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Venianakis T, Primikyri A, Opatz T, Petry S, Papamokos G, Gerothanassis IP. NMR and Docking Calculations Reveal Novel Atomistic Selectivity of a Synthetic High-Affinity Free Fatty Acid vs. Free Fatty Acids in Sudlow's Drug Binding Sites in Human Serum Albumin. Molecules 2023; 28:7991. [PMID: 38138481 PMCID: PMC10745614 DOI: 10.3390/molecules28247991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Saturation transfer difference (STD), inter-ligand NOEs (INPHARMA NMR), and docking calculations are reported for investigating specific binding sites of the high-affinity synthetic 7-nitrobenz-2-oxa-1,3-diazoyl-4-C12 fatty acid (NBD-C12 FA) with non-labeled human serum albumin (HSA) and in competition with the drugs warfarin and ibuprofen. A limited number of negative interligand NOEs between NBD-C12 FA and warfarin were interpreted in terms of a short-range allosteric competitive binding in the wide Sudlow's binding site II (FA7) of NBD-C12 FA with Ser-202, Lys-199, and Trp-214 and warfarin with Arg-218 and Arg-222. In contrast, the significant number of interligand NOEs between NBD-C12 FA and ibuprofen were interpreted in terms of a competitive binding mode in Sudlow's binding site I (FA3 and FA4) with Ser-342, Arg-348, Arg-485, Arg-410, and Tyr-411. NBD-C12 FA has the unique structural properties, compared to short-, medium-, and long-chain saturated and unsaturated natural free fatty acids, of interacting with well-defined structures with amino acids of both the internal and external polar anchor sites in Sudlow's binding site I and with amino acids in both FA3 and FA4 in Sudlow's binding site II. The NBD-C12 FA, therefore, interacts with novel structural characteristics in the drug binding sites I and II and can be regarded as a prototype molecule for drug development.
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Affiliation(s)
- Themistoklis Venianakis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (T.V.); (A.P.)
| | - Alexandra Primikyri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (T.V.); (A.P.)
| | - Till Opatz
- Department of Chemistry, Johannes Gutenberg-University, Duesbergweg, 10–14, 55128 Mainz, Germany;
| | - Stefan Petry
- Sanofi-Aventis Deutschland GmbH, Integrated Drug Discovery, Industriepark Höchst, 65926 Frankfurt am Main, Germany;
| | - Georgios Papamokos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (T.V.); (A.P.)
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138, USA
| | - Ioannis P. Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (T.V.); (A.P.)
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Christou A, Parisis NA, Venianakis T, Barbouti A, Tzakos AG, Gerothanassis IP, Goulas V. Ultrasound-Assisted Extraction of Taro Leaf Antioxidants Using Natural Deep Eutectic Solvents: An Eco-Friendly Strategy for the Valorization of Crop Residues. Antioxidants (Basel) 2023; 12:1801. [PMID: 37891880 PMCID: PMC10604219 DOI: 10.3390/antiox12101801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/13/2023] [Accepted: 09/22/2023] [Indexed: 10/29/2023] Open
Abstract
Colocasia esculenta L. leaves are considered a by-product of taro cultivation and are discarded as environmental waste, despite their valuable phenolic composition. Their valorization to obtain value-added substances for medicinal, food, and cosmetic applications is the aim of the current work. An ultrasound-assisted extraction was developed for the environmentally friendly and sustainable isolation of taro leaf antioxidants using natural deep eutectic solvents (NaDESs). Among the utilized solvents, the NaDES based on betaine and ethylene glycol provided the best extraction efficiencies in terms of polyphenolic content and antioxidant activity. Multi-response optimization suggested a solvent-to-solid ratio of 10 mL g-1, a processing time of 60 min, an extraction temperature of 60 °C, and a water content of 33.8% (w/w) as optimal extraction parameters. Leaf extract obtained under these optimum operational parameters demonstrated a strong radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (65.80 ± 0.87%), a high ferric reducing antioxidant power (126.62 ± 1.92 μmol TE g-1 sample), and significant protection against oxidative stress-induced DNA damage. The chromatographic characterization of the optimum extract revealed its richness in flavonoids (flavones and flavonols). The outcomes of the present study suggest that the proposed method could serve as a highly efficient and green alternative for the recovery of polyphenols from agricultural wastes.
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Affiliation(s)
- Atalanti Christou
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Lemesos 3603, Cyprus
| | - Nikolaos A. Parisis
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece; (N.A.P.); (T.V.); (A.G.T.); (I.P.G.)
| | - Themistoklis Venianakis
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece; (N.A.P.); (T.V.); (A.G.T.); (I.P.G.)
| | - Alexandra Barbouti
- Department of Anatomy-Histology-Embryology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece;
| | - Andreas G. Tzakos
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece; (N.A.P.); (T.V.); (A.G.T.); (I.P.G.)
| | - Ioannis P. Gerothanassis
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece; (N.A.P.); (T.V.); (A.G.T.); (I.P.G.)
| | - Vlasios Goulas
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Lemesos 3603, Cyprus
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Venianakis T, Siskos MG, Papamokos G, Gerothanassis IP. Structural Studies of Monounsaturated and ω-3 Polyunsaturated Free Fatty Acids in Solution with the Combined Use οf NMR and DFT Calculations-Comparison with the Liquid State. Molecules 2023; 28:6144. [PMID: 37630396 PMCID: PMC10459368 DOI: 10.3390/molecules28166144] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Molecular structures, in chloroform and DMSO solution, of the free fatty acids (FFAs) caproleic acid, oleic acid, α-linolenic acid, eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA) are reported with the combined use of NMR and DFT calculations. Variable temperature and concentration chemical shifts of the COOH protons, transient 1D NOE experiments and DFT calculations demonstrate the major contribution of low molecular weight aggregates of dimerized fatty acids through intermolecular hydrogen bond interactions of the carboxylic groups, with parallel and antiparallel interdigitated structures even at the low concentration of 20 mM in CDCl3. For the dimeric DHA, a structural model of an intermolecular hydrogen bond through carboxylic groups and an intermolecular hydrogen bond between the carboxylic group of one molecule and the ω-3 double bond of a second molecule is shown to play a role. In DMSO-d6 solution, NMR and DFT studies show that the carboxylic groups form strong intermolecular hydrogen bond interactions with a single discrete solvation molecule of DMSO. These solvation species form parallel and antiparallel interdigitated structures of low molecular weight, as in chloroform solution. This structural motif, therefore, is an intrinsic property of the FFAs, which is not strongly affected by the length and degree of unsaturation of the chain and the hydrogen bond ability of the solvent.
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Affiliation(s)
| | | | - George Papamokos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (T.V.); (M.G.S.)
| | - Ioannis P. Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (T.V.); (M.G.S.)
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Hussain H, Siddiqui H, Gerothanassis IP. Editorial: Re-emergence of natural products for drug discovery in honor of Prof. Dr. M. Iqbal Choudhary. Front Pharmacol 2023; 14:1227732. [PMID: 37475715 PMCID: PMC10354788 DOI: 10.3389/fphar.2023.1227732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 06/23/2023] [Indexed: 07/22/2023] Open
Affiliation(s)
- Hidayat Hussain
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle, Germany
| | - Hina Siddiqui
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Ioannis P. Gerothanassis
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, Ioannina, Greece
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Alexandri E, Venianakis T, Primikyri A, Papamokos G, Gerothanassis IP. Molecular Basis for the Selectivity of DHA and EPA in Sudlow's Drug Binding Sites in Human Serum Albumin with the Combined Use of NMR and Docking Calculations. Molecules 2023; 28:molecules28093724. [PMID: 37175134 PMCID: PMC10180286 DOI: 10.3390/molecules28093724] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/15/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
Medium- and long-chain saturated and unsaturated free fatty acids (FFAs) are known to bind to human serum albumin (HSA), the main plasma carrier protein. Atomic-level structural data regarding the binding mode in Sudlow's sites I (FA7) and II (FA4, FA3) of the polyunsaturated ω-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), however, are largely unknown. Herein, we report the combined use of saturation transfer difference (STD) and Interligand NOEs for Pharmacophore Mapping (INPHARMA) NMR techniques and molecular docking calculations to investigate the binding mode of DHA and EPA in Sudlow's sites Ι and ΙΙ of HSA. The docking calculations and the significant number of interligand NOEs between DHA and EPA and the drugs warfarin and ibuprofen, which are stereotypical ligands for Sudlow's sites I and II, respectively, were interpreted in terms of competitive binding modes and the presence of two orientations of DHA and EPA at the binding sites FA7 and FA4. The exceptional flexibility of the long-chain DHA and EPA and the formation of strongly folded structural motives are the key properties of HSA-PUFA complexes.
