Vanadium(III) binding strengths of small biomolecules

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Új, funkcionalizált peptidszármazékok előállítása és oldategyensúlyi vizsgálata = Synthesis and solution equilibrium studies of new, functionalised derivatives of peptides

A pályázat keretében 15 új peptidhidroxámsavat állítottunk elő és szisztematikusan megvizsgáltuk azt, hogy a ligandumok építőelemeinek (terminális aminocsoport jelenléte, a hidroxámsavcsoport nitrogénjének szubsztituense, a peptidlánc hossza, az oldalláncban jelenlevő erősen koordinálódni képes donorcsoport jelenléte) megváltoztatása hogyan befolyásolja fémionmegkötő képességüket. A ligandumok esszenciális (Fe3+, Cu2+, Ni2+, Zn2+, Mo(VI)) és toxikus (Al3+) fémionokkal való kölcsönhatásának tanulmányozására pH-potenciometriát, ESI-MS-t és spektrális módszereket (UV-VIS, NMR, CD, ESR) alkalmaztunk, meghatározva az oldatbeli részecskék összetételét, stabilitási szorzat értékeit és legvalószínűbb oldatszerkezetét. | Fifteen new peptide hydroxamic acids have been synthesized, characterized and a systematic study has been carried out to explore the effect of the change of the building blocks (presence of the terminal amino group, substituent at the nitrogen of the hydroxamic moiety, length of the peptide chain, presence of strongly coordinating donor in the side chain) of the ligands on their metal binding capability. The interaction of the peptide hydroxamic acids with essencial (Fe3+, Cu2+, Ni2+, Zn2+, Mo(VI)) and toxic (Al3+) metal ions has been studied using pH-potentiometry, ESI-MS and different spectroscopic (UV-VIS, NMR, CD, ESR) techniques

[(?6 -p-cymene)Ru(H2O)3] 2+ Binding Capability of Aminohydroxamates - A Solution and Solid State Study

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Synthesis, characterization and albumin binding capabilities of quinizarin containing ternary cobalt(III) complexes

Four Co(III) ternary complexes with the composition of [(Co(4 N))2(quin)](ClO4)4 or [(Co(4 N))2(quinS)](ClO4)3, where 4 N = tris(2-aminoethyl)amine (tren) or tris(2-pyridylmethyl)amine (tpa), quinH2 = quinizarin (1,4-dihydroxy-9,10-anthraquinone), quinSH3 = quinizarin-2-sulfonic acid (1,4-dihydroxy-9,10-anthraquinone-2-sulfonic acid), were synthesized, characterized and their human serum albumin (HSA) binding capabilities were also tested. The complexes can be considered as likely chaperons of quinizarins which are structural models for anthracycline-based anticancer drugs like doxorubicin. All the Co(III) complexes are dinuclear and were isolated as mixture of isomers. Comparison of the cyclic voltammograms of the free ligands and the appropriate Co(III) complexes revealed that the new signals belonging to reversible processes in the range −400–0 mV (vs. Ag/AgCl) for the complexes can be attributed to the reversible reduction of the Co(III) centre. These potentials are in the range of typical (O,O) chelated Co(III) ternary complexes bearing 4 N donor ligands and follow the order being more positive for the tpa containing complexes. Presence of the sulfonate group in the quinizarin results in slightly more negative reduction potential of the Co(III) complexes. HSA binding capabilities of the quinH2 and quinSH3 ligands as well as the appropriate complexes showed that quinSH3 has higher affinity to the protein than quinH2 while none of the complexes seem to bind to HSA

[1,5]-Hydride Shift-Cyclization versus C(sp2)-H Functionalization in the Knoevenagel-Cyclization Domino Reactions of 1,4- and 1,5-Benzoxazepines

Domino cyclization reactions of N-aryl-1,4- and 1,5-benzoxazepine derivatives involving [1,5]-hydride shift or C(sp2)-H functionalization were investigated. Neuroprotective and acetylcholinesterase activities of the products were studied. Domino Knoevenagel-[1,5]-hydride shift-cyclization reaction of N-aryl-1,4-benzoxazepine derivatives with 1,3-dicarbonyl reagents having active methylene group afforded the 1,2,8,9-tetrahydro-7bH-quinolino [1,2-d][1,4]benzoxazepine scaffold with different substitution pattern. The C(sp3)-H activation step of the tertiary amine moiety occurred with complete regioselectivity and the 6-endo cyclization took place in a complete diastereoselective manner. In two cases, the enantiomers of the chiral condensed new 1,4-benzoxazepine systems were separated by chiral HPLC, HPLC-ECD spectra were recorded, and absolute configurations were determined by time-dependent density functional theory- electronic circular dichroism (TDDFT-ECD) calculations. In contrast, the analogue reaction of the regioisomeric N-aryl-1,5-benzoxazepine derivative did not follow the above mechanism but instead the Knoevenagel intermediate reacted in an SEAr reaction [C(sp2)-H functionalization] resulting in a condensed acridane derivative. The AChE inhibitory assays of the new derivatives revealed that the acridane derivative had a 6.98 uM IC50 value