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Wenzig EM, Widowitz U, Kunert O, Chrubasik S, Bucar F, Knauder E, Bauer R. Phytochemical composition and in vitro pharmacological activity of two rose hip (Rosa canina L.) preparations. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2008; 15:826-835. [PMID: 18707854 DOI: 10.1016/j.phymed.2008.06.012] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 06/27/2008] [Indexed: 05/26/2023]
Abstract
The aim of the present study was to compare powdered rose hip with and without fruits (Rosae pseudofructus cum/sine fructibus, Rosa canina L., Rosaceae) with regard to their phytochemical profile and their in vitro anti-inflammatory and radical-scavenging properties. The two powders were subsequently extracted with solvents of increasing polarity and tested for inhibition of cyclooxygenase (COX-1, COX-2) and of 5-LOX-mediated leukotriene B(4) (LTB(4)) formation as well as for DPPH-radical-scavenging capacity. While the water and methanol extracts were inactive in the COX-1, COX-2 and LTB(4) inhibition assays, the n-hexane and the dichloromethane extracts inhibited all three enzymes. In the active extracts, the triterpenoic acids ursolic acid, oleanolic acid and betulinic acid were identified, although only in minute amounts. Furthermore, oleic, linoleic and alpha-linolenic acid were identified apart from several saturated fatty acids. Even though unsaturated fatty acids are known to be good inhibitors of COX-1, COX-2 and LT formation, no clear correlation between their concentration in the extracts and their activity was found. We suggest that other, yet unidentified, lipophilic constituents might play a more important role for the observed in vitro inhibitory activity on arachidonic acid metabolism. Some of the extracts also showed considerable DPPH radical scavenging activity, the methanolic extracts being most potent. The radical scavenging activity of the extracts correlated very well with their total phenolic content, while ascorbic acid contributes only little to the radical-scavenging activity due to its low concentration present in the extracts. In summary, extracts derived from powdered rose hip without fruits were more effective in all assays carried out compared with extracts derived from powdered rose hip with fruits.
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100 |
2
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Zangger K, Oz G, Haslinger E, Kunert O, Armitage IM. Nitric oxide selectively releases metals from the amino-terminal domain of metallothioneins: potential role at inflammatory sites. FASEB J 2001; 15:1303-5. [PMID: 11344121 DOI: 10.1096/fj.00-0641fje] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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24 |
81 |
3
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Miksits M, Maier-Salamon A, Aust S, Thalhammer T, Reznicek G, Kunert O, Haslinger E, Szekeres T, Jaeger W. Sulfation of resveratrol in human liver: Evidence of a major role for the sulfotransferases SULT1A1 and SULT1E1. Xenobiotica 2008; 35:1101-19. [PMID: 16418064 DOI: 10.1080/00498250500354253] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Sulfation of resveratrol, a polyphenolic compound present in grapes and wine with anticancer and cardioprotective activities, was studied in human liver cytosol. In the presence of 3'-phosphoadenosine-5'-phosphosulfate, three metabolites (M1-3) whose structures were identified by mass spectrometry and NMR as trans-resveratrol-3-O-sulfate, trans-resveratrol-4'-O-sulfate, and trans-resveratrol-3-O-4'-O-disulfate, respectively. The kinetics of M1 formation in human liver cytosol exhibited an pattern of substrate inhibition with a K(i) of 21.3 +/- 8.73 microM and a V(max)/K(m) of 1.63 +/- 0.41 microLmin(-1)mg(-1) protein. Formation of M2 and M3 showed sigmoidal kinetics with about 56-fold higher V(max)/K(m) values for M3 than for M2 (2.23 +/- 0.14 and 0.04 +/- 0.01 microLmin(-1)mg(-1)). Incubation in the presence of human recombinant sulfotransferases (SULTs) demonstrated that M1 is almost exclusively catalysed by SULT1A1 and only to a minor extent by SULT 1A2, 1A3 and 1E1, whereas M2 is selectively formed by SULT1A2. M3 is mainly catalysed by SULT1A2 and 1A3. In conclusion, the results elucidate the enzymatic pathways of resveratrol in human liver, which must be considered in humans following oral uptake of dietary resveratrol.
