Person: Rosales Conrado, Noelia
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First Name
Noelia
Last Name
Rosales Conrado
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
Area
Química Analítica
Identifiers
12 results
Search Results
Now showing 1 - 10 of 12
Item Effect of Storage and Drying Treatments on Antioxidant Activity and Phenolic Composition of Lemon and Clementine Peel Extracts(Molecules, 2023) Gómez Mejía, Esther; Sacristán Navarro, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaObtaining polyphenols from horticultural waste is an emerging trend that enables the valorization of resources and the recovery of value-added compounds. However, a pivotal point in the exploitation of these natural extracts is the assessment of their chemical stability. Hence, this study evaluates the effect of temperature storage (20 and −20 ◦C) and drying methods on the phenolic composition and antioxidant activity of clementine and lemon peel extracts, applying HPLC-DADMS, spectrophotometric methods, and chemometric tools. Vacuum-drying treatment at 60 ◦C proved to be rather suitable for retaining the highest antioxidant activity and the hesperidin, ferulic, and coumaric contents in clementine peel extracts. Lemon extracts showed an increase in phenolic acids after oven-drying at 40 ◦C, while hesperidin and rutin were sustained better at 60 ◦C. Hydroethanolic extracts stored for 90 days preserved antioxidant activity and showed an increase in the total phenolic and flavonoid contents in lemon peels, unlike in clementine peels. Additionally, more than 50% of the initial concentration was maintained up to 51 days, highlighting a half-life time of 71 days for hesperidin in lemon peels. Temperature was not significant in the preservation of the polyphenols evaluated, except for in rutin and gallic acid, thus, the extracts could be kept at 20 ◦C.Item Anti-inflammatory activity of ethyl acetate and n-butanol extracts from Ranunculus macrophyllus Desf. and their phenolic profile(Journal of Ethnopharmacology, 2021) Deghima, Amirouche ; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Baali, Faiza; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Bedjou, FatihaEthnopharmacological relevance: The members of the genus Ranunculus have counter-irritating properties and thus, they are traditionally used for treating anti-inflammatory disorders and other skin conditions. Ranunculus macrophyllus Desf. is a wild medicinal plant growing in Algeria and traditionally used to treat some cutaneous skin disorders. Aim: The aim of this study was to characterize the composition of the ethyl acetate and n-butanol extracts from Ranunculus macrophyllus Desf. as well as to elucidate and to compare their effect against acute skin inflammation. Moreover, both the antioxidant activity and the acute toxicity of the plant extracts were also studied. Materials and methods: Spectrophotometric and chromatographic methods were employed to identify and quantify phenolic compounds and triterpenoids from R. macrophyllus Desf. fractions. The antioxidant activity was estimated using the phosphomolebdenum, DPPH, reducing power and β-carotene bleaching assays. The ethyl acetate and n-butanol extracts were screened for their anti-inflammatory activities using ex-vivo membrane stabilizing assays and in-vivo acute skin inflammation model. Results: Ethyl acetate fraction showed the highest amounts of total phenolic compounds (413 ± 4 μg GAE/mg extract) and triterpenoids (70.4 ± 1.8 μg UAE/mg extract). Rutin, hesperidin, myricetin and kaempferol were the major compounds identified in the different fractions. Ethyl acetate fraction exhibited strong DPPH• radical scavenging ability (IC50 1.6 ± 0.2 μg/mL), high total antioxidant capacity (447 ± 7 μg AAE/mg extract) and reducing power (514 ± 8 μg AAE/mg extract). Ethyl acetate fraction inhibited (73.4 ± 0.3) % of linoleic acid peroxidation. Ethyl acetate and n-butanol fractions did not have any visible toxicity at 2000 mg/kg and presented excellent membrane stabilizing ability. The inhibition of xylene induced ear inflammation was (38 ± 4) % and (46 ± 1) % for RM-B and RM-EA, respectively. Conclusions: The high content of both phenolic compounds and triterpenoids combined with the remarkable antiinflammatory effect and antioxidant activity of ethyl acetate and n-butanol extracts from R. macrophyllus Desf. support the wide spread use of this traditional plant on some skin disorders (inflammatory skin disorders).Item Valorisation of the green waste parts from large-leaved buttercup (Ranunculus macrophyllus Desf.): phenolic profile and health promoting