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Affiliation(s)
- Eleni Alexandri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
| | - Themistoklis Venianakis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
| | - Alexandra Primikyri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
| | - Georgios Papamokos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
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Venianakis T, Siskos M, Papamokos G, Gerothanassis IP. NMR and DFT studies of monounsaturated and ω-3 polyunsaturated free fatty acids in the liquid state reveal a novel atomistic structural model of DHA. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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Hussain H, Siddiqui H, Gerothanassis IP. Prof. Dr. M. Iqbal Choudhary-A lifetime career dedicated to remarkable services in "natural products sciences". Front Pharmacol 2023; 14:1119419. [PMID: 36778013 PMCID: PMC9912981 DOI: 10.3389/fphar.2023.1119419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 01/12/2023] [Indexed: 01/27/2023] Open
Affiliation(s)
- Hidayat Hussain
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany,*Correspondence: Hidayat Hussain, , ; Hina Siddiqui, ; Ioannis P. Gerothanassis,
| | - Hina Siddiqui
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan,*Correspondence: Hidayat Hussain, , ; Hina Siddiqui, ; Ioannis P. Gerothanassis,
| | - Ioannis P. Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR, Greece,*Correspondence: Hidayat Hussain, , ; Hina Siddiqui, ; Ioannis P. Gerothanassis,
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Gerothanassis IP. Ligand-observed in-tube NMR in natural products research: A review on enzymatic biotransformations, protein-ligand interactions, and in-cell NMR spectroscopy. ARAB J CHEM 2023. [DOI: 10.1016/j.arabjc.2022.104536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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9
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Papaemmanouil CD, Peña-García J, Banegas-Luna AJ, Kostagianni AD, Gerothanassis IP, Pérez-Sánchez H, Tzakos AG. ANTIAGE-DB: A Database and Server for the Prediction of Anti-Aging Compounds Targeting Elastase, Hyaluronidase, and Tyrosinase. Antioxidants (Basel) 2022; 11:antiox11112268. [PMID: 36421454 PMCID: PMC9686885 DOI: 10.3390/antiox11112268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/03/2022] [Accepted: 11/09/2022] [Indexed: 11/18/2022] Open
Abstract
Natural products bear a multivariate biochemical profile with antioxidant, anti-inflammatory, antibacterial, and antitumoral properties. Along with their natural sources, they have been widely used both as anti-aging and anti-melanogenic agents due to their effective contribution in the elimination of reactive oxygen species (ROS) caused by oxidative stress. Their anti-aging activity is mainly related to their capacity of inhibiting enzymes like Human Neutrophil Elastase (HNE), Hyaluronidase (Hyal) and Tyrosinase (Tyr). Herein, we accumulated literature information (covering the period 1965–2020) on the inhibitory activity of natural products and their natural sources towards these enzymes. To navigate this information, we developed a database and server termed ANTIAGE-DB that allows the prediction of the anti-aging potential of target compounds. The server operates in two axes. First a comparison of compounds by shape similarity can be performed against our curated database of natural products whose inhibitory potential has been established in the literature. In addition, inverse virtual screening can be performed for a chosen molecule against the three targeted enzymes. The server is open access, and a detailed report with the prediction results is emailed to the user. ANTIAGE-DB could enable researchers to explore the chemical space of natural based products, but is not limited to, as anti-aging compounds and can predict their anti-aging potential. ANTIAGE-DB is accessed online.
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Affiliation(s)
- Christina D. Papaemmanouil
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece
| | - Jorge Peña-García
- Structural Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department, Universidad Católica de Murcia (UCAM), 30107 Guadalupe, Spain
| | - Antonio Jesús Banegas-Luna
- Structural Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department, Universidad Católica de Murcia (UCAM), 30107 Guadalupe, Spain
| | - Androniki D. Kostagianni
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece
| | - Ioannis P. Gerothanassis
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece
| | - Horacio Pérez-Sánchez
- Structural Bioinformatics and High Performance Computing Research Group (BIO-HPC), Computer Engineering Department, Universidad Católica de Murcia (UCAM), 30107 Guadalupe, Spain
- Correspondence: (H.P.-S.); (A.G.T.)
| | - Andreas G. Tzakos
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece
- Institute of Materials Science and Computing, University Research Center of Ioannina (URCI), 45110 Ioannina, Greece
- Correspondence: (H.P.-S.); (A.G.T.)
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Raza M, Siddiqui H, Khan M, Ullah S, Rizvi F, Ahmad R, Gerothanassis IP, Wahab AT, Choudhary MI. Ultrasonic-assisted synthesis of amantadine derivatives-in vitro urease and α-glucosidase inhibitory activities, mechanistic, and computational studies. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ahmed R, Siskos MG, Siddiqui H, Gerothanassis IP. Density functional theory calculations of δ( 13 C) and δ( 1 H) chemical shifts and 3 J( 13 COO 1 H) coupling constants as structural and analytical tools in hydroperoxides: Prospects and limitations of 1 H 13 C heteronuclear multiple bond correlation experiments. Magn Reson Chem 2022; 60:970-984. [PMID: 35830967 DOI: 10.1002/mrc.5298] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/18/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
Density functional theory (DFT) calculations of δ(13 C) and δ(1 H) chemical shifts and 3 J(13 COO1 H) coupling constants of three model hydroperoxides of the naturally occurring cis-11-OOH and trans-9-OOH isomers of oleate and 9-cis, 11-trans-16-OOH endo hydroperoxide of methyl linolenate are reported. The computational δ(OOH) for various functionals and basis sets were found to be nearly identical for the cis/trans geometric isomers. The chemical shifts of the methine CHOOH protons and carbons, on the contrary, are highly diagnostic for the identification of cis/trans geometric isomerism. The chemical shifts of the olefinic protons and carbons strongly depend on the orientation of the hydroperoxide unit relative to the double bond and, thus, of importance in conformational analysis. The results are in very good agreement with the available experimental data. For the various diastereomeric pairs of the model endo-hydroperoxide, the strongly deshielded OOH resonances, due to the presence of an intramolecular hydrogen bond between the hydroperoxide proton and an oxygen of the endo-peroxide ring, along with the δ(CHOOH), are highly diagnostic for identification and structure elucidation of complex erythro- and threo- diastereomeric pairs of endo-hydroperoxides; the computational results are in very good agreement with the available experimental data. The 3 J(13 COO1 H) coupling constants were found to be < 2 Hz for the cis-trans geometric models and < 0.5 Hz for the endo-hydroperoxide and, thus, unimportant in stereochemical analysis. Sharp resonances of the hydroperoxide protons, with Δν1/2 < 3 Hz, are required for the successful implementation of the 1 H13 C heteronuclear multiple bond correlation (HMBC) technique.
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Affiliation(s)
- Raheel Ahmed
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Michael G Siskos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Hina Siddiqui
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Ioannis P Gerothanassis
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
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Primikyri A, Papamokos G, Venianakis T, Sakka M, Kontogianni VG, Gerothanassis IP. Structural Basis of Artemisinin Binding Sites in Serum Albumin with the Combined Use of NMR and Docking Calculations. Molecules 2022; 27:molecules27185912. [PMID: 36144648 PMCID: PMC9506303 DOI: 10.3390/molecules27185912] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/04/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
Artemisinin is known to bind to the main plasma protein carrier serum albumin (SA); however, there are no atomic level structural data regarding its binding mode with serum albumin. Herein, we employed a combined strategy of saturation transfer difference (STD), transfer nuclear Overhauser effect spectroscopy (TR-NOESY), STD–total correlation spectroscopy (STD-TOCSY), and Interligand Noes for PHArmacophore Mapping (INPHARMA) NMR methods and molecular docking calculations to investigate the structural basis of the interaction of artemisinin with human and bovine serum albumin (HSA/BSA). A significant number of inter-ligand NOEs between artemisinin and the drugs warfarin and ibuprofen as well as docking calculations were interpreted in terms of competitive binding modes of artemisinin in the warfarin (FA7) and ibuprofen (FA4) binding sites. STD NMR experiments demonstrate that artemisinin is the main analyte for the interaction of the A. annua extract with BSA. The combined strategy of NMR and docking calculations of the present work could be of general interest in the identification of the molecular basis of the interactions of natural products with their receptors even within a complex crude extract.
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Alexandri E, Primikyri A, Papamokos G, Venianakis T, Gkalpinos VK, Tzakos AG, Karydis-Messinis A, Moschovas D, Avgeropoulos A, Gerothanassis IP. NMR and computational studies reveal novel aspects in molecular recognition of unsaturated fatty acids with non-labelled serum albumin. FEBS J 2022; 289:5617-5636. [PMID: 35380736 DOI: 10.1111/febs.16453] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 03/12/2022] [Accepted: 04/03/2022] [Indexed: 12/19/2022]
Abstract
An approach based on the combined use of saturation transfer difference (STD), Tr-NOESY and Inter-ligand NOEs for PHArmacophore Mapping (INPHARMA) NMR techniques and docking calculations is reported, for the first time, for mapping interactions and specific binding sites of caproleic acid (10 : 1 cis-9), oleic acid (18 : 1 cis-9), linoleic acid (18 : 2 cis-9,12) and linolenic (18 : 3, cis-9,12,15) free fatty acids (FFAs) with non-labelled serum albumin (BSA/HSA). Significant negative inter-ligand NOEs between the FFAs and the drugs ibuprofen and warfarin, through competition experiments, were observed. The inter-ligand NOEs and docking calculations were interpreted in terms of competitive binding mode, the significant folding of the bis allylic region and the presence of two orientations of the FFAs in the warfarin binding site (FA7), due to two potential distinctive anchoring polar groups of amino acids. This conformational flexibility is the reason that, the location and conformational states of the FFAs in the binding site of warfarin could not be determined accurately, despite numerous available X-ray structural studies. α-Linolenic acid competes favourably with warfarin at the binding site FA7. Isothermal titration calorimetry experiments of the preformed HSA/α-linolenic acid complex upon titration with warfarin show a significant reduction in the binding constant of warfarin, in very good agreement with NMR and computational data. The combined use, therefore, of STD, Tr-NOESY and INPHARMA NMR, ITC and docking calculations may find promising applications in the field of protein-lipid recognition research.
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Affiliation(s)
- Eleni Alexandri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Alexandra Primikyri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Georgios Papamokos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Themistoklis Venianakis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Vasileios K Gkalpinos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Andreas G Tzakos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | | | - Dimitrios Moschovas
- Department of Materials Science & Engineering, University of Ioannina, Greece
| | | | - Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
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Hernychova L, Alexandri E, Tzakos AG, Zatloukalová M, Primikyri A, Gerothanassis IP, Uhrik L, Šebela M, Kopečný D, Jedinák L, Vacek J. Serum albumin as a primary non-covalent binding protein for nitro-oleic acid. Int J Biol Macromol 2022; 203:116-129. [PMID: 35063491 DOI: 10.1016/j.ijbiomac.2022.01.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 12/25/2021] [Accepted: 01/08/2022] [Indexed: 12/19/2022]
Abstract
This work explores the interaction of 9/10-nitro-oleic acid (NO2-OA) with human serum albumin (HSA). The molecular mechanism of the biological action of NO2-OA is to our knowledge based on a reversible covalent reaction-Michael addition of nucleophilic amino acid residues of proteins. Since HSA is an important fatty acid transporter, a key question is whether NO2-OA can bind covalently or non-covalently to HSA, similarly to oleic acid (OA), which can interact with the FA1-FA7 binding sites of the HSA molecule. 1H NMR studies and competition analysis with OA and the drugs ibuprofen and warfarin were used to investigate a potential non-covalent binding mode. NO2-OA/HSA binding was confirmed to compete with warfarin for FA-7 with significantly higher affinity. NO2-OA competes with ibuprofen for FA-3 and FA-6, however, in contrast to the situation with warfarin, the binding affinities are not significantly different. The described interactions are based exclusively on non-covalent binding. No covalent binding of NO2-OA to HSA was detected by MS/MS. More detailed studies based on MALDI-TOF-MS and Ellman's assay indicated that HSA can be covalently modified in the presence of NO2-OA to a very limited extent. It was also shown that NO2-OA has a higher affinity to HSA than that of OA.
