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Reuter H, van Bodegraven AM, Bender E, Knies C, Diek N, Beginn U, Hammerbacher K, Schneider V, Kinscherf R, Bonaterra GA, Svajda R, Rosemeyer H. Guanosine Nucleolipids: Synthesis, Characterization, Aggregation and X-Ray Crystallographic Identification of Electricity-Conducting G-Ribbons. Chem Biodivers 2019; 16:e1900024. [PMID: 30793846 DOI: 10.1002/cbdv.201900024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 02/22/2019] [Indexed: 11/06/2022]
Abstract
The lipophilization of β-d-riboguanosine (1) with various symmetric as well as asymmetric ketones is described (→3a-3f). The formation of the corresponding O-2',3'-ketals is accompanied by the appearance of various fluorescent by-products which were isolated chromatographically as mixtures and tentatively analyzed by ESI-MS spectrometry. The mainly formed guanosine nucleolipids were isolated and characterized by elemental analyses, 1 H-, 13 C-NMR and UV spectroscopy. For a drug profiling, static topological polar surface areas as well as 10 logPOW values were calculated by an increment-based method as well as experimentally for the systems 1-octanol-H2 O and cyclohexane-H2 O. The guanosine-O-2',3'-ketal derivatives 3b and 3a could be crystallized in (D6 )DMSO - the latter after one year of standing at ambient temperature. X-ray analysis revealed the formation of self-assembled ribbons consisting of two structurally similar 3b nucleolipid conformers as well as integrated (D6 )DMSO molecules. In the case of 3a ⋅ DMSO, the ribbon is formed by a single type of guanosine nucleolipid molecules. The crystalline material 3b ⋅ DMSO was further analyzed by differential scanning calorimetry (DSC) and temperature-dependent polarization microscopy. Crystallization was also performed on interdigitated electrodes (Au, distance, 5 μm) and visualized by scanning electron microscopy. Resistance and amperage measurements clearly demonstrate that the electrode-bridging 3b crystals are electrically conducting. All O-2',3'-guanosine ketals were tested on their cytostatic/cytotoxic activity towards phorbol 12-myristate 13-acetate (PMA)-differentiated human THP-1 macrophages as well as against human astrocytoma/oligodendroglioma GOS-3 cells and against rat malignant neuroectodermal BT4Ca cells.
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Affiliation(s)
- Hans Reuter
- Anorganische Chemie II, Strukturchemie, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
| | - Anna Maria van Bodegraven
- Organic Chemistry I - Bioorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
| | - Eugenia Bender
- Organic Chemistry I - Bioorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
| | - Christine Knies
- Organic Chemistry I - Bioorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
| | - Nadine Diek
- Organic Chemistry I - Organic Materials Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
| | - Uwe Beginn
- Organic Chemistry I - Organic Materials Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
| | - Katharina Hammerbacher
- Anatomy and Cell Biology, Department of Medical Cell Biology, Philipps-, University of Marburg, Robert-Koch-Strasse 8, DE-35032, Marburg, Germany
| | - Vanessa Schneider
- Anatomy and Cell Biology, Department of Medical Cell Biology, Philipps-, University of Marburg, Robert-Koch-Strasse 8, DE-35032, Marburg, Germany
| | - Ralf Kinscherf
- Anatomy and Cell Biology, Department of Medical Cell Biology, Philipps-, University of Marburg, Robert-Koch-Strasse 8, DE-35032, Marburg, Germany
| | - Gabriel A Bonaterra
- Anatomy and Cell Biology, Department of Medical Cell Biology, Philipps-, University of Marburg, Robert-Koch-Strasse 8, DE-35032, Marburg, Germany
| | - Rainer Svajda
- Department of Physics, Workshop for Electronics/IT, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
| | - Helmut Rosemeyer
- Organic Chemistry I - Bioorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastrasse 7, DE-49069, Osnabrück, Germany
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Lipid-modified oligonucleotide conjugates: Insights into gene silencing, interaction with model membranes and cellular uptake mechanisms. Bioorg Med Chem 2016; 25:175-186. [PMID: 27810441 DOI: 10.1016/j.bmc.2016.10.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 10/18/2016] [Accepted: 10/19/2016] [Indexed: 12/13/2022]
Abstract
The ability of oligonucleotides to silence specific genes or inhibit the biological activity of specific proteins has generated great interest in their use as research tools and therapeutic agents. Unfortunately, their biological applications meet the limitation of their poor cellular accessibility. Developing an appropriate delivery system for oligonucleotides is essential to achieve their efficient cellular uptake. In the present work a series of phosphorothioate lipid-oligonucleotide hybrids were synthesized introducing covalently single or double lipid tails at both 3'- and 5'-termini of an antisense oligonucleotide. Gene transfections in cultured cells showed antisense luciferase inhibition without the use of a transfecting agent for conjugates modified with the double-lipid tail at 5'-termini. The effect of the double lipid-tailed modification was further studied in detail in several model membrane systems as well as in cellular uptake experiments. During these studies the spontaneous formation of self-assembled microstructures is clearly observed. Lipidation allowed the efficient incorporation of the oligonucleotide in HeLa cells by a macropinocytosis mechanism without causing cytotoxicity in cells or altering the binding properties of the oligonucleotide conjugates. In addition, both single- and double-tailed compounds showed a similar behavior in lipid model membranes, making them useful in nucleotide-based technologies.
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Werz E, Rosemeyer H. Terminal lipophilization of a unique DNA dodecamer by various nucleolipid headgroups: Their incorporation into artificial lipid bilayers and hydrodynamic properties. Beilstein J Org Chem 2015; 11:913-29. [PMID: 26124894 PMCID: PMC4464448 DOI: 10.3762/bjoc.11.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/08/2015] [Indexed: 01/01/2023] Open
Abstract
A series of six cyanine-5-labeled oligonucleotides (LONs 10-15), each terminally lipophilized with different nucleolipid head groups, were synthesized using the recently prepared phosphoramidites 4b-9b. The insertion of the LONs within an artificial lipid bilayer, composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE), was studied by single molecule fluorescence spectroscopy and microscopy with the help of an optically transparent microfluidic sample carrier with perfusion capabilities. The incorporation of the lipo-oligonucleotides into the bilayer was studied with respect to efficiency (maximal bilayer brightness) as well as stability against perfusion (final stable bilayer brightness). Attempts to correlate these parameters with the log P values of the corresponding nucleolipid head groups failed, a result which clearly demonstrates that not only the lipophilicity but mainly the chemical structure and topology of the head group is of decisive importance for the optimal interaction of a lipo-oligonucleotide with an artificial lipid bilayer. Moreover, fluorescence half-live and diffusion time values were measured to determine the diffusion coefficients of the lipo-oligonucleotides.
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Affiliation(s)
- Emma Werz
- Organic Chemistry I - Bioorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastr. 7, 49069 Osnabrück, Germany ; Ionovation GmbH, Westerbreite 7, 49078 Osnabrück, Germany
| | - Helmut Rosemeyer
- Organic Chemistry I - Bioorganic Chemistry, Institute of Chemistry of New Materials, University of Osnabrück, Barbarastr. 7, 49069 Osnabrück, Germany
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