scholarly journals Synthesis of Silver Nanoparticles Using Aqueous Leaf Extract of Mimosa albida (Mimosoideae): Characterization and Antioxidant Activity

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 503 ◽  
Author(s):  
Fernanda Pilaquinga ◽  
Dennis Amaguaña ◽  
Jeroni Morey ◽  
Mauricio Moncada-Basualto ◽  
Josué Pozo-Martínez ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antioxidant Capacity ◽  
Aqueous Extract ◽  
High Performance ◽  
Analytical Techniques ◽  
Differential Pulse ◽  
Reducing Agents ◽  
Electrochemical Analysis ◽  
Total Phenolic ◽  
Array Detector

The search for sensitive and rapid analytical techniques for the determination of natural antioxidants is an area in constant growth due, among other aspects, to the complexity of plant matrices. In this study, silver nanoparticles prepared with the aqueous extract of Mimosa albida leaves were used to assess their polyphenolic content and antioxidant capacity. Silver nanoparticles were characterized by different techniques. As a result, nanoparticles of 6.5 ± 3.1 nm were obtained. The total phenolic content in the extract was 1320.4 ± 17.6 mg of gallic acid equivalents GAE· 100 g−1 and in the nanoparticles 257.3 ± 5.1 mg GAE· 100 g−1. From the phenolic profile analyzed by ultra high-performance liquid chromatography (UPLC) with a diode-array detector (DAD), the presence of apigenin and luteolin in the plant extract is postulated. The antioxidant capacity measured by oxygen radical absorbance capacity ORAC-fluorescein assay was 86917 ± 6287 and 7563 ± 967 µmol ET g−1 in the extract and nanoparticles respectively. Electrochemical analysis by cyclic voltammetry (CV) confirmed the effective reduction capacity of the Mimosa albida leaves extract to reduce Ag ions to AgNPs and differential pulse voltammetry (DPV) suggested the presence of two main reducing agents in the extract. From this study, it was concluded that the aqueous extract of Mimosa albida contains reducing agents capable of synthesizing silver nanoparticles, which can be used in the phytochemical industry.

scholarly journals Schisandra rubriflora Plant Material and In Vitro Microshoot Cultures as Rich Sources of Natural Phenolic Antioxidants

Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 488
Author(s):  
Agnieszka Szopa ◽  
Michał Dziurka ◽  
Sebastian Granica ◽  
Marta Klimek-Szczykutowicz ◽  
Paweł Kubica ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Phenolic Compounds ◽  
Antioxidant Capacity ◽  
Phenolic Acids ◽  
High Performance ◽  
Total Phenolic ◽  
Array Detector ◽  
Plant Materials

Schisandra rubriflora is a dioecious, underestimated medicinal plant species known from traditional Chinese medicine. The present study was aimed at characterising the polyphenolic profile composition and the related antioxidant capacity of S. rubriflora fruit, stem and leaf and in vitro microshoot culture extracts. Separate analyses of material from female and male specimens were carried out. This study was specifically aimed at detailed characterisation of the contribution of phenolic compounds to overall antioxidant activity using ultra-high-performance liquid chromatography with a photodiode array detector coupled to electrospray ionization ion trap mass spectrometry (UHPLC-DAD-ESI-MS3) and a high-performance liquid chromatography-diode array detector (HPLC-DAD). Using UHPLC-DAD-ESI-MS3, twenty-seven phenolic compounds from among phenolic acids and flavonoids were identified. Concentrations of three phenolic acids (neochlorogenic, chlorogenic and cryptochlorogenic acids) and eight flavonoids (hyperoside, rutoside, isoquercitrin, guaijaverin, trifolin, quercetin, kaempferol, and isorhamnetin) were determined using HPLC-DAD using reference standards. The highest total phenolic content was confirmed for the stem and leaf extracts collected in spring. The contents of phenolic compounds of in vitro biomasses were comparable to that in the fruit extracts. The methanolic extracts from the studied plant materials were evaluated for their antioxidant properties using various in vitro assays, namely free radicals scavenging estimation using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), ferric-reducing antioxidant power (FRAP) and cupric-reducing antioxidant capacity (CUPRAC) as well as QUick, Easy, New, CHEap, and Reproducible CUPRAC (QUENCHER-CUPRAC) assays. A close relationship between the content of polyphenolic compounds in S. rubriflora and their antioxidant potential has been documented.