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Affiliation(s)
- Lenka Hernychova
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Žlutý kopec 7, Brno 656 53, Czech Republic
| | - Eleni Alexandri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina 451 10, Greece
| | - Andreas G Tzakos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina 451 10, Greece; Institute of Materials Science and Computing, University Research Center of Ioannina (URCI), 451 10 Ioannina, Greece
| | - Martina Zatloukalová
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 775 15, Czech Republic
| | - Alexandra Primikyri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina 451 10, Greece
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina 451 10, Greece
| | - Lukas Uhrik
- Research Centre for Applied Molecular Oncology, Masaryk Memorial Cancer Institute, Žlutý kopec 7, Brno 656 53, Czech Republic
| | - Marek Šebela
- Department of Biochemistry, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc 783 71, Czech Republic
| | - David Kopečný
- Department of Experimental Biology, Faculty of Science, Palacký University, Šlechtitelů 27, Olomouc 783 71, Czech Republic
| | - Lukáš Jedinák
- Department of Organic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, Olomouc 771 46, Czech Republic
| | - Jan Vacek
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 775 15, Czech Republic; The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, Brno 612 65, Czech Republic.
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Kontogianni VG, Gerothanassis IP. Analytical and Structural Tools of Lipid Hydroperoxides: Present State and Future Perspectives. Molecules 2022; 27:2139. [PMID: 35408537 PMCID: PMC9000705 DOI: 10.3390/molecules27072139] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/20/2022] [Accepted: 03/22/2022] [Indexed: 11/17/2022] Open
Abstract
Mono- and polyunsaturated lipids are particularly susceptible to peroxidation, which results in the formation of lipid hydroperoxides (LOOHs) as primary nonradical-reaction products. LOOHs may undergo degradation to various products that have been implicated in vital biological reactions, and thus in the pathogenesis of various diseases. The structure elucidation and qualitative and quantitative analysis of lipid hydroperoxides are therefore of great importance. The objectives of the present review are to provide a critical analysis of various methods that have been widely applied, and more specifically on volumetric methods, applications of UV-visible, infrared, Raman/surface-enhanced Raman, fluorescence and chemiluminescence spectroscopies, chromatographic methods, hyphenated MS techniques, NMR and chromatographic methods, NMR spectroscopy in mixture analysis, structural investigations based on quantum chemical calculations of NMR parameters, applications in living cells, and metabolomics. Emphasis will be given to analytical and structural methods that can contribute significantly to the molecular basis of the chemical process involved in the formation of lipid hydroperoxides without the need for the isolation of the individual components. Furthermore, future developments in the field will be discussed.
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Affiliation(s)
- Vassiliki G. Kontogianni
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
| | - Ioannis P. Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece
- International Center for Chemical and Biological Sciences, H.E.J. Research Institute of Chemistry, University of Karachi, Karachi 75270, Pakistan
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Tsagogiannis E, Vandera E, Primikyri A, Asimakoula S, Tzakos AG, Gerothanassis IP, Koukkou AI. Characterization of Protocatechuate 4,5-Dioxygenase from Pseudarthrobacter phenanthrenivorans Sphe3 and In Situ Reaction Monitoring in the NMR Tube. Int J Mol Sci 2021; 22:9647. [PMID: 34502555 PMCID: PMC8431788 DOI: 10.3390/ijms22179647] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 11/16/2022] Open
Abstract
The current study aims at the functional and kinetic characterization of protocatechuate (PCA) 4,5-dioxygenase (PcaA) from Pseudarthrobacter phenanthrenivorans Sphe3. This is the first single subunit Type II dioxygenase characterized in Actinobacteria. RT-PCR analysis demonstrated that pcaA and the adjacent putative genes implicated in the PCA meta-cleavage pathway comprise a single transcriptional unit. The recombinant PcaA is highly specific for PCA and exhibits Michaelis-Menten kinetics with Km and Vmax values of 21 ± 1.6 μM and 44.8 ± 4.0 U × mg-1, respectively, in pH 9.5 and at 20 °C. PcaA also converted gallate from a broad range of substrates tested. The enzymatic reaction products were identified and characterized, for the first time, through in situ biotransformation monitoring inside an NMR tube. The PCA reaction product demonstrated a keto-enol tautomerization, whereas the gallate reaction product was present only in the keto form. Moreover, the transcriptional levels of pcaA and pcaR (gene encoding a LysR-type regulator of the pathway) were also determined, showing an induction when cells were grown on PCA and phenanthrene. Studying key enzymes in biodegradation pathways is significant for bioremediation and for efficient biocatalysts development.
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Affiliation(s)
- Epameinondas Tsagogiannis
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (E.V.); (S.A.)
| | - Elpiniki Vandera
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (E.V.); (S.A.)
| | - Alexandra Primikyri
- Laboratory of Organic Chemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (A.P.); (A.G.T.); (I.P.G.)
| | - Stamatia Asimakoula
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (E.V.); (S.A.)
| | - Andreas G. Tzakos
- Laboratory of Organic Chemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (A.P.); (A.G.T.); (I.P.G.)
| | - Ioannis P. Gerothanassis
- Laboratory of Organic Chemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (A.P.); (A.G.T.); (I.P.G.)
| | - Anna-Irini Koukkou
- Laboratory of Biochemistry, Sector of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (E.T.); (E.V.); (S.A.)
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17
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Fatima S, Varras PC, Atia-Tul-Wahab, Choudhary MI, Siskos MG, Gerothanassis IP. On the molecular basis of H 2O/DMSO eutectic mixtures by using phenol compounds as molecular sensors: a combined NMR and DFT study. Phys Chem Chem Phys 2021; 23:15645-15658. [PMID: 34268541 DOI: 10.1039/d0cp05861k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
NMR and DFT studies of phenol compounds as molecular sensors were carried out to investigate H2O/DMSO eutectic mixtures at a molecular level. The experimental 1H NMR chemical shifts of the OH groups, δexp(OH), of phenol, paracoumaric acid, and vanillic acid show maximum deshielding and, thus, hydrogen bond interactions in the range of mole fractions 0.20 < χ(DMSO) < 0.33. In the mole fractions χ(DMSO) < 0.2, a progressive decrease in δexp(OH) was observed which demonstrates a decrease in hydrogen bond interactions at infinite dilution in H2O, despite the increase in the number of available hydrogen bond acceptor and donor sites. DFT calculated δcalc(OH) of minimum energy solvation clusters were shown to be in reasonable agreement with the pattern in experimental δexp(OH) data. The chemical shift deshielding and, thus, increased hydrogen bond interactions in the natural product + DMSO + nH2O (n = 2, 3) solvation clusters, relative to complexes in DMSO or H2O solutions, cannot be attributed to a single structural parameter of the cooperative interactions between H2O and DMSO molecules with the phenol OH groups of the natural products. The minimum energy conformers of phenol compounds + 2H2O + DMSO complexes are in excellent agreement with a recent low temperature neutron diffraction experiment of 3D2O + DMSO and demonstrate a general structural motif of solvation complexes. The combined use of 1H NMR and DFT studies with emphasis on δ(OH) of phenol compounds, as molecular sensors, can provide an effective method for the study of solute-solvent interactions at the atomic level.
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Affiliation(s)
- Sana Fatima
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 7527, Pakistan
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18
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Ahmed R, Varras PC, Siskos MG, Siddiqui H, Choudhary MI, Gerothanassis IP. NMR and Computational Studies as Analytical and High-Resolution Structural Tool for Complex Hydroperoxides and Diastereomeric Endo-Hydroperoxides of Fatty Acids in Solution-Exemplified by Methyl Linolenate. Molecules 2020; 25:E4902. [PMID: 33113947 PMCID: PMC7660186 DOI: 10.3390/molecules25214902] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/17/2020] [Accepted: 10/21/2020] [Indexed: 12/28/2022] Open
Abstract
A combination of selective 1D Total Correlation Spectroscopy (TOCSY) and 1H-13C Heteronuclear Multiple Bond Correlation (HMBC) NMR techniques has been employed for the identification of methyl linolenate primary oxidation products without the need for laborious isolation of the individual compounds. Complex hydroperoxides and diastereomeric endo-hydroperoxides were identified and quantified. Strongly deshielded C-O-O-H 1H-NMR resonances of diastereomeric endo-hydroperoxides in the region of 8.8 to 9.6 ppm were shown to be due to intramolecular hydrogen bonding interactions of the hydroperoxide proton with an oxygen atom of the five-member endo-peroxide ring. These strongly deshielded resonances were utilized as a new method to derive, for the first time, three-dimensional structures with an assignment of pairs of diastereomers in solution with the combined use of 1H-NMR chemical shifts, Density Functional Theory (DFT), and Our N-layered Integrated molecular Orbital and molecular Mechanics (ONIOM) calculations.
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Affiliation(s)
- Raheel Ahmed
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; (R.A.); (M.I.C.)
| | - Panayiotis C. Varras
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (P.C.V.); (M.G.S.)
| | - Michael G. Siskos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (P.C.V.); (M.G.S.)
| | - Hina Siddiqui
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; (R.A.); (M.I.C.)
| | - M. Iqbal Choudhary
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; (R.A.); (M.I.C.)
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 214412, Saudi Arabia
| | - Ioannis P. Gerothanassis
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; (R.A.); (M.I.C.)
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (P.C.V.); (M.G.S.)
