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1.
Molecules ; 26(20)2021 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-34684768

RESUMEN

The enrichment of commonly consumed foods with bioactive components might be helpful in promoting health and reducing the risk of disease, so the enrichment of probiotic fermented milk with vitamin C can be considered appropriate. The effect of vitamin C addition depends on the source of origin (rosehip, acerola and ascorbic acid in powder form) on the growth and survival of Lactobacillus rhamnosus and the quality of fermented milk on the 1st and 21st day of storage was analyzed. The pH, total acidity, vitamin C, syneresis, color, texture profile and numbers of bacterial cells in fermented milk were determined. The organoleptic evaluation was also performed. The degradation of vitamin C in milk was shown to depend on its source. The lowest reduction of vitamin C was determined in milk with rosehip. The least stable was vitamin C naturally found in control milk. The addition of rosehip and acerola decreased syneresis and lightness of milk color, increasing the yellow and red color proportion. In contrast, milk with ascorbic acid was the lightest during the whole experimental period and was characterized by a very soft gel. The growth of Lactobacillus rhamnosus during fermentation was most positively affected by the addition of rosehip. However, the best survival of Lactobacillus rhamnosus was demonstrated in milk with acerola. On the 21st day of storage, the number of L. rhamnosus cells in the control milk and the milk with vitamin C was >8 log cfu g-1, so these milks met the criterion of therapeutic minimum. According to the assessors, the taste and odor contributed by the addition of rosehip was the most intense of all the vitamin C sources used in the study.


Asunto(s)
Ácido Ascórbico/administración & dosificación , Productos Lácteos Cultivados/análisis , Productos Lácteos Cultivados/microbiología , Lacticaseibacillus rhamnosus/metabolismo , Probióticos/metabolismo , Animales , Ácido Ascórbico/aislamiento & purificación , Estabilidad de Medicamentos , Fermentación , Almacenamiento de Alimentos , Humanos , Concentración de Iones de Hidrógeno , Malpighiaceae/química , Odorantes , Polvos , Rosa/química , Gusto
2.
Molecules ; 26(15)2021 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-34361724

RESUMEN

Orchids are rich treasure troves of various important phytomolecules. Among the various medicinal orchids, Ansellia africana stands out prominently in the preparing of various herbal medicines due to its high therapeutic importance. The nodal explants of A. africana were sampled from asymbiotically germinated seedlings on basal Murashige and Skoog (MS) medium and were micropropagated in MS medium supplemented with 3% sucrose and 10 µM meta topolin (mT) + 5 µM naphthalene acetic acid (NAA) +15 µM indole butyric acid (IBA) + 30 µM phloroglucinol (PG). In the present study, the essential oil was extracted by hydrodistillation and the oleoresins by the solvent extraction method from the micropropagated A. africana. The essential oil and the oleoresins were analysed by Gas Chromatography (GC) and GC/MS (Mass spectrometry). A total of 84 compounds were identified. The most predominant components among them were linoleic acid (18.42%), l-ascorbyl 2,6-dipalmitate (11.50%), linolenic acid (10.98%) and p-cresol (9.99%) in the essential oil; and eicosane (26.34%), n-butyl acetate (21.13%), heptadecane (16.48%) and 2-pentanone, 4-hydroxy-4-methyl (11.13%) were detected in the acetone extract; heptadecane (9.40%), heneicosane (9.45%), eicosane (6.40%), n-butyl acetate (14.34%) and styrene (22.20%) were identified and quantified in the ethyl acetate extract. The cytotoxic activity of essential oil and oleoresins of micropropagated A. africana was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide) assay on Vero cells compared to the standard drug doxorubicin chloride. The present research contains primary information about the therapeutic utility of the essential oil and oleoresins of A. africana with a promising future research potential of qualitative and quantitative improvement through synchronised use of biotechnological techniques.


Asunto(s)
Citotoxinas/aislamiento & purificación , Aceites Volátiles/aislamiento & purificación , Orchidaceae/química , Extractos Vegetales/aislamiento & purificación , Plantones/química , Acrilatos/aislamiento & purificación , Alcanos/aislamiento & purificación , Animales , Ácido Ascórbico/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Chlorocebus aethiops , Cresoles/aislamiento & purificación , Medios de Cultivo/química , Medios de Cultivo/farmacología , Citotoxinas/farmacología , Cromatografía de Gases y Espectrometría de Masas , Hidroponía/métodos , Ácido Linoleico/aislamiento & purificación , Extracción Líquido-Líquido/métodos , Aceites Volátiles/farmacología , Orchidaceae/metabolismo , Palmitatos/aislamiento & purificación , Pentanoles/aislamiento & purificación , Pentanonas/aislamiento & purificación , Extractos Vegetales/farmacología , Plantas Medicinales , Plantones/metabolismo , Sudáfrica , Estireno/aislamiento & purificación , Células Vero , Ácido alfa-Linolénico/aislamiento & purificación
3.
Molecules ; 26(15)2021 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-34361729