effects study(Waste and biomass valorization, 2020) Deghima, Amirouche; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Baali, Faiza; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Bedjou, Fatiha; SpringerDue to the extensive use of Ranunculus macrophyllus Desf. roots for medicinal purposes, most of the leafy green parts are just wasted. The aim of this work is to valorize the leafy green parts and promote their application in different modern industries. Methods For this purpose, we studied the phenolic profile of R. macrophyllus Desf. (RM-B) using chromatographic and spectrophotometric methods and we tested the in-vitro antioxidant activity and the in-vivo effect of RM-B on plasma and liver antioxidant statuts. Results RM-B contained high amounts of polyphenols (675 mg GAE/100 g dry weigh dw) and flavonoids (105 mg QE/100 g dw). In-vitro, RM-B exhibited promising radical scavenging activity against 2,2′-azino-bis(3-éthylbenzothiazoline-6-sulphonique) (ABTS+·) (IC50: 247 µg/mL), hydrogen peroxide radicals (IC50: 626 µg/mL) and inhibited oxidative red blood cells hemolysis (IC50: 120 µg/mL), RM-B also showed strong reducing power (982 µM FeSO4/mg extract). In-vivo, RM-B improved the radical scavenging ability and reducing power of plasma and enhanced liver antioxidant status by increasing catalase and reduced glutathione levels and decreasing malondialdhyde levels without altering the key serum biochemical parameters reflecting liver and kidney functions. Polyphenols identified using capillary LC-DAD and LC–MS/MS analyses like hesperidin (131.2 mg/100 g dw), rutin (29.0 mg/100 g dw) and p-coumaric acid (5.8 mg/100 g dw), may be responsible for the health promoting effects of RM-B. Conclusion We may conclude that R. macrophyllus Desf. is a good source of beneficial polyphenols with strong antioxidant, anti-hemolytic and health-promoting effects, which promotes its use in pharmaceutical, medicinal and nutraceutical industries.Item A combined approach based on matrix solid-phase dispersion extraction assisted by titanium dioxide nanoparticles and liquid chromatography to determine polyphenols from grape residues(Journal of Chromotography A, 2021) Gómez Mejía, Esther; Hartwig Mikkelsen, Line; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María Yolanda; ElsevierA simple and efficient low-cost matrix solid phase dispersion (MSPD) extraction assisted by TiO2 nanopar- ticles and diatomaceous earth has been developed for the extraction of phenolic compounds from grape and grape pomace wastes. Experimental conditions for MSPD extraction were optimized by a facto- rial design and a surface response methodology. The simultaneous identification and quantification of eight main natural polyphenols (caffeic, p-coumaric, dihydroxybenzoic and gallic acid, rutin, resveratrol, quercetin and catechin) was possible by combining MSPD and capillary liquid chromatography coupled to a diode array detection and a mass simple quadrupole analyzer (cLC-DAD-MS). Good linearity and acceptable LOD (0.05–62 μg· g −1 ) and LOQ (0.2–207 μg· g −1 ) were obtained. The quantities of extracted polyphenols were within 2.4 and 333 μg· g −1, with catechin and rutin the most abundant compounds in rape pomace and grape wastes, respectively. Furthermore, considering the prospective uses of the win- ery bioresidues, the extracts have been characterised in terms of bioactive properties (several antioxidant activities and bacterial inhibition against Staphylococcus aureus, Escherichia coli and Pseudomona aerugi- nosa) and parameters such as total polyphenol and total flavonoid content. The high antioxidant activity (IC 50 5.0 ± 0.4 μg ·g −1 against DPPH radical) and antibacterial activity (2.2 ± 0.3 mg· mL −1 ) suggests that the methodology developed is efficient, rapid and promising for the extraction of phenolic compounds with potential application as bioactive ingredients in food and cosmetic industries.Item Residual brewing yeast as a source of polyphenols: Extraction, identification and quantification by chromatographic and chemometric tools(Food Chemistry, 2018) León González, María Eugenia De; Gómez Mejía, Esther; Rosales Conrado, Noelia; Madrid Albarrán, María YolandaA method combining aqueous extraction, reversed-phase high-performance capillary liquid chromatography with photodiode array detection (cLC-DAD) and chemometric tools, was developed to determine phenolic compounds in residual brewing yeast. The effect of temperature, nature of extraction solvent and method for separation of extract solution were studied to optimize the extraction conditions on the basis of total phenolic