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19
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Varras PC, Siskos MG, Gritzapis PS, Gerothanassis IP. The fleeting existence of the classical vinyl cation structure. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1752402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Panayiotis C. Varras
- Department of Chemistry, Section of Organic Chemistry & Biochemistry, University of Ioannina, Ioannina, Greece
| | - Michael G. Siskos
- Department of Chemistry, Section of Organic Chemistry & Biochemistry, University of Ioannina, Ioannina, Greece
| | | | - Ioannis P. Gerothanassis
- Department of Chemistry, Section of Organic Chemistry & Biochemistry, University of Ioannina, Ioannina, Greece
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20
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Kontogianni VG, Primikyri A, Sakka M, Gerothanassis IP. Erratum to Simultaneous determination of artemisinin and its analogues and flavonoids in Artemisia annua crude extracts with the use of NMR spectroscopy. Magn Reson Chem 2020; 58:685. [PMID: 32495516 DOI: 10.1002/mrc.5010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 02/07/2020] [Indexed: 06/11/2023]
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21
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Kontogianni VG, Primikyri A, Sakka M, Gerothanassis IP. Simultaneous determination of artemisinin and its analogs and flavonoids in Artemisia annua crude extracts with the use of NMR spectroscopy. Magn Reson Chem 2020; 58:232-244. [PMID: 31733071 DOI: 10.1002/mrc.4971] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/04/2019] [Accepted: 11/08/2019] [Indexed: 06/10/2023]
Abstract
Artemisia annua is a promising and potent antimalarial herbal drug. This activity has been ascribed to its component artemisinin, a sesquiterpene lactone. The ability to determine artemisinin and its known analogs in plant extracts is an especially difficult task because the compounds are present in low concentrations, are thermolabile, and lack ultraviolet or fluorescent chromophores. We report herein a facile and rapid 1-D 1 H, 1-D total correlation spectroscopy, 2-D 1 H-13 C heteronuclear single quantum coherence, and 1 H-13 C heteronuclear multiple bond correlation nuclear magnetic resonance techniques for the simultaneous identification and quantification of artemisinin and five of its analogs along with five flavonoids, an aromatic ketone, and camphor (in total, 13 compounds) in crude diethyl ether A. annua extract without the need of laborious isolation of the individual analytes. The above method was validated in terms of precision, linearity, and limit of detection. The analytical results were found to be in excellent agreement with those obtained with the use of the time consuming high-performance liquid chromatography with diode-array detection and liquid chromatography with tandem mass spectrometry for the compounds that standards were available.
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Affiliation(s)
- Vassiliki G Kontogianni
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Alexandra Primikyri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Marianna Sakka
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
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22
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Siskos MG, Varras PC, Gerothanassis IP. DFT calculations of O–H⋯O 1H NMR chemical shifts in investigating enol-enol tautomeric equilibria: Probing the impacts of intramolecular hydrogen bonding vs stereoelectronic interactions. Tetrahedron 2020. [DOI: 10.1016/j.tet.2020.130979] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Goulas V, Hadjivasileiou L, Primikyri A, Michael C, Botsaris G, Tzakos AG, Gerothanassis IP. Valorization of Carob Fruit Residues for the Preparation of Novel Bi-Functional Polyphenolic Coating for Food Packaging Applications. Molecules 2019; 24:molecules24173162. [PMID: 31480264 PMCID: PMC6749202 DOI: 10.3390/molecules24173162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/21/2019] [Accepted: 08/29/2019] [Indexed: 12/20/2022] Open
Abstract
The food industry has become interested in the development of innovative biomaterials with antioxidant and antimicrobial properties. Although several biopolymers have been evaluated for food packaging, the use of polyphenolic coatings has been unexplored. The purpose of this work was to develop an antioxidant and antimicrobial coating for food packaging through the polymerization of carob phenolics. At first, the polyphenolic coatings were deposited in glass surfaces polymerizing different concentrations of carob extracts (2 and 4 mg mL−1) at three pH values (7, 8 and 9). Results demonstrated that the coating produced at pH 8 and at a concentration of 4 mg mL−1 had the most potent antioxidant and antimicrobial potential. Then, the coating was applied directly on the salmon fillet (coating) and on the plastic container (active packaging). Peroxide and thiobarbituric acid-reactive substances (TBARS) methods were used to measure the potency to inhibit lipid oxidation in salmon fillets. Furthermore, the anti-Listeria activity of coatings was also assessed. Results showed a significant decrease of lipid oxidation during cold storage of salmon fillets for both treatments; the superiority of applied coating directly on the salmon fillets was also highlighted. Regarding the antimicrobial potency, the polyphenolic coating depleted the growth of Listeria monocytogenes after 10 days storage; while the active packaging had no effect on Listeria monocytogenes. Overall, we describe the use of low-cost carob polyphenols as precursors for the formation of bifunctional coatings with promising applications in food packaging.
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Affiliation(s)
- Vlasios Goulas
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3603, Cyprus.
| | - Loukas Hadjivasileiou
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3603, Cyprus
| | | | - Christodoulos Michael
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3603, Cyprus
| | - George Botsaris
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of Technology, Limassol 3603, Cyprus
| | - Andreas G Tzakos
- Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece
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Symeou S, Tsiafoulis CG, Gerothanassis IP, Miltiadou D, Tzamaloukas O. Nuclear magnetic resonance screening of changes in fatty acid and cholesterol content of ovine milk induced by ensiled olive cake inclusion in Chios sheep diets. Small Rumin Res 2019. [DOI: 10.1016/j.smallrumres.2019.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Hadjimbei E, Botsaris G, Goulas V, Alexandri E, Gekas V, Gerothanassis IP. Functional stability of goats' milk yoghurt supplemented with
Pistacia atlantica
resin extracts and
Saccharomyces boulardii. INT J DAIRY TECHNOL 2019. [DOI: 10.1111/1471-0307.12629] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Elena Hadjimbei
- Department of Agricultural Sciences, Biotechnology and Food Science Cyprus University of Technology P.O. Box 50329Lemesos Cyprus
| | - George Botsaris
- Department of Agricultural Sciences, Biotechnology and Food Science Cyprus University of Technology P.O. Box 50329Lemesos Cyprus
| | - Vlasios Goulas
- Department of Agricultural Sciences, Biotechnology and Food Science Cyprus University of Technology P.O. Box 50329Lemesos Cyprus
| | - Eleni Alexandri
- Nuclear Magnetic Resonance Center, Department of Chemistry, Section of Organic Chemistry and Biochemistry University of Ioannina Ioannina Greece
| | - Vassilis Gekas
- Department of Agricultural Sciences, Biotechnology and Food Science Cyprus University of Technology P.O. Box 50329Lemesos Cyprus
| | - Ioannis P Gerothanassis
- Nuclear Magnetic Resonance Center, Department of Chemistry, Section of Organic Chemistry and Biochemistry University of Ioannina Ioannina Greece
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Mari SH, Varras PC, Atia-tul-Wahab, Choudhary IM, Siskos MG, Gerothanassis IP. Solvent-Dependent Structures of Natural Products Based on the Combined Use of DFT Calculations and 1H-NMR Chemical Shifts. Molecules 2019; 24:E2290. [PMID: 31226776 PMCID: PMC6631582 DOI: 10.3390/molecules24122290] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/13/2019] [Accepted: 06/18/2019] [Indexed: 01/09/2023] Open
Abstract
Detailed solvent and temperature effects on the experimental 1H-NMR chemical shifts of the natural products chrysophanol (1), emodin (2), and physcion (3) are reported for the investigation of hydrogen bonding, solvation and conformation effects in solution. Very small chemical shift of │Δδ│ < 0.3 ppm and temperature coefficients │Δδ/ΔΤ│ ≤ 2.1 ppb/K were observed in DMSO-d6, acetone-d6 and CDCl3 for the C(1)-OH and C(8)-OH groups which demonstrate that they are involved in a strong intramolecular hydrogen bond. On the contrary, large chemical shift differences of 5.23 ppm at 298 K and Δδ/ΔΤ values in the range of -5.3 to -19.1 ppb/K between DMSO-d6 and CDCl3 were observed for the C(3)-OH group which demonstrate that the solvation state of the hydroxyl proton is a key factor in determining the value of the chemical shift. DFT calculated 1H-NMR chemical shifts, using various functionals and basis sets, the conductor-like polarizable continuum model, and discrete solute-solvent hydrogen bond interactions, were found to be in very good agreement with the experimental 1H-NMR chemical shifts even with computationally less demanding level of theory. The 1H-NMR chemical shifts of the OH groups which participate in intramolecular hydrogen bond are dependent on the conformational state of substituents and, thus, can be used as molecular sensors in conformational analysis. When the X-ray structures of chrysophanol (1), emodin (2), and physcion (3) were used as input geometries, the DFT-calculated 1H-NMR chemical shifts were shown to strongly deviate from the experimental chemical shifts and no functional dependence could be obtained. Comparison of the most important intramolecular data of the DFT calculated and the X-ray structures demonstrate significant differences for distances involving hydrogen atoms, most notably the intramolecular hydrogen bond O-H and C-H bond lengths which deviate by 0.152 tο 0.132 Å and 0.133 to 0.100 Å, respectively, in the two structural methods. Further differences were observed in the conformation of -OH, -CH3, and -OCH3 substituents.
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Affiliation(s)
- Saima H. Mari
- H.E.J. Research Institute of chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 7527, Pakistan; Saimahassanmari123@gmail (S.H.M.); (I.M.C.)
| | - Panayiotis C. Varras
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (P.C.V.); (M.G.S.)
| | - Atia-tul-Wahab
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 7527, Pakistan
| | - Iqbal M. Choudhary
- H.E.J. Research Institute of chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 7527, Pakistan; Saimahassanmari123@gmail (S.H.M.); (I.M.C.)
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 7527, Pakistan
| | - Michael G. Siskos
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (P.C.V.); (M.G.S.)
| | - Ioannis P. Gerothanassis
- H.E.J. Research Institute of chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 7527, Pakistan; Saimahassanmari123@gmail (S.H.M.); (I.M.C.)
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece; (P.C.V.); (M.G.S.)