RESUMEN

Tyrosinase (TYR) is a type III copper oxidase present in fungi, plants and animals. The inhibitor of human TYR plays a vital role in pharmaceutical and cosmetic fields by preventing synthesis of melanin in the skin. To search for an effective TYR inhibitor from various plant extracts, a kinetic study of TYR inhibition was performed with mushroom TYR. Among Panax ginseng, Alpinia galanga, Vitis vinifera and Moringa oleifera, the extracts of V. vinifera seed, A. galanga rhizome and M. oleifera leaf reversibly inhibited TYR diphenolase activity with IC50 values of 94.8 ± 0.2 µg/mL, 105.4 ± 0.2 µg/mL and 121.3 ± 0.4 µg/mL, respectively. Under the same conditions, the IC50 values of the representative TYR inhibitors of ascorbic acid and kojic acid were found at 235.7 ± 1.0 and 192.3 ± 0.4 µg/mL, respectively. An inhibition kinetics study demonstrated mixed-type inhibition of TYR diphenolase by A. galanga and V. vinifera, whereas a rare uncompetitive inhibition pattern was found from M. oleifera with an inhibition constant of Kii 73 µg/mL. Phytochemical investigation by HPLC-MS proposed luteolin as a specific TYR diphenolase ES complex inhibitor, which was confirmed by the inhibition kinetics of luteolin. The results clearly showed that studying TYR inhibition kinetics with plant extract mixtures can be utilized for the screening of specific TYR inhibitors.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Proteínas Fúngicas/antagonistas & inhibidores , Luteolina/farmacología , Monofenol Monooxigenasa/antagonistas & inhibidores , Moringa oleifera/química , Agaricales/química , Agaricales/enzimología , Alpinia/química , Ácido Ascórbico/química , Ácido Ascórbico/aislamiento & purificación , Ácido Ascórbico/farmacología , Pruebas de Enzimas , Inhibidores Enzimáticos/química , Proteínas Fúngicas/aislamiento & purificación , Ensayos Analíticos de Alto Rendimiento , Concentración 50 Inhibidora , Cinética , Luteolina/química , Luteolina/aislamiento & purificación , Monofenol Monooxigenasa/aislamiento & purificación , Panax/química , Extractos Vegetales/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Pironas/química , Pironas/aislamiento & purificación , Pironas/farmacología , Rizoma/química , Semillas/química , Vitis/química
4.
Molecules ; 25(15)2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-32756431

RESUMEN

The aim of the study was to investigate the effect of high-pressure processing (HPP) and thermal processing (TP) on the bioaccessibility of vitamin C and anthocyanins as well as changes in the antioxidant capacity (AC) using ABTS+• and DPPH• tests on blackcurrant (Ribes nigrum L.) puree during the steps in the digestive process. The puree was subjected to HPP at 200, 400, and 600 MPa for 5 min (room temperature) or TP at 85 °C for 10 min. The controls were untreated puree (P) and fruit crushed in a mortar (M). All the samples were digested in a static in vitro digestion model, including the mouth, stomach, and small intestine, and subjected to dialysis. The vitamin C, anthocyanin, and antioxidant capacity were monitored at each step of the digestion process. The potential bioaccessibility of the antioxidants studied was calculated in relation to the undigested sample. TP and HPP enabled a high content of vitamin C, anthocyanins, and AC to be maintained. After simulated digestion in the small intestine, a significant decrease was observed in the vitamin C and anthocyanins (approximately 98%) content. However, a high stability (approximately 70%) of both compounds was noted at the gastric stage. HPP and TP significantly affected the potential bioaccessibility of vitamin C and anthocyanins, although the bioaccessibility of both compounds in the samples treated using HPP was higher than when using TP. Moreover, the potential bioaccessibility of vitamin C after HPP treatment (400 and 600 MPa) was higher than the bioaccessibility calculated for the M and P control samples. TP and HPP treatment negatively affected anthocyanin bioaccessibility after dialysis. The most favorable pressure was 400 MPa, as it allowed maintaining the best antioxidant activity after digestion.