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75 |
4
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Kretschmer N, Rinner B, Deutsch AA, Lohberger B, Knausz H, Kunert O, Blunder M, Boechzelt H, Schaider H, Bauer R. Naphthoquinones from Onosma paniculata induce cell-cycle arrest and apoptosis in melanoma Cells. JOURNAL OF NATURAL PRODUCTS 2012; 75:865-9. [PMID: 22530779 PMCID: PMC3361261 DOI: 10.1021/np2006499] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2011] [Indexed: 05/26/2023]
Abstract
Activity-guided fractionation of a petroleum ether-soluble extract of the roots of Onosma paniculata, which has been shown to affect the cell cycle and to induce apoptosis in melanoma cells, led to the isolation of several shikonin derivatives, namely, β-hydroxyisovalerylshikonin (1), acetylshikonin (2), dimethylacrylshikonin (3), and a mixture of α-methylbutyrylshikonin and isovalerylshikonin (4+5). All compounds exhibited strong cytotoxicity against eight cancer cell lines and MRC-5 lung fibroblasts, with 3 found to possess the most potent cytotoxicity toward four melanoma cell lines (SBcl2, WM35, WM9, and WM164). Furthermore, 3 and the mixture of 4+5 were found to interfere with cell-cycle progression in these cell lines and led to an increasing number of cells in the subG1 region as well as to caspase-3/7 activation, indicating apoptotic cell death.
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review-article |
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5
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Miksits M, Wlcek K, Svoboda M, Kunert O, Haslinger E, Thalhammer T, Szekeres T, Jäger W. Antitumor activity of resveratrol and its sulfated metabolites against human breast cancer cells. PLANTA MEDICA 2009; 75:1227-1230. [PMID: 19350482 DOI: 10.1055/s-0029-1185533] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Resveratrol (3,4',5-trihydroxy- trans-stilbene) is a naturally occurring polyphenolic compound found in grapes, wine and medicinal plants with a variety of biological and pharmacological activities including pronounced anticancer properties. These effects are observed despite its extremely low bioavailability and rapid clearance from the circulation due to extensive sulfation and glucuronidation in the intestine and liver. In order to determine whether its metabolites demonstrate any cytotoxic properties, three major human sulfated conjugates of resveratrol were synthesized and their anticancer activity evaluated against three breast cancer cell lines (two hormone-dependent: MCF-7 and ZR-75-1; one hormone-independent: MDA-MB-231) and one immortalized breast epithelial cell line (MCF-10A). We found that, in contrast to resveratrol, all three sulfated metabolites were less potent against MCF-7, MDA-MB-231 and ZR-75-1 cells ( trans-resveratrol 3- O-sulfate < trans-resveratrol 4'- O-sulfate < trans-resveratrol 3- O-4'- O-disulfate) indicating that any conjugation of the phenolic groups with sulfuric acid strongly affecting the cytotoxicity. Interestingly, all sulfated metabolites were reduced about 10-fold, but showed nearly equal cytotoxicity towards nonmalignant MCF-10A breast cells (IC (50 s): 202-228 microM). In summary, in contrast to resveratrol its sulfated metabolites showed poor cytotoxicity in human malignant and nonmalignant breast cancer cell lines. However, the in vitro activity of the metabolites may not necessarily reflect their in vivo function, given the fact that the ubiquitously existing human sulfatases could convert the metabolites back to resveratrol in humans.
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Wray V, Federau T, Henklein P, Klabunde S, Kunert O, Schomburg D, Schubert U. Solution structure of the hydrophilic region of HIV-1 encoded virus protein U (Vpu) by CD and 1H NMR spectroscopy. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1995; 45:35-43. [PMID: 7775007 DOI: 10.1111/j.1399-3011.1995.tb01565.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The HIV-1 specific Vpu is a class I oligomeric membrane phosphoprotein of unknown structure and mechanism. The first experimental evidence for the position of secondary structural elements present in the hydrophilic C-terminal region of Vpu under various solution regimes is reported. CD data for nine overlapping 15 amino-acid fragments and 3 longer fragments indicate the presence of only transitory amounts of stable structure in aqueous solution alone, while with increasing trifluoroethanol content limiting structures were found indicating two helical segments in the hydrophilic region of Vpu. These limiting structures were more precisely defined from a detailed study of Vpu41-58, Vpu52-74 and Vpu63-81, by a combination of 2D 1H NMR spectroscopy, distance geometry, and restrained molecular dynamics and energy minimization calculations. Sets of low-energy conformations compatible with the quantitative NOE data indicate that Vpu41-58 has an alpha-helix from residues 42 to 50 while a second helix is found for Vpu52-74 from residues 57 to 69. Vpu63-81 shows only the presence of a single reverse turn at residues 74 to 77, without any evidence of helix, under the same conditions. From CD measurements the first helix extends back to residue 30 and is connected to the N-terminal anchor of Vpu. Thus the hydrophilic region of Vpu consists of two alpha-helices joined by a flexible region of 6 or 7 residues, which contains the phosphoacceptor sites of Vpu at positions 52 and 56. The second helix is followed by a single reverse turn and a flexible C-terminus.