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 7527, Pakistan
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Ahmed R, Siddiqui H, Choudhary MI, Gerothanassis IP. 1 H- 13 C HMBC NMR experiments as a structural and analytical tool for the characterization of elusive trans/cis hydroperoxide isomers from oxidized unsaturated fatty acids in solution. Magn Reson Chem 2019; 57:S69-S74. [PMID: 30702165 DOI: 10.1002/mrc.4844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
The radical-dependent oxidation of unsaturated fatty acids is a fundamental reaction in lipid chemistry, biochemistry, and technology. We report herein the first successful application of 1 H-13 C HMBC NMR experiment for the identification and quantification of complex and minor (3.9% to 0.85%) components of cis and trans primary hydroperoxide isomers of oxidized oleate and linoleate methyl esters in solution, without the need of laborious isolation of the individual components.
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Affiliation(s)
- Raheel Ahmed
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Hina Siddiqui
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Muhammad Iqbal Choudhary
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
- Department of Biochemistry, Faculty of Science, King Abdul-Aziz University, Jeddah, Saudi Arabia
| | - Ioannis P Gerothanassis
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
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Primikyri A, Sayyad N, Quilici G, Vrettos EI, Lim K, Chi SW, Musco G, Gerothanassis IP, Tzakos AG. Probing the interaction of a quercetin bioconjugate with Bcl-2 in living human cancer cells with in-cell NMR spectroscopy. FEBS Lett 2018; 592:3367-3379. [PMID: 30207377 DOI: 10.1002/1873-3468.13250] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 01/11/2023]
Abstract
In-cell NMR spectroscopy has emerged as a powerful technique for monitoring biomolecular interactions at an atomic level inside intact cells. However, current methodologies are inadequate at charting intracellular interactions of nonlabeled proteins and require their prior isotopic labeling. Herein, we describe for the first time the monitoring of the quercetin-alanine bioconjugate interaction with the nonlabeled antiapoptotic protein Bcl-2 inside living human cancer cells. STD and Tr-NOESY in-cell NMR methodologies were successfully applied in the investigation of the binding, which was further validated in vitro. In-cell NMR proved a very promising strategy for the real-time probing of the interaction profile of potential drugs with their therapeutic targets in native cellular environments and could, thus, open a new avenue in drug discovery.
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Affiliation(s)
- Alexandra Primikyri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Nisar Sayyad
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece.,Department of Pharmaceutical Chemistry, College of Health Sciences, University of KwaZulu-Natal (Westville Campus), Durban, South Africa
| | - Giacomo Quilici
- Biomolecular NMR Laboratory Genetics and Cell Biology, S. Raffaele Scientific Institute, Milan, Italy
| | - Eirinaios I Vrettos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Kyungeun Lim
- Disease Target Structure Research Center, KRIBB, Daejeon, Korea
| | - Seung-Wook Chi
- Disease Target Structure Research Center, KRIBB, Daejeon, Korea
| | - Giovanna Musco
- Biomolecular NMR Laboratory Genetics and Cell Biology, S. Raffaele Scientific Institute, Milan, Italy
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
| | - Andreas G Tzakos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Greece
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Diamantis DA, Ramesova S, Chatzigiannis CM, Degano I, Gerogianni PS, Karadima KE, Perikleous S, Rekkas D, Gerothanassis IP, Galaris D, Mavromoustakos T, Valsami G, Sokolova R, Tzakos AG. Exploring the oxidation and iron binding profile of a cyclodextrin encapsulated quercetin complex unveiled a controlled complex dissociation through a chemical stimulus. Biochim Biophys Acta Gen Subj 2018; 1862:1913-1924. [DOI: 10.1016/j.bbagen.2018.06.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 06/04/2018] [Accepted: 06/06/2018] [Indexed: 01/20/2023]
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Siskos MG, Choudhary MI, Gerothanassis IP. Refinement of labile hydrogen positions based on DFT calculations of 1H NMR chemical shifts: comparison with X-ray and neutron diffraction methods. Org Biomol Chem 2018; 15:4655-4666. [PMID: 28513720 DOI: 10.1039/c7ob01019b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Numerous gas phase electron diffraction, ultra-fast electron diffraction, X-ray and neutron diffraction experiments on β-dicarbonyl compounds exhibiting enol-enol tautomeric equilibrium, with emphasis on acetylacetone and dibenzoylmethane, have so far been reported with conflicting results on the structural details of the O-HO intramolecular hydrogen bond and resulted in alternative hypotheses on the intramolecular hydrogen bond potential function either a double minimum potential corresponding to two tautomeric forms in equilibrium or a single symmetrical one. We demonstrate herein, firstly, that the DFT calculated OH 1H NMR chemical shifts of acetylacetone and dibenzoylmethane exhibit a strong linear dependence on the computed OO hydrogen bond length of ∼-50 ppm Å-1 and as a function of the O-HO bond angle of ∼1 ppm per degree, upon the transfer of the hydrogen atom from the ground state toward the transition state. Secondly, the refinement of labile hydrogen atomic positions in intramolecular hydrogen bonds based on the root-mean-square deviation between experimentally determined and DFT calculated 1H NMR chemical shifts in solution can provide high resolution structures of O-H and O(H)O bond lengths and O-HO bond angles with an accuracy of ∼10-2 Å and ∼0.5°, respectively. Thirdly, the calculated 1H NMR chemical shifts in solution of the two ground state tautomers in equilibrium of acetylacetone and dibenzoylmethane are in excellent agreement with the experimental value, even for moderate basis sets for energy minimization. In contrast, the single symmetrical structure in a strongly delocalized system is a transition state with calculated 1H NMR chemical shifts which strongly deviate from the experimental value. Fourth, the DFT calculated ground state O-H bond lengths of acetylacetone and dibenzoylmethane are in quantitative agreement with the literature data which take into account the effect of quantum nuclear motion. The DFT structural results are critically discussed with respect to the state-of-the-art variable temperature X-ray and neutron diffraction methods.
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Affiliation(s)
- Michael G Siskos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR 45110, Greece.
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Alexandri E, Ahmed R, Siddiqui H, Choudhary MI, Tsiafoulis CG, Gerothanassis IP. High Resolution NMR Spectroscopy as a Structural and Analytical Tool for Unsaturated Lipids in Solution. Molecules 2017; 22:E1663. [PMID: 28981459 PMCID: PMC6151582 DOI: 10.3390/molecules22101663] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 09/28/2017] [Accepted: 10/01/2017] [Indexed: 12/13/2022] Open
Abstract
Mono- and polyunsaturated lipids are widely distributed in Nature, and are structurally and functionally a diverse class of molecules with a variety of physicochemical, biological, medicinal and nutritional properties. High resolution NMR spectroscopic techniques including 1H-, 13C- and 31P-NMR have been successfully employed as a structural and analytical tool for unsaturated lipids. The objective of this review article is to provide: (i) an overview of the critical 1H-, 13C- and 31P-NMR parameters for structural and analytical investigations; (ii) an overview of various 1D and 2D NMR techniques that have been used for resonance assignments; (iii) selected analytical and structural studies with emphasis in the identification of major and minor unsaturated fatty acids in complex lipid extracts without the need for the isolation of the individual components; (iv) selected investigations of oxidation products of lipids; (v) applications in the emerging field of lipidomics; (vi) studies of protein-lipid interactions at a molecular level; (vii) practical considerations and (viii) an overview of future developments in the field.
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Affiliation(s)
- Eleni Alexandri
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece.
| | - Raheel Ahmed
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
| | - Hina Siddiqui
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
| | - Muhammad I Choudhary
- Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 214412, Saudi Arabia.
| | | | - Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, GR-45110 Ioannina, Greece.
- H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
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Chatzikonstantinou AV, Chatziathanasiadou MV, Ravera E, Fragai M, Parigi G, Gerothanassis IP, Luchinat C, Stamatis H, Tzakos AG. Enriching the biological space of natural products and charting drug metabolites, through real time biotransformation monitoring: The NMR tube bioreactor. Biochim Biophys Acta Gen Subj 2017; 1862:1-8. [PMID: 28974426 DOI: 10.1016/j.bbagen.2017.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/26/2017] [Accepted: 09/29/2017] [Indexed: 12/28/2022]
Abstract
BACKGROUND Natural products offer a wide range of biological activities, but they are not easily integrated in the drug discovery pipeline, because of their inherent scaffold intricacy and the associated complexity in their synthetic chemistry. Enzymes may be used to perform regioselective and stereoselective incorporation of functional groups in the natural product core, avoiding harsh reaction conditions, several protection/deprotection and purification steps. METHODS Herein, we developed a three step protocol carried out inside an NMR-tube. 1st-step: STD-NMR was used to predict the: i) capacity of natural products as enzyme substrates and ii) possible regioselectivity of the biotransformations. 2nd-step: The real-time formation of multiple-biotransformation products in the NMR-tube bioreactor was monitored in-situ. 3rd-step: STD-NMR was applied in the mixture of the biotransformed products to screen ligands for protein targets. RESULTS Herein, we developed a simple and time-effective process, the "NMR-tube bioreactor", that is able to: (i) predict which component of a mixture of natural products can be enzymatically transformed, (ii) monitor in situ the transformation efficacy and regioselectivity in crude extracts and multiple substrate biotransformations without fractionation and (iii) simultaneously screen for interactions of the biotransformation products with pharmaceutical protein targets. CONCLUSIONS We have developed a green, time-, and cost-effective process that provide a simple route from natural products to lead compounds for drug discovery. GENERAL SIGNIFICANSE This process can speed up the most crucial steps in the early drug discovery process, and reduce the chemical manipulations usually involved in the pipeline, improving the environmental compatibility.
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Affiliation(s)
- Alexandra V Chatzikonstantinou
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece; Department of Biological Applications and Technologies, University of Ioannina, 45110 Ioannina, Greece
| | - Maria V Chatziathanasiadou
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece
| | - Enrico Ravera
- Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance in MetalloProteins (CIRMMP), 50019 Sesto Fiorentino, Italy; Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy
| | - Marco Fragai
- Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance in MetalloProteins (CIRMMP), 50019 Sesto Fiorentino, Italy; Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy
| | - Giacomo Parigi
- Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance in MetalloProteins (CIRMMP), 50019 Sesto Fiorentino, Italy; Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy
| | - Ioannis P Gerothanassis
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece
| | - Claudio Luchinat
- Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance in MetalloProteins (CIRMMP), 50019 Sesto Fiorentino, Italy; Department of Chemistry "Ugo Schiff", University of Florence, 50019 Sesto Fiorentino, Italy
| | - Haralambos Stamatis
- Department of Biological Applications and Technologies, University of Ioannina, 45110 Ioannina, Greece
| | - Andreas G Tzakos
- Department of Chemistry, Section of Organic Chemistry and Biochemistry, University of Ioannina, 45110 Ioannina, Greece.