Asunto(s)
Antioxidantes/química , Ribes/química , Antocianinas/análisis , Antocianinas/aislamiento & purificación , Ácido Ascórbico/análisis , Ácido Ascórbico/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Digestión , Frutas/química , Frutas/metabolismo , Presión Hidrostática , Ribes/metabolismo , Espectrofotometría , Temperatura
5.
Molecules ; 25(7)2020 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-32235298

RESUMEN

Girardinia diversifolia, also known as Himalayan nettle, is a perennial herb used in Nepal to make fiber as well as in traditional medicine for the treatment of several diseases. To date, phytochemical studies and biological assays on this plant are scarce. Thus, in the present work, the G. diversifolia extracts have been evaluated for their potential pharmaceutical, cosmetic and nutraceutical uses. For this purpose, detailed phytochemical analyses were performed, evidencing the presence of phytosterols, fatty acids, carotenoids, polyphenols and saponins. The most abundant secondary metabolites were ß- and γ-sitosterol (11 and 9% dw, respectively), and trans syringin (0.5 mg/g) was the most abundant phenolic. Fatty acids with an abundant portion of unsaturated derivatives (linoleic and linolenic acid at 22.0 and 9.7 mg/g respectively), vitamin C (2.9 mg/g) and vitamin B2 (0.12 mg/g) were also present. The antioxidant activity was moderate while a significant ability to inhibit acetylcholinesterase (AChE), butyrilcholinesterase (BuChE), tyrosinase, α-amylase and α-glucosidase was observed. A cytotoxic effect was observed on human ovarian, pancreatic and hepatic cancer cell lines. The effect in hepatocarcinoma cells was associated to a downregulation of the low-density lipoprotein receptor (LDLR), a pivotal regulator of cellular cholesterol homeostasis. These data show the potential usefulness of this species for possible applications in pharmaceuticals, nutraceuticals and cosmetics.


Asunto(s)
Anticolesterolemiantes/aislamiento & purificación , Antioxidantes/aislamiento & purificación , Citotoxinas/aislamiento & purificación , Inhibidores Enzimáticos/aislamiento & purificación , Fitoquímicos/aislamiento & purificación , Urticaceae/química , Anticolesterolemiantes/farmacología , Antioxidantes/farmacología , Ácido Ascórbico/aislamiento & purificación , Ácido Ascórbico/farmacología , Carotenoides/aislamiento & purificación , Carotenoides/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Citotoxinas/farmacología , Inhibidores Enzimáticos/farmacología , Ácidos Grasos/aislamiento & purificación , Ácidos Grasos/farmacología , Glucósidos/aislamiento & purificación , Glucósidos/farmacología , Humanos , Fenilpropionatos/aislamiento & purificación , Fenilpropionatos/farmacología , Fitoquímicos/farmacología , Fitosteroles/aislamiento & purificación , Fitosteroles/farmacología , Extractos Vegetales/química , Polifenoles/aislamiento & purificación , Polifenoles/farmacología , Receptores de LDL/antagonistas & inhibidores , Receptores de LDL/genética , Receptores de LDL/metabolismo , Riboflavina/aislamiento & purificación , Riboflavina/farmacología , Saponinas/aislamiento & purificación , Saponinas/farmacología , Sitoesteroles/aislamiento & purificación , Sitoesteroles/farmacología
6.
Sensors (Basel) ; 19(15)2019 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-31357512

RESUMEN

By means of electrospinning with the thermal annealing process, we investigate a highly efficient sensing platform driven by a hierarchical hetero-nanostructure for the sensitive detection of biologically relevant molecules, consisting of single crystalline ruthenium dioxide nanorods (RuO2 NRs) directly grown on the surface of electrospun tungsten trioxide nanofibers (WO3 NFs). Electrochemical measurements reveal the enhanced electron transfer kinetics at the prepared RuO2 NRs-WO3 NFs hetero-nanostructures due to the incorporation of conductive RuO2 NRs nanostructures with a high surface area, resulting in improved relevant electrochemical sensing performances for detecting H2O2 and L-ascorbic acid with high sensitivity.


Asunto(s)
Ácido Ascórbico/aislamiento & purificación , Técnicas Biosensibles , Técnicas Electroquímicas , Peróxido de Hidrógeno/aislamiento & purificación , Ácido Ascórbico/química , Peróxido de Hidrógeno/química , Nanofibras/química , Nanoestructuras/química , Nanotubos/química , Óxidos/química , Compuestos de Rutenio/química , Tungsteno/química
7.
Sensors (Basel) ; 19(15)2019 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-31357396