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Schultheiss J, Kunert O, Gase U, Scharf KD, Nover L, Rüterjans H. Solution structure of the DNA-binding domain of the tomato heat-stress transcription factor HSF24. EUROPEAN JOURNAL OF BIOCHEMISTRY 1996; 236:911-21. [PMID: 8665913 DOI: 10.1111/j.1432-1033.1996.00911.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Two-dimensional-NMR and three-dimensional-NMR experiments were performed to determine the solution structure of the DNA-binding domain of the tomato heat-stress transcription factor HSF24. Samples of uniformly 15N-labeled and 15N, 13C-labeled recombinant proteins were used in the investigation. A near-complete assignment of the backbone 1H, 15N, and 13C resonances was obtained by three-dimensional triple-resonance experiments, whereas three-dimensional 15N-TOCSY-heteronuclear-single-quantum-correlation-spectroscopy, HCCH-COSY and HCCH-TOCSY spectra were recorded for side-chain assignments, 885 non-redundant distance constraints from two-dimensional-homonuclear and three-dimensional-15N-edited and 13C-edited NOESY spectra and 40 hydrogen-bond constraints from exchange experiments were used for structure calculations. The resulting three-dimensional structure contains a three-helix bundle and a small four-stranded antiparallel beta-sheet that forms a hydrophobic core. The two C-terminal helices are parts of a highly conserved helix-turn-helix motif that is probably involved in DNA recognition and binding. In contrast to heat-stress factors from yeast and animals, the plant heat-stress factors lack a loop of 11 amino acid residues inserted between beta3 and beta4. This leads to a tight turn between these beta-strands.
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Comparative Study |
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Michail K, Matzi V, Maier A, Herwig R, Greilberger J, Juan H, Kunert O, Wintersteiger R. Hydroxymethylfurfural: an enemy or a friendly xenobiotic? A bioanalytical approach. Anal Bioanal Chem 2007; 387:2801-14. [PMID: 17377781 DOI: 10.1007/s00216-007-1121-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2006] [Revised: 12/12/2006] [Accepted: 01/08/2007] [Indexed: 10/23/2022]
Abstract
Hydroxymethylfurfural (HMF), a well-known heterocyclic Maillard reaction product, has often been studied for its potential toxic, mutagenic, and carcinogenic effects. Recent clinical studies, however, have strongly suggested that HMF might have exciting antitumor potential. We report on the development and validation of a bioanalytical assay for HMF that could be suitable as a basis for pharmacokinetic models in cancer patients. Two strategies were tested, i.e., direct and indirect methodologies. A direct isocratic LC determination at 283 nm was designed. Two indirect attempts involved derivatization coupled to HPLC-UV. It was possible to resolve the stereoisomers of the HMF derivative, and factors influencing their equilibrium ratio are discussed. HMF was extracted from the biomatrix by solid-phase extraction using different cartridges. A comparative study was made of the implemented methods as well as the extraction protocols. Both indirect assays proved to be more sensitive and were used to assess HMF quantitatively in human plasma. However, the newly introduced derivatization conditions led to the highest sensitivity with a LOD (S/N ratio = 3) of at least 2 pmol analyte on column. The assay selectivity was satisfactory in pre- and post-dose real samples. The mean recoveries of the assays were 79% and 89%, with acceptable accuracies and reproducibilities. Figure Schematic representation of hydroxymethylfurfural (HMF) in human plasma.
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Adams M, Kunert O, Haslinger E, Bauer R. Inhibition of leukotriene biosynthesis by quinolone alkaloids from the fruits of Evodia rutaecarpa. PLANTA MEDICA 2004; 70:904-908. [PMID: 15490316 DOI: 10.1055/s-2004-832614] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The n-hexane extract of the fruits of Evodia rutaecarpa showed a considerable inhibiting effect on leukotriene biosynthesis in human granulocytes. Bioassay-guided fractionation of the extract led to the isolation of the 5 quinolone alkaloids: 1-methyl-2-nonyl-4(1H)-quinolinone, 1-methyl-2-(6Z)-6-undecenyl-4(1H)-quinolinone, 1-methyl-2-(4Z,7Z)-4,7-tridecadienyl-4(1H)-quinolinone, evocarpine and 1-methyl-2-(6Z,9Z)-6,9-pentadecadienyl-4(1H)-quinolinone. The compounds exhibited inhibitory activity on leukotriene biosynthesis in a bioassay using human polymorphonuclear granulocytes, with IC50 values of 12.1, 10.0, 10.1, 14,6 and 12.3 microM, respectively. Structure elucidation of the compounds was achieved by 1D and 2D NMR experiments and comparison of spectral data with literature data.