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Charisiadis P, Kontogianni VG, Tsiafoulis CG, Tzakos AG, Gerothanassis IP. Determination of Polyphenolic Phytochemicals using Highly Deshielded -OH 1 H-NMR Signals. Phytochem Anal 2017; 28:159-170. [PMID: 27981663 DOI: 10.1002/pca.2656] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 09/22/2016] [Accepted: 09/26/2016] [Indexed: 06/06/2023]
Affiliation(s)
- Pantelis Charisiadis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR, -45110, Greece
| | - Vassiliki G Kontogianni
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR, -45110, Greece
| | | | - Andreas G Tzakos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR, -45110, Greece
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR, -45110, Greece
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Siskos MG, Choudhary MI, Gerothanassis IP. Hydrogen Atomic Positions of O-H···O Hydrogen Bonds in Solution and in the Solid State: The Synergy of Quantum Chemical Calculations with ¹H-NMR Chemical Shifts and X-ray Diffraction Methods. Molecules 2017; 22:E415. [PMID: 28272366 PMCID: PMC6155303 DOI: 10.3390/molecules22030415] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 02/27/2017] [Accepted: 03/03/2017] [Indexed: 12/21/2022] Open
Abstract
The exact knowledge of hydrogen atomic positions of O-H···O hydrogen bonds in solution and in the solid state has been a major challenge in structural and physical organic chemistry. The objective of this review article is to summarize recent developments in the refinement of labile hydrogen positions with the use of: (i) density functional theory (DFT) calculations after a structure has been determined by X-ray from single crystals or from powders; (ii) ¹H-NMR chemical shifts as constraints in DFT calculations, and (iii) use of root-mean-square deviation between experimentally determined and DFT calculated ¹H-NMR chemical shifts considering the great sensitivity of ¹H-NMR shielding to hydrogen bonding properties.
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Affiliation(s)
- Michael G Siskos
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - M Iqbal Choudhary
- H.E.J. Research Institute of Chemistry, International Center for Biological and Chemical Sciences, University of Karachi, Karachi 75270, Pakistan.
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
- H.E.J. Research Institute of Chemistry, International Center for Biological and Chemical Sciences, University of Karachi, Karachi 75270, Pakistan.
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35
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Siskos MG, Choudhary MI, Tzakos AG, Gerothanassis IP. 1H ΝΜR chemical shift assignment, structure and conformational elucidation of hypericin with the use of DFT calculations – The challenge of accurate positions of labile hydrogens. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.10.072] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Kontogianni VG, Tsoumani ME, Kellici TF, Mavromoustakos T, Gerothanassis IP, Tselepis AD, Tzakos AG. Deconvoluting the Dual Antiplatelet Activity of a Plant Extract. J Agric Food Chem 2016; 64:4511-4521. [PMID: 27161160 DOI: 10.1021/acs.jafc.6b00544] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A thorough evaluation of the antiplatelet activity profile of hexane olive leaf extract in human platelets indicated a potent activity accomplished through a two axis inhibition of platelet activation triggered both by ADP and thrombin. To delineate the extract components responsible for this dual activity, an NMR based method was established to determine and quantify the triterpenoid content leading to the characterization of uvaol, erythrodiol, and oleanolic acid. The antiplatelet profile of the total extract and of the 3 determined triterpenoids was evaluated against in vitro platelet aggregation induced by several platelet agonists as also on PAC-1 binding and P-selectin membrane expression both in healthy volunteers and in platelets from patients with an acute coronary syndrome receiving dual antiplatelet therapy with aspirin and ticagrelor. The extract was identified to inhibit ADP-induced platelet activation due to its erythrodiol content and TRAP-induced platelet activation due to the activity of uvaol and oleanolic acid.
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Affiliation(s)
- Vassiliki G Kontogianni
- Laboratory of Organic Chemistry, Department of Chemistry, University of Ioannina , 45110 Ioannina, Greece
| | - Maria E Tsoumani
- Atherothrombosis Research Centre/Laboratory of Biochemistry, Department of Chemistry, University of Ioannina , 45110 Ioannina, Greece
| | - Tahsin F Kellici
- Laboratory of Organic Chemistry, Department of Chemistry, University of Ioannina , 45110 Ioannina, Greece
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens , Athens, Greece
| | - Thomas Mavromoustakos
- Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens , Athens, Greece
| | - Ioannis P Gerothanassis
- Laboratory of Organic Chemistry, Department of Chemistry, University of Ioannina , 45110 Ioannina, Greece
| | - Alexandros D Tselepis
- Atherothrombosis Research Centre/Laboratory of Biochemistry, Department of Chemistry, University of Ioannina , 45110 Ioannina, Greece
| | - Andreas G Tzakos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Ioannina , 45110 Ioannina, Greece
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Vujicic M, Nikolic I, Kontogianni VG, Saksida T, Charisiadis P, Vasic B, Stosic-Grujicic S, Gerothanassis IP, Tzakos AG, Stojanovic I. Ethyl Acetate Extract of Origanum vulgare L. ssp. hirtum Prevents Streptozotocin-Induced Diabetes in C57BL/6 Mice. J Food Sci 2016; 81:H1846-53. [PMID: 27219840 DOI: 10.1111/1750-3841.13333] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/06/2016] [Accepted: 04/14/2016] [Indexed: 12/20/2022]
Abstract
Type 1 diabetes (T1D) is an autoimmune disease that develops as a consequence of pancreatic β-cell death induced by proinflammatory mediators. Because Origanum vulgare L. ssp. hirtum (Greek oregano) contains antiinflammatory molecules, we hypothesized that it might be beneficial for the treatment of T1D. An ethyl acetate extract of oregano (EAO) was prepared from the leaves by a polar extraction method. Phytochemical composition was determined by liquid chromatography-UV diode array coupled to ion-trap mass spectrometry with electrospray ionization interface (LC/DAD/ESI-MS(n) ). In vitro immunomodulatory effect of EAO was estimated by measuring proliferation (MTT) or cytokine secretion (ELISA) from immune cells. Diabetes was induced by multiple low doses of streptozotocin (MLDS) in male C57BL/6 mice and EAO was administered intraperitoneally for 10 d. Determination of cellular composition (flow cytometry) and cytokine production (ELISA) was performed on 12th d after diabetes induction. EAO suppressed the function of both macrophages and lymphocytes in vitro. In vivo, EAO treatment significantly preserved pancreatic islets and reduced diabetes incidence in MLDS-challenged mice. Besides down-modulatory effect on macrophages, EAO reduced the number of total CD4(+) and activated CD4(+) CD25(+) T cells. Furthermore, EAO affected the number of T helper 1 (Th1) and T helper 17 (Th17) cells through downregulation of their key transcription factors T-bet and RORγT. Because EAO treatment protects mice from development of hyperglycemia by reducing proinflammatory macrophage/Th1/Th17 response, this plant extract could represent a basis for future diabetes therapy.
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Affiliation(s)
- Milica Vujicic
- Dept. of Immunology, Inst. for Biological Research "Sinisa Stankovic,", Univ. of Belgrade, 11060, Belgrade, Serbia
| | - Ivana Nikolic
- Dept. of Immunology, Inst. for Biological Research "Sinisa Stankovic,", Univ. of Belgrade, 11060, Belgrade, Serbia
| | - Vassiliki G Kontogianni
- Dept. of Chemistry, Section of Organic Chemistry and Biochemistry, Univ. of Ioannina, GR-45110, Ioannina, Greece
| | - Tamara Saksida
- Dept. of Immunology, Inst. for Biological Research "Sinisa Stankovic,", Univ. of Belgrade, 11060, Belgrade, Serbia
| | - Pantelis Charisiadis
- Dept. of Chemistry, Section of Organic Chemistry and Biochemistry, Univ. of Ioannina, GR-45110, Ioannina, Greece
| | - Bobana Vasic
- Dept. of Immunology, Inst. for Biological Research "Sinisa Stankovic,", Univ. of Belgrade, 11060, Belgrade, Serbia
| | - Stanislava Stosic-Grujicic
- Dept. of Immunology, Inst. for Biological Research "Sinisa Stankovic,", Univ. of Belgrade, 11060, Belgrade, Serbia
| | - Ioannis P Gerothanassis
- Dept. of Chemistry, Section of Organic Chemistry and Biochemistry, Univ. of Ioannina, GR-45110, Ioannina, Greece
| | - Andreas G Tzakos
- Dept. of Chemistry, Section of Organic Chemistry and Biochemistry, Univ. of Ioannina, GR-45110, Ioannina, Greece
| | - Ivana Stojanovic
- Dept. of Immunology, Inst. for Biological Research "Sinisa Stankovic,", Univ. of Belgrade, 11060, Belgrade, Serbia
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Sakka M, Tzortzis G, Mantzaris MD, Bekas N, Kellici TF, Likas A, Galaris D, Gerothanassis IP, Tzakos AG. PRESS: PRotEin S-Sulfenylation server. Bioinformatics 2016; 32:2710-2. [DOI: 10.1093/bioinformatics/btw301] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Accepted: 05/06/2016] [Indexed: 12/12/2022] Open
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Goulas V, Minas IS, Kourdoulas PM, Lazaridou A, Molassiotis AN, Gerothanassis IP, Manganaris GA. (1)H NMR Metabolic Fingerprinting to Probe Temporal Postharvest Changes on Qualitative Attributes and Phytochemical Profile of Sweet Cherry Fruit. Front Plant Sci 2015; 6:959. [PMID: 26617616 PMCID: PMC4639632 DOI: 10.3389/fpls.2015.00959] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 10/21/2015] [Indexed: 05/23/2023]
Abstract
Sweet cherry fruits (Prunus avium cvs. 'Canada Giant', 'Ferrovia') were harvested at commercial maturity stage and analyzed at harvest and after maintenance at room temperature (storage at ∼20°C, shelf life) for 1, 2, 4, 6, and 8 days, respectively. Fruit were initially analyzed for respiration rate, qualitative attributes and textural properties: 'Canada Giant' fruit were characterized by higher weight losses and stem browning index, being more intense over the late stages of shelf life period; meanwhile 'Ferrovia' possessed appreciably better performance even after extended shelf life period. A gradual decrease of respiration rate was monitored in both cultivars, culminated after 8 days at 20°C. The sweet cherry fruit nutraceutical profile was monitored using an array of instrumental techniques (spectrophotometric assays, HPLC, (1)H-NMR). Fruit antioxidant capacity was enhanced with the progress of shelf life period, concomitant with the increased levels of total anthocyanin and of phenolic compounds. 'Ferrovia' fruit presented higher contents of neochlorogenic acid and p-coumaroylquinic acid throughout the shelf life period. We further developed an (1)H-NMR method that allows the study of primary and secondary metabolites in a single running, without previous separation and isolation procedures. Diagnostic peaks were located in the aliphatic region for sugars and organic acids, in the aromatic region for phenolic compounds and at 8.2-8.6 ppm for anthocyanins. This NMR-based methodology provides a unifying tool for quantitative and qualitative characterization of metabolite changes of sweet cherry fruits; it is also expected to be further exploited for monitoring temporal changes in other fleshy fruits.