RESUMEN

In the present work, ternary mixtures of Acetaminophen, Ascorbic acid and Uric acid were resolved using the Electronic tongue (ET) principle and Cyclic voltammetry (CV) technique. The screen-printed integrated electrode array having differentiated response for the three oxidizable compounds was formed by Graphite, Prussian blue (PB), Cobalt (II) phthalocyanine (CoPc) and Copper oxide (II) (CuO) ink-modified carbon electrodes. A set of samples, ranging from 0 to 500 µmol·L-1, was prepared, using a tilted (33) factorial design in order to build the quantitative response model. Subsequently, the model performance was evaluated with an external subset of samples defined randomly along the experimental domain. Partial Least Squares Regression (PLS) was employed to construct the quantitative model. Finally, the model successfully predicted the concentration of the three compounds with a normalized root mean square error (NRMSE) of 1.00 and 0.99 for the training and test subsets, respectively, and R2 ≥ 0.762 for the obtained vs. expected comparison graphs. In this way, a screen-printed integrated electrode platform can be successfully used for voltammetric ET applications.


Asunto(s)
Acetaminofén/aislamiento & purificación , Ácido Ascórbico/aislamiento & purificación , Técnicas Biosensibles , Ácido Úrico/aislamiento & purificación , Acetaminofén/química , Ácido Ascórbico/química , Cobre/química , Técnicas Electroquímicas/métodos , Electrodos , Nariz Electrónica , Ferrocianuros/química , Grafito/química , Humanos , Indoles/química , Compuestos Organometálicos/química , Ácido Úrico/química
8.
Water Environ Res ; 91(5): 455-461, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30740828

RESUMEN

Eutectic freeze crystallization was developed to recover sodium erythorbate (NaE) from wastewater at pHs 4.1, 5.3, and 6.5. Two substances (A and B) were sequentially recovered from the samples. The recovery rate of substance A was 2.06, 1.83, and 3.03 g/L at pHs 4.1, 5.3, and 6.5, respectively; while that of B was 5.51, 3.09, and 3.26 g/L at the corresponding pHs. The analysis results of the two recovered substances indicated that substance A was mostly Na2 SO4 ·10H2 O, while substance B was mainly NaE. Salt recovery was most successful at pH 4.1 with the purity of recovered NaE reaching 87.53 wt%. Moreover, the chemical oxygen demand and electric conductivity of the ice were far smaller than the initial wastewater. The concentration effect was minimal due to the formation of Na2 SO4 ·10H2 O and NaE crystals. This combined crystallization strategy can potentially become an economic technology to recover NaE from wastewater. Practitioner points Segregation of NaE and Na2 SO4 ·10H2 O during the freeze crystallization process. Recovering 5.53 kg NaE with the purity of 87.53 wt% from 1 m3 wastewater. Decreasing chemical oxygen demand and electric conductivity of wastewater through freeze crystallization technology.


Asunto(s)
Ácido Ascórbico/química , Ácido Ascórbico/aislamiento & purificación , Congelación , Aguas Residuales/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Cristalización , Concentración de Iones de Hidrógeno , Hielo/análisis , Factores de Tiempo
9.
J Sep Sci ; 40(20): 4041-4049, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28841257

RESUMEN

For the first time, we coupled a microextraction technique using a magnetic ionic liquid with voltammetric determination. A hydrophobic magnetic ionic liquid that contains the tetrachloromanganate(II) anion, namely, aliquat tetrachloromanganate(II), was synthesized and used for the extraction of ascorbic acid from aqueous solutions followed by voltammetric determination. The extraction procedure was carried out using a single drop microextraction technique in which the ascorbic acid containing magnetic ionic liquid was separated with a magnet and then cast onto the surface of a carbon paste electrode modified with TiO2 nanoparticles for the voltammetric quantification of the extracted ascorbic acid. Electrochemical quantification was carried out in a blank phosphate buffer solution. After optimizing different experimental conditions, a linear concentration range of 1.50-40.0 nM with a detection limit of 0.43 nM was obtained for the determination of ascorbic acid. The presented approach was successfully applied to the determination of ascorbic acid in samples of vitamin C effervescent tablets and orange juice.


Asunto(s)
Ácido Ascórbico/aislamiento & purificación , Electrodos , Jugos de Frutas y Vegetales/análisis , Líquidos Iónicos , Iones , Microextracción en Fase Líquida , Magnetismo , Comprimidos
10.
Molecules ; 22(12)2017 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-29206179

RESUMEN

The purpose of this study was to determine the possibility of using chokeberry powder as a supplement in apple juice to increase the nutritional value of the final product with the aim of developing a new functional food product. Also, to determine the influence of ultrasound assisted extraction on the bioactive compounds content, nutritional composition and antioxidant potential of apple juice with added chokeberry powder. The juice samples with added chokeberry powder had higher antioxidant capacity, irrespective of the extraction technique used. Apple juice samples with added chokeberry powder treated with high intensity ultrasound had significantly higher content of all analyzed bioactive compounds. The application of high intensity ultrasound significantly reduced the extraction time of the plant material. A positive correlation between vitamin C content, total phenols, flavonoids and anthocyanins content and antioxidant capacity was determined in juice samples with added chokeberry powder treated with high intensity ultrasound.