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10
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Pferschy-Wenzig EM, Getzinger V, Kunert O, Woelkart K, Zahrl J, Bauer R. Determination of falcarinol in carrot (Daucus carota L.) genotypes using liquid chromatography/mass spectrometry. Food Chem 2009. [DOI: 10.1016/j.foodchem.2008.10.042] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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44 |
11
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Adams M, Mahringer A, Kunert O, Fricker G, Efferth T, Bauer R. Cytotoxicity and p-glycoprotein modulating effects of quinolones and indoloquinazolines from the Chinese herb Evodia rutaecarpa. PLANTA MEDICA 2007; 73:1554-1557. [PMID: 18058680 DOI: 10.1055/s-2007-993743] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The antimycobacterial quinolones 1-methyl-2-undecyl-4-quinolone, dihydroevocarpine and evocarpine as well as the indoloquinazoline alkaloids rutaecarpine and evodiamine - all from the Chinese medicinal herb Evodia rutaecarpa - were tested in two in vitro assays, for cytotoxicity and interaction with p-glycoprotein (p-gp). Cytotoxicity was measured in a cell proliferation assay against CCRF-CEM leukemia cells and their p-gp over-expressing subline CEM/ADR5000. An assay monitoring the p-gp-dependent accumulation of the dye calcein in porcine brain capillary endothelial cells (PBCECs) was used to study interactions of the test substances with this efflux pump. Rutaecarpine and evodiamine showed quite high toxicity with IC (50) values from 2.64 to 4.53 microM and were weak modulators of p-gp activity. The degrees of resistance in CEM/ADR5000 towards the saturated quinolones 1-methyl-2-undecyl-4-quinolone and dihydroevocarpine were between 3 and 4. In the calcein assay, these two quinolones were shown to be moderate modulators of p-gp activity. Evocarpine, on the other side, is not transported by p-gp, and showed only slight toxicity at the highest test concentration of 30 microM.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Animals
- Antineoplastic Agents, Phytogenic/administration & dosage
- Antineoplastic Agents, Phytogenic/pharmacology
- Antineoplastic Agents, Phytogenic/therapeutic use
- Blood-Brain Barrier/metabolism
- Cell Line, Tumor/drug effects
- Cell Line, Tumor/metabolism
- Cell Proliferation/drug effects
- Drug Resistance, Multiple
- Endothelium, Vascular/cytology
- Evodia
- Humans
- Indolequinones/administration & dosage
- Indolequinones/pharmacology
- Indolequinones/therapeutic use
- Medicine, Chinese Traditional
- Phytotherapy
- Plant Extracts/administration & dosage
- Plant Extracts/pharmacology
- Plant Extracts/therapeutic use
- Quinolones/administration & dosage
- Quinolones/pharmacology
- Quinolones/therapeutic use
- Swine
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Taschwer M, Weiß JA, Kunert O, Schmid MG. Analysis and characterization of the novel psychoactive drug 4-chloromethcathinone (clephedrone). Forensic Sci Int 2014; 244:e56-9. [PMID: 25280452 DOI: 10.1016/j.forsciint.2014.09.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/01/2014] [Accepted: 09/14/2014] [Indexed: 11/19/2022]
Abstract
Novel psychoactive drugs, such as amphetamine-, cathinone-, benzofury- and tryptamine derivatives, gained high popularity on the global drug market in the last years. These drugs are sold via the Internet as for example "research chemicals", "room odorizers" or "lawn fertilizers" by different online suppliers. They are also known as "Legal Highs", among them, cathinone derivatives play an important role. Well known substituted cathinone derivatives are mephedrone, brephedrone and flephedrone. Since a couple of weeks, a chlorine substituted methcathinone derivative, namely clephedrone (4-chloromethcathinone), is commercially available via the Internet from www.deboralabs.com. The goal of this study was to confirm identity of this substance, which was done successfully by GC-MS and NMR. Since all cathinone derivatives are chiral, it was found out, whether the purchased sample was present as a racemic mixture. For this purpose, methods for enantioseparation by GC and CE were developed and applied successfully. In case of CE a chiral selector was added, whereas chiral separation with GC-MS was done indirectly, after derivatization of clephedrone with trifluoroacetyl-l-prolyl chloride.
