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194 results on '"Tuenter, Emmy"'

6. Phytochemical characterization and antifungal potential of leaf extracts of Mosiera bullata.

Author

Pérez-Gómez, Lianny, Pérez-Martínez, Aurora T., Matheeussen, An, Pieters, Luc, Mendez, Daniel, Quirós-Molina, Yemeys, Trujillo, Reinaldo, Tuenter, Emmy, and Cos, Paul

Subjects
ENDEMIC plants, ENDEMIC species, PHYTOPATHOGENIC microorganisms, NATURAL products, PLANT species
Abstract

The investigation of natural alternatives to conventional fungicides is of imminent need. Mosiera bullata (Britton & P. Wilson) Bisse is a Cuban endemic plant species belonging to the Myrtaceae family. The objective of the present study was to perform a bioassay-guided fractionation to explore the potential of extracts and fractions from M. bullata leaves against a panel of fungal plant pathogens. The M. bullata total extract was confirmed to have good antifungal activity against R. oryzae (IC50 = 4.86 µg/mL) and moderate activity against F. oxysporum (IC50 = 352.40 µg/mL) and F. solani (IC50 = 427.38 µg/mL) and fungicidal effect against R. oryzae. Five compounds belonging to the class of phloroglucinol dimers were tentatively characterized by UHPLC-HRMS and reported for the first time in M. bullata and the genus Mosiera. These results suggest the potential of M. bullata total extract as a natural antifungal product for the control of diseases in agriculture. [ABSTRACT FROM AUTHOR]

Published
2024
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12. Validation and optimisation of reduced glutathione quantification in erythrocytes by means of a coulometric high‐performance liquid chromatography analytical method.

Author

Lauwers, Stef, Van Herreweghe, Maxim, Foubert, Kenn, Theunis, Mart, Breynaert, Annelies, Tuenter, Emmy, and Hermans, Nina

Abstract

Glutathione (GSH), a tripeptide that consists of cysteine, glutamate and glycine, is present in all mammalian tissues in the millimolar range. Besides having numerous cellular functions, GSH is an important antioxidant and is considered a valuable biomarker in evaluating oxidative stress. This paper provides a sensitive analytical method using HPLC‐ECD to quantify GSH in erythrocytes, validated using the ICH guidelines for Bioanalytical Method Validation. The sample preparation was optimised using centrifugal filtration and a hypotonic phosphate buffer for extracting GSH from erythrocytes. HPLC‐ECD parameters were adjusted to allow a fast, reversed phase, isocratic separation in 10 min. The detector response was linear between 0.3 and 9.5 μg/mL with a satisfactory regression coefficient and a LOQ of 0.11 μg/mL. Intra‐ and inter‐day repeatability ranged between 1.10% and 8.57% with recoveries ranging from 94.3% to 106.0%. Dilution integrity, benchtop, freeze–thaw and long‐term stability were investigated. Samples were stable for up to 6 months at −80°C. This method has a good linear response and is repeatable, precise and accurate. It minimises GSH auto‐oxidation using a centrifugal filter during sample preparation, instead of acidification. Therefore, this analytical method is suitable for quantifying GSH in erythrocytes as a marker of oxidative stress. [ABSTRACT FROM AUTHOR]

Published
2024
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20. A new alkaloid from Pancratium maritimum - Structure elucidation using computer-assisted structure elucidation (CASE) and evaluation of cytotoxicity and anti-SARS-CoV-2 activity.

Author

Le, Ngoc-Thao-Hien, De Jonghe, Steven, Erven, Kristien, Neyts, Johan, Pannecouque, Christophe, Vermeyen, Tom, Herrebout, Wouter A., Pieters, Luc, and Tuenter, Emmy

Abstract

Pancratium maritimum L. (or 'sea daffodil') is one of the most studied plant species in the Amaryllidaceae family. Recently, due to the advancement of new probabilistic methods and spectroscopic techniques, the potential for phytochemical investigations on isomeric compounds has significantly improved. In this study, application of these techniques in combination with conventional phytochemical analysis led to the isolation and identification of a new alkaloid named 2β,10bα-dihydroxy-9- O -demethylhomolycorine from P. maritimum , together with 17 known ones. Assessment of anti-SARS-CoV-2 activity and cytotoxicity on a Vero E6 cell line for all compounds revealed four compounds with weak anti-SARS-CoV-2 potency at non-cytotoxic concentrations, namely of 9- O -demethylhomolycorine (EC 50 = 44 µM), galanthamine (EC 50 = 70 µM), 1- O -acetyl-norpluviine (EC 50 = 80 µM) and 1- O -acetyl-10- O -methylpseudolycorine (EC 50 = 47 µM). On the other hand, cytotoxicity was observed for 2β,10bα-dihydroxy-9- O -demethylhomolycorine (CC 50 = 13.28 µM), haemanthamine (CC 50 = 0.76 µM), 6α- and 6β-haemanthidine (CC 50 = 5.43 µM), 11-hydroxyvittatine (CC 50 = 10.57 µM) and pseudolycorine (CC 50 = 3.41 µM). [Display omitted] • A new alkaloid was described: 2β,10bα-dihydroxy-9- O -demethylhomolycorine. • Three alkaloids were reported for the first time in P. maritimum. • Four alkaloids exhibited weak in vitro anti-SARS-CoV-2 activity (EC50 = 44–80 μM). • Six other compounds exhibited cytotoxicity on VeroE6 cells (CC50 = 0.76 – 13.28 μM). [ABSTRACT FROM AUTHOR]