Asunto(s)
Antioxidantes/aislamiento & purificación , Ácido Ascórbico/aislamiento & purificación , Jugos de Frutas y Vegetales/análisis , Extracción Líquido-Líquido/métodos , Malus/química , Photinia/química , Antocianinas/química , Antocianinas/aislamiento & purificación , Antioxidantes/química , Ácido Ascórbico/química , Flavonoides/química , Flavonoides/aislamiento & purificación , Frutas/química , Extracción Líquido-Líquido/instrumentación , Fenoles/química , Fenoles/aislamiento & purificación , Extractos Vegetales/química , Polifenoles/química , Polifenoles/aislamiento & purificación , Polvos , Sonicación/instrumentación , Sonicación/métodos
11.
Pak J Pharm Sci ; 30(5): 1665-1669, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29084688

RESUMEN

The aim of the study was to investigate the effects of effects of storage and temperature on the antioxidant potential, vitamin-C contents, total as well as selected individual phenolic acids and flavonoids of fresh aqueous leaves extract of Azadirachta Indica. The antioxidant activity of Azadirachta Indica leaves aqueous extract was determined by scavenging of DPPH free radical, while the phenolic compounds and vitamin-C contents by HPLC method. The analyses were carried out on crude extract of fresh leaves and after storage time of 1, 2 and 3 month at temperature of 20, 30 and 50°C. Storage for longer duration and rise in temperature caused decreasing the phenolic acids and vitamin C contents as well as antioxidant potential. Vitamin C contents were decreased up to 91% upon storage for 3 months at 50°C, while the anti-oxidant potential was decreased 29 %. The effect of storage time and temperature on individual phenolic acid and flavonoids were also remarkable, except ferulic acid which increased upon storage and rise in temperature.


Asunto(s)
Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Azadirachta/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Polifenoles/farmacología , Temperatura , Antioxidantes/aislamiento & purificación , Ácido Ascórbico/aislamiento & purificación , Compuestos de Bifenilo/química , Cromatografía Líquida de Alta Presión , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Picratos/química , Extractos Vegetales/aislamiento & purificación , Polifenoles/aislamiento & purificación , Factores de Tiempo
12.
Crit Rev Food Sci Nutr ; 56(12): 2053-68, 2016 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-25751787

RESUMEN

Natural antioxidants such as vitamin C, tocopherols and tocotrienols, carotenoids, and phenolic compounds are largely distributed in plant products. Most of them are not synthesized by human and need to be introduced with diet according to the Recommended Daily Intake (RDI). This work was aimed to give a comprehensive overview on the occurrence of these antioxidants in plants, in particular in plant foods, on the mechanisms of biosynthesis, and on conventional (liquid-liquid or solid-liquid extraction, Soxhlet) and innovative (enzymatic-assisted, pressurized fluid, supercritical fluid, ultrasound-assisted, microwave-assisted, pulsed electric field) extraction systems.


Asunto(s)
Antioxidantes/análisis , Antioxidantes/metabolismo , Frutas/química , Verduras/química , Animales , Antioxidantes/aislamiento & purificación , Ácido Ascórbico/análisis , Ácido Ascórbico/biosíntesis , Ácido Ascórbico/aislamiento & purificación , Carotenoides/análisis , Carotenoides/biosíntesis , Carotenoides/aislamiento & purificación , Dieta , Humanos , Fenoles/análisis , Fenoles/aislamiento & purificación , Fenoles/metabolismo , Plantas Comestibles/metabolismo , Ingesta Diaria Recomendada , Tocoferoles/análisis , Tocoferoles/aislamiento & purificación , Tocoferoles/metabolismo
13.
Anal Bioanal Chem ; 408(30): 8701-8712, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27405873