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Journal Article |
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Wenzig E, Kunert O, Ferreira D, Schmid M, Schühly W, Bauer R, Hiermann A. Flavonolignans from Avena sativa. JOURNAL OF NATURAL PRODUCTS 2005; 68:289-292. [PMID: 15730266 DOI: 10.1021/np049636k] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Three flavonolignans derived from the flavone tricin were isolated from Avena sativa herb. This is the first report of the presence of flavonolignans in A. sativa. In the known compounds 1a and 1b, a coniferyl alcohol moiety is linked to the flavone by an ether bond; in the new natural product 2, it is linked by C-C bonds. Structure elucidation of compound 2 was performed by 1D and 2D NMR experiments, and the absolute configuration was determined from circular dichroic data.
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Pferschy-Wenzig EM, Atanasov AG, Malainer C, Noha S, Kunert O, Schuster D, Heiss EH, Oberlies NH, Wagner H, Bauer R, Dirsch VM. Identification of isosilybin a from milk thistle seeds as an agonist of peroxisome proliferator-activated receptor gamma. JOURNAL OF NATURAL PRODUCTS 2014; 77:842-7. [PMID: 24597776 PMCID: PMC4003856 DOI: 10.1021/np400943b] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Indexed: 06/02/2023]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARγ) is a key regulator of glucose and lipid metabolism. Agonists of this nuclear receptor are used in the treatment of type 2 diabetes and are also studied as a potential treatment of other metabolic diseases, including nonalcoholic fatty liver disease. Silymarin, a concentrated phenolic mixture from milk thistle (Silybum marianum) seeds, is used widely as a supportive agent in the treatment of a variety of liver diseases. In this study, the PPARγ activation potential of silymarin and its main constituents was investigated. Isosilybin A (3) caused transactivation of a PPARγ-dependent luciferase reporter in a concentration-dependent manner. This effect could be reversed upon co-treatment with the PPARγ antagonist T0070907. In silico docking studies suggested a binding mode for 3 distinct from that of the inactive silymarin constituents, with one additional hydrogen bond to Ser342 in the entrance region of the ligand-binding domain of the receptor. Hence, isosilybin A (3) has been identified as the first flavonolignan PPARγ agonist, suggesting its further investigation as a modulator of this nuclear receptor.
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Research Support, N.I.H., Extramural |
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39 |
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Blunder M, Orthaber A, Bauer R, Bucar F, Kunert O. Efficient identification of flavones, flavanones and their glycosides in routine analysis via off-line combination of sensitive NMR and HPLC experiments. Food Chem 2017; 218:600-609. [DOI: 10.1016/j.foodchem.2016.09.077] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 09/11/2016] [Accepted: 09/12/2016] [Indexed: 12/21/2022]
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Krasteva I, Bratkov V, Bucar F, Kunert O, Kollroser M, Kondeva-Burdina M, Ionkova I. Flavoalkaloids and Flavonoids from Astragalus monspessulanus. JOURNAL OF NATURAL PRODUCTS 2015; 78:2565-2571. [PMID: 26558405 DOI: 10.1021/acs.jnatprod.5b00502] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A new flavonol tetraglycoside, quercetin-3-O-[α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranosyl]-7-O-β-D-glucopyranoside (1), and two new flavonol alkaloids, N-(8-methylquercetin-3-O-[α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranosyl])-3-hydroxypiperidin-2-one (2) and N-(8-methylkaempferol-3-O-[α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranosyl])-3-hydroxypiperidin-2-one (3), were isolated from the aerial parts of Astragalus monspessulanus ssp. monspessulanus. Two rare flavonoids with an unusual 3-hydroxy-3-methylglutaric acid moiety, quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-[6-O-(3-hydroxy-3-methylglutaryl)-β-D-galactopyranoside (4) and kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-[6-O-(3-hydroxy-3-methylglutaryl)-β-D-galactopyranoside (5), were isolated from the aerial parts of A. monspessulanus ssp. illyricus. In addition, the eight known flavonoids alangiflavoside (6), alcesefoliside (7), mauritianin (8), quercetin-3-β-robinobioside (9), cosmosine (10), apigenin-4'-O-glucoside (11), trifolin (12), and rutin (13) were isolated from aerial parts of A. monspessulanus ssp. monspessulanus. Their structures were elucidated via NMR and HRESIMS data. In a model that tested t-BuOOH-induced oxidative stress on isolated rat hepatocytes, flavonoids 1-13 had statistically significant cytoprotective activity similar to that of silymarin, tested at 60 μg/mL. The most prominent effects were observed for flavonoids 1, 4, 7, and 12.