content (TPC), total flavonoids content (TFC) and antioxidant capacity. Polyphenols were determined by cLC-DAD. Flavonols as rutin and kaempferol, flavonoids as naringin, phenolic acids as gallic acid and antioxidants as trans-ferulic and p-coumaric acids were found and quantified in the brewing residue. Data were subjected to evaluation using multifactor ANOVA and principal component analysis (PCA), both showing that lyophilization pretreatment affects the content of individual polyphenols and that residual brewing yeast contains higher polyphenol amounts than the liquid beer waste. The obtained results suggest that residual brewing yeast could be a source of polyphenols.Item Extraction, identification and quantification of polyphenols from spent coffee grounds by chromatographic methods and chemometric analyses(Waste Management , 2019) Ramón-Gonçalves, Marina; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaA solid-liquid extraction method using ethanol-water mixtures was combined with cLC-DAD, LC-MS/MS and chemometric analyses for establishing the optimum extraction conditions of valuable polyphenols from spent coffee grounds. Chlorogenic and p-coumaric acids were the most abundant polyphenols found, ranging from 0.02 to 4.8 mg g−1 and 0.173–0.50 mg g−1, respectively. In addition, total polyphenol content (9–29 mg GAE g−1 DW), total flavonoid content (11–27 mg QE g−1 DW), total antioxidant activity (0.3–7 mg GAE g−1 DW) and free radical scavenging ability (DPPH assay, 64–927 µg extract g−1 at EC50) of obtained extracts were determined. Response surface methodology allowed obtaining predictive models for the extraction of each individual polyphenol. On the other hand, multifactorial ANOVA was used to establish differences between coffee and spent coffee ground extracts. Principal component analysis was also employed to relate antioxidant activities, total polyphenol and total flavonoid contents with both the polyphenols extracted and the residue coffee type. The overall results suggested that spent coffee grounds could be reused as a promising, inexpensive and natural source of bioactive polyphenols with potential industrial applications, thus minimizing the waste disposal and environmental impact.Item Citrus peels waste as a source of value-added compounds: Extraction and quantification of bioactive polyphenols(FOOD CHEMISTRY, 2019) Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaA method combining solid-liquid extraction based on ethanolic aqueous solution, cLC-DAD and chemometrics, was performed to extract and quantify polyphenols from citrus peels. LC-MS/MS was also employed for chemical profiling. The effect of extraction variables on the recovery was examined by experimental factorial design. Data were evaluated using multifactorial-ANOVA, response surface analysis and Principal Component Analysis. trans-Ferulic and p-coumaric antioxidants were found in lower quantities (<1.4 mg·g−1) in all peel extracts. Narangin flavonoid was also identified in all samples, while rutin flavonol was determined in the concentration range of 3.3–4.7 mg·g−1. The most abundant polyphenol in the extracts obtained from all evaluated citrus samples was the flavanone hesperidin (280–673 mg·g−1). Furthermore, peel extracts were evaluated in terms of total polyphenol and flavonoid content, total antioxidant activity and DPPH free radical scavenging. The obtained results suggested that evaluated citrus peel by-products could be reused as a source of polyphenols and transformed into value-added products.Item Neuroprotective activity of selenium nanoparticles against the effect of amino acid enantiomers in Alzheimer’s disease(Analytical and Bioanalytical Chemistry, 2022) Vicente Zurdo, David; Rodríguez-Blázquez, Sandra; Gómez Mejía, Esther; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaAlzheimer’s disease (AD), the most prevalent neurodegenerative disease, is characterized by extracellular accumulation of amyloid-beta protein (Aβ), which is believed to be the very starting event of AD neurodegeneration. In this work, D-Phe, D-Ala, and D-Glu amino acids, which are the non-occurring enantiomeric form in the human body, and also D-Asp and DL-SeMet, have proved to be amyloidogenic regarding Aβ42 aggregation in TEM studies. These amyloidogenic amino acid enantiomers also widened Aβ42 fibrils up to 437% regarding Aβ42 alone, suggesting that Aβ42 aggregation is enantiomerically dependent. To inhibit enantiomeric-induced amyloid aggregation, selenium nanoparticles stabilized with chitosan (Ch-SeNPs) were successfully synthesized and employed. Thus, Ch-SeNPs reduced and even