scholarly journals Investigation on Green Synthesis, Biocompatibility, and Antibacterial Activity of Silver Nanoparticles Prepared Using Cistus incanus

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5028
Author(s):  
Wioletta Florkiewicz ◽  
Klaudia Pluta ◽  
Dagmara Malina ◽  
Karolina Rudnicka ◽  
Anna Żywicka ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antioxidant Capacity ◽  
Gallic Acid ◽  
Aqueous Extract ◽  
Total Phenolic Content ◽  
Phenolic Content ◽  
Dry Weight ◽  
Total Phenolic ◽  
Composition Analysis ◽  
Cistus Incanus

This paper describes the plant-mediated preparation of silver nanoparticles with aqueous extract and infusion of Cistus incanus leaves. To evaluate aqueous extract and infusion antioxidant capacity and total phenolic content the DPPH and Folin–Ciocalteau methods were utilized. The antioxidant capacity and total phenolic content of extract and infusion were equal to 85.97 ± 6.54 mg gallic acid equivalents per gram of dry weight.; 10.76 ± 0.59 mg/mL and 12.65 ± 1.04 mg gallic acid equivalents per gram of dry weight.; 3.10 ± 0.14 mg/mL, respectively. The formed nanoparticles displayed the characteristic absorption band in the 380–450 nm wavelength range. The average size of particles was in the 68.8–71.2 nm range. Morphology and phase composition analysis revealed the formation of spherical nanoparticles with a face-centred cubic structure. Immune compatibility tests of nanoparticles and plant extracts showed no activation of the THP1-XBlue™ monocyte. Cytotoxicity tests performed with L929 mice fibroblasts showed that nanoparticles should be utilized at a concentration of 16 ppm. The minimum inhibitory concentrations determined with the microdilution method for nanoparticles prepared with plant infusion for S. aureus and S. epidermidis were 2 ppm and 16 ppm, respectively.

scholarly journals Beta-Cyclodextrin-Decorated Magnetic Activated Carbon as a Sorbent for Extraction and Enrichment of Steroid Hormones (Estrone, β-Estradiol, Hydrocortisone and Progesterone) for Liquid Chromatographic Analysis

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 248
Author(s):  
Anele Mpupa ◽  
Azile Nqombolo ◽  
Boris Mizaikoff ◽  
Philiswa Nosizo Nomngongo
Keyword(s):  
Electron Microscopy ◽  
Activated Carbon ◽  
High Performance ◽  
Solid Phase ◽  
Extraction Procedure ◽  
Carbon Adsorbent ◽  
Analytical Techniques ◽  
Array Detector ◽  
Magnetic Activated Carbon ◽  
Wastewater Samples

A β-cyclodextrin-decorated magnetic activated carbon adsorbent was prepared and characterized using various analytical techniques (X-ray diffraction (XRD), scanning electron microscopy–electron diffraction spectroscopy (SEM-EDS) and transmission electron microscopy (TEM)), and the adsorbent was used in the development of a magnetic solid-phase microextraction (MSPE) method for the preconcentration of estrone, β-estradiol, hydrocortisone and progesterone in wastewater and river water samples. This method was optimized using the central composite design in order to determine the experimental parameters affecting the extraction procedure. The quantification of hormones was achieved using high-performance liquid chromatography equipped with a photodiode array detector (HPLC-DAD). Under optimum conditions, the linearity ranged from 0.04 to 300 µg L−1 with a correlation of determinations of 0.9969–0.9991. The limits of detection and quantification were between 0.01–0.03 and 0.033–0.1 µg L−1, with intraday and interday precisions at 1.1–3.4 and 3.2–4.2. The equilibrium data were best described by the Langmuir isotherm model, and high adsorption capacities (217–294 mg g−1) were obtained. The developed procedure demonstrated high potential as an effective technique for use in wastewater samples without significant interferences, and the adsorbent could be reused up to eight times.