Published
2023
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26. An in-depth multiphasic analysis of the chocolate production chain, from bean to bar, demonstrates the superiority of Saccharomyces cerevisiae over Hanseniaspora opuntiae as functional starter culture during cocoa fermentation

Author

Díaz-Muñoz, Cristian, primary, Van de Voorde, Dario, additional, Tuenter, Emmy, additional, Lemarcq, Valérie, additional, Van de Walle, Davy, additional, Soares Maio, José Pedro, additional, Mencía, Alejandra, additional, Hernandez, Carlos Eduardo, additional, Comasio, Andrea, additional, Sioriki, Eleni, additional, Weckx, Stefan, additional, Pieters, Luc, additional, Dewettinck, Koen, additional, and De Vuyst, Luc, additional

Published
2023
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29. Inhibitory Effect on Nitric Oxide Release in LPS-Stimulated Macrophages and Free Radical Scavenging Activity of Croton linearis Jacq. Leaves

Author

García Díaz, Jesús, primary, González Fernández, Rosalia, additional, Escalona Arranz, Julio César, additional, Llauradó Maury, Gabriel, additional, Méndez Rodríguez, Daniel, additional, De Vooght, Linda, additional, Molina, Enrique, additional, Tuenter, Emmy, additional, Pieters, Luc, additional, and Cos, Paul, additional

Published
2022
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30. Acute Effects of Cocoa Flavanols on Blood Pressure and Peripheral Vascular Reactivity in Type 2 Diabetes Mellitus and Essential Hypertension

Author

Tanghe, Anouk, primary, Heyman, Elsa, additional, Lespagnol, Elodie, additional, Stautemas, Jan, additional, Celie, Bert, additional, Op ‘t Roodt, Jos, additional, Rietzschel, Ernst, additional, Dias Soares, Danusa, additional, Hermans, Nina, additional, Tuenter, Emmy, additional, Shadid, Samyah, additional, and Calders, Patrick, additional

Published
2022
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31. Acute Effects of Cocoa Flavanols on Blood Pressure and Peripheral Vascular Reactivity in Type 2 Diabetes Mellitus and Essential Hypertension

Author

Tanghe, Anouk, Heyman, Elsa, Lespagnol, Elodie, Stautemas, Jan, Celie, Bert, Roodt, Jos Op J.O.t., Rietzschel, Ernst Robert, Soares, Danusa Dias, Hermans, Nina, Tuenter, Emmy, Shadid, Samyah, Calders, Patrick, Tanghe, Anouk, Heyman, Elsa, Lespagnol, Elodie, Stautemas, Jan, Celie, Bert, Roodt, Jos Op J.O.t., Rietzschel, Ernst Robert, Soares, Danusa Dias, Hermans, Nina, Tuenter, Emmy, Shadid, Samyah, and Calders, Patrick

Abstract

Background: Type 2 diabetes mellitus (T2DM) is associated with a high risk of vascular complications. Interestingly, cocoa flavanols (CF) can exert beneficial vascular effects in non‐dia-betic subjects. However, these effects have only been scarcely studied in T2DM. Therefore, we per-formed a study to assess the effects on vascular reactivity of a single dose of CF (790 mg) in T2DM and whether certain antihypertensive drugs may modulate these effects. Methods: 24 non‐diabetic and 11 T2DM subjects were studied in a cross‐over design. Fasting blood samples, blood pressure (BP), and arterial vasoreactivity (flow‐mediated dilation) were assessed before and 70 min after capsule ingestion. Muscle microvascular reactivity was only assessed after capsule ingestion. Age, waist‐to‐hip ratio, BP at baseline, and the use of antihypertensive drugs were regarded as covariates in a mixed models analysis. Results: CF ingestion did not affect any parameter. However, independ-ent of the type of capsules ingested, a decrease in diastolic BP by 3 mmHg (95% CI: −4.0; −2.0) and an increase in the change in brachial artery diameter (pre vs. post occlusion) by 0.06 mm (95% CI: 0.01; 0.12) were detected in the non‐diabetic group, while they remained unchanged in the T2DM group. Conclusion: No beneficial effects of CF were detected on vascular reactivity parameters in T2DM and non‐diabetic participants., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2022

36. Epimeric Mixture Analysis and Absolute Configuration Determination Using an Integrated Spectroscopic and Computational Approach—A Case Study of Two Epimers of 6-Hydroxyhippeastidine.