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Adams M, Wube AA, Bucar F, Bauer R, Kunert O, Haslinger E. Quinolone alkaloids from : a potent new group of antimycobacterial compounds. Int J Antimicrob Agents 2005; 26:262-4. [PMID: 16051468 DOI: 10.1016/j.ijantimicag.2005.06.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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35 |
18
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Schühly W, Hüfner A, Pferschy-Wenzig EM, Prettner E, Adams M, Bodensieck A, Kunert O, Oluwemimo A, Haslinger E, Bauer R. Design and synthesis of ten biphenyl-neolignan derivatives and their in vitro inhibitory potency against cyclooxygenase-1/2 activity and 5-lipoxygenase-mediated LTB4-formation. Bioorg Med Chem 2009; 17:4459-65. [PMID: 19481465 DOI: 10.1016/j.bmc.2009.05.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2008] [Revised: 05/03/2009] [Accepted: 05/07/2009] [Indexed: 11/25/2022]
Abstract
A set of ten derivatives of methylhonokiol, an anti-inflammatory active biphenyl-type neolignan from Magnolia grandiflora, has been evaluated for their in vitro cyclooxygenase-1/2 (COX-1/2) inhibitory activity using assays with purified prostaglandin H synthase (PGHS)-1 and PGHS-2 enzymes as well as for their 5-lipoxygenase (5-LOX) mediated LTB(4) formation inhibitory activity using an assay with activated human polymorphonuclear leukocytes. The derivatization reactions included methylation, acetylation, hydrogenation, epoxydation and isomerization. Five of the derivatives are new to science. The most active compound against COX-1 and COX-2 was methylhonokiol with IC(50) values of 0.1 microM, whereas the most active compound against LTB(4) formation was (E)-3'-propenyl-5-(2-propenyl)-biphenyl-2,4'-diol with an IC(50) value of 1.0 microM. Structure-activity relationship studies showed that the polarity of the derivatives plays a crucial role in their activity towards COX-1/2 enzyme and 5-LOX mediated LTB(4) formation.
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Journal Article |
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Gröblacher B, Maier V, Kunert O, Bucar F. Putative mycobacterial efflux inhibitors from the seeds of Aframomum melegueta. JOURNAL OF NATURAL PRODUCTS 2012; 75:1393-1399. [PMID: 22789014 DOI: 10.1021/np300375t] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
In order to identify new putative efflux pump inhibitors that represent an appropriate target in antimycobacterial chemotherapy, nine paradol- and gingerol-related compounds (1-9) isolated from the seeds of Aframomum melegueta were assessed for their potential to inhibit ethidium bromide (EtBr) efflux in a Mycobacterium smegmatis model. Five of the compounds from A. melegueta and NMR spectroscopic data of the diketone 6-gingerdione (2) and its enolic tautomers, methyl-6-gingerol (5) and rac-6-dihydroparadol (7), are presented herein for the first time. After determination of their antimycobacterial activities and modulatory effects on the MIC of antibiotics as well as their synergistic effects in combination with antibiotics against M. smegmatis mc(2) 155, their impact on EtBr accumulation and efflux was evaluated using a microtiter plate-based fluorometric assay. The compounds exhibited moderate to weak antimycobacterial activities, and the best modulators induced a 4- to 16-fold decrease of the MICs of EtBr and rifampicin as well as a reduction of the MIC of isoniazid with fractional inhibitory concentration index values indicating synergistic activities in some cases. 6-Paradol (3), 8-gingerol (6), and rac-6-dihydroparadol (7) were the most potent EtBr efflux inhibitors in M. smegmatis mc(2) 155, displaying EtBr efflux inhibiting activities comparable to reference inhibitors.
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Swamy RC, Kunert O, Schühly W, Bucar F, Ferreira D, Rani VS, Kumar BR, Appa Rao AVN. Structurally unique biflavonoids from Selaginella chrysocaulos and Selaginella bryopteris. Chem Biodivers 2007; 3:405-13. [PMID: 17193277 DOI: 10.1002/cbdv.200690044] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Chemical investigation of Selaginella chrysocaulos from Northeast India yielded three new (i.e., 1-3) and two known biflavonoids. From Selaginella bryopteris, collected in the southern part of India, one new (11) and eleven known biflavonoids of the amentoflavone- and hinokiflavone-type were isolated and identified. The structures of the compounds were elucidated by 1D- and 2D-NMR spectroscopy, and by mass spectrometry. The absolute configurations of chiral biflavonoids with flavanone subunits (from S. bryopteris) were determined with the aid of circular-dichroism (CD) spectroscopy. Several very rare or even unprecedented substructures in biflavonoids were found.
