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1.
J Agric Food Chem ; 60(23): 5803-12, 2012 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-22448669

RESUMEN

Polyphenolic-rich berry fruits are known to activate redox-sensitive cellular signaling molecules such as phosphatidylinositol-3-kinase (PI3 kinase)/kinase B (Akt), resulting in a cascade of downstream signaling pathways. This study investigated the ability of strawberry (SB), wild blueberry (WBB), and cranberry (CB) extracts to induce the activation of PI3 kinase/Akt signaling in vitro in human umbilical endothelial cells (HUVECs) and whether this activation would enhance cell migration and angiogenesis. Anthocyanin profiles of the extracts were characterized using HPLC-ESI/MS, and Akt activation was investigated using the Alpha Screen SureFire assay. The total anthocyanin contents of SB, WBB, and CB extracts were 81.7, 82.5, and 83.0 mg/100 g fresh weight, respectively. SB, WBB, and CB extracts activated Akt in a dose-dependent manner via PI3 kinase and induced cell migration and angiogenesis in vitro in HUVECs. The results from this study suggest that polyphenolics in berry fruits may play a role in promoting vascular health.


Asunto(s)
Movimiento Celular/efectos de los fármacos , Células Endoteliales/efectos de los fármacos , Frutas/química , Transducción de Señal , Antocianinas/farmacología , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Células Endoteliales/metabolismo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Neovascularización Patológica , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Extractos Vegetales/farmacología , Polifenoles/farmacología , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo
2.
J AOAC Int ; 94(2): 589-95, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21563694

RESUMEN

The accuracy, repeatability, and reproducibility characteristics of a method for measuring levels of zearalenone (ZON) in botanical root products, soybeans, grains, and grain products were determined by an AOAC single-laboratory validation procedure. Replicates of 10 test portions of each powdered root product (black cohosh, ginger, ginseng), brown rice flour, brown rice grain, oat flour, rice bran, soybeans, and wheat flour at each spiking level (ZON at 0, 50, 100, and 200 microg/kg) were analyzed on 3 separate days. Test samples were extracted with methanol-water (75 + 25, v/v). The extracts were centrifuged or filtered, diluted with phosphate-buffered saline (PBS) containing 0.5% Tween 20, and filtered; the filtrates were applied to an immunoaffinity column containing antibodies specific for ZON. After the column was washed with methanol-PBS (15 + 85, v/v) containing 0.5% Tween 20 and then with water, the toxin was eluted from the column with methanol, and the eluate was diluted with water. The eluate containing the toxin was then subjected to RPLC with fluorescence detection. All commodities that were found to contain ZON at < 10 microg/kg were used for the recovery study. The average within-day and between-days recoveries of ZON added at levels of 50-200 microg/kg ranged from 82 to 88% and from 81 to 84%, respectively, for all test commodities. The total average of within- and between-day SD and RSDr values for all test commodities ranged from 2.5 to 7.3 microg/kg and from 4.6 to 6.2%, respectively. HorRat values were <1.3 for all matrixes examined. The tested method was found to be acceptable for the matrixes examined.


Asunto(s)
Cromatografía Liquida/métodos , Suplementos Dietéticos/análisis , Grano Comestible/química , Análisis de los Alimentos , Glycine max/química , Zearalenona/química , Estrógenos no Esteroides/química , Preparaciones de Plantas/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
3.
J AOAC Int ; 93(3): 936-42, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20629398

RESUMEN

Edible oils are consumed directly, and used as ingredients in food, soaps, and skin products. However, oils such as olive oil, peanut oil, and sesame oil could be contaminated with aflatoxins, which are detrimental to human and animal health. A method using immunoaffinity column cleanup with RPLC separation and fluorescence detection (FLD) for determination of aflatoxins (AF) B1, B2, G1, and G2 in olive oil, peanut oil, and sesame oil was developed and validated. Test samples were extracted with methanol-water (55 + 45, v/v). After shaking and centrifuging, the lower layer was filtered, diluted with water, and filtered through glass microfiber filter paper. The filtrate was then passed through an immunoaffinity column, and the toxins were eluted with methanol. The toxins were then subjected to RPLC/FLD analysis after postcolumn UV photochemical derivatization. The accuracy and repeatability characteristics of the method were determined. Recoveries of AFB1 spiked at levels from 1.0 to 10.0 microg/kg in olive oil, peanut oil, and sesame oil ranged from 82.9 to 98.6%. RSDs ranged from 0.6 to 8.9%. HorRat values were < 0.2 for all of the matrixes tested. Recoveries of AF spiked at levels from 2.0 to 20.0 microg/kg ranged from 87.7 to 102.2%. RSDs ranged from 1.3 to 12.6%. HorRat values were < 0.4 for all of the matrixes tested. LC/MS/MS with multiple-reaction monitoring was used to confirm the identities of aflatoxins in a naturally contaminated peanut oil.