scholarly journals Total Polyphenol and Flavonoid Content and Antioxidant Capacity of Some Varieties of Persea americana Peels Consumed in Cameroon

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ruth Edwige Kemadjou Dibacto ◽  
Boris Ronald Tonou Tchuente ◽  
Maxwell Wandji Nguedjo ◽  
Yves Martial Tongue Tientcheu ◽  
Emilienne Carine Nyobe ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Aqueous Extract ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
Persea Americana ◽  
Total Phenolic ◽  
Total Polyphenol ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Dpph Scavenging

Fruit peels are increasingly being used as functional foods nowadays. Peelings of twelve varieties of Persea americana fruits consumed in Cameroon were investigated for their phenolic compounds (polyphenols and flavonoids) using three solvents systems, water, ethanol: water (50 : 50 v / v ), and ethanol, and antioxidant activity using total antioxidant capacity (TAC), ferric reducing antioxidant power (FRAP), and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging methods. Total polyphenol, flavonoids, and antioxidant potential of the peels significantly varied with P. americana variety and also with the extraction solvents in the order ethanol > ethanol: water > water. Total phenolic content varied from 2407 (Fuerte florid) to 673 (Semil) mg GAE/g DM, respectively, while flavonoids varied from 986 to 119 mg QE/g DM for Fuerte florid and Hickson varieties, respectively. TAC, respectively, varied between 132.87 and 126.85 mg AAE/g DM with Hass and Semil varieties, respectively. The highest DPPH scavenging capacity was recorded for the ethanolic extract with Lula (86.33%) and the least for the aqueous extract with the Semil (30.11%) variety. With FRAP, the highest capacity was obtained with hydroethanolic extract of Fuerte florid (0.43 mg AAE/g DM) and the least for aqueous extract with the Semil (0.269 mg AAE/g DM) variety. In conclusion, varieties of avocado peels are a good source of antioxidants. Solvent extraction significantly affected the concentration of bioactive compounds but not the potency of the antioxidants. A weakly positive correlation but not significant between the quantity of polyphenol, flavonoid, and antioxidant capacity of avocado peelings was obtained in this study.

scholarly journals Total Phenolic Composition and Antioxidant Activity of Silver Nanoparticles using Aqueous Extract of Chilca Leaves (Baccharis latifolia)

2021 ◽  
Vol 18 (1) ◽  
pp. 79-91
Author(s):  
Fernanda Pilaquinga ◽  
Camila Granja ◽  
Eliza Jara ◽  
Mauricio Moncada-Basualto ◽  
Josu� Pozo-Mart�nez ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Silver Nanoparticles ◽  
Aqueous Extract ◽  
Total Phenolic ◽  
Phenolic Composition

scholarly journals An Investigation on Phenolic and Antioxidant Capacity of Under-utilized Food Legumes Consumed in China

Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 438
Author(s):  
Yaqian Zhang ◽  
Maninder Meenu ◽  
Hansong Yu ◽  
Baojun Xu
Keyword(s):  
Antioxidant Capacity ◽  
High Performance ◽  
Total Phenolic ◽  
Velvet Bean ◽  
Local Society ◽  
Food Legumes ◽  
Wide Range ◽  
Major Producer ◽  
Phytochemical Profile ◽  
High Level