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Affiliation(s)
- Vlasios Goulas
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of TechnologyLemesos, Cyprus
- Nuclear Magnetic Resonance Center, Department of Chemistry, University of IoanninaIoannina, Greece
| | - Ioannis S. Minas
- School of Agriculture, Aristotle University of ThessalonikiThessaloniki, Greece
| | - Panayiotis M. Kourdoulas
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of TechnologyLemesos, Cyprus
| | - Athina Lazaridou
- School of Agriculture, Aristotle University of ThessalonikiThessaloniki, Greece
| | | | - Ioannis P. Gerothanassis
- Nuclear Magnetic Resonance Center, Department of Chemistry, University of IoanninaIoannina, Greece
| | - George A. Manganaris
- Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus University of TechnologyLemesos, Cyprus
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Siskos MG, Tzakos AG, Gerothanassis IP. Accurate ab initio calculations of O-HO and O-H(-)O proton chemical shifts: towards elucidation of the nature of the hydrogen bond and prediction of hydrogen bond distances. Org Biomol Chem 2015. [PMID: 26196256 DOI: 10.1039/c5ob00920k] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The inability to determine precisely the location of labile protons in X-ray molecular structures has been a key barrier to progress in many areas of molecular sciences. We report an approach for predicting hydrogen bond distances beyond the limits of X-ray crystallography based on accurate ab initio calculations of O-HO proton chemical shifts, using a combination of DFT and contactor-like polarizable continuum model (PCM). Very good linear correlation between experimental and computed (at the GIAO/B3LYP/6-311++G(2d,p) level of theory) chemical shifts were obtained with a large set of 43 compounds in CHCl3 exhibiting intramolecular O-HO and intermolecular and intramolecular ionic O-H(-)O hydrogen bonds. The calculated OH chemical shifts exhibit a strong linear dependence on the computed (O)HO hydrogen bond length, in the region of 1.24 to 1.85 Å, of -19.8 ppm Å(-1) and -20.49 ppm Å(-1) with optimization of the structures at the M06-2X/6-31+G(d) and B3LYP/6-31+G(d) level of theory, respectively. A Natural Bond Orbitals (NBO) analysis demonstrates a very good linear correlation between the calculated (1)H chemical shifts and (i) the second-order perturbation stabilization energies, corresponding to charge transfer between the oxygen lone pairs and σ antibonding orbital and (ii) Wiberg bond order of the O-HO and O-H(-)O hydrogen bond. Accurate ab initio calculations of O-HO and O-H(-)O (1)H chemical shifts can provide improved structural and electronic description of hydrogen bonding and a highly accurate measure of distances of short and strong hydrogen bonds.
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Affiliation(s)
- Michael G Siskos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR 45110, Greece.
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41
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Papaemmanouil C, Tsiafoulis CG, Alivertis D, Tzamaloukas O, Miltiadou D, Tzakos AG, Gerothanassis IP. Selective One-Dimensional Total Correlation Spectroscopy Nuclear Magnetic Resonance Experiments for a Rapid Identification of Minor Components in the Lipid Fraction of Milk and Dairy Products: Toward Spin Chromatography? J Agric Food Chem 2015; 63:5381-5387. [PMID: 25986319 DOI: 10.1021/acs.jafc.5b01335] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report a rapid, direct, and unequivocal spin-chromatographic separation and identification of minor components in the lipid fraction of milk and common dairy products with the use of selective one-dimensional (1D) total correlation spectroscopy (TOCSY) nuclear magnetic resonance (NMR) experiments. The method allows for the complete backbone spin-coupling network to be elucidated even in strongly overlapped regions and in the presence of major components from 4 × 10(2) to 3 × 10(3) stronger NMR signal intensities. The proposed spin-chromatography method does not require any derivatization steps for the lipid fraction, is selective with excellent resolution, is sensitive with quantitation capability, and compares favorably to two-dimensional (2D) TOCSY and gas chromatography-mass spectrometry (GC-MS) methods of analysis. The results of the present study demonstrated that the 1D TOCSY NMR spin-chromatography method can become a procedure of primary interest in food analysis and generally in complex mixture analysis.
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Affiliation(s)
| | | | | | - Ouranios Tzamaloukas
- ⊥Department of Agricultural Sciences, Biotechnology and Food Sciences, Cyprus University of Technology, Post Office Box 50329, Limassol 3603, Cyprus
| | - Despoina Miltiadou
- ⊥Department of Agricultural Sciences, Biotechnology and Food Sciences, Cyprus University of Technology, Post Office Box 50329, Limassol 3603, Cyprus
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42
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Primikyri A, Chatziathanasiadou MV, Karali E, Kostaras E, Mantzaris MD, Hatzimichael E, Shin JS, Chi SW, Briasoulis E, Kolettas E, Gerothanassis IP, Tzakos AG. Direct binding of Bcl-2 family proteins by quercetin triggers its pro-apoptotic activity. ACS Chem Biol 2014; 9:2737-41. [PMID: 25211642 DOI: 10.1021/cb500259e] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Bcl-2 family proteins are important regulators of apoptosis and its antiapoptotic members, which are overexpressed in many types of cancer, are of high prognostic significance, establishing them as attractive therapeutic targets. Quercetin, a natural flavonoid, has drawn much attention because it exerts anticancer effects, while sparing normal cells. A multidisciplinary approach has been employed herein, in an effort to reveal its mode of action including dose-response antiproliferative activity and induced apoptosis effect, biochemical and physicochemical assays, and computational calculations. It may be concluded that, quercetin binds directly to the BH3 domain of Bcl-2 and Bcl-xL proteins, thereby inhibiting their activity and promoting cancer cell apoptosis.
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Affiliation(s)
| | | | - Evdoxia Karali
- Foundation
of Research and Technology−Hellas, Institute of Molecular Biology
and Biotechnology, Division of Biomedical Research, University Campus, 45110 Ioannina, Greece
| | - Eleftherios Kostaras
- Foundation
of Research and Technology−Hellas, Institute of Molecular Biology
and Biotechnology, Division of Biomedical Research, University Campus, 45110 Ioannina, Greece
| | | | | | - Jae-Sun Shin
- Medical
Proteomics Research Center, KRIBB, Daejeon 305-806, Republic of Korea
| | - Seung-Wook Chi
- Medical
Proteomics Research Center, KRIBB, Daejeon 305-806, Republic of Korea
| | | | - Evangelos Kolettas
- Foundation
of Research and Technology−Hellas, Institute of Molecular Biology
and Biotechnology, Division of Biomedical Research, University Campus, 45110 Ioannina, Greece
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43
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Primikyri A, Mazzone G, Lekka C, Tzakos AG, Russo N, Gerothanassis IP. Understanding zinc(II) chelation with quercetin and luteolin: a combined NMR and theoretical study. J Phys Chem B 2014; 119:83-95. [PMID: 25486072 DOI: 10.1021/jp509752s] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The Zn(II) chelation with natural flavonoids, quercetin and luteolin, was investigated by the use of NMR spectroscopy and various levels of ab initio calculations. Very sharp phenolic OH (1)H resonances in DMSO-d6 were observed for both free and complexed quercetin which allowed (i) the unequivocal assignment with the combined use of (1)H-(13)C HSQC and HMBC experiments and (ii) the determination of complexation sites which were found to be the CO-4 carbonyl oxygen and the deprotonated C-5 OH group of quercetin and CO-4 carbonyl oxygen and the deprotonated C-5 OH group of luteolin. DOSY experiments allowed the determination of the effective molecular weight of the Zn-quercetin complex which was shown to be mainly 1:1. DFT calculations of the 1:1 complex in the gas phase demonstrated that the C-3 O(-) and CO-4 sites are favored for quercetin at both GGA and LDA approximations and the C-5 O(-) and CO-4 groups of luteolin at the LDA approximation. Quantum chemical calculations were also performed by means of the conductor polarizable model in DMSO by employing various functionals. The energetically favored Zn chelation sites of the 1:1 complex were found to be either the C-3 O(-) and CO-4 or C-5 O(-) and CO-4 sites, depending on the functional used, for quercetin and the C-5 O(-) and CO-4 sites for luteolin.