Asunto(s)
Aflatoxinas/análisis , Contaminación de Alimentos/análisis , Aceites de Plantas/análisis , Aceite de Sésamo/análisis , Aflatoxina B1/análisis , Cromatografía Liquida , Aceite de Oliva , Aceite de Cacahuete
4.
Planta Med ; 76(15): 1758-61, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20379957

RESUMEN

One new cucurbitane-type triterpenoid glycoside, momordicoside U (1), together with five known cucurbitane-type triterpenoids and related glycosides, 3ß,7 ß,25-trihydroxycucurbita-5,23 (E)-dien-19-al (2), momordicine I (3), momordicine II (4), 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-ß-glucopyranoside (5), and kuguaglycoside G (6), were isolated from the whole plant of Momordica charantia. Their structures were determined by chemical and spectroscopic methods. Momordicoside U (1) was evaluated for insulin secretion activity in an in vitro insulin secretion assay and displayed moderate activity.


Asunto(s)
Células Secretoras de Insulina/efectos de los fármacos , Insulina/metabolismo , Momordica charantia/química , Saponinas/farmacología , Triterpenos/farmacología , Animales , Línea Celular , Glicósidos/química , Glicósidos/aislamiento & purificación , Secreción de Insulina , Ratones , Resonancia Magnética Nuclear Biomolecular , Saponinas/química , Saponinas/aislamiento & purificación , Triterpenos/química , Triterpenos/aislamiento & purificación
5.
J Sep Sci ; 33(2): 200-5, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20029846

RESUMEN

Enantioseparation of the pyrrolizidine alkaloid isomers intermedine and lycopsamine, isolated from Symphytum uplandicum, is discussed. The separatory power of two immobilized carbohydrate-based chiral HPLC columns, Chiralpak IA and IC, in different chromatographic conditions is compared. The study demonstrated the importance of solvent and column selection while developing such chiral HPLC separation methods. The baseline HPLC separation of the two alkaloid isomers in preparatory scale is reported for the first time. The optimized separations were achieved on a Chiralpak IA column with mobile phases of ACN/methanol (80:20) and methanol/methyl-t-butyl ether (90:10), both containing 0.1% diethylamine.


Asunto(s)
Cromatografía Líquida de Alta Presión/instrumentación , Consuelda/química , Alcaloides de Pirrolicidina/aislamiento & purificación , Estructura Molecular , Extractos Vegetales/química , Alcaloides de Pirrolicidina/química , Solventes/química , Estereoisomerismo
6.
J AOAC Int ; 91(1): 21-32, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18376582

RESUMEN

Preparations of blue cohosh (Caulophyllum thalictroides) have been used traditionally by Native Americans for medicinal purposes. Dietary supplements containing dried roots or extracts of blue cohosh rhizomes are available as dietary supplements. The safety and efficacy of these preparations have not been systematically evaluated. Recent studies indicate that ingestion of specific alkaloids in blue cohosh preparations can produce birth defects and neonatal heart failure. Blue cohosh also contains saponins, which may be responsible for uterine-stimulating effects. We determined the amounts of major alkaloids and saponins in preparations of blue cohosh by high-performance liquid chromatography (HPLC). Alkaloids and saponins were monitored with a photodiode array detector and an evaporative light-scattering detector, respectively. Profiles were compared with those of authenticated blue cohosh root extracts. Identities of the alkaloids and saponins were confirmed by HPLC/mass spectrometry and nuclear magnetic resonance spectrometry. Calculations based on the results of analyses of dietary supplements showed that maximum daily intake of alkaloids and saponins will vary with the form (e.g., root, liquid extract) and doses recommended in product labeling. Intakes may vary from < 1 to 75 mg/day for alkaloids and from about 9 to 420 mg/day for saponins.