RESUMEN

Capillary electrophoresis is commonly applied for the analysis of pharmaceutical products due to its high separation efficiency and selectivity. For this purpose, electrospray-ionization-(ESI)-interfering additives or electrolytes are often required, which complicates the identification of impurities and degradation products by mass spectrometry (MS). Here, a capillary zone electrophoresis (CZE) method with ultraviolet (UV) absorption detection for the simultaneous determination and quantification of ascorbic acid and acetylsalicylic acid in effervescent tablets was developed. Related degradation products were identified via CZE-CZE-MS. Systematic optimization yielded 100 mM tricine (pH = 8.8) as appropriate background electrolyte, resulting in baseline separation of ascorbic acid, acetylsalicylic acid, and related anionic UV-active degradation products. The CZE-UV method was successfully validated regarding the guidelines of the Food and Drug Administration. The validated method was applied to trace the degradation rate of the active pharmaceutical ingredients at defined ambient conditions. A heart-cut CZE-CZE-MS approach, including a 4-port-nL-valve, was performed for the identification of the observed degradation products. This 2D setup enables a precise cutting of accurate sample volumes (20 nL) and the independent operation of two physically separated CZE dimensions, which is especially beneficial regarding MS detection. Hence, the ESI-interfering tricine electrolyte components were separated from the analytes in a second electrophoretic dimension prior to ESI-MS detection. The degradation products were identified as salicylic acid and mono- and diacetylated ascorbic acid. This setup is expected to be generally applicable for the mass spectrometric characterization of CZE separated analytes in highly ESI-interfering electrolyte systems. Graphical Abstract A CZE-UV method for the quantification of effervescent tablet ingredients and degradation products was developed and validated. In order to identify unknown degradation products separated in the CZE-UV, a 2D heart-cut approach was performed applying a mechanical 4-port-valve. The unknown substances were transferred from the 1st to the 2nd dimension followed by the separation of ESI-interfering tricine from the analytes prior to mass spectrometric detection.


Asunto(s)
Ácido Ascórbico/aislamiento & purificación , Aspirina/aislamiento & purificación , Electroforesis Capilar/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrofotometría Ultravioleta/métodos , Ácido Ascórbico/química , Aspirina/química , Tampones (Química) , Glicina/análogos & derivados , Glicina/química , Guías como Asunto , Comprimidos , Estados Unidos , United States Food and Drug Administration
14.
Sensors (Basel) ; 16(8)2016 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-27527176

RESUMEN

A simple, novel concept for the one-step fabrication of a low-cost, easy-to-use droplet-based electrochemical (EC) sensor is described, in which the EC reagents are contained in a droplet and the droplet assay is operated on a simple planar surface instead of in a complicated closed channel/chamber. In combination with an elegant carbon electrode configuration, screen-printed on a widely available polyethylene terephthalate (PET) substrate, the developed sensor exhibits a stable solution-restriction capacity and acceptable EC response, and thus can be used directly for the detection of different analytes (including ascorbic acid (AA), copper ions (Cu(2+)), 2'-deoxyguanosine 5'-triphosphate (dGTP) and ferulic acid (FA)), without any pretreatment. The obtained, acceptable linear ranges/detection limits for AA, Cu(2+), dGTP and FA are 0.5-10/0.415 mM, (0.0157-0.1574 and 0.1574-1.5736)/0.011 mM, 0.01-0.1/0.008 mM and 0.0257-0.515/0.024 mM, respectively. Finally, the utility of the droplet-based EC sensor was demonstrated for the determination of AA in two commercial beverages, and of Cu(2+) in two water samples, with reliable recovery and good stability. The applicability of the droplet-based sensor demonstrates that the proposed EC strategy is potentially a cost-effective solution for a series of biochemical sensing applications in public health, environmental monitoring, and the developing world.


Asunto(s)
Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Monitoreo del Ambiente/métodos , Tereftalatos Polietilenos/química , Ácido Ascórbico/aislamiento & purificación , Cobre/aislamiento & purificación , Ácidos Cumáricos/aislamiento & purificación , Nucleótidos de Desoxiguanina/aislamiento & purificación , Humanos
15.
Biomed Chromatogr ; 29(1): 1-20, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25381720

RESUMEN

In recent years demands on the amount of information that can be obtained from the analysis of a single sample have increased. For time and economic reasons it is necessary to examine at the same time larger number of compounds, and compounds from different groups. This can best be seen in such areas as clinical analysis. In many diseases, the best results for patients are obtained when treatment fits the individual characteristics of the patient. Dosage monitoring is important at the beginning of therapy and in the full process of treatment. In the treatment of many diseases biogenic amines (dopamine, serotonin) and methylxanthines (theophylline, theobromine, caffeine) play an important role. They are used as drugs separately or in combination with others to support and strengthen the action of other drugs - for example, the combination of caffeine and paracetamol. Vitamin supplementation may be also an integral part of the treatment process. Specification of complete sample preparation parameters for extraction of the above compounds from biological matrices has been reviewed. Particular attention was given to the preparation stage and extraction methods. This review provides universal guidance on establishing a common procedures across laboratories to facilitate the preparation and analysis of all discussed compounds.