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Research Support, Non-U.S. Gov't |
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Kunert O, Stingl H, Rosian E, Krssák M, Bernroider E, Seebacher W, Zangger K, Staehr P, Chandramouli V, Landau BR, Nowotny P, Waldhäusl W, Haslinger E, Roden M. Measurement of fractional whole-body gluconeogenesis in humans from blood samples using 2H nuclear magnetic resonance spectroscopy. Diabetes 2003; 52:2475-82. [PMID: 14514629 DOI: 10.2337/diabetes.52.10.2475] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Several problems limit quantification of gluconeogenesis. We applied in vitro 2H-nuclear magnetic resonance (NMR) spectroscopy to simultaneously measure 2H in all glucose carbons for direct assessment of gluconeogenesis. This method was compared with 2H measurement in carbons 5 and 2 using gas chromatography-mass spectrometry (hexamethylenetetramine [HMT]) and with in vivo 13C magnetic resonance spectroscopy (MRS). After 14 h of fasting, and following 2H2O ingestion, blood was obtained from nine healthy and seven type 2 diabetic subjects. Glucose was purified, acetylated, and analyzed for 2H in carbons 1-6 with 2H-NMR. Using 5:2 ratios, gluconeogenesis increased (P < 0.05) over time and mean gluconeogenesis was lower in control subjects than in type 2 diabetic patients (63 +/- 3 vs. 75 +/- 2%, P < 0.01). 13C-MRS revealed higher hepatic glycogenolysis in control subjects (3.9 +/- 0.4 vs. 2.3 +/- 0.2 micromol.kg(-1).min(-1)) yielding mean contribution of gluconeogenesis of 65 +/- 3 and 77 +/- 2% (P < 0.005). Measurement of gluconeogenesis by 2H-NMR correlated linearly with 13C-MRS (r = 0.758, P = 0.0007) and HMT (r = 0.759, P = 0.0007). In an additional protocol, 2H enrichments demonstrated a fast decline of gluconeogenesis from approximately 100 to approximately 68% (P < 0.02) within 4 h of galactose infusion after 40-44 h of fasting. Thus, in vitro 2H-NMR offers an alternative approach to determine fractional gluconeogenesis in good agreement with standard methods and allows monitoring of rapid metabolic alterations.
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Evaluation Study |
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Kretschmer N, Rinner B, Stuendl N, Kaltenegger H, Wolf E, Kunert O, Boechzelt H, Leithner A, Bauer R, Lohberger B. Effect of costunolide and dehydrocostus lactone on cell cycle, apoptosis, and ABC transporter expression in human soft tissue sarcoma cells. PLANTA MEDICA 2012; 78:1749-1756. [PMID: 23047249 DOI: 10.1055/s-0032-1315385] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Human soft tissue sarcomas represent a rare group of malignant tumours that frequently exhibit chemotherapeutic resistance and increased metastatic potential following unsuccessful treatment. In this study, we investigated the effects of costunolide and dehydrocostus lactone, which have been isolated from Saussurea lappa using activity-guided isolation, on three soft tissue sarcoma cell lines of various origins. The effects on cell proliferation, cell cycle distribution, apoptosis induction, and ABC transporter expression were analysed. Both compounds inhibited cell viability dose- and time-dependently. IC50 values ranged from 6.2 µg/mL to 9.8 µg/mL. Cells treated with costunolide showed no changes in cell cycle, little in caspase 3/7 activity, and low levels of cleaved caspase-3 after 24 and 48 h. Dehydrocostus lactone caused a significant reduction of cells in the G1 phase and an increase of cells in the S and G2/M phase. Moreover, it led to enhanced caspase 3/7 activity, cleaved caspase-3, and cleaved PARP indicating apoptosis induction. In addition, the influence of costunolide and dehydrocostus lactone on the expression of ATP binding cassette transporters related to multidrug resistance (ABCB1/MDR1, ABCC1/MRP1, and ABCG2/BCRP1) was examined using real-time RT-PCR. The expressions of ABCB1/MDR1 and ABCG2/BCRP1 in liposarcoma and synovial sarcoma cells were significantly downregulated by dehydrocostus lactone. Our data demonstrate for the first time that dehydrocostus lactone affects cell viability, cell cycle distribution and ABC transporter expression in soft tissue sarcoma cell lines. Furthermore, it led to caspase 3/7 activity as well as caspase-3 and PARP cleavage, which are indicators of apoptosis. Therefore, this compound may be a promising lead candidate for the development of therapeutic agents against drug-resistant tumours.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 2
