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Complexes of metals as potential anion receptors
Marečková, Vendula ; Vojtíšek, Pavel (advisor) ; Mosinger, Jiří (referee)
An important class of anion receptors are based on bimetallic complexes with phenols bearing an pendant arms in 2,6-positions. A ligand of this type, 2,6-bis[(N- methylpiperazine-1-yl)methyl]-4-formyl phenol (L1), was prepared using the Mannich reaction. An attempt to prepare a similar compound L2 yield only an oily product. The molecular structure of compound L1 was determinated by X-ray diffraction. Comparison of the L1 structure with similar ones from CCDC showed important influence of the intramolecular H-bond on pendant arms orientations in this type of compounds. Further synthetic exploitation of the aldehyde group (in the position 4) was tested by reaction with 4-nitroaniline. The Shiff base (L3) was obtained but only as an oily substance. Reactions of L1 with Cu(ii) and Zn(ii) perchlorate or acetate produce complexes; the compound [Cu2L1(OH)(OAc)(H2O)]ClO4 (K1) was obtained in a crystallic form. The interactions of anion-bimetallic complex receptor were discused from stereochemical point of view using the structural data from CCDC in the last part of this work.
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Human glutamate carboxypeptidases II and III
Navrátil, Michal ; Konvalinka, Jan (advisor) ; Obšil, Tomáš (referee) ; Pavlíček, Jiří (referee)
The herein presented Ph.D. dissertation describes kinetic and structural characterization of human glutamate carboxypeptidases II and III (GCPII and GCPIII) using a complete panel of their natural substrates. These enzymes hydrolyze C-terminal glutamate from their substrates. They share 67 % sequence identity and also similar enzymatic activities. This thesis quantitatively compares human GCPII and GCPIII in terms of their ability to hydrolyze the substrates N-acetyl-L-aspartyl-L-glutamate (NAAG), folyl-poly-γ-L-glutamic acids (FolGlun) and β-citryl-L-glutamate (BCG). We demonstrated that GCPIII hydrolyzes its substrates in a metal- dependent manner, that BCG is a specific substrate of GCPIII, and that NAAG and FolGlun are specific substrates of GCPII. We also provide indirect biochemical evidence that GCPIII might feature a heterometallic active-site cluster. Additionally, we characterized the relevance of a surface exosite of GCPII, the arene-binding site (ABS), for the hydrolysis of FolGlun substrates using mutagenesis and enzyme kinetics and showed that polymorphic His475Tyr variant of GCPII hydrolyzes FolGlun substrates with the same kinetic parameters as the wild-type enzyme. Furthermore, this thesis focuses on structural aspects of the substrate specificities of GCPII and GCPIII: we present...
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Complexes of 2,6-bis[(N-methylpiperazine-1-yl)methyl]-4-formyl phenol
Marečková, Vendula ; Vojtíšek, Pavel (advisor) ; Kubíček, Vojtěch (referee)
Thirteen new dinuclear complexes of ligand 2,6-bis[(N-methylpiperazine-1- yl)methyl]-4-formyl phenol (L1) were prepared. Copper(II) and palladium(II) salts were used for the syntheses. Following compounds were prepared: [Cu2L1(CH3COO)2]ClO4, [Cu2L1(CF3COO)2(ClO4)][Cu2L1(CF3COO)2]ClO4, [Pd2L1(CH3COO)3], [Pd2L1(CF3COO)3], [Pd2L1(Cl)4]. These ones should act as anion receptors. The acetates were exchanged for phenylphosphinates in the case of the complex cation [Cu2L1(CH3COO)2]+ and the structure of [Cu2L1(phPO2H)2]ClO4 was obtained. Geometry of coordination shell of Cu2+ - ions in prepared complexes is tetragonal pyramid. The UV-VIS spectroscopy was used for study of interactions in system of the ligand - metal - anion. Interactions between the ligand and metals in oxidation state 2 were observed as well as interactions between the complex [Cu2L1(CH3COO)2]ClO4 and sodium salts.
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Complexes of metals as potential anion receptors
Marečková, Vendula ; Vojtíšek, Pavel (advisor) ; Mosinger, Jiří (referee)
An important class of anion receptors are based on bimetallic complexes with phenols bearing an pendant arms in 2,6-positions. A ligand of this type, 2,6-bis[(N- methylpiperazine-1-yl)methyl]-4-formyl phenol (L1), was prepared using the Mannich reaction. An attempt to prepare a similar compound L2 yield only an oily product. The molecular structure of compound L1 was determinated by X-ray diffraction. Comparison of the L1 structure with similar ones from CCDC showed important influence of the intramolecular H-bond on pendant arms orientations in this type of compounds. Further synthetic exploitation of the aldehyde group (in the position 4) was tested by reaction with 4-nitroaniline. The Shiff base (L3) was obtained but only as an oily substance. Reactions of L1 with Cu(ii) and Zn(ii) perchlorate or acetate produce complexes; the compound [Cu2L1(OH)(OAc)(H2O)]ClO4 (K1) was obtained in a crystallic form. The interactions of anion-bimetallic complex receptor were discused from stereochemical point of view using the structural data from CCDC in the last part of this work.
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