Asunto(s)
Ácido Ascórbico/aislamiento & purificación , Aminas Biogénicas/aislamiento & purificación , Fraccionamiento Químico/métodos , Complejo Vitamínico B/aislamiento & purificación , Xantinas/aislamiento & purificación , Ácido Ascórbico/análisis , Ácido Ascórbico/química , Aminas Biogénicas/análisis , Aminas Biogénicas/química , Humanos , Modelos Moleculares , Complejo Vitamínico B/análisis , Complejo Vitamínico B/química , Xantinas/análisis , Xantinas/química
16.
Artículo en Inglés | MEDLINE | ID: mdl-24472745

RESUMEN

In fish, vitamins are part of the first line of the antioxidant defense, they are directly related to stress and disease, and they are involved in the maintenance of various physiological processes and metabolic reactions. In general, fish are unable to synthesize vitamin C due to a deficiency in gulonolactone oxidase (GLO), the enzyme responsible for its de novo synthesis. Vitamin E is involved in the immune response and perhaps one of its main physiological functions is to protect membranes from oxidative damage (lipid peroxidation) associated with free radical production. In fish muscle, vitamin E has an important role as an antioxidant in vivo and its content is highly related to the stability of lipids and fats. The aim of this study was to determine the content of vitamins C and E in muscle from different species of elasmobranch and teleost fishes. The concentrations of vitamins C and E were determined by high performance liquid chromatography (HPLC). The concentration of vitamin C found for the group of elasmobranchs was lower (p=0.001) than that for teleosts. For Mustelus henlei vitamin C was found in only one individual; in Tetrapturus audax and Totoaba macdonaldi vitamin C concentration was below the detection limit. The concentration of vitamin E was lower in the group of elasmobranchs (p=0.03) compared with that of teleosts. The main differences in the antioxidant system between teleosts and elasmobranchs appear to be the specific type and levels of antioxidant compounds, as well as the synergistic interactions among the antioxidants present in their tissues.


Asunto(s)
Ácido Ascórbico/aislamiento & purificación , Músculo Esquelético/metabolismo , Vitamina E/aislamiento & purificación , Animales , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Elasmobranquios/metabolismo , Peces/metabolismo , Peroxidación de Lípido , Oxidación-Reducción , Vitamina E/metabolismo
17.
Electrophoresis ; 34(14): 2085-91, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23161669

RESUMEN

A simple procedure for preparing inexpensive paper-based three-electrode electrochemical cells is described here. They consist of small circular pads of hydrophilic paper defined by hydrophobic barriers printed on paper with wax-based ink. The back face of these pads is insulated by thermally laminating a polyethylene layer and working, reference and counter electrodes are drawn on paper by using commercial pencil leads. At last, a controlled volume of sample containing a supporting electrolyte was laid to soak in paper channels. Their performance was evaluated by assaying these devices as both simple cells suitable for recording voltammograms on static samples and low-cost detectors for flowing systems. Voltammetric tests, conducted by using potassium hexacyanoferrate(II) as model prototype, were also exploited for identifying the brand and softness of graphite sticks enabling paper to be marked with lines displaying the best conductivity. By taking advantage of the satisfactory information thus gained, pencil drawn electrodes were tested as amperometric detectors for the separation of ascorbic acid and sunset yellow, which were chosen as prototype electroactive analytes because they are frequently present concomitantly in several food matrices, such as soft drinks and fruit juices. This separation was performed by planar thin layer chromatography conducted on microfluidic paper-based devices prepared by patterning on filter paper two longitudinal hydrophobic barriers, once again printed with wax-based ink. Factors affecting both separation and electrochemical detection were examined and optimised, with best performance achieved by using a 20 mM acetate running buffer (pH 4.5) and by applying a detection potential of 0.9 V. Under these optimum conditions, the target analytes could be separated and detected within 6 min. The recorded peaks were well separated and characterized by good repeatability and fairly good sensitivity, thus proving that this approach is indeed suitable for rapidly assembling inexpensive and reliable electrochemical detectors for flow analysis systems.