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Affiliation(s)
- Alexandra Primikyri
- Department of Chemistry, University of Ioannina , Ioannina, GR-45 110, Greece
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44
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Charisiadis P, Tsiafoulis CG, Tzakos AG, Gerothanassis IP. Dynamic changes in composition of extracts of natural products as monitored by in situ NMR. Magn Reson Chem 2014; 52:764-768. [PMID: 25139153 DOI: 10.1002/mrc.4128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 07/24/2014] [Accepted: 07/27/2014] [Indexed: 06/03/2023]
Abstract
The direct in situ NMR observation and quantification, based on the aldehyde -CH chemical shift region, of the inter-conversion of secoiridoid derivatives due to temperature and solvent effects is demonstrated in complex extracts of natural products without prior isolation of the individual components. The equilibrium between the aldehyde hydrate form and the dialdehyde form of the oleuropein aglycon of an olive leaf aqueous extract in D(2)O was shown to be temperature dependent. The resulting thermodynamic values of the Van't Hoff plot with ΔH(o) = -26.34 ± 1.00 kJ mol(-1) and TΔS° (298 K) = -24.70 ± 1.00 kJ mol(-1) demonstrate a significant entropy term which nearly compensates the effect of enthalpy at room temperature. The equilibrium between the two diastereomeric hemiacetal forms and the dialdehyde form of the oleuropein 6-O-β-d-glucopyranoside aglycon of an olive leaf aqueous extract in CD(3) OD was also shown to be strongly temperature dependent again because of the significant entropy term (TΔS° (298 K) = -26.50 ± 1.39 kJ mol(-1)) compared with that of the enthalpy term (ΔH(o) = -36.64 ± 1.46 kJ mol(-1)). This is the first demonstration of the significant role of the entropy parameter in determining the equilibrium of chemical transformations in complex mixtures of natural products due to solvent and temperature effects.
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Affiliation(s)
- Pantelis Charisiadis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR-45110, Greece
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45
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Charisiadis P, Kontogianni VG, Tsiafoulis CG, Tzakos AG, Siskos M, Gerothanassis IP. 1H-NMR as a structural and analytical tool of intra- and intermolecular hydrogen bonds of phenol-containing natural products and model compounds. Molecules 2014; 19:13643-82. [PMID: 25185070 PMCID: PMC6271058 DOI: 10.3390/molecules190913643] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 11/23/2022] Open
Abstract
Experimental parameters that influence the resolution of 1H-NMR phenol OH signals are critically evaluated with emphasis on the effects of pH, temperature and nature of the solvents. Extremely sharp peaks (Δν1/2≤2 Hz) can be obtained under optimized experimental conditions which allow the application of 1H-13C HMBC-NMR experiments to reveal long range coupling constants of hydroxyl protons and, thus, to provide unequivocal assignment of the OH signals even in cases of complex polyphenol natural products. Intramolecular and intermolecular hydrogen bonds have a very significant effect on 1H OH chemical shifts which cover a region from 4.5 up to 19 ppm. Solvent effects on -OH proton chemical shifts, temperature coefficients (Δδ/ΔT), OH diffusion coefficients, and nJ(13C, O1H) coupling constants are evaluated as indicators of hydrogen bonding and solvation state of phenol -OH groups. Accurate 1H chemical shifts of the OH groups can be calculated using a combination of DFT and discrete solute-solvent hydrogen bond interaction at relatively inexpensive levels of theory, namely, DFT/B3LYP/6-311++G (2d,p). Excellent correlations between experimental 1H chemical shifts and those calculated at the ab initio level can provide a method of primary interest in order to obtain structural and conformational description of solute-solvent interactions at a molecular level. The use of the high resolution phenol hydroxyl group 1H-NMR spectral region provides a general method for the analysis of complex plant extracts without the need for the isolation of the individual components.
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Affiliation(s)
- Pantelis Charisiadis
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - Vassiliki G Kontogianni
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | | | - Andreas G Tzakos
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - Michael Siskos
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
| | - Ioannis P Gerothanassis
- Section of Organic Chemistry & Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR-45110, Greece.
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46
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Magnani F, Pappas CG, Crook T, Magafa V, Cordopatis P, Ishiguro S, Ohta N, Selent J, Bosnyak S, Jones ES, Gerothanassis IP, Tamura M, Widdop RE, Tzakos AG. Electronic sculpting of ligand-GPCR subtype selectivity: the case of angiotensin II. ACS Chem Biol 2014; 9:1420-5. [PMID: 24787922 PMCID: PMC4374176 DOI: 10.1021/cb500063y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
GPCR subtypes possess distinct functional
and pharmacological profiles,
and thus development of subtype-selective ligands has immense therapeutic
potential. This is especially the case for the angiotensin receptor
subtypes AT1R and AT2R, where a functional negative control has been
described and AT2R activation highlighted as an important cancer drug
target. We describe a strategy to fine-tune ligand selectivity for
the AT2R/AT1R subtypes through electronic control of ligand aromatic-prolyl
interactions. Through this strategy an AT2R high affinity (Ki = 3 nM) agonist analogue that exerted 18,000-fold
higher selectivity for AT2R versus AT1R was obtained. We show that
this compound is a negative regulator of AT1R signaling since it is
able to inhibit MCF-7 breast carcinoma cellular proliferation in the
low nanomolar range.
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Affiliation(s)
- Francesca Magnani
- Laboratory
of Molecular Biology, Medical Research Council, Cambridge CB2 0QH, United Kingdom
| | | | - Tim Crook
- Division
of Cancer Research, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Vassiliki Magafa
- Department
of Pharmacy, University of Patras, Patra 26504, Greece
| | - Paul Cordopatis
- Department
of Pharmacy, University of Patras, Patra 26504, Greece
| | - Susumu Ishiguro
- Department of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
| | - Naomi Ohta
- Department of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas 66506, United States
| | - Jana Selent
- Research
Programme on Biomedical Informatics (GRIB), Department of Experimental
and Health Sciences, Universitat Pompeu Fabra, IMIM (Hospital del Mar Medical Research Institute), Dr. Aiguader 88, E-08003 Barcelona, Spain
| | - Sanja Bosnyak
- Department
of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
| | - Emma S. Jones
- Department
of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
| | | | - Masaaki Tamura
- Division
of Cancer Research, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Robert E. Widdop
- Department
of Pharmacology, Monash University, Clayton, Victoria 3800, Australia
| | - Andreas G. Tzakos
- Department
of Chemistry, University of Ioannina, Ioannina 45110, Greece
- Cancer
Biobank Center, University of Ioannina, Ioannina 45110, Greece
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47
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Theodorou V, Skobridis K, Alivertis D, Gerothanassis IP. Synthetic methodologies in organic chemistry involving incorporation of [¹⁷O] and [¹⁸O] isotopes. J Labelled Comp Radiopharm 2014; 57:481-508. [PMID: 24996002 DOI: 10.1002/jlcr.3212] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/06/2014] [Accepted: 05/15/2014] [Indexed: 11/09/2022]
Abstract
This review is a critical survey of the literature that aims to highlight the most significant developments on synthetic strategies involving stable oxygen isotopes ([(17)O] and [(18)O]). The labeling methodologies are categorized in groups, according to the oxygen-containing functional group.
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Affiliation(s)
- Vassiliki Theodorou
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR-451 10, Greece
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48
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Siskos MG, Kontogianni VG, Tsiafoulis CG, Tzakos AG, Gerothanassis IP. Investigation of solute-solvent interactions in phenol compounds: accurate ab initio calculations of solvent effects on 1H NMR chemical shifts. Org Biomol Chem 2014; 11:7400-11. [PMID: 24071830 DOI: 10.1039/c3ob41556b] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Accurate (1)H chemical shifts of the -OH groups of polyphenol compounds can be calculated, compared to experimental values, using a combination of DFT, polarizable continuum model (PCM) and discrete solute-solvent hydrogen bond interactions. The study focuses on three molecular solutes: phenol, 4-methylcatechol and the natural product genkwanin in DMSO, acetone, acetonitrile, and chloroform. Excellent linear correlation between experimental and computed chemical shifts (with the GIAO method at the DFT/B3LYP/6-311++G(2d,p) level) was obtained with minimization of the solvation complexes at the DFT/B3LYP/6-31+G(d) and DFT/B3LYP/6-311++G(d,p) level of theory with a correlation coefficient of 0.991. The use of the DFT/B3LYP/6-31+G(d) level of theory for minimization could provide an excellent means for the accurate prediction of the experimental OH chemical shift range of over 8 ppm due to: (i) strong intramolecular and solute-solvent intermolecular hydrogen bonds, (ii) flip-flop intramolecular hydrogen bonds, and (iii) conformational effects of substituents of genkwanin. The combined use of ab initio calculations and experimental (1)H chemical shifts of phenol -OH groups provides a method of primary interest in order to obtain detailed structural, conformation and electronic description of solute-solvent interactions at a molecular level.
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Affiliation(s)
- Michael G Siskos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina GR 45110, Greece.
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49
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Tsiafoulis CG, Skarlas T, Tzamaloukas O, Miltiadou D, Gerothanassis IP. Direct nuclear magnetic resonance identification and quantification of geometric isomers of conjugated linoleic acid in milk lipid fraction without derivatization steps: Overcoming sensitivity and resolution barriers. Anal Chim Acta 2014; 821:62-71. [DOI: 10.1016/j.aca.2014.03.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 02/28/2014] [Accepted: 03/07/2014] [Indexed: 01/06/2023]
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50
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Kontogianni VG, Charisiadis P, Margianni E, Lamari FN, Gerothanassis IP, Tzakos AG. Olive leaf extracts are a natural source of advanced glycation end product inhibitors. J Med Food 2014; 16:817-22. [PMID: 24044491 DOI: 10.1089/jmf.2013.0016] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Advanced glycation end products (AGEs), which are readily formed and accumulated with sustained hyperglycemia, contribute to the development of diabetic complications. As a consequence, inhibition of AGE formation constitutes an attractive therapeutic/preventive target. In the current study, we explored the phytochemical composition and the in vitro effect of two different olive leaf extracts (an aqueous and a methanolic) on AGE formation. The methanolic olive leaf extract inhibited fluorescent AGE formation in a bovine serum albumin (BSA)-ribose system, whereas the aqueous extract had no effect in both BSA-fructose and BSA-ribose systems. The phytochemical profile was investigated with liquid chromatography-ultraviolet-visible (UV-Vis) diode array coupled to electrospray ionization multistage mass spectrometry (LC/DAD/ESI-MS(n)). Quantification of the major phenolic compounds was performed with high performance liquid chromatography with UV-Vis diode array detection and nuclear magnetic resonance spectroscopy. Among the major phenolic components (luteolin, hydroxytyrosol, luteolin-4'-O-β-D-glucopyranoside, luteolin-7-O-β-D-glucopyranoside, and oleuropein), luteolin and luteolin-4'-O-β-D-glucopyranoside were assigned as potent inhibitors of AGE formation. The extraction procedure greatly affects the composition and therefore the anti-glycation potential of olive leaves.
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