed the study of loosely bonded supramolecules, originating from these organic salts. Based on the observation that ionic liquids formed cationic [C(q+1)X(q)](+) and anionic [C(q)X(q+1)](-) supramolecular aggregates, we have investigated mixed networks, formed by different cations coordinated to a selected anion or by different anions bonded to a given cation, i.e., [C1...X...C2](+) and [X1...C...X2](-), with the aim to build a scale of the cation-anion interaction strength. The qualitative order of intrinsic bond strength to Br- was found to be the following: [emim](+) > [bmim](+) > [mor1,2](+) > [hmim]+ > [omim](+) > [mor1,4](+) > [bupy](+) > [bpyrr](+) > [picol](+) > [bm(2)im](+) > [TBA](+). Similarly, the interaction energies to 1-butyl-3-methylimidazolium (bmim) species envisaged two classes of anions: species tightly coordinated to the cationic moiety that include CF3COO(-), Br(-), N(CN)2(-), and BF4(-) and anions loosely interacting with the alkylimidazolium species such as OTf(-), PF6(-), and Tf2N(-).


Asunto(s)
Lípidos/química , Aniones/química , Bromuros/química , Cationes/química , Modelos Moleculares , Espectrometría de Masa por Ionización de Electrospray
16.
Fitoterapia ; 77(3): 203-7, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16545528

RESUMEN

A new acylated flavonol glycoside, quercetin 3-O-(2-trans-caffeoyl)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-glucopyranoside (1), together with the known 25R,26-[(beta-D-glucopyranosyl)oxy]-22alpha-hydroxy-5beta-furostan-3-beta-yl O-alpha-l-rhamnopyranosyl-(1-->4)-beta-D-glucopyranoside (2), anemonin (3), beta-D-glucosyl-p-hydroxyphenylethyl alcohol (4), and 1-beta-O-caffeoyl-D-glucose (5) were isolated from Helleborus foetidus leaves and identified on the basis of detailed spectral analysis.


Asunto(s)
Glicósidos/química , Glicósidos/aislamiento & purificación , Helleborus/química , Quercetina/análogos & derivados , Lactonas/química , Lactonas/aislamiento & purificación , Espectroscopía de Resonancia Magnética/métodos , Hojas de la Planta/química , Quercetina/química , Quercetina/aislamiento & purificación , Saponinas/química , Saponinas/aislamiento & purificación
17.
Phytochemistry ; 66(13): 1593-600, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15963543

RESUMEN

The pyrrolizidine alkaloid (PA) content of flowers, leaves, and roots of Anchusa strigosa (Boraginaceae) was analysed by ESI-LC-MS. Six PAs, including two new natural compounds, were detected, characterized by NMR spectroscopy, and quantified in each plant organ. The results indicated that the highest total concentration of PAs was in the leaves (23.63 mg/g of dried part), followed by the flowers (19.77 mg/g), and finally by the roots (1.80 mg/g). All PAs isolated were subjected to Spodoptera exigua and Pieris brassicae larvae. Feeding activity by both herbivore species using a bioassay was inhibited up to circa 75% depending on PA and applied concentration.


Asunto(s)
Depresores del Apetito/química , Boraginaceae/química , Alcaloides de Pirrolicidina/química , Animales , Depresores del Apetito/aislamiento & purificación , Depresores del Apetito/farmacología , Conducta Alimentaria/efectos de los fármacos , Flores/química , Larva , Lepidópteros/crecimiento & desarrollo , Espectroscopía de Resonancia Magnética , Rotación Óptica , Hojas de la Planta/química , Raíces de Plantas/química , Alcaloides de Pirrolicidina/aislamiento & purificación , Alcaloides de Pirrolicidina/farmacología , Espectrometría de Masa por Ionización de Electrospray
18.
J Agric Food Chem ; 52(21): 6510-5, 2004 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-15479015

RESUMEN

A liquid chromatography-mass spectrometry (LC-MS)-based method was developed for the characterization of flavonoids from Sechium edule (Jacq) Swartz (Cucurbitaceae) edible organs, a plant cultivated since pre-Colombian times in Mexico where the fruit is called chayote. Chayote is used for human consumption in many countries; in addition to the fruits, stems, leaves and the tuberous part of the roots are also eaten. Eight flavonoids, including three C-glycosyl and five O-glycosyl flavones, were detected, characterized by nuclear magnetic resonance spectroscopic data, and quantified in roots, leaves, stems, and fruits of the plant by LC-photodiode array-MS. The aglycone moieties are represented by apigenin and luteolin, while the sugar units are glucose, apiose, and rhamnose. The results indicated that the highest total amount of flavonoids was in the leaves (35.0 mg/10 g of dried part), followed by roots (30.5 mg/10 g), and finally by stems (19.3 mg/10 g).


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Cucurbitaceae/química , Flavonoides/análisis , Espectrometría de Masas/métodos , Estructuras de las Plantas/química
20.
Talanta ; 115: 863-9, 2013 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-24054675

RESUMEN

A new nonenzymatic platinum Te oxide nanowires modified electrode (Pt/TeO2-NWs) for amperometric detection of hydrogen peroxide (H2O2) is proposed. The modified electrode has been developed by direct drop casting, with TeO2 nanowires (TeO2-NWs), synthesized by thermal evaporation of Te(0) in an oxygen atmosphere. The morphological and spectroscopic characterization of the TeO2-NWs as synthesized on Pt foil was performed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. XPS and XRD analyses are especially involved to gain information on the chemical environment of TeO2-NWs in contact with Pt surface. Moreover electrochemical characterization of these new modified Pt/TeO2-NWs modified electrodes was performed by Cyclic Voltammetry (CV) and Cronoamperometry (CA) in phosphate buffer (pH=7; I=0.2) to investigate the sensing properties of this material against H2O2. The proposed sensor exhibits a wide linear and dynamic range from 2 µM to 16 mM (R(2)=0.9998) and the detection limit is estimated to be 0.6 µM (S/N=3). Moreover, this sensor shows a rapid amperometric response time of less than 5s and possessed good reproducibility. These results indicate that Pt/TeO2-NWs composite is suitable to be used as material for sensing applications.


Asunto(s)
Técnicas Electroquímicas , Peróxido de Hidrógeno/análisis , Nanocables/química , Platino (Metal)/química , Telurio/química , Tampones (Química) , Electrodos , Concentración de Iones de Hidrógeno , Límite de Detección , Microscopía Electrónica de Rastreo , Nanocables/ultraestructura , Espectroscopía de Fotoelectrones , Reproducibilidad de los Resultados
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