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121 results on '"Rédei, Dóra"'

3. New Members of the Centrapalus Coumarin and Pauciflorin Series from Centrapalus pauciflorus.

Author

Saidu, Muhammad Bello, Krstić, Gordana, Bombicz, Petra, De, Sourav, Barta, Anita, Ali, Hazhmat, Zupkó, István, Berkecz, Róbert, Gallah, Umar Shehu, Rédei, Dóra, and Hohmann, Judit

Subjects
PULMONOLOGY, BIOACTIVE compounds, CHEST pain, TRADITIONAL medicine, X-ray diffraction, BREAST
Abstract

Monoterpene and 5-methylcoumarin- or 5-methylchromone-coupled meroterpenoids occurring mainly in the Asteraceae species proved to have high potency against protozoans, worms, and various tumor cells, which make them interesting targets for searching for new bioactive compounds. The African plant Centrapalus pauciflorus was applied in traditional medicine for healing chest pain and stomach aches. Three new meroterpenoids named centrapalus coumarin N (2), pauciflorins P (3), and Q (4), and the already known cyclohoehnelia coumarin (1), were isolated from the chloroform extract of C. pauciflorus, together with centrapalus coumarin O (5), which was obtained for the first time from a natural source. The structures were established from HRESIMS, 1D (1H NMR, 13C NMR JMOD) and 2D NMR (HSQC, HMBC, 1H-1H COSY, NOESY) spectroscopies, and the absolute stereochemistry of 5 was determined by single-crystal X-ray diffraction. Compounds 1, 2, and 5 are hybrid molecules of 5-methylcoumarin–monoterpene origin. Centrapalus coumarin N is the first example of meroterpenoids, where a monoterpene is fused with a coumarin and an acetophenone unit. Pauciflorins P and Q are dimeric meroterpenoid isomers. Centrapalus coumarins N and O were tested for antiproliferative activity against human adherent breast (MCF-7, MDA-MB-231), cervical (HeLa, SiHa), and ovarian (A2780) cancer cell lines, and were additionally included to obtain data concerning cancer selectivity. Both compounds exhibited moderate (IC50 > 10 µM) but selective activity against A2780 cells. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Diterpenoids from Euphorbia dulcis with Potassium Ion Channel Inhibitory Activity with Selective G Protein-Activated Inwardly Rectifying Ion Channel (GIRK) Blocking Effect

Author

Kúsz, Norbert, primary, Orvos, Péter, additional, Bereczki, Laura, additional, Fertey, Pierre, additional, Bombicz, Petra, additional, Csorba, Attila, additional, Tálosi, László, additional, Jakab, Gusztáv, additional, Hohmann, Judit, additional, and Rédei, Dóra, additional

Published
2018
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33. Diterpenoids from Euphorbia dulciswith Potassium Ion Channel Inhibitory Activity with Selective G Protein-Activated Inwardly Rectifying Ion Channel (GIRK) Blocking Effect

Author

Kúsz, Norbert, Orvos, Péter, Bereczki, Laura, Fertey, Pierre, Bombicz, Petra, Csorba, Attila, Tálosi, László, Jakab, Gusztáv, Hohmann, Judit, and Rédei, Dóra

Abstract

Nine new (1–9) and two known (10, 11) jatrophane diterpenoids were isolated from the methanol extract of Euphorbia dulcis. The structure elucidation of the compounds was performed by means of extensive spectroscopic analysis, including HRESIMS, 1D (1H, JMOD), and 2D (HSQC, HMBC, 1H–1H-COSY, NOESY) NMR experiments. The absolute configuration of compound 1was determined by single-crystal X-ray diffraction. The electrophysiological effects of compounds 1–11and the five diterpenoids (12–16) previously isolated from Euphorbia taurinensiswere investigated on stable transfected HEK-GIRK1/4 (Kir3.1/3.4) and HEK-hERG (Kv11.1) cell lines using automated patch-clamp equipment. The majority of the diterpenoids showed significant blocking activity on GIRK channels (60.8–88.7% at 10 μM), while compounds 1, 2, 9–11, 13, and 14exerted notable inhibitory effects even at 1 μM concentration. None of the jatrophane diterpenoids interfered with the function of hERG proteins; however, compound 14remarkably hampered K+flow through hERG channels. These selective activities suggest that jatrophane diterpenoids may represent a group of potential lead compounds for the development of novel therapeutic agents against atrial fibrillation.

Published
2018
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34. Bioactivity-Guided Investigation of the Anti-Inflammatory Activity of Hippophae rhamnoides Fruits.