Author

Le, Ngoc-Thao-Hien, Vermeyen, Tom, Aerts, Roy, Herrebout, Wouter A., Pieters, Luc, and Tuenter, Emmy

Subjects
NATURAL products, COMMUNITIES
Abstract

Structural elucidation has always been challenging, and misassignment remains a stringent issue in the field of natural products. The growing interest in discovering unknown, complex natural structures accompanies the increasing awareness concerning misassignments in the community. The combination of various spectroscopic methods with molecular modeling has gained popularity in recent years. In this work, we demonstrated, for the first time, its power to fully elucidate the 2-dimensional and 3-dimensional structures of two epimers in an epimeric mixture of 6-hydroxyhippeastidine. DFT calculation of chemical shifts was first performed to assist the assignment of planar structures. Furthermore, relative and absolute configurations were established by three different ways of computer-assisted structure elucidation (CASE) coupled with ORD/ECD/VCD spectroscopies. In addition, the significant added value of OR/ORD computations to relative and absolute configuration determination was also revealed. Remarkably, the differentiation of two enantiomeric scaffolds (crinine and haemanthamine) was accomplished via OR/ORD calculations with cross-validation by ECD and VCD. [ABSTRACT FROM AUTHOR]

Published
2023
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39. Novel flavonol-3-O-methylethers from Zanthoxylum pistaciifolium Griseb. (Rutaceae).

Author

Heredia Díaz, Yamilé, Tuenter, Emmy, Garcia-Díaz, Jesús, Ochoa Pacheco, Ania, Cos, Paul, Pieters, Luc, and Escalona Arranz, Julio César

Subjects
ZANTHOXYLUM, RUTACEAE, HERBAL medicine, PLASMODIUM falciparum, TRYPANOSOMA cruzi
Abstract

Zanthoxylum pistaciifolium Griseb. is a tree endemic to Cuba, occasionally used in herbal medicine. Previously, the antitrypanosomal activity of a n-hexane–2-butanone extract of Z. pistaciifolium leaves and of its constituent skimmianine were published. In the current study a more thorough examination of the respective extract is performed, which led to the isolation and identification of three flavonoids, more specifically, the flavonol-3-O-methylethers kaempferol-3-O-methylether (1) and novel compounds kaempferol-3-O-methylether-5-O-β-D-glucoside (2) and kaempferol-8-hydroxy-3,7-O-dimethylether-5-O-β-D-glucoside (3). All compounds were screened for their antimicrobial and antiprotozoal activity and cytotoxicity towards MRC-5 SV2 cells. Compound 1 showed a moderate to weak activity against Trypanosoma cruzi (IC50 30.8 μM), T. brucei (IC50 15.4 μM) and Plasmodium falciparum (IC50 53.8 μM), but also showed cytotoxicity (CC50 19.0 μM). Compounds 2 and 3 did not display activity in any of the assays (IC50 and CC50 > 64 μM). [ABSTRACT FROM AUTHOR]

Published
2022
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43. Antiplasmodial Oleanane Triterpenoids from Terminalia albida Root Bark

Author

Baldé, Mamadou A., primary, Tuenter, Emmy, additional, Traoré, Mohamed S., additional, Peeters, Laura, additional, Matheeussen, An, additional, Cos, Paul, additional, Caljon, Guy, additional, Vermeyen, Tom, additional, Herrebout, Wouter, additional, Balde, Aliou M., additional, Foubert, Kenn, additional, and Pieters, Luc, additional

Published
2021
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48. In Vitro Anti-Inflammatory, Anti-Oxidant, and Cytotoxic Activities of Four Curcuma Species and the Isolation of Compounds from Curcuma aromatica Rhizome

Author

Pintatum, Aknarin, primary, Maneerat, Wisanu, additional, Logie, Emilie, additional, Tuenter, Emmy, additional, Sakavitsi, Maria E., additional, Pieters, Luc, additional, Berghe, Wim Vanden, additional, Sripisut, Tawanun, additional, Deachathai, Suwanna, additional, and Laphookhieo, Surat, additional

Published
2020
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