China is a major producer of various kinds of food legumes. Some of the under-utilized food legumes are consumed by the local society from different areas in China. The antioxidant capacity and phytochemical profile of these under-utilized food legumes haven’t been investigated until now. In this study, colorimetric and high-performance liquid chromatography was employed to explore the antioxidant capacity and phytochemical profile of 21 under-utilized food legumes. Different legumes under investigation exhibit a wide range of variations in their total phenolic content (TPC), total flavonoids content (TFC) and condensed tannins content (CTC). Among all the legume samples, the velvet bean from Hechi, Guangxi exhibited the highest antioxidant capacity while the white flat bean from Shangrao, Shanxi presented the least antioxidant capacity. Gallic acid was observed to be a major phenolic acid and its content in the velvet bean was significantly higher compared to the other legume samples explored in this study. The composition of flavonoids was different among all the legumes. Kaempferol was observed to be the most predominant flavonoid. The findings of this study will be beneficial for plant breeders, food scientists and consumers for the better selection of germplasm with a high level of phytochemicals that in turn possess maximum health benefits.

scholarly journals Bio-Functional Properties of Bee Pollen: The Case of “Bee Pollen Yoghurt”

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 423 ◽  
Author(s):  
Ioannis Karabagias ◽  
Vassilios Karabagias ◽  
Ilias Gatzias ◽  
Kyriakos Riganakos
Keyword(s):  
Antioxidant Capacity ◽  
Total Phenolic Content ◽  
High Performance ◽  
Phenolic Content ◽  
Total Phenolic ◽  
Ionization Mass ◽  
Bee Pollen ◽  
Surface And Interface ◽  
Full Characterization

The objectives of the present work were: (a) to characterize bee pollen from the region of Epirus in terms of biofunctional activity parameters as assessed by (i) the determination of specific polyphenols using high performance liquid chromatography electrospray ionization mass spectrometry (HPLC/ESI-MS), (ii) antioxidant capacity (DPPH assay), and (iii) total phenolic content (Folin-Ciocalteu assay), and (b) to prepare yoghurts from cow, goat, and sheep milk supplemented with different concentrations of grounded bee pollen (0.5, 1.0, 2.5 and 3.0%, w/v), and study afterwards the trend in antioxidant capacity and total phenolic content along with product’s sensory properties. Results showed that bee pollen ethanolic extracts are a rich source of phytochemicals based on the high total phenolic content and in vitro antioxidant activity that were monitored. The addition of grounded bee pollen in yoghurts resulted in a food matrix of a higher in vitro antioxidant capacity and total phenolic content, whereas it improved the yoghurt’s taste, odour, appearance, and cohesion; the latter indicates its beneficial use as a general food surface and interface material enhancer due to the possible formation of surface/interface active lipid-linked proteins. Based on the present findings, bee pollen yoghurt is proposed as a novel and costless functional food whereas it may comprise a research basis for food or material science in the scientific society of the future. Results were further supported by implementation of advanced chemometric analyses providing a full characterization of the product’s uniqueness.

scholarly journals Phytochemical Composition and Antioxidant Capacity of 30 Chinese Teas

Antioxidants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 180 ◽  
Author(s):  
Guo-Yi Tang ◽  
Cai-Ning Zhao ◽  
Xiao-Yu Xu ◽  
Ren-You Gan ◽  
Shi-Yu Cao ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
High Performance ◽  
Food Additives ◽  
Water Soluble ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenolic ◽  
Antioxidant Compounds ◽  
Antioxidant Power ◽  
Phenolic Contents ◽  
Trolox Equivalent

Tea has been reported to prevent and manage many chronic diseases, such as cancer, diabetes, obesity, and cardiovascular diseases, and the antioxidant capacity of tea may be responsible for these health benefits. In this study, the antioxidant capacities of fat-soluble, water-soluble, and bound-insoluble fractions of 30 Chinese teas belonging to six categories, namely green, black, oolong, dark, white, and yellow teas, were systematically evaluated, applying ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays. In addition, total phenolic contents of teas were determined by Folin–Ciocalteu method, and the contents of 18 main phytochemical compounds in teas were measured by high-performance liquid chromatography (HPLC). The results found that several teas possessed very strong antioxidant capacity, and caffeine, theaflavine, gallic acid, chlorogenic acid, ellagic acid, and kaempferol-3-O-glucoside, as well as eight catechins, were the main antioxidant compounds in them. Thus, these teas could be good natural sources of dietary antioxidants, and their extracts might be developed as food additives, nutraceuticals, cosmetics, and pharmaceuticals.