Author

Rédei, Dóra, Kúsz, Norbert, Jedlinszki, Nikoletta, Blazsó, Gábor, Zupkó, István, and Hohmann, Judit

Subjects
*ANIMALS, *ANTI-inflammatory agents, *BIOLOGICAL assay, *BIOLOGICAL models, *CELL physiology, *CHROMATOGRAPHIC analysis, *DEXTRAN, *FRUIT, *HISTAMINE, *INFLAMMATION, *MAST cells, *POLYSACCHARIDES, *SEROTONIN, *VASODILATORS, *THERAPEUTICS
Abstract

According to modern ethnobotanical records, the fruit of Hippophae rhamnoides is effective in the treatment of different allergic symptoms. In order to obtain pharmacological evidence for this observation, the fruit was investigated for anti-inflammatory activity using in vivo animal models. Aqueous and 70% MeOH extracts were tested in 48/80-induced rat paw edema assay after oral administration, and it was found that the 70% MeOH extract (500 mg/kg) reduced significantly edema volume (0.660 ± 0.082 mL vs. control 0.935 ± 0.041 mL). Extracts of different parts of the fruit (pulp, peel, seed) were investigated in the same assay, and the peel extract was shown to exhibit maximum edema-reducing effect (0.470 ± 0.124 mL vs. control 0.920 ± 0.111 mL). This extract was used to elucidate the mode of action. Different inflammation inducers (serotonin, histamine, dextran, bradykinin, and carrageenan) were applied in the rat paw model, but the extract inhibited only the compound 48/80 elicited inflammation. The active extract was then fractionated by solvent-solvent partitioning and chromatographic methods with the guidance of the 48/80-induced anti-inflammatory assay, and the main compounds responsible for the activity were identified as ursolic acid and oleanolic acid. Our data suggest that the activity is most probably based on a membrane stabilizing effect caused by the inhibition of degranulation of mast cells. Moreover, previously unknown 2,5-bis-aryl-3,4-dimethyltetrahydrofuran lignans, nectandrin B, fragransin A2, and saucernetindiol were isolated and identified from H. rhamnoides for the first time. [ABSTRACT FROM AUTHOR]

Published
2018
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43. Discovery and Biological Evaluation of a New Family of Potent Modulators of Multidrug Resistance: Reversal of Multidrug Resistance of Mouse Lymphoma Cells by New Natural Jatrophane Diterpenoids Isolated from Euphorbia Species

Author

Hohmann, Judit, primary, Molnár, Joseph, additional, Rédei, Dóra, additional, Evanics, Ferenc, additional, Forgo, Peter, additional, Kálmán, Alajos, additional, Argay, Gyula, additional, and Szabó, Pál, additional

Published
2002
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46. Isolation of Phorbol Esters from Euphorbia grandicornisand Evaluation of Protein Kinase C- and Human Platelet-Activating Effects of Euphorbiaceae Diterpenes

Author

Tsai, Ju-Ying, Rédei, Dóra, Forgo, Peter, Li, Yu, Vasas, Andrea, Hohmann, Judit, and Wu, Chin-Chung

Abstract

Human platelets contain conventional (α and β) and novel isoforms of PKC (δ and θ), and PKC activation can result in platelet aggregation and secretion reaction that are important for thrombus formation. Several tumor-promoting Euphorbiaceae diterpenes are known to act as direct activators of PKC, but many types of such diterpenes have not been studied as platelet stimulators. In the present study, two new and five known phorbol esters were isolated from Euphorbia grandicornis. Two of the isolated phorbol esters together with compounds representing ingenane, jatrophane, and myrsinane structural types were studied on PKC activation and platelet stimulation. The investigated phorbol esters and ingenane esters induced blood platelet aggregation and ATP secretion. PKC activation was demonstrated by inducing membrane translocation of PKCs, phosphorylation of PKC substrates, and activation of PKC signaling pathways. The PKC-activating effect of the compounds correlated well with their efficacy to cause platelet stimulation. Moreover, by using an isoform-specific PKC inhibitor, it was found that besides conventional PKCs novel PKCs also play a positive role in platelet activation caused by phorbol/ingenane esters, especially in regulating platelet aggregation. The present results suggest that platelets afford a useful model for studying PKC activators of natural origin or their chemical derivatives.

Published
2016
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48. Jatrophane Diterpenes from Euphorbia esulaas Antiproliferative Agents and Potent Chemosensitizers to Overcome Multidrug Resistance

Author

Vasas, Andrea, Sulyok, Edvárd, Rédei, Dóra, Forgo, Peter, Szabó, Pál, Zupkó, István, Berényi, Ágnes, Molnár, Joseph, and Hohmann, Judit

Abstract

Phytochemical study of whole, undried plants of Euphorbia esulaled to the isolation of six new (1–6) jatrophane diterpene polyesters, named esulatins H–M, together with the known compounds 2α,3β,5α,7β,15β-pentaacetoxy-9α-nicotinoyloxyjatropha-6(17),11-dien-14-one (7), salicinolide (8), and euphosalicin (9). The structures and relative configuration of 1–6were established on the basis of extensive spectroscopic analysis, including HRESIMS and one- and two-dimensional NMR techniques. All these compounds, together with diterpenes (10–14) isolated previously from this plant, were evaluated for their antiproliferative activity against HeLa, Ishikawa, and MCF7 cells. The multidrug-resistance-reversing activities were also investigated on L5178 mouse lymphoma cells transfected with the pHa MDR1/A retrovirus DNA. Preliminary structure–activity relationship data are discussed.

Published
2011
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