completely inhibited Aβ42 aggregation produced in the presence of some amino acid enantiomers. In addition, through UV–Vis spectroscopy and fluorescence studies, it was deduced that Ch-SeNPs were able to interact differently with amino acids depending on their enantiomeric form. On the other hand, antioxidant properties of amino acid enantiomers were evaluated by DPPH and TBARS assays, with Tyr enantiomers being the only ones showing antioxidant effect. All spectroscopic data were statistically analysed through experimental design and response surface analysis, showing that the interaction between the Ch-SeNPs and the amino acids studied was enantioselective and allowing, in some cases, to establish the concentration ratios in which this interaction is maximum.Item Valorization of citrus reticulata blanco peels to produce enriched wheat bread: phenolic bioaccessibility and antioxidant potential(Antioxidants, 2023) Gómez Mejía, Esther; Sacristán, Iván; Rosales Conrado, Noelia; León González, María Eugenia De; Madrid Albarrán, María YolandaThe fortification of foods with bioactive polyphenols aims to improve their functional properties and to provide health benefits. Yet, to exert their benefits, phenolic compounds must be released from the food matrix and absorbed by the small intestine after digestion, so assessing their bioaccessibility is crucial to determine their potential role. This work aims to incorporate Citrus reticulata Blanco peel extracts into wheat bread as a promising opportunity to increase their bioactive potential, along with supporting the sustainable management of citrus-industry waste. A control and a wheat bread enriched at 2% and 4% (w/v) with a phenolic extract from mandarin peels were prepared and analyzed for antioxidant activity and phenolic composition using LC-MS and UV-Vis spectrophotometry. In addition, in vitro digestion was performed, and the digested extracts were analyzed with HPLC-MS/MS. The results showed a significant increase in total flavonoid content (TFC, 2.2 ± 0.1 mg·g−1), antioxidant activity (IC50 = 37 ± 4 mg·g−1), and contents of quercetin, caffeic acid, and hesperidin in the 4% (w/v) enriched bread. Yet, most polyphenols were completely degraded after the in vitro digestion process, barring hesperidin (159 ± 36 μg·g−1), highlighting the contribution of citrus enrichment in the development of an enriched bread with antioxidant potential.Item Bioactive polyphenols from Ranunculus macrophyllus Desf. Roots: quantification, identification and antioxidant activity(South African Journal of Botany, 2020) Deghima, Amirouche; Righi, Nadjat; Rosales Conrado, Noelia; León González, María Eugenia De; Gómez Mejía, Esther; Madrid Albarrán, María Yolanda; Baali, Faiza; Bedjou, FatihaRanunculus macrophyllus Desf. is an Algerian medicinal plant whose roots are used in traditional medicine to cure feminine infertility and other diseases, however there are no studies regarding its phytochemistry and biological activities. The aim of this work is to study the phytochemical composition and antioxidant activity of different solvents fractions from the roots of Ranunculus macrophyllus Desf. Spectrophotometric and chromatographic methods were used to study the phytochemical composition; while antiradical, iron chelating ability, reducing power and lipid peroxidation were studied in-vitro. The ethyl acetate fraction showed the highest values of total phenolic compounds (271.0 ± 0.2 µg GAE/mg dry extract (d.e), flavonols (24 ± 5 µg RE/ mg d.e) and condensed tannins (129 ± 10 µg CE/mg d.e), while the hexane fraction contained the highest amount of triterpenoids (91 ± 7 µg UAE/mg d.e). The highest radical scavenging ability was recorded for the ethyl acetate fraction against DPPH (IC50 = 3.7 ± 0.1 µg/mL) and ABTS (IC50 = 81 ± 3 µg/mL) whereas the hexane fraction had the best hydrogen peroxide radical scavenging (IC50 = 380 ± 4 µg/mL). The ethyl acetate fraction had the best total antioxidant capacity (TAC = 361 ± 1 µAAE/ mg extract) and reducing power (310 ± 2 µAAE/mg extract). The β-carotene bleaching was inhibited at high rate even after 24 h by the ethyl acetate fraction (81.0 ± 0.5 %). All activities were correlated with the polyphenolic content of the fractions. Capillary LC-DAD and LC-MS/MS analysis of ethyl acetate fraction revealed high amounts of gallic acid (9.3 ± 0.6 mg/g d.e), dihydroxybenzoic acid (8.1 ± 0.2 mg/g d.e) and hesperidin (5.9 ± 0.6 mg/g d.e). With such high amounts of polyphenols and strong antioxidant activity Ranunculus macrophyllus Desf. roots could have a potential use in pharmaceutical and nutraceutical industries.