Asunto(s)
Técnicas Electroquímicas/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Ácido Ascórbico/aislamiento & purificación , Compuestos Azo/aislamiento & purificación , Electrodos , Diseño de Equipo , Papel , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
18.
Anal Bioanal Chem ; 405(7): 2255-63, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23208284

RESUMEN

This work describes a comparison of three types of commercial high-performance liquid chromatography silica monolithic columns with different inner diameters and generations of monolithic sorbent: a "classic" monolithic column, the first generation (Onyx™ monolithic C(18), 100 mm × 4.6 mm, Phenomenex); a "narrow" monolithic column for fast separation at lower flow rates (Chromolith® Performance RP-18e, 100 mm × 3 mm, Merck); and a recently introduced "high-resolution" monolithic column, the next generation (Chromolith® HighResolution RP-18e, 100 mm × 4.6 mm, Merck). Separation efficiency (number of theoretical plates, height equivalent to a theoretical plate and van Deemter curves), working pressure, the symmetry factor and resolution were critical aspects of the comparison in the case of the separation of ascorbic acid, paracetamol and caffeine. The separations were performed under isocratic conditions with a mobile phase consisting of 10:90 (v/v) acetonitrile-phosphoric acid (pH 2.80). Detailed comparison of the newest-generation monolithic column (Chromolith® HighResolution) with the previously introduced monolithic sorbents was performed and proved the advantages of the Chromolith® HighResolution column.


Asunto(s)
Acetaminofén/aislamiento & purificación , Ácido Ascórbico/aislamiento & purificación , Cafeína/aislamiento & purificación , Cromatografía Líquida de Alta Presión/métodos , Acetaminofén/química , Adsorción , Ácido Ascórbico/química , Cafeína/química , Cromatografía Líquida de Alta Presión/instrumentación
19.
Molecules ; 17(3): 3165-80, 2012 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-22418924

RESUMEN

The present investigation was carried out to appraise the levels of total phenols and vitamin C as well as antioxidant potential at three different ripening stages (un-ripe, semi-ripe and fully-ripe) of guava (Psidium guajava L.) fruit collected from three different geographical regions of Pakistan (Islamabad, Faisalabad and Bhakkar). The antioxidant potential of guava fruit extracts was assessed by means of different in-vitro antioxidant assays, namely inhibition of peroxidation in linoleic acid system, reducing power and radical scavenging capability. Overall, fruit at the un-ripe stage (G1) exhibited the highest levels of TPC, TFC, reducing power and DPPH radical scavenging activity, followed by the semi-ripe (G2) and fully-ripe (G3) stages. On the other hand, vitamin C content increased as the fruit maturity progressed, with highest value seen at the fully-ripe stage (G3) followed by the semi-ripe (G2) and un-ripe stage (G1). The concentration of vitamin C in fruits varied as: Faisalabad (136.4-247.9 mg 100 g⁻¹), Islamabad (89.7-149.7 mg 100 g⁻¹) and Bhakkar (73.1-129.5 mg 100 g⁻¹). The results showed that different stages of maturation and geographical locations had profound effects on the antioxidant activity and vitamin C contents of guava fruit.


Asunto(s)
Depuradores de Radicales Libres/química , Frutas/química , Extractos Vegetales/química , Psidium/química , Ácido Ascórbico/química , Ácido Ascórbico/aislamiento & purificación , Compuestos de Bifenilo/química , Flavonoides/química , Flavonoides/aislamiento & purificación , Depuradores de Radicales Libres/aislamiento & purificación , Ácido Linoleico/química , Peroxidación de Lípido/efectos de los fármacos , Pakistán , Fenoles/química , Fenoles/aislamiento & purificación , Picratos/química , Extractos Vegetales/aislamiento & purificación , Sustancias Reductoras/química , Sustancias Reductoras/aislamiento & purificación
20.
Acta Pharm Hung ; 82(1): 3-14, 2012.
Artículo en Húngaro | MEDLINE | ID: mdl-22570982

RESUMEN

Parsley (Petroselinum crispum L.) is a very popular spice and vegetable in Europe, it is widely spread and easy to grow. It's herb and fruits are known to be diuretic, smooth muscle relaxant and hepatoprotective. The most important identified active ingredients are flavonoids, cumarins and vitamin C. Apigenin and its glycosides are the main flavonoids in parsley, it can be found relatively large amounts in the leaves. The bioactive flavonoid apigenin has antiinflammatory, antioxidant and anticancer activities. The objectives of this study were the preparation and detemination of the apigenin content of the parsley extract and the formulation using inert pellets by layering the apigenin in fluid-bed process.


Asunto(s)
Apigenina/aislamiento & purificación , Apigenina/metabolismo , Petroselinum , Extractos Vegetales/química , Extractos Vegetales/farmacología , Antiinflamatorios/farmacología , Anticarcinógenos/farmacología , Antioxidantes/farmacología , Apigenina/análisis , Apigenina/química , Ácido Ascórbico/aislamiento & purificación , Química Farmacéutica , Cumarinas/aislamiento & purificación , Implantes de Medicamentos , Humanos , Extractos Vegetales/análisis
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