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Antineoplastic Agents, Phytogenic/chemistry
- Antineoplastic Agents, Phytogenic/isolation & purification
- Antineoplastic Agents, Phytogenic/pharmacology
- Apoptosis/drug effects
- Blotting, Western
- Caspase 3/metabolism
- Caspase 7/metabolism
- Cell Cycle/drug effects
- Cell Proliferation/drug effects
- Cell Survival
- Dose-Response Relationship, Drug
- Drug Screening Assays, Antitumor
- Enzyme Activation/drug effects
- Gene Expression Regulation, Neoplastic
- Humans
- Inhibitory Concentration 50
- Lactones/chemistry
- Lactones/isolation & purification
- Lactones/pharmacology
- Multidrug Resistance-Associated Proteins/genetics
- Multidrug Resistance-Associated Proteins/metabolism
- Neoplasm Proteins/genetics
- Neoplasm Proteins/metabolism
- Proteolysis
- Real-Time Polymerase Chain Reaction
- Sarcoma/genetics
- Sarcoma/pathology
- Saussurea/chemistry
- Sesquiterpenes/chemistry
- Sesquiterpenes/isolation & purification
- Sesquiterpenes/pharmacology
- Time Factors
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Gachet MS, Kunert O, Kaiser M, Brun R, Zehl M, Keller W, Muñoz RA, Bauer R, Schuehly W. Antiparasitic compounds from Cupania cinerea with activities against Plasmodium falciparum and Trypanosoma brucei rhodesiense. JOURNAL OF NATURAL PRODUCTS 2011; 74:559-66. [PMID: 21438586 DOI: 10.1021/np100415m] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In a survey of plants from Ecuador with antiprotozoal activity, Cupania cinerea was found to show significant in vitro activity against the Plasmodium falciparum K1 strain and Trypanosoma brucei rhodesiense. Subsequently, activity-guided isolation of the n-hexane and dichloromethane extracts from the bark of C. cinerea afforded two diterpene glycosides (1 and 2), named cupacinoside and 6'-de-O-acetylcupacinoside, and a lactonized triterpene bearing an oxepin moiety named cupacinoxepin (3), together with the known compounds scopoletin (4), caryophyllene oxide (5), two bisabolane sesquiterpenes (6 and 7), lichexanthone (8), gustastatin (9), lupenone (10), betulone (11), 17β,21β-epoxyhopan-3-one (12), taraxerol (13), and taraxerone (14). For compound 3, X-ray crystallography was employed to elucidate the relative configuration. For cupacinosides (1) and (2) and cupacinoxepin (3), in vitro activities against the P. falciparum K1 strain (IC(50)1, 1.3; 2, 1.8; and 3, 8.7 μM) and T. b. rhodesiense (IC(50)1, 4.5; 2, 15.8; and 3, 71.6 μM) were found. Cytotoxicity toward L-6 cells is discussed for all the compounds isolated.
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Liu X, Kunert O, Blunder M, Fakhrudin N, Noha SM, Malainer C, Schinkovitz A, Heiss EH, Atanasov AG, Kollroser M, Schuster D, Dirsch VM, Bauer R. Polyyne hybrid compounds from Notopterygium incisum with peroxisome proliferator-activated receptor gamma agonistic effects. JOURNAL OF NATURAL PRODUCTS 2014; 77:2513-21. [PMID: 25333853 PMCID: PMC4251066 DOI: 10.1021/np500605v] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Indexed: 06/04/2023]
Abstract
In the search for peroxisome proliferator-activated receptor gamma (PPARγ) active constituents from the roots and rhizomes of Notopterygium incisum, 11 new polyacetylene derivatives (1-11) were isolated. Their structures were elucidated by NMR and HRESIMS as new polyyne hybrid molecules of falcarindiol with sesquiterpenoid or phenylpropanoid moieties, named notoethers A-H (1-8) and notoincisols A-C (9-11), respectively. Notoincisol B (10) and notoincisol C (11) represent two new carbon skeletons. When tested for PPARγ activation in a luciferase reporter assay with HEK-293 cells, notoethers A-C (1-3), notoincisol A (9), and notoincisol B (10) showed promising agonistic activity (EC50 values of 1.7 to 2.3 μM). In addition, notoincisol A (9) exhibited inhibitory activity on NO production of stimulated RAW 264.7 macrophages.
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review-article |
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