scholarly journals Does Fermentation Really Increase the Phenolic Content in Cereals? A Study on Millet

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 303 ◽  
Author(s):  
Diletta Balli ◽  
Maria Bellumori ◽  
Laura Pucci ◽  
Morena Gabriele ◽  
Vincenzo Longo ◽  
...  
Keyword(s):  
High Performance ◽  
Phenolic Content ◽  
Ex Vivo ◽  
Tyrosine Phosphatase ◽  
Total Phenolic ◽  
Array Detector ◽  
Allosteric Inhibitors ◽  
Fermentation Time ◽  
Phenolic Extract

Millet is underutilized in Europe, despite its advantages compared to other common cereals. In Asia and Africa, millet is mainly eaten in fermented form; its consumption has beneficial properties on human health. Three millet batches were compared in terms of free and bound phenols by High Performance Liquid Chromatography-Diode Array Detector-Mass Spectrometry (HPLC-DAD-MS). The richest one in terms of bound phenols was selected for testing via a basic (0.1 M NaOH) and an acidic (1.2 M H2SO4) hydrolysis, in which 149.3 and 193.6 mg/100 g of phenols were recovered, respectively. The ability of fermentation, with yeast and Lactobacilli, to increase the content of phenolic compounds was verified. Five withdrawalswere performed to verify the influence of fermentation time on the total phenolic content. The greatest phenolic content was observed after 72 h. Fermentation increased the cinnamic acids and flavonoids contents by approximately 30%. Vitexin and vitexin 2″-O-rhamnoside contents were significantly higher in the fermented millet; these compounds partially inhibit the protein tyrosine phosphatase enzyme, which is overexpressed in type-2 diabetes. A molecular dynamic simulation showed the two flavonoids to be allosteric inhibitors. The phenolic extract from fermented millet demonstrated a higher level of antioxidant protection on human erythrocytes by ex vivo cellular antioxidant activity in red blood cells. In this context, functional foods based on fermented millet could represent a new trend in European markets.

scholarly journals Environmentally Friendly Hydrothermal Processing of Melon by-Products for the Recovery of Bioactive Pectic-Oligosaccharides

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1702
Author(s):  
Xiana Rico ◽  
Beatriz Gullón ◽  
Remedios Yáñez
Keyword(s):  
High Performance ◽  
Value Added ◽  
Amperometric Detection ◽  
Exchange Chromatography ◽  
Effect Of Temperature ◽  
Total Phenolic ◽  
Array Detector ◽  
Hydrothermal Processing ◽  
Wide Range ◽  
By Products

Melon by-products, that currently lack high value-added applications, could be a sustainable source of bioactive compounds such as polysaccharides and antioxidants. In this work, melon peels were extracted with water to remove free sugars, and the water-insoluble solids (WISs) were subjected to hydrothermal processing. The effect of temperature on the composition of the obtained liquors and their total phenolic content was evaluated. The selected liquors were also characterized by matrix assisted laser desorption/ionization-time of flight mass spectroscopy (MALDI-TOF MS), fourier transform infrared spectroscopy (FTIR) and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC–PAD), and its phenolic compounds were identified and quantified by high-performance liquid chromatography-diode array detector-tandem mass spectrometry (HPLC–DAD–MS/MS). In addition, the spent solids from the hydrothermal treatment were characterized and their potential use was assessed. At the optimal conditions of 140 °C (severity 2.03), the total oligosaccharide yield accounted for 15.24 g/100 g WIS, of which 10.07 g/100 g WIS were oligogalacturonides. The structural characterization confirmed the presence of partially methyl esterified oligogalacturonides with a wide range of polymerization degrees. After precipitation, 16.59 g/100 g WIS of pectin were recovered, with a galacturonic acid content of 55.41% and high linearity.

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