Asunto(s)
Alcaloides/análisis , Caulophyllum/química , Suplementos Dietéticos/análisis , Saponinas/análisis , Cromatografía Líquida de Alta Presión , Espectrometría de Masas
7.
J AOAC Int ; 90(4): 1042-9, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17760342

RESUMEN

Conditions were optimized for the simultaneous, alkaline, aqueous methanol extraction of aflatoxins (AFL), i.e., B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2), and ochratoxin A (OTA) with subsequent purification, isolation, and determination of the toxins in ginseng and ginger. Powdered roots were extracted with methanol-0.5% NaHCO3 solution (7 + 3). After shaking and centrifugation, the supernatant was diluted with 100 mM phosphate buffer containing 1% Tween 20 and filtered through glass microfiber filter paper. The filtrate was then passed through an immunoaffinity column, and the toxins were eluted with methanol. The AFL were separated and determined by reversed-phase liquid chromatography (RPLC) with fluorescence detection after postcolumn UV photochemical derivatization. OTA was separated and determined by RPLC with fluorescence detection. Recoveries of AFL added at 2-16 ng/g and OTA added at 1-8 ng/g to ginseng were 72-80 and 86-95%, respectively. Recoveries of AFL and OTA added to ginger were similar to those for ginseng. A total of 39 commercially available ginger products from 6 manufacturers were analyzed. Twenty-six samples were found to be contaminated with AFL at 1-31 ng/g and 29 samples, with OTA at 1-10 ng/g. Ten samples contained no AFL or OTA. Ten ginseng finished products were also analyzed; 3 contained AFL at 0.1 ng/g and 4 contained OTA at levels ranging from 0.4 to 1.8 ng/g. LC/tandem mass spectrometry with multiple-reaction monitoring of 3 collisionally induced product ions from the protonated molecular ions of OTA, AFB1, and AFG1 was used to confirm the identities of the toxins in extracts of the finished products.


Asunto(s)
Aflatoxinas/análisis , Cromatografía por Intercambio Iónico/métodos , Análisis de los Alimentos/métodos , Inmunoensayo/métodos , Ocratoxinas/análisis , Zingiber officinale/metabolismo , Centrifugación , Cromatografía Liquida/métodos , Contaminación de Alimentos , Espectrometría de Masas , Panax/metabolismo , Extractos Vegetales/metabolismo , Raíces de Plantas/metabolismo , Solventes , Espectrofotometría Ultravioleta/métodos
8.
Phytochem Anal ; 17(4): 243-50, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16910040

RESUMEN

Teucrium species, such as germander, are rich in neo-clerodane diterpenoids and have been used in traditional folk medicine for their stimulant, diuretic, antipyretic and antiseptic properties. However, the furano neo-clerodane diterpenoids present in germander have been implicated in the in vivo hepatotoxicity of this botanical. In this study, authenticated germander (Teucrium chamaedrys L. and Teucrium canadense L.) was used as the source material. Methanol extracts of powdered plant mate rial were prepared and analysed by HPLC using Synergi Max-RP columns with monitoring at 220 nm. Limited amounts of teucrin A and other diterpenoid standards were analysed on a Synergi Max-RP column in order to determine their retention times and to generate calibration curves. The same standards were subjected to concurrent mass spectral analysis. Teucrin A and diterpenoids such as dihydroteugin, teuflin, teuflidin and teucvidin were tentatively identified in the plant extracts by HPLC-MS and 1H-NMR experiments. For the isolation of teucrium diterpenoids on a semipreparative scale, a solid-phase extraction method was developed for the first time using styrene divinylbenzene and strata-X sorbents for teucrin A and teuflin, respectively. Semi-preparative HPLC of the methanol extract of the powdered aerial parts of Teucrium plants was carried out on a semipreparative Synergi Max-RP column with photodiode array detection in order to confirm the identities of some diterpenoids by HPLC-MS and NMR.


Asunto(s)
Diterpenos/química , Teucrium/química , Cromatografía Líquida de Alta Presión/métodos , Diterpenos/análisis , Diterpenos/aislamiento & purificación , Resonancia Magnética Nuclear Biomolecular , Espectrometría de Masa por Ionización de Electrospray
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