- Synthesis and properties of supramolecular ionic networks
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The synthesis of a supramolecular ionic network, its physical properties, and the use of this network property to form macroscopic porphyrin fibers are described. These ionic networks are compared to ionic liquids. Current ionic liquid compositions have a charge and molar ratio of 1:1 where an anionic species is matched with a cationic species; however, alteration of this molar ratio while maintaining the charge ratio of 1:1 by using multivalent cationic/anionic molecular pairs affords new ionically cross-linked networks with interesting properties. Copyright
- Wathier, Michel,Grinstaff, Mark W.
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- Synthesis of monomeric acridine derived nucleic acid intercalators
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A series of antiviral compounds consisting of an intercalating acridine derived part, a spacer region and a reactive EDTA-derived conjugate was synthesized in an easy sequence. In the presence of ascorbate a reduction of the phage-titer of MS2 phages by several logarithmic decades was achieved.
- Csuk, René,Raschke, Christian,G?the, Gunnar,Rei?mann, Stefan
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- NOVEL CHELATOR AND USE THEREOF
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The present invention relates to dimeric pentadentate chelators with exceptionally strong binding of metal ions, for detection, immobilization and purification of biomolecules. Dimeric chelators offer a cooperativity of binding of two adjacent immobilized metal ions simultaneously to a histidine-tagged biomolecule, which gives advantageous properties regarding strength of binding compared to a corresponding monomer chelator. In addition, a dimer increases the selectivity (ease of separation) against non-tagged biomolecules with low metal-ion affinity. The dimeric pentadentate chelator according to the invention has the following general formula (I) wherein Sc is a scaffold or a connecting structure that contains at least two functional groups enabling coupling of two pentadentate chelators (PD), and PD is a pentadentate chelator having the formula (II).
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Page/Page column 15
(2011/12/14)
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- Synthesis of pathogen inactivating nucleic acid intercalators
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A series of antiviral compounds consisting of an intercalating acridine derived part, a spacer region and a reactive EDTA-derived conjugate was synthesized in an easy sequence starting from 1,ω-alkyldiamines. As shown in model screenings, in the presence of ascorbic acid the Fe-complexes of these compounds reduced the phage-titer of MS2-phages by several logarithmic decades.
- Csuk, René,Barthel, Alexander,Brezesinski, Thorsten,Raschke, Christian
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p. 975 - 988
(2007/10/03)
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- DNA AFFINITY CLEAVING SEQUENCE SPECIFIC CLEAVAGE OF DNA BY DISTAMYCIN-EDTA*Fe(II) AND EDTA-DISTAMYCIN*Fe(II)
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The attachment of EDTA*Fe(II) to distamycin changes the sequence specific DNA binding antibiotic into a sequence specific DNA cleaving molecule.We report the synthesis of EDTA-distamycin (ED) which has the metal chelator, EDTA, tethered to the carboxy terminus of the N-methylpyrrole tripeptide moiety of the antibiotic, distamycin.EDTA-distamycin*Fe(II) (ED*Fe(II)) at 1E-6M concentration efficiently cleaves pBR322 DNA (1E-5M in base pairs) in the presence of oxygen and dithiothreitol (DTT).Using Maxam-Gilbert sequencing gel analyses, we find that ED*Fe(II) affords DNA cleavage patterns of unequal intensity covering two to four contiguous base pairs adjacent to a five base pair site consisting of adenines (A) and thymines (T).The multiple cleavages at each site might be evidence for a diffusible oxidizing species, perhaps hydroxyl radical.The unequal intensity of cleavage on each side of the A + T site permit assignment of major and minor orientations of the tripeptide binding unit.A comparison of the cleavage specificity of ED*Fe(II) with distamycin-EDTA*Fe(II), (DE*Fe(II)) which has EDTA*Fe(II) attached to the amino terminus of the N-methylpyrrole tripeptide, shows DNA cleavage patterns at the same sites but with intensities of opposite polarity.Maxam-Gilbert sequencing gel analysis of the DNA cleavage patterns by ED*Fe(II) and DE*Fe(II) on both DNA strands of a 381 base pair restriction fragment reveals asymmetric DNA cleavage patterns.Cleavage is shifted to the 3' side of each DNA strand.A model consistent with this cleavage pattern indicates one preferred binding site for ED*Fe(II) and DE*Fe(II) is 3'-TTTAA-5' with the "amino end" of the tripeptide oriented to the 3' end of the thyamine rich strand.This "DNA affinity cleavage" method which consists of attaching cleaving functions to DNA binding molecules followed by DNA cleavage pattern analyses using Maxam-Gilbert sequencing gels may be a useful direct method for determining the binding site and orientation of small molecules on native DNA.
- Taylor, John S.,Schultz, Peter G.,Dervan, Peter B.
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p. 457 - 465
